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 OUTLINES

 OF

 A MECHANICAL THEORY OF STORMS, CONTAINING

 THE TRUE LAW OF LUNAR INFLUENCE, WITH

 PRACTICAL INSTRUCTIONS TO THE NAVIGATOR, TO ENABLE HIM APPROXIMATELY TO CALCULATE THE COMING CHANGES OF THE WIND AND WEATHER, FOR ANY GIVEN DAY, AND FOR ANY PART OF THE OCEAN. 

 BY T. BASSNETT. 

 Ἡ δε μεσοτης εν πασιν ασφαλεϛερα

 NEW YORK: D. APPLETON & COMPANY, 346 & 348 BROADWAY, AND 16 LITTLE BRITAIN, LONDON. 1854. 

 Entered, according to Act of Congress, in the year 1853, by T. BASSNETT, In the Clerk's Office of the Southern District of New York. 

CONTENTS. 

SECTION FIRST. 

Present State of the Science of Meteorology--Primordial Condition of the Solar System--Theory of Gravitation the great key of Nature--Bessell's doubts of its perfect adequacy--the Newtonian Vacuum: its difficulties--Nature of the element called Ether--The Medium of Space and the Electric Fluid--Ponderosity of Matter--Dynamical law of Equilibrium--Specific heat and its relation to space--A Plenum not opposed to Gravitation--The medium of space in motion--Formation of Vortices--A new principle developed--Elements of the problem--Hutton's theory of the production of rain--Indications of change and the cause--Action of the Ethereal Current--Physical process of Atmospheric Derangement--Redfield's theory of Storms: its difficulties--All storms are of brief duration and limited extent. 13

SECTION SECOND. 

Mechanical action of the Moon--The Moon's mass--Axis of the Terral Vortex affected by the Moon: its inclination and position: its displacement--An example of the principle--Corrections necessary--Milwaukie storm--New York storm--Ottawa storm--Liverpool storm--Names and recurring order of the storm-producing agents--Record of the weather--Second New York storm. 58

SECTION THIRD. 

Lunar influence rejected by the learned--Their conclusions not valid--Modifying causes in accordance with these principles--Years and seasons vary in character--Superficial temperature of different Planets--No storms on the planet Mars--Rotation the cause of Ocean and Atmospheric Currents--Pressure of the atmosphere and its regular and irregular variations--Terrestrial Magnetism--Internal Constitution of the Globe--Magnetic variations--Cause of these variations--Magnetic storms--Aurora Borealis: its altitude--Earthquakes; their possible connection with Storms. 101

SECTION FOURTH. 

The solar spots--Law of periodicity compared with the theory--Existence of another planet beyond Neptune probable--Masses of the Sun and Planet yet uncertain--The Law of Gravitation not above suspicion--Proofs of this--The full of the Moon--Density of the Ethereal Medium: its law in the Solar Vortex--Bode's law of the planetary distances--Law of planetary density--Law connecting the present and former diameters of the planets--Disturbing action of the Ether--Kepler's third law not rigidly exact--Inconsistencies of Astronomers--Nature of light and heat--Distinction between light and heat. 147

SECTION FIFTH. 

Comets--Their small inclinations--Their motions chiefly direct--Comet of 1770 and 1844--Cause of acceleration in the case of Encke--Anomalous motions of the comet of 1843--Change of diameter at different distances of a comet from the sun--Cause of this change--Nature of the nebulosity--Formation of the tail--Compound nature of a comet's light--motion and direction of a comet's tail--Phenomena presented by the great comet of Halley--Mass of a comet--The Zodial light--Nebulous stars--Shooting stars--Periodic showers--Periodicity doubtful--Cause of the apparent periodicity--Cause for being more numerous in Autumn than in Spring. 187

SECTION SIXTH. 

State of the polar ice since 1845--Sir John Franklin's track--Probable existence of islands north of Behring's Straits--Possibility of subsisting in the Arctic islands--News from the Investigator--Necessity of searching in a higher latitude than the Investigator visited--Franklin's misfortunes due to Scientific Errors--Relative levels of the Atlantic and Pacific Oceans--The Arctic seas more accessible in a few years--Conclusion. 233

PREFACE. 

On presenting to the public a work of this novel character, overstepping, as it does, the barriers erected by modern systems to thefurther progress of knowledge, a few words of explanation may not beinappropriate. Early imbued with a desire to understand the _causes_ ofnatural phenomena, the author devoured with avidity the interpretationscontained in the elementary works of orthodox science, until reason andobservation rendered him dissatisfied with the repast. To him itappeared that there was an evident tendency in scholastic instruction, to make the knowledge of nature inaccessible to the many, that the worldmight be made more dependent on the few; while many of the _establishedprinciples_, on which the learned rested, seemed to be at variance withthe simplicity and consistency of truth. Thus situated, he ventured tothink for himself, and looking back on the history of the past, andfinding so many cases in which the philosophy of to-day was supplantedby a different system on the morrow, he was led to suspect thepossibility of future revolutions, and was thus determined to be nolonger embarrassed by previous systems, nor deterred by opinionshowever learned, which conflicted with a rational recognition of themechanical nature of all physical phenomena. 

The science of meteorology, to which the following pages are devoted, is, and always has been, a confessedly complex subject; and on thisaccount, any suggestions and facts which observation gleans, --no matterhow humble the source may be, should not be denied a hearing by thoseprofessedly engaged in the pursuit of truth. Step by step, the authorbecame more and more confirmed in his doubts of the soundness of manymodern theories; and in 1838 he had attained a position which enabledhim to allege in the public prints of the day, that there did existcertain erroneous dogmas in the schools, which stood in the way of afuller development of the causes of many meteorological phenomena. Thisannunciation was made in general terms, and no notice was taken of it. Subsequently, he forwarded to the British Association of Science, thenconvened at Birmingham, a communication of similar tenor; and at a laterdate still, a more particular statement of the advantages of hisdiscoveries to the navigator and agriculturist, was sent to the Britishadmiralty. The first of these communications was treated with silentcontempt; the last elicited some unimportant reply. In 1844 a memorialwas presented to Congress, accompanied with a certified copy of_predictions_ of the weather, written several weeks before the event, and attested in due form by two impartial witnesses; but neither didthis result in any inquiry as to its truth. During the time sinceelapsed, he has been engaged in pursuits which prevented him frompressing the subject elsewhere, until the spring of 1853, he broughthis theory under the notice of the Smithsonian Institution. This led toa correspondence between himself and the gentlemanly Secretary of theInstitution, whose doubts of the truth of his allegations were expressedwith kindness, and whose courtesy was in strange contrast with theconduct of others. In the communications which he forwarded to thatInstitution, he gave a detailed statement of the difficulties he had metwith, and expressed the hope that an Institution, created for thepurpose of increasing and diffusing knowledge, would feel justified inlending the influence of its name to facilitate the completion of atheory which was yet undeniably imperfect. In view of this, a test wasproposed. [1] "Give us, for example, a prediction of the weather for onemonth in each season of the year 1854, for the City of Washington. " Thistest the author refused, for the reason that he did not consider itnecessary to wait so long; but he informed the Secretary of theInstitution, that he would prepare an outline of his theory, which wouldenable him to decide upon the merits of the discoveries claimed. Thisoutline is contained in the following pages. During the summer of 1853he called upon Professor Henry, then at Chicago, with his manuscript;but a sudden indisposition prevented that gentleman from having it read. He, however, strongly recommended its publication from such impressionshe then received. [2] This the author had resolved on, from a sense ofduty to the world at large, although the promise was rather ofprospective loss than of present benefit. The peculiar form under whichthe theory appears, is, therefore, a result of the circumstances abovestated, and of the author's present inability to enter into the minutedetails of a subject, which embraces in its range the whole visiblecreation. 

In extending the theory to other phenomena, he has only fearlesslyfollowed out the same principles which have conducted him to a knowledgeof a disturbing cause, to which atmospheric storms owe their origin, andin doing so he has conferred with no one. For whatever of merit or ofblame may therefore justly attach to these views, he alone isresponsible. If he has charged the scientific with inconsistency, orwith sometimes forgetting that the truth of their unnecessarily abstruseinvestigations depends on the truth of the data, he at least isconscientious; for he is too well aware that to provoke an unfavorableverdict by contending against such fearful odds, is not the surest wayto either wealth or fame, or even to an acknowledgment of at least _themite_, which he cannot but feel that he has contributed to the treasuryof knowledge. That the scientific organisations of the day do tend tocurb the aberrations of a fanciful philosophy, cannot be denied; but atthe same time there is engendered such a slavish subordination as checksthe originality of thought, and destroys that perfect freedom from thetrammels of system, so necessary to success in the pursuit of truth. Ofsuch an influence the author explicitly asserts his entire independence. 

In thus introducing his theory, the reader is forewarned that he willnot find it dressed in the fascinating garb of the popular literature ofthe day, whose chief characteristic is to promise much when possessinglittle. It is, however, a plant of the author's own raising, unpropped, unpruned, with none of the delicate tendrils or graceful festoons of thetrellissed vine; yet he flatters himself that its roots are watered bythe springs of truth, and hopes that he who is in quest of _that_, willnot find, amidst its many clusters, any fruit to set his teeth onedge. 

FOOTNOTES:

[1] Extract from a letter from Professor Henry. 

[2] This gentleman kindly offered to contribute from his own privatemeans, to forward the publication, but he could do nothing officiallywithout submitting the manuscript to three different censors. He whoclaims a new discovery, will seldom be satisfied to have it judged bymen who are engaged in the same investigations, however pure andhonorable they may be. Is this Institution adopting the best plan ofaiding truth, in its struggles against error? Should any man sit asjudge in his own trial? If there had been a powerful Institution tostand between Galileo and the scientific of his day, his doctrines wouldnot have been condemned, and the world would have been fifty years morein advance. 

MECHANICAL THEORY OF STORMS. 

SECTION FIRST. 

PRESENT STATE OF METEOROLOGY. 

The present state of the science of which we are about to treat, cannotbe better defined than in the words of the celebrated Humboldt, who hasdevoted a long life to the investigation of this department of Physics. He says: "The processes of the absorption of light, the liberation ofheat, and the variations in the elastic and electric tension, and in thehygrometric condition of the vast aërial ocean, are all so intimatelyconnected together, that each individual meteorological process ismodified by the action of all the others. The complicated nature ofthese disturbing causes, increases the difficulty of giving a fullexplanation of these involved meteorological phenomena; and likewiselimits, or _wholly precludes_ the possibility of that predeterminationof atmospheric changes, which would be so important for horticulture, agriculture, and navigation, no less than for the comfort and enjoymentof life. Those who place the value of meteorology in this problematicspecies of prediction, rather than in the knowledge of the phenomenathemselves, are firmly convinced that this branch of science, on accountof which so many expeditions to distant mountainous regions have beenundertaken, has not made any very considerable progress for centuriespast. The confidence which they refuse to the physicist they yield tochanges of the moon, and to certain days marked in the calender by thesuperstition of a by-gone age. "

The charge thus skilfully repelled, contains, however, much truth; therehas been no adequate return of the vast amount of labor and expense thusfar devoted to this branch of knowledge. And it is not wonderful thatthe popular mind should expect a result which is so much in accordancewith the wants of mankind. Who is there whose happiness, and health, andcomfort, _and_ safety, and prosperity, may not be more or less affectedby reducing to law, the apparently irregular fluctuations of theweather, and the predetermination of the storm? To do this would be thecrowning triumph of the age; and the present theory has pioneered theway for its speedy accomplishment. 

ORIGINAL CONDITION OF THE EARTH. 

That the present order of things had a beginning, is taught by everyanalogy around us, and as we have the glaring fact forced upon us, thatour globe has experienced a far higher temperature on its surface thanobtains at present, and moreover, as it is demonstrated beyond a cavil, that the interior is now of far higher temperature than is due to solarradiation, we are justified in concluding, not only that the conditionof the interior of our globe is that of fusion, but that its originaltemperature was far higher than at present; so that the inference isallowable that there has been a time when the whole globe was _perhaps_in this state. But why should we stop here? There are three states ofmatter, the solid, the fluid, and the gaseous; and with this passingglance at the question, we will jump at once to the theory of LaPlace, --that not only our own globe, but the whole solar system, hasbeen once in the nebulous state. 

In justice to himself, the author ought to remark, that he had reasonedhis way up to this starting point, before even the name of La Place hadreached his ears. He makes the remark in order to disclaim any desire toappropriate that which belongs to another; as he may innocently speak ofthings hereafter, the idea of which has occurred to others. It is nothis intention here to say a word _pro_ or _con_ on the nebularhypothesis; it is sufficient to allude to the facts, that the directionof rotation and of revolution is the same for all the planets andsatellites of our system; and that the planes on which these motions areperformed, are nearly coincident. That this concordance is due to onecommon cause, no one acquainted with the theory of probabilities willpretend to deny. 

GREAT OBJECT OF LA PLACE. 

The science of Astronomy occupies a pre-eminent rank in the physicalcircle, not only on account of that dignity conferred upon it in themost remote antiquity, or as being the grand starting point--theearliest born of science--from whence we must contemplate the visiblecreation, if we would reduce its numerous details into one harmoniouswhole; but also on account of its practical fruits, of the value ofwhich modern commerce is an instance. Accordingly we will glance at itspast history. In the earliest ages there was no doubt a rational viewentertained of the movements of the planets in space. From the Chaldeansto the Arabs, a belief prevailed, that space was filled with a pureethereal fluid, whose existence probably did not rest on any more solidfoundation than analogy or tradition. One hundred years after Copernicushad given to the world the true arrangements of our planetary system, Descartes advanced his theory of vortices in the ethereal medium, inwhich the planets were borne in orbits around the sun, and thesatellites around their primaries. This idea retained its ground withvarious additions, until the Geometry of Newton reconciled the laws ofKepler with the existence of a power pertaining to matter, varyinginversely as the squares of the distances, to which power he showed theweight of terrestrial bodies was owing, and also the revolution ofthe moon about the earth. Since Newton's day, those deviations from thestrict wording of Kepler's laws, have been referred to the same law, and the avowed object of the author of the "Mechanique Celeste, " was tobring all the great phenomena of nature within the grasp of analysis, byreferring them to one single principle, and one simple law. And in hisIntroduction to the Theory of the Moon, he remarks: "Hence itincontestibly follows, that the law of gravitation is the sole cause ofthe lunar inequalities. "

BESSEL'S OPINION. 

However beautiful the conception, it must be admitted that in its _àpriori_ aspect, it was not in accordance with human experience andanalogy to anticipate a successful issue. In nature law re-acts uponlaw, and change induces change, through an almost endless chain ofconsequences; and it might be asked, why a simple law of matter shouldthus be exempt from the common lot? Why, in a word, there should be nointrinsic difference in matter, by which the gravitation of similar ordissimilar substances should be affected? But experiment has detected nosuch differences; a globe of lead and a globe of wood, of equal weight, attract contiguous bodies with equal force. It is evident, therefore, that if there be such differences, human means are not yet refinedenough to detect them. Was the issue successful then? Generallyspeaking, we may say yes. But where there is a discrepancy betweentheory and observation, however small that may be, it shows there isstill something wanting; and a high authority (Professor Bessel) says inrelation to this: "But I think that the certainty that the theory basedupon this law, _perfectly_ explains all the observations, is notcorrectly inferred. " We will not here enumerate the cases to whichsuspicion might be directed, neither will we more than just allude tothe fact, that the Theory of Newton requires a vacuum, in order that theplanetary motions may be mathematically exact, and permanent in theirstability. 

A VACUUM REQUIRED BY MODERN SYSTEMS. 

Whatever may be the practical belief of the learned, their fundamentalprinciples forbid the avowal of a plenum, although the undulatory theoryof light renders a plenum necessary, and is so far virtually recognizedby them, and a correction for resistance is applied to the Comet ofEncke. Yet there has been no attempt made to reconcile these opposingprinciples, other than by supposing that the celestial regions arefilled with an extremely rare and elastic fluid. That no definite viewhas been agreed on, is not denied, and Sir John Herschel speculates onthe reality of a resisting medium, by suggesting questions that willultimately have to be considered, as: "What is the law of density of theresisting medium which _surrounds_ the sun? Is it in rest or in motion?If the latter, in what direction does it move?" In these queries hestill clings to the idea of Encke, that the resistance is confined tothe neighborhood of the sun and planets, like a ponderable fluid. Butthe most profound analyst the world has ever boasted, speaks lesscautiously, (Poisson Rech. ) "It is difficult to attribute, as is usuallydone, the incandescence of aërolites to friction against the moleculesof the atmosphere, at an elevation above the earth where the density ofthe air is almost null. May we not suppose that the electric fluid, in aneutral condition, forms a kind of atmosphere, extending far beyond themass of our atmosphere, yet _subject to terrestrial attraction_, yet_physically imponderable_, and, consequently, following our globe in itsmotion?" The incandescence of aërolites must, therefore, be owing tofriction against the molecules of the electric fluid which forms anatmosphere around the globe. According to this view, some force keeps itthere, yet it is not ponderable. As it is of limited extent, this is notthe medium whose undulations brings to light the existence of the stars;neither is Encke's, nor Herschel's, nor any other resisting medium. Where shall we find the present established principles of science? If wegrant the Newtonians a plenum, they still cling to attraction of _allmatter_ in some shape. If we confine them to a vacuum, they willvirtually deny it. Is not this solemn trifling? How much more noblewould it be to exhibit a little more tolerance, seeing that theythemselves know not what to believe? We do not offer these remarks asargument, but merely as indications of that course of reasoning by whichwe conclude that the upholders of the present systems of science are notentitled to any other ground than the pure Newtonian basis of aninterplanetary vacuum. 

DIFFICULTIES OF THIS VIEW. 

This, then, is the state of the case: Matter attracts matter directly asthe mass, and inversely as the squares of the distances. This law isderived from the planetary motions; space is, consequently, a void; and, therefore, the power which gives mechanical momentum to matter, istransferred from one end of creation to the other, without any physicalmedium to convey the impulse. At the present day the doctrines ofDescartes are considered absurd; yet here is an absurdity of a fardeeper dye, without we resort to the miraculous, which at onceobliterates the connection between cause and effect, which it is thepeculiar province of physical science to develop. Let us take anotherview. The present doctrine of light teaches that light is an undulationof an elastic medium necessarily filling all space; and this branch ofscience probably rests on higher and surer grounds than any other. Everytest applied to it by the refinements of modern skill, strengthens itsclaims. Here then the Newtonian vacuum is no longer a void. If we getover this difficulty, by attributing to this medium a degree of tenuityalmost spiritual, we shall run upon Scylla while endeavoring to shunCharybdis. Light and heat come bound together from the sun, by the samepath, and with the same velocity. Heat is therefore due also to anexcitement of this attenuated medium. Yet this heat puts our atmospherein motion, impels onward the waves of the sea, wafts our ships todistant climes, grinds our corn, and in various ways does the work ofman. If we expose a mass of metal to the sun's rays for a single hourthe temperature will be raised. To do the same by an artificial fire, would consume fuel, and this fuel would generate the strength or forceof a horse. Estimate, therefore, the amount of force received from thesun in a single day for the whole globe, and we shall find that nothingbut a material medium will suffice to convey this force. 

Let us appeal to analogy. The undulations of our atmosphere producesound; that is, convey to the ear a part of a mechanical force impartedto a solid body--a bell for instance. Let us suppose this force to equalone pound. On account of the elasticity of the bell, the whole of theforce is not instantaneously imparted to the surrounding air; but thedenser the air the sooner it loses its motion. In a dense fluid likewater, the motion is imparted quickly, and the sound is not a ring but aclick. If we diminish the density of the air, the loss of motion isretarded; so that we might conceive it possible, provided the bell couldbe suspended in a _perfect vacuum_, without a mechanical tie, and therewas no friction to overcome from the rigidity of its particles, that thebell would vibrate forever, although its sound could never reach theear. We see, therefore, that the mechanical effect in a given time, isowing to the density of the medium. But can we resort to such ananalogy? Every discovery in the science confirms more and more theanalogy between the motions of air and the medium of space; the angle ofreflexion and incidence follows the same law in both; the law ofradiation and interference; and if experiments were instituted, therecan be but little doubt that sound has also got its spectrum. 

ETHER IMPONDERABLE. 

The medium of space, therefore, is capable of conveying a mechanicalforce from one body to another; it therefore possesses inertia. Does italso possess gravity? If we forsake not the principles of science, it isbut right that we expect science shall abide by her own principles. Condensation in every elastic medium is as the compressing power, according to all experiments. In the case of our atmosphere under thelaw of gravitation, the density of air, (supposing it to be infinitelyexpansible, ) at a height only of ten semidiameters of the earth aboveits surface, would have only a density equal to the density of one cubicinch of such air we breathe, if that cubic inch was to be expanded so asto fill a globular space whose centre should be the earth, and whosesurface should take inside the whole visible creation. Such a mediumcould convey no mechanical force from the sun, and therefore the mediumof space cannot be ponderable. Simple as the argument is, it isunassailable. 

ELECTRIC FLUID THE MEDIUM OF SPACE. 

Let us take yet another view. All experiments prove that the phenomenonwe call electricity, is owing to a disturbance of the equilibrium ornatural condition of a highly elastic fluid. In certain conditions ofthe atmosphere, this fluid is accumulated in the region of the clouds, and by its tension is enabled to force a passage through opposingobstacles, in order to restore the equilibrium. By experiment it isfound that dry dense air opposes the greatest obstacle to its escape. Asthe air is rarefied, this obstacle diminishes; until in a vacuum thetransmission may be considered instantaneous. There ought to be, therefore, a greater escape of electricity from the clouds upwards thandownwards; and, if space be void, or only filled with an extremelyattenuated matter, the electricity of the earth, considered as anelastic fluid without ponderosity, (and no law of condensation from thelaw of gravity in harmony with its other attributes, will allow us toconsider it otherwise, ) _would long since have left the earth_. The sameobjection applies in the case of the galvanic and magnetic fluids. If weentertain the idea that electricity is a mere disturbance of naturalcondition, wherein two fluids are united, and that an excess of one isnecessarily attended by deficiency in the other, we depart from thefirst rule of philosophy, which teaches us to admit no greater number ofcauses than are sufficient to explain the phenomenon. For we fearlesslyassert that not a single fact exists in electrical science, which can beexplained better on Dufoy's theory than on Franklin's; and the formerobjections would still apply. 

NEWTONIAN GRAVITY. 

But what is gravity? According to Newton: "Hæc est qualitas omnium inquibus experimenta instituere licet, et propterea per Reg.  3 deuniverses affirmanda est. " _Vide_ Prin. Lib. Ter. Cor.  2. Prop.  vi. 

Now the other primary qualities of matter are unaffected bycircumstances. The inertia of a particle of matter is the same atJupiter as on the earth, so also is its extension; but not so withgravity. It depends on other matter, and on its distance from it; andmay be less or greater at different times, and in different places. Itis, therefore, not philosophical to say that all matter is necessarilyponderous, inasmuch as it is a virtue not residing in itself alone, butneeds the existence of other matter to call it into action. If an atomwere isolated in space it would have no weight. If influenced by othermatter, there must be some physical medium to convey the influence, orgravity is not in accordance with the laws of force and motion. Whichhorn of the dilemma shall we take? Let us first admit that there is aprinciple of gravitation, affecting all planetary or atomic matter, andthat there exists a highly elastic medium, pervading all space, conveying to us the light of the most distant stars, and that thismedium is not affected by gravity. In this summary way, therefore, wehave arrived at the pivot on which this theory turns. 

The prominent feature of the theory, therefore, is the necessity it willshow for the existence of an all-pervading medium, and that it possessesinertia without ponderosity. That electricity is nothing more than theeffects of the condensation and rarefaction of this medium by force. That it also pervades all atomic matter, whose motions necessarily movethe medium; and, consequently, that there can be no motion without somedegree of electricity. That no change can take place in bodies either bychemical decomposition, by increase or decrease of temperature, byfriction or contact, without in some measure exciting electricity ormotion of the ether. That galvanism and magnetism are but etherealcurrents without condensation, induced by peculiar superficial andinternal molecular arrangement of the particles of certain substances. That light and heat are effects of the vibrations of atoms, propagatedthrough this universal medium from body to body. That the atomic motionof heat can be produced by the motion of translation or momentum ofbodies in the gross, that is, by friction, by compression, &c. ; and canbe reconverted into momentum at our pleasure. Hence the latent heat orspecific atomic motion of combustibles, originally derived from the sun, is transferred to atoms, which are capable of being inclosed incylinders, so as to make use of their force of expansion, which is thusconverted into momentum available for all the wants of man. 

GRAVITY MECHANICAL. 

When we come to a full examination of this theory, we shall furtherreason that this _ether_ so far from being of that quasi spiritualnature which astronomers would have us believe, is a fearfully energeticfluid, possessing considerable inertia and elasticity; that its law ofcondensation is that of all other fluids, that is, as the compressingforce directly; and that its effects are simply a product of matter andmotion. We will next endeavor to prove that the gravity of planetarymatter could not exist without this ethereal medium, by showing that itis an effect produced by the interference of _opposing waves_, whereby abody is prevented from radiating into space its own atomic motion, fromthe side opposite which another body is placed, as much as on theopposite side, and consequently it is propelled by its own motiontowards the other body. And this effect following the simple law ofinertia and radiation, is directly as the mass, and inversely as thesquares of the distances. 

GREAT PRINCIPLE OF DYNAMICS. 

One great principle to be kept in view in this investigation, is thatwhich teaches that the product of matter, angular velocity, and distancefrom the centre of motion, must ever be a constant quality in everybalanced system. Yet this principle does not seem to be observed in thecase of the planets. We will, however, endeavor to show that it isrigidly observed. And we will extend the principle further, and contendthat all the phenomena of nature are consequences of the constanttendency of matter to conform to this principle of equilibrium, whensuffering temporary derangement from the operation of other laws. Thatthroughout the system of nature, equal spaces possess equal force. Thatwhat we call temperature, is nothing more than the motion of equilibriumor atomic momentum of space; or, in other words, that if all space werefluid, and in a state of equilibrium, the product of each atom of equalvolume, by its motion would be a constant quality. From this it wouldseem to follow, that the specific heat of bodies should be inversely astheir atomic weights; and this does, no doubt, _approximately_ obtain aswas proved by Dulong and Petit, for metallic substances, more recentlyby Regnault, and has since been extended by Garnier to other substances. But it is to the gaseous state that we must look for confirmation of theprinciple that equal spaces possess equal power; and in doing so, itwill be necessary to bear in mind, that the ether also is affected bytemperature. 

SPECIFIC HEAT. 

It has been contended by some that the medium which conveys theimpression of light through transparent, bodies, is necessarily moredense within the body than without; but according to this theory theconverse is true. A ray of light is a mechanical impulse, propagatedthrough an elastic medium, and, like a wave in water, tends to the sideof least resistance. Within a refracting body the ether is rarefied, notonly by the proximity of the atoms of the body (or its density), butalso by the motions of those atoms; so that if two _simple_ gases ofdifferent specific gravity be made equal in density by compression, their refraction will be approximately as their specific heats. In thecase of solids and liquids, or even compound gases, there is a continualabsorption of motion to produce the cohesion of composition andaggregation. And the specific heats of compound gases will be foundgreater than those of simple gases, in proportion to the loss of volumeby combination, _ceteris paribus_. If impenetrability be a law ofmatter, the more a portion of atomic matter is condensed, the less etherwill be found in the same space. The same is also true when the naturaldensity or specific gravity of a gas is greater than that of another. And the lighter the gas, the more will this circumstance vitiate theexperiments to determine its specific heat. There is, therefore, thisgreat source of fallacy in such experiments, viz. : that the etherpermeates all fluids and solids, and that _its specific heat probablyfar exceeds that of all other matter_. This is a fundamental position ofthe theory, in support of which we will introduce a fact announced byM.  V. Regnault, which was published in the Comptes Rendus of the FrenchAcademy for April, 1853. He says: "In the course of my researches I haveencountered, indeed, at every step, anomalies which appeared to meinexplicable, in accordance with the theories formally recognized. Forthe sake of illustration I will quote one instance: 1st, a mass of gas, under a pressure of ten atmospheres, is contained in a space which issuddenly doubled; the pressure falls to five atmospheres. 2d. Tworeservoirs of equal capacity are placed in a calorimeter; the one isfilled with a gas, under a pressure of ten atmospheres; the second isperfectly empty. In these two experiments, the initial and finalconditions of the gas are the same; but this identity of condition isaccompanied by calorific results which are very different; for while inthe former experiment there is a reduction of temperature, in the secondthe calorimeter does not indicate the slightest alteration oftemperature. " This experiment tends to confirm the theory. In the firstexperiment, the sudden doubling of the space causes the ether also toexpand, inasmuch as the sides of the vessel prevent the instantaneouspassage of the external ether. In the second, both vessels are full, oneof ether, and the other of air mixed with ether; so that there is noactual expansion of the space, and consequently no derangement of thequantity of motion in that space. 

LAW OF SPECIFIC HEAT. 

From this view it is evident that the specific heat of elastic fluidscan only be considered as approximately determined. If equal spacespossess equal momenta, and the ethereal or _tomic_ matter be inverselyas the weight of the atomic matter in the same space, it follows thatthe product of the specific gravities and specific heats of the simplegases should be constant; or that the specific heats should be inverselyas the specific gravities, --taking pound for pound in determining thosespecific heats. If we test the matter by the data now afforded, it isbest to obey the injunction, "_In medio tutissimus ibis_. " In thefollowing table, the first column are the values obtained by Regnault;in the second, the former values; and in the third, the mean of the two. 

 Gases. Reg. Specific heats. Former specific heats. Mean. Atmospheric air, . 237 . 267 . 252 Oxygen, . 218 . 236 . 227 Nitrogen, . 244 . 275 . 260 Hydrogen, 3. 405 3. 294 3. 350

The specific gravities of these gases, according to the best tables inour possession, are:

 Specific gravities. Mean. Products. Atmospheric air, 1. 0000 × . 252 = . 252 Oxygen, 1. 1111 × . 227 = . 252 Nitrogen, 0. 9722 × . 260 = . 252 Hydrogen, 0. 0745 × 3. 350 = . 249

As might be expected, there is a greater discrepancy in the case ofhydrogen. 

If we test the principle by the vapor of water, we must consider that itis composed of two volumes of hydrogen and one volume of oxygen, andthat one volume disappears; or that one-third of the whole atomicmotion is consumed by the interference of the vibrations of the ether, necessary to unite the atoms, and form an atom of water. We musttherefore form this product from its specific gravity and two-thirds ofits specific heat. On no one subject in chemistry has there been so muchlabor expended, as in determining the specific heat of watery vapor. Inrelation to this, Regnault observes: "It is important to remark that animmense number of experiments have been made, to find the specific heatof steam, and that it is about one-half of what it was thought to be. "He gives its value . 475; but this is vitiated still, by thenon-recognition of the specific heat of the ether. Former experimentsgive . 847. Perhaps Regnault's numbers are entitled to the most weight. Instead of taking the mean, therefore, we will give double weight to hisresults; so that we get . 600 for the specific heat of vapor, and as itsspecific gravity is . 625, the product . 400 × . 625 is . 250, the same asfor hydrogen. Little importance, however, should be attached to suchcoincidences, owing to the uncertainty of the numbers. If our positionbe correct, the specific heat of hydrogen should be 10 times greaterthan of oxygen. The atomic weights are as 1 to 8, while their volumesare as 2 to 1; therefore, for equal spaces, the matter is as 1 to 16. Calling the specific heat 10 to 1, and taking the amount due to half thespace, the product becomes as 8 to 16; but in the rarer gas there is_8 times_ as much ethereal momentum or matter, which, added to theatomic matter, renders the spaces equal. [3] Regnault's results give aratio of specific heats = 1 to 3. 405/. 215 = 1 to 15. 6. 

THE GOLDEN MEAN. 

The history of science proves how few have practically respected theadage of the ancients, which we have chosen for our motto; words whichought to be written in letters of gold in every language under the sun. Descartes, by considering the mechanical impulse of the ether sufficientto explain the planetary motions, failed to detect the force of gravityin the heavens. Newton, on the other hand, feeling that his law wassufficient to explain them, and requiring a vacuum for its mathematicalaccuracy, rejected the notion of an ethereal medium. His successors, following too closely in his footsteps, and forgetting the golden law, have forced themselves into a position by no means enviable. Theshort-period comet has driven them to a resisting medium, which, whileaccording to Encke's hypothesis of increasing density around the sun, itexplains the anomalies of one periodical comet, requires a differentlaw of density for another, and a negative resistance for a third. 

OUTLINES OF THE PROBLEM. 

From the position we now occupy, we can see the outlines of the problembefore us, viz. : To reconcile the existence of an ethereal medium withthe law of gravitation, and to show the harmony between them. We shallthus occupy the middle ground, and endeavor to be just to the genius ofDescartes, without detracting from the glory of Newton, by demonstratingthe reality of the Cartesian vortices, and by showing that the ether isnot affected by gravitation, but on the other hand is _least dense_ inthe centre of our system. But what (it may be asked) has this to do withthe theory of storms? Much every way. And we may so far anticipate oursubject as to _assert_ that every phenomenon in meteorology where forceis concerned, is dependent on the motions of the great sea of electricfluid which surrounds us, in connection with its great specific, caloric. If we are chargeable with overweening pretensions, let it beattributed to the fact that for the last fifteen years we have treatedthe weather as an astronomical phenomenon, calculated by simple formulæ, and that the evidence of its truth has been almost daily presented tous, so as to render it by this time one of the most familiar andpalpable of all the great fundamental laws of nature. True, we haveneither had means nor leisure to render the theory as perfect as wemight have done, the reason of which we have already communicated. 

MOTIONS OF THE STARS. 

In investigating the question now before us, we shall first take thecase of an ethereal vortex without any reference to the ponderablebodies which it contains, considering the ether to possess only inertia. If there be a vortex around the sun, it is of finite extent; for if theether be co-extensive with space, and the stars likewise suns withsurrounding vortices, the solar vortex cannot be infinite. That there isan activity in the heavens which the mere law of attraction isincompetent to account for, is an admitted fact. The proper motions ofthe fixed stars have occupied the attention of the greatest names inastronomy, and motions have been detected, which according to the theoryof gravity, requires the admission of invisible masses of matter intheir neighborhood, compared with which the stars themselves areinsignificant. But this is not the only difficulty. No law ofarrangement in the stars can exist that will save the Stellar systemfrom ultimate destruction. The case assumed by Sir John Herschel, of acluster, wherein the periods shall be equal, cannot be made to fulfilthe conditions of being very numerous, without infringing the othercondition--the non-intersection of their orbits; while the outside starswould have to obey another law of gravitation, and consequently would bestill more liable to derangement from their ever-changing distancesfrom each other, and from those next outside; in brief, the stability ofthose stars composing the cluster would necessarily depend on theexistence of outside stars, and plenty of them. But those outside starswould follow the common law of gravity, and must ultimately bring ruinon the whole. We know such clusters do exist in the heavens, and thatthe law of gravity alone must bring destruction upon them. This is acase wherein modern science has been instrumental in drawing a veil overthe fair proportions of nature. That such collections of stars are notdesigned thus to derange the order of nature, proves _à priori_, thatsome other conservative principle must exist; that the medium of spacemust contain many vortices--eddies, as it were, in the great etherealocean, whose currents are sweeping along the whole body of stars. Weshall consider, (as a faint shadowing of the glorious empire ofOmnipotence, ) that the whole infinite extent of space is full of motionand power to its farthest verge; and it may be an allowable stretch ofthe imagination to conceive that the whole comprises one infinitecylindrical vortex, whose axis is the only thing in the universe in astate of absolute unchangeableness. 

VORTICOSE MOTION. 

Let us for a moment admit the idea of an infinite ocean of fluid matter, having inertia without gravity, and rotating around an infinite axis, inthis case there is nothing to counteract the effect of the centrifugalforce. The elasticity of the medium would only oppose resistance in avortex of finite diameter. Where it is infinite, each cylindrical layeris urged outward by its own motion, and impelled also by those behind. The result would be that all the fluid would at last have left the axis, around which would exist an absolute and eternal void; into whichneither sound, nor light, nor aught material, could enter. The case ofa finite vortex is very different. However great the velocity ofrotation, and the tendency of the central parts to recede from the axis, there would be an inward current down either pole, and meeting at theequatorial plane to be thence deflected in radii. But this radiationwould be general from every part of the axis, and would be kept up aslong as the rotation continued, if the polar currents can supply thedrain of the radial stream, that is, if the axis of the vortex is nottoo long for the velocity of rotation and the elasticity of the ether, there will be no derangement of the density, only a tendency. And inthis case the periodic times of the parts of the vortex will be directlyas the distances from the axis, and the absolute velocities will beequal. 

FORMATION OF VORTICES. 

There is reason to suspect that Newton looked at this question with ajaundiced eye. To do it justice, we must consider the planetary matterin a vortex, as the exponent of its motion, and not as originating ordirecting it. If planetary matter becomes involved in any vortex, itintroduces the law of gravitation, which counteracts the expulsive forceof the radial stream, and is thus enabled to retain its position in thecentre. A predominating mass in the centre will, by its influence, retain other masses of matter at a distance from the centre, even whenexposed to the full power of the radial stream. If the power of thecentral mass is harmoniously adjusted to the rotation of the vortex, (and the co-existence of the phenomena is itself the proof that such anadjustment does obtain, ) the two principles will not clash or interferewith each other. Or in other words, that whatever might have been theinitial condition of the solar vortex, the ultimate condition wasnecessarily one of equilibrium, or the system of the planets would notnow exist. With this view of its constitution, we must consider that theperiodic times of the planets approximately correspond to the times ofthe contiguous parts of the vortex. Consequently, in the solar vortex, the density of the ether is directly as the square roots of thedistances from the axis. This is not the place fully to enter into adiscussion of the question, or to show that the position of each planetin the system is due to the outstanding, uncompensated, portion of theexpulsive force of the radial stream, modified by the density of theether within the planets, and also by their own densities, diameters, inclinations of axis, and periods of rotation. That Jupiter could notremain in the orbit of Mercury, nor Mercury in that of Jupiter, bymerely exchanging periods and distances, but that each planet can onlybe in equilibrio in its own orbit. That any change in the eccentricitiesof the planetary orbits will neither increase nor diminish the action ofthe radial stream of the vortex, and consequently will not interferewith the law of gravitation. In relation to the numerous questions thatwill spring up from such a position, it is sufficient here to say, thatit is believed all objections can be satisfactorily answered; while, bythis light, a long range of phenomena that have hitherto baffled thesagacity of the wise, come out plainly, and discover their parentage. 

In cometary astronomy we shall find much to substantiate these views. The anomalies in their motions, the discrepancies in their periods, calculated from different sets of observations, their nebulosities andappendages, will all receive a satisfactory solution; and these lawlesswanderers of the deep be placed in a more interesting light. 

TEST OF A THEORY. 

It has been remarked that the best evidence of the truth of a theory, isits ability to refer to some general principle, the greatest number ofrelevant phenomena, that, like the component masses of the chiselledarch, they may mutually bind and strengthen each other. This we claimto be the characteristic of this theory. At the outset it was notintended to allude to more than was actually necessary to give anoutline of the theory, and to introduce the main question, yetuntouched. We have exhibited the stones of which the arch is composed;but they may be pasteboard, --for the reader has not handled them. Wewill now produce the keystone, and put it in its place. This he shallhandle and weigh. He will find it hard, --a block of granite, cut fromthe quarry of observed facts, and far too heavy to be held in its placeby a mere pasteboard structure. 

ENUNCIATION OF THE THEORY. 

Quitting, therefore, the region of the planets, we will come down to thesurface of our own globe, to seek for some more palpable evidence of thetruth of the following propositions:

1st. That space is filled with an elastic fluid, possessing inertiawithout weight. 

2d. That the parts of this fluid in the solar system circulate, afterthe manner of a vortex, with a direct motion. 

3d. That there are also secondary vortices, in which the planets areplaced. 

4th. That the earth is also placed in a vortex of the ethereal medium. 

5th. That the satellites are passively carried around their primaries, with the ethereal current, and have no rotation relative to the ether, and therefore they always present the same face to their primaries, andhave no vortex. 

The consideration of these propositions involves many others, manydifficulties, many apparent anomalies and contradictions, which shouldbespeak for such a theory, --the offspring of observation, without theaid afforded by the knowledge of others, and of toil without leisure, --alarge share of indulgence. With this we will close these preliminaryremarks, and present our theory of the physical cause which disturbsthe equilibrium of our atmosphere, and which appears the principal agentin the production of storms, in the following words:

The dynamical axis of the terral vortex passes through the centre ofgravity of the earth and moon, and is continually circulating over theearth's surface in both hemispheres, in a spiral, --its latitude andlongitude, at any particular time, being dependent, --

1st. On the relative mass of the moon. 

2d. On the inclination of the axis of the vortex to the earth's axis. 

3d. On the longitude of the ascending node of the vortex on the lunarorbit. 

4th. On the longitude of the ascending node of the lunar orbit on theecliptic. 

5th. On the eccentricity of the lunar orbit at the time. 

6th. On the longitude of the perigee of the lunar orbit at the time. 

7th. On the moon's true anomaly at the time. 

MASS OF THE MOON. 

Those elements which represent the moon's distance and motion areaccurately known, and may be taken from the Nautical Almanac, being allembodied in the moon's parallax or semi-diameter, and in the declinationand right ascension; but for the most important element, --the moon'smass, we in vain look to astronomy. In fact, it may be averred that theimportance attached to astronomical authority, concerning the mass ofthe moon, has caused more trouble than any other question of the wholetheory, until we trusted implicitly to the theory itself to determineit. The determination of three unknown elements, viz. : the moon's mass, the inclination of the axis of the vortex, and the right ascension ofthat axis, is a more difficult problem than at first sight appears, owing to the nature of the phenomena, which affords the only clue forits solution. There are six principal vortices ever in operation on thesurface of the earth, and their disturbing influence extends from 200 to400 miles. To find the precise centre, by one observer confined to oneplace, is difficult; and to separate them, so as to be fully assuredthat you have the right one, is perhaps still more so. Happily thistedious labor is accomplished, and we are able with confidence to givethe following important elements, as very close approximations to thetruth:

 Mass of the moon 1/72. 3 Obliquity of the axis of the vortex 15° to 32° variable. Right ascension of ditto 250° to 290° variable. 

It must be borne in mind that we are now discussing the main or centralvortex of the earth; but before applying them to the calculation, wewill explain the _modus operandi_, waiving for the present theconsideration of the law of density in the Terral vortex. It is evidentat first sight that if the periodic times of the parts of the vortexcontiguous to the moon, are equal to the moon's period approximately, that the velocity of the ether is greater at the surface of the earththan the velocity of that surface. Now, we have before argued that theether possesses inertia, it therefore would under such circumstancesexert some mechanical action. Consequently, the aërial envelope of ourglobe, or its superior stratum, is impelled eastward by _convection_[4]of the more rapidly rotating ether. And from the extreme tenuity of itsupper layers, is probably forced into immense waves, which will observeto a certain degree, a general parallelism north and south. 

ATMOSPHERIC CURRENTS. 

It is a well-known fact, that the prevailing current of the atmospherein high latitudes is from the westward. The cause of this is ascribed byProfessor Dove to the transfer of the equatorial portions to a higherlatitude, by which the excess of its rotative velocity is made apparent, by outstripping the slower moving surface in its progress eastward. Nodoubt some effect is due to this, but still a difficulty remains. Let usfollow this current. The polar current reaches the surface on theborders of the trades with less rotative velocity than the surface, andis, therefore, met by the surface as a current partaking of bothmotions. In the northern hemisphere it is north-east deflected to eastas it approaches the southern trades. By the same reasoning, coming fromthe north before it readies the surface, it ought to be also anorth-east wind above the lower westerly currents. Now it is an observedfact, that while in the latitude of New York, for instance, the lowerwesterly winds are to the easterly, as 3 or 4 to 1, in the highestregions of observed clouds, the ratio is much increased; and accordingto our own observations in this place, [5] we have never seen the highestcirrus clouds moving westward. How then is this continual interchangekept up? Assuredly we cannot have a current from the poles without acontrary current to the poles. If we go into the arctic circle, we againfind the westerly and northerly winds predominating. If the current fromthe equator follows the surface, the westerly winds ought to besouth-west. If it be above the surface wind, then the surface wind isthe polar current, and ought to be north-east. Whereas, from thetestimony of all who have visited these regions, the prevailing windsare north-west. How can this be?

Again, it is proved that the upper current near the equator is also fromthe westward--as near due west as possible. Take the latitude of StVincent. The difference between the cosine of 13° and radius appliedto the circumference, is about 600 miles, which would give 25 miles perhour to the eastward, in lat.  13°. But to do this, it is necessary totransfer it suddenly from the equator; for by a slow motion the easterlytendency would be lost. Give it 24 hours from the equator to lat.  13°, without any loss of easterly tendency, and it comes to that latitudewith a velocity of 38 miles per hour to the northward, and only 25 tothe eastward; we have, therefore, a wind from south-west by south. Yetit is known that in the tropics the highest visible clouds move from thewestward. But as no such case could occur as a transfer in twenty-fourhours without loss, and if we diminish the time, the wind is still moresoutherly. Meteorologists usually cite the falling of ashes at Jamaicaduring the eruption of Coseguina, in Guatamala, in February 1835, ascoming from south-west, whereas the true direction was about westsouth-west, and the trade wind below was about north. But do we denythat there is an interchange between the frigid and torrid zones? By nomeans; but we would show that the great controlling power is external toour atmosphere, and that the relative velocities of the earth and theatmosphere is not alone adequate to account for it. By this view thepolar current is a north-west wind (which is impossible by ProfessorDove's theory), or is carried eastward by electric convection. 

HUTTON'S THEORY. 

Whether we adopt the views of Fourier or Poullet, as to the temperatureof the planetary spaces, it is certain that it is at least equal to, orless than, the lowest temperature of our globe. It is also a well-knownfact, that the capacity of air to hold vapor in solution, increases in ahigher ratio than the temperature, so that the intermingling ofsaturated portions of air, at different temperatures, must _necessarily_be attended by precipitation of moisture. This idea was advanced byDoctor Hutton, and considered competent to account for the prominentmeteorological phenomena, until Professor Espy broached a questionableprinciple, (and which is rendered still more so by the lateinvestigations of Regnault, ) in opposition to Hutton's theory. That thetheory is deficient, no one can gainsay. That Espy has rendered thequestion clearer, is equally hazardous to assert. Hutton failed inshowing a cause for such intermingling on a sufficient scale; whileEspy, it may be suspected, has misinterpreted facts, and incautiouslyrejected the only element possessing the power of raising the storm. 

GREAT SPECIFIC HEAT OF THE ETHER. 

Whatever may be the degree of condensation or rarefaction in the terralvortex, there must necessarily be a current down the pole or axis, thence to be deflected along the equatorial plane of the vortex, andthis drain will be as perpetual as the rarefaction of the centre, (caused by the centrifugal force of rotation, ) which calls it forth. Itwill now be perceived that the fluid of the vortex, which we shall stillterm ether, is neither more nor less than the electric fluid, --themighty energising principle of space, --the source of motion, --the causeof magnetism, galvanism, light, heat, gravity, of the aurora, thelightning, the zodiacal light, of the tails and nebulosities of comets, of the great currents of our atmosphere, of the samiel, the hurricane, and the earthquake. It will be perceived that we treat it as any otherfluid, in relation to its law of motion and condensation. But we have noright to base our calculations on its resistance, by the analogiespresented by ponderable or atomic matter. Atomic fluids, --even pure air, may be considered viscid and tenacious when compared to an infinitelydivisible fluid, between whose particles (if we may use the term) no_attraction_ of any kind exists. No ponderable matter can come in closecontact without feeling the influence of the gravitating force which, atinsensible distances, --such as the breadth of a wave of ether, isincreased in power, and becomes a cohering and combining force. Wecontend that this fluid is the only fluid of space; when condensed it ispositive, and seeks to escape; when rarefied it is negative, andreceives from the contiguous space a restoration of its power. That itcan give and receive, from planetary matter, what we call motion; andconsequently can affect the temperature of such matter, and be in turnaffected by it. And finally that, for its degree of inertia, it exceedsin elasticity and specific heat all other matter. 

PROCESS OF DERANGEMENT. 

This premised, we see that as the axis of the vortex traverses thesurface of the earth, there is a tendency to derange the electric stateof the parts travelled over, by bringing the atmosphere and surface ofthe earth under the rarefied centre of the vortex. For it is not theether of the atmosphere alone that is affected. It is called forth fromthe earth itself, and partakes of the temperature of thecrust, --carrying up into the upper regions the vapor-loaded atmosphereof the surface. The weather now feels close and warm; even in winterthere is a balmy change in the feelings. The atmosphere then fills withhaze, even to the highest regions of the clouds; the clouds themselvesare ill defined; generally the wind comes in at E.  S-E. , or S. , gettingvery fresh by the time it chops round to W. In from six to twelve hoursfrom the time of the meridian passage, in this latitude, the Big Cumulihave formed, and commenced their march eastward. In summer time there isalways thunder and lightning, when the passage is attended or followedby a storm. In winter, generally, but not always. In summer, thediameter of the storm is contracted; in winter, dilated; in consequenceof this, summer is the best season to trace the vortices of the earththrough their revolutions. Let us now attend a little to the results. The ether of the surface atmosphere partakes of the temperature of thatatmosphere, so also the ether of the earth's crust partakes of thetemperature of the crust; and its escape is rapid, compared with theascent of the air. When it arrives at the colder layers of air above, its temperature sinks, and, on account of the greater specific caloric, it imparts a much higher temperature to those layers than is due totheir position; an elevation consequently takes place, --begetting adrain from below, until the upper regions are loaded with a warm andvapory atmosphere. If the action of the sun conspires at the same timeto increase the effect, the storm will be more violent. In twelve hoursafter the meridian passage of the vortex, the storm is brought under theparts of the ethereal atmosphere of the earth most remote from the axis;a reaction now takes place; the cold ether of space rushes in, and, onaccount of its great specific caloric, it abstracts from the warmatmosphere more than pertains to the difference of temperature, andthere is a great condensation. Rain and hail may form in fearfulquantities; and when the equilibrium is restored, the temperature willhave fallen many degrees. 

As it is important that we should have a clear view of the character ofthe ether, we will revert to the principle we have advocated, viz. : thatin equal spaces there are equal momenta. What the ether wants ininertia, is made up by its motion or specific heat, considering in thiscase inertia to stand for weight when compared with ponderable matter;so that to raise an equivalent amount of inertia of ether to the sametemperature as atmospheric air, will require as much more motion orspecific heat as its matter is less. And this we conceive to be a law ofspace in relation to all free or gaseous matter. To apply it to solidswould require a knowledge of the amount of force constituting thecohesion of the solid. 

INFLUENCE OF DIMINISHED PRESSURE. 

But there is another principle which modifies these effects. We havealready adverted to the action of the tangential current of the vortexforcing the outer layers of the atmosphere into waves. These waves willbe interfered with by the different vortices, sometimes being increasedand sometimes diminished by them. [6] If these waves are supposed verywide, (which would be the case in the attenuated outside layers of theatmosphere, ) the action of the vortex will be greater in its passageover a place, which at the time corresponded to the depression point ofthe wave, that is, to the line of low barometer; because here therewould be less resistance to overcome in the passage of the ether fromthe surface of the earth into space; so that we may conceive each vortexmaking a line of storms each day around the earth, separated by lessdisturbed intervals. After the formation of the storm, it of course hasnothing to do with the vortex that produced it; it travels in thegeneral direction of the local atmosphere of the place--in intratropicallatitudes westward, in extratropical latitudes eastward. If, therefore, the disturbance forms at the place of observation, there will probablybe no storm; but further eastward its action would be more apparent orviolent. It is impossible, of course, to lay down any generaldescription which shall meet every case. It is a knowledge that can onlybe acquired by observation, and then is not readily or easilycommunicated. There are many contingencies to be allowed for, and manymodifying causes to keep sight of, to enter into which would only betedious; we shall, therefore, confine ourselves to the prominentphenomena. 

ACTION OF THE POLAR CURRENT. 

We have seen how the passage of the axis of the vortex may derange theelectric tension of the parts passed over; but there is another mode ofaction not yet adverted to. 

[Illustration: Fig. 1]

When the moon is at her perigee, the axis of the vortex passes throughthe centre of gravity of the earth and moon at C, and cuts off thesegment RR. At the apogee, on account of her greater distance, and ofher consequent power to _push_ the earth out from the axis of the vortexXX, the segment R′R′ is only cut off by the axis; and the angle whichthe axis makes with the surface will vary with the arcs AR and A′R′; forthese arcs will measure the inclination from the nature of the circle. In passing from the perigee to the apogee the axis will pass over thelatitudes intermediate between R and R′ in both hemispheres, neitherreaching to the equator E, nor to the pole P. Let us now suppose ameridian of the earth, represented by the line NRS, N being north, and Ssouth, and the surface of the atmosphere by N′S′; XX still representingthe axis of the vortex, ordinarily inclined 34° or 35° to the surface. Let us also conceive the rotation of the earth to cease, (the action ofthe vortex remaining the same, ) thus leaving the axis over a particularlongitude. If the ether possesses inertia, there will be an actualscooping out of the upper portions, driving them southward to a certaindistance, where the atmosphere will be piled up above the ordinarylevel. There will, therefore, be a strong contrary current at thesurface of the earth to restore the equilibrium, and if the action beviolent, the surface wind will be increased; so that if it be consideredtangential to the surface at S, its own momentum will tend to make itleave the surface and mount up to T; and in this way increase the actiondue to the ether. Now, although the axis is never stationary, buttravels round the earth in less than twenty-five hours, yet there is atendency to this mode of action; and it is even sometimes palpable tothe observer when the axis has passed immediately to the northward; forthe pinnate shafts and branching plumes of the cirri often reach far tothe south of the southern boundary of the storm. These shafts are alwayslonger when radiating from the northward than when proceeding from thesouthward. The cause is understood by the above figure. At such a time, after dark, the auroral shafts will also be seen over the storm to thenorthward, but will be invisible to those beneath. There is this to beobserved, however, that the visibility of the ethereal current (or theaurora) is more frequent when the passage of the vortex is not attendedwith any great commotion, its free passage being perhaps obstructed bytoo dry an atmosphere; hence it becomes more visible. But it may beasserted that a great aurora is never seen except when a vortex is near, and to the northward, and within a few hours of its passage over themeridian. We have, however, seen partial auroras to the south when noneexisted north, and also cases when the radiation was from west, but theyare never as bright as in the north. They are all due, however, to thesame cause; and we have frequently followed a vortex for three days tothe northward, (that is, seen the effects of its meridian passage, ) at700 miles distance, by the aurora, and even by the lightning, whichproves plainly that the _exterior layers_ of our atmosphere can reflecta flash of lightning, assisted by the horizontal refraction, otherwisethe curvature of the earth would sink it ten miles below the horizon. 

[Illustration: Fig. 2]

LIMITS OF THE VORTEX. 

The action of the polar current of the ether, therefore, tends to causea depression of the barometer, and an elevation to the _northward_ andsouthward, and there is a general set of the wind below to the point ofgreatest depression. The action of the tangential current works theouter surface of the atmosphere into great ridges and hollows, whosedistances apart as well as actual dimensions, are continually changingunder the influences of causes not yet alluded to, and it is in thehollows where the action of the polar current will be principallyexpended. Luckily for the earth, the axis of the vortex is never long inpassing over any particular place. In this latitude, whose naturalcosine is three-fourths, the velocity _westward_ is over 700 miles perhour; but at its extreme limits north, the motion is much slower, and isrepeated for two or three days in nearly the same latitude, for then itbegins to return to the south; thus oscillating in about one siderealperiod of the moon. At its southern limit, the vortex varies but slowlyin latitude for the same time, but the velocity is much greater. Theextreme latitudes vary at different times with the eccentricity of thelunar orbit, with the place or longitude of the perigee, and with thelongitude of the moon's ascending node, but in no case can the _centralvortex_ reach within 5° of the equator, or higher than about 75° oflatitude north or south. Hence there are no storms strictly speakingbeyond 88°[7] of latitude; although a storm may be raging close by, atthe turning point south, and draw in a very strong gale from thenorthward with a clear sky above. So also, although rains and shortsqualls may be frequent in the vapor-loaded atmosphere of the equator, yet the hurricane does not reach there, owing to the adjustment of themass and distance of the moon, and the inclination of the axes of thevortices to the axis of the earth. If the temperature of the upper limitor highest latitude of the vortex, was equal to the temperature whichobtains at its lowest limit, and the daily extremes of the solarinfluence as great, the hurricanes would be as violent at the one as theother, and even more so on account of the smaller velocity. But thedeficiency of temperature and moisture, (which last is all-important, )prevents the full development of the effect. And even in the tropics, the progress of the sun, by its power in directing the great annualcurrents of the atmosphere, only conspires in the summer and autumnmonths, to bring an atmosphere in the track of the vortices, possessingthe full degree of moisture and deficiency of electric tension, toproduce the derangement necessary to call forth the hurricane in itsgreatest activity. 

ROUTINE OF A STORM. 

The novelty and originality of this theory will perhaps justify us indwelling a little longer on what observation has detected. The vortex(and we are now speaking only of the central vortex) does not derangeevery place alike, but _skips_ over large tracts of longitude in itsprogress westward. We speak here of the immovable axis of the vortex asin motion; in reality it is the rotation of the earth which brings everymeridian under its influence in some latitude once every twenty-fourhours. The centre of greatest derangement forms the nucleus, towardswhich the surface currents, under certain restrictions, flow. Thestrongest current will, however, usually be from the south, on accountof the inclination of the axis of the vortex to the surface of theearth. [8] These currents continuing onwards by their vires inertiæ, according to the first law of motion, assist somewhat in conveying thewarm surface wind, loaded with moisture, into the region of cloud; andthe diminution of temperature causes the condensation of large masses ofvapor, according to Hutton's views; and the partial vacuum thusproduced, causes a still greater intermingling. But we have alreadyshown that this is not the sole cause, nor is it ever more thanpartially accomplished. The ether of the lower atmosphere, and of thecrust of the earth, is disturbed, and rushes towards the rarefied axisfrom the surface, and with the temperature of the surface, thusconveying the surface atmosphere, in a measure, along with it. In theupper regions, this ether (or electric fluid) cools down, or parts withsome of its heat, to the air of those regions, and, by its greatspecific caloric, necessarily and unduly increases the temperature ofthe air. This, by its expansion and ascension will cause a furtherinflux from below, until the upper atmosphere becomes loaded with vapor. In twelve hours, at least, a reaction must take place, as that part ofthe earth's surface is carried six or seven thousand miles from theaxis, where the ether is more dense. This in turn descends to thesurface, carrying with it the temperature of space, at least 60° belowzero; a great condensation must follow; local derangements of theelectric equilibrium in the centre of large clouds, when thecondensation is active, must now take place, while partiallynonconducting masses intervene, to prevent an instantaneous restorationof the equilibrium, until the derangement is sufficient to cause thenecessary tension, when all obstacles are rent asunder, and the etherissues forth, clothed in the power and sublimity of the lightning. It isa fearfully-energetic fluid, and, when sufficiently disturbed, competentto produce the most violent tornado, or the most destructive earthquake. That these two phenomena have simultaneously occurred, seems wellauthenticated; but the earthquake, of course, must be referred generallyto derangements of the electric equilibrium of the earth's interior, ofwhich at present we know but little. 

The day or morning previous to the passage of the vortex, is frequentlyvery fine, calm, mild, and sleepy weather, --commonly called a weatherbreeder. After the storm has fully matured, there is an approach of theclouds to the surface, a reduction of the temperature above, and thehuman body feels the change far more than is due to the fall oftemperature. This is owing to the cold ether requiring so much heat toraise its temperature to that of surrounding bodies, or, in other words, is due to its great specific caloric. In summer, this falling of theupper layers in front of the storm is so apparent, that every part isseen to expand under the eye by perspective, --swelling, and curling, andwrithing, like the surface of water or oil when just commenced boiling. The wind now partakes of the motion of the external ether, and moveswith the storm eastward (in this latitude), or from N-E. To S-E. , untilthe action ceases. 

CONDITIONS NECESSARY TO PRODUCE A STORM. 

The vortex, in its passage round the earth, may only meet with a fewlocalities favorable for producing a very violent storm; but thesenuclei will generally be connected by bands of cloudy atmosphere; sothat could we view them from the moon, the earth would be belted likethe planet Jupiter. There is reason to suspect, also, that there arevariations in the energy of the ethereal motions, independent of theconditions of the earth and its atmosphere, which affects even theradial stream of the sun. For the zodiacal light, which is caused bythis radial stream, is at times much more vivid than at others. Also inthe case of the aurora, on our own globe. On this point there is much tosay, but here is not the place. The conditions favorable for theproduction of a storm at the _central_ passage of a vortex, are aprevious exemption from excitement _ceteris paribus_, a high temperatureand dew point, a depression of the barometer, and local accumulation ofelectric tension, positive or negative; and these are influenced by thestorms in other places controlling the aërial currents, and thusdetermining the atmosphere of the place. 

LATERAL VORTICES. 

We have already alluded to the lateral vortices of the terral system. Wemust now resort to a diagram. 

In the following figure, the arrows represent the ethereal current ofthe terral vortex; the linear circle, the earth; C the centre of gravityof the earth and moon, and, consequently, the central vortex or axis ofthe vortex of the earth, I represents the position of the inner vortex, and O that of the outer vortex. These two last are eddies, caused by theobstacle presented by the earth in being _pushed_ out from the centre bythe moon, and are called lateral vortices. There are, therefore, twolateral vortices, and one central, in both hemispheres, and by thissimple arrangement is the earth watered, and the atmospheric circulationproduced. 

[Illustration: Fig. 3]

ILLUSTRATION OF THEIR ACTION. 

If we place a globe in a vessel of water, so that the vertex shall onlyjust be covered, and place the globe eccentrically in the vessel so thatthe centre of the vessel may not be too far from the outside of theglobe, and then impart an equable but slow motion to the water, in themanner of a vortex; by viewing the reflected light of the sky from thesurface of the water above the globe, we shall be able to trace asuccession of dimples, originating at I and O, and passing off with thecurrent, and dying away. The direction of the fluid in these littleeddies, will be the same as the direction of the current in the mainvortex. If we displace the globe, so as to remove it far from the centreof the vessel, and impart the same motion, the vortex I will be found atE, and the direction of the current will be contrary to the directionof the fluid in the vessel. In the case of the earth and moon, thedisplacement can never change the position of the inner vortex much. Itwill always be to the right hand of the central vortex in northlatitudes, and in consequence of the ether striking our globe in such aposition, the current that is deflected from its true path, by theprotuberance of the earth forcing it inside, is prevented by thecircular current of the parts nearer the axis of the vortex, frompassing off; so that a vortex is formed, and is more violent, _ceterisparibus_, than the vortex at O. 

ORDER OF OCCURRENCE. 

Whether this mode of action has been correctly inferred, matters little;the lateral vortices follow the law of such a position. The inner vortexalways precedes the central from five to eight days, when ascending inthis latitude, and comes to the meridian after the moon. The outervortex, on the contrary, follows the central in its monthly round, andcomes to the meridian before the moon. It will be readily understoodthat if the axes of these lateral vortices be produced through theearth, they will pass through similar vortices in the oppositehemisphere; but as the greatest latitude of the one, corresponds to theleast latitude of the other, the same calculation will not answer forboth. The same remark applies to the central vortex also. 

Thus there are six passages each month over latitude 41°; but as thereare intervals of 3° to 6° between two consecutive passages of the samevortex, it may happen that an observer in the middle latitude, wouldperhaps see nothing of their effects without looking for them. Generallyspeaking, they are not only seen, but felt. The time of the passage ofthe outer vortex ascending, corresponds so nearly (in 38° of latitude)at certain times, with the passage of the central vortex descending, that the two may be considered one if attention is not directed to it. The orbits of these lateral vortices depend, like that of the centralvortex, on the orbit of the moon for eccentricity, but the longitudes ofthe perigee will not correspond with the longitude of the moon'sperigee. This follows from the theory. As the elements of these orbitsare only approximately determined, we shall confine our calculations tothe orbit of the central vortex. 

REDFIELD'S THEORY OF STORMS. 

It will now appear plainly to the reader, that this theory of stormsdiffers in every particular from the rival theories of Redfield andEspy, both as to the cause and the _modus agendi_. It would appear atfirst sight, as if the discovery of these vortices would at once remedythe great defect in the theory of Redfield, viz. : that no adequate causeis assigned for the commencement and continuation of the vorticosemotion, in the great circular whirlwinds which compose a storm. Thefacts, however, are adverse to such an application. According toMr.  Redfield, the rotation of a circular storm in the northernhemisphere is from right to left, and the reverse in the southern. Theauthor's attention has, of course, been considerably directed to thispoint; but in every case he has been unfortunate in finding in theclouds a rotation from left to right. Some cases are mentioned in theappended record of the weather. He has also noticed many of those smallwhirlwinds on arid plains, in Egypt, in Mexico, and in California, which, in the great majority of cases, were also from left to right. Hisopportunities, however, have not extended to the southern hemisphere. This theory has not, however, been formed on theoretic views, but bylooking nature in the face for years, and following her indications. Accordingly, we find that the changes of the wind in a storm forbid theadoption of the circular hypothesis. 

WHIRLWINDS VERY LIMITED IN DIAMETER. 

The theory, as extended by Col.  Reid, rests on a simple rotation arounda progressing centre, and is found sometimes supported by evidence ofthe most violent action at the centre, and sometimes by showing that thecentral portion is often in a state of calm. We do not attempt toreconcile these views; but would merely observe, that an atmosphericvortex must be subject to the same dynamical laws as all other vortices;and inasmuch as the medium cannot differ greatly in density, from thecentre to the circumference, the periodic times of the parts of thevortex, must be directly as their distances from the axis, andconsequently the absolute velocities must be equal. If Mr.  Redfieldresorts to a spirally inward current, it would be a centripetal insteadof a centrifugal current, and therefore could not cause the barometer tofall, which was the best feature of the theory in its primitive form. The absolute velocity of the wind is the important element which mostconcerns us. In the case of a tornado of a few yards in diameter, thereis no doubt a circular motion, caused by the meeting of opposingcurrents; but this may be considered a circle of a very small diameter. The cause is due to a rapid escape of electric or ethereal matter, fromthe crust of the earth, called forth by the progressing, disturbed spaceabove; this involves the air, and an ascending column in rotation begetsthe rush on all sides to that column in straight lines: consequently, the velocities will be inversely as the distances from the axis, and theforce of the current as the squares of the velocities. On the circulartheory, no increase of velocity would be conferred by the approach ofthe centre, and consequently no increase of power. 

OBJECTION TO CIRCULAR STORMS. 

Another objection to the circular theory of storms, is the uniformity ofphase. If that theory be true, we see no reason why a person should notbe sometimes on the northern side of the gale. By referring to adiagram, we perceive that on the northern side the changes of the windpursue a contrary direction to what they do on the south, yet in ninecases out of ten, each vessel meeting a hurricane will find the samechanges of wind as are due to the southern side of the storm. It istrue, that if a vessel be to the northward of a great hurricane, therewill almost certainly be a north-east gale drawn in, and this might beset down as the outer limits of a circular storm. But when the stormreally begins, the wind comes round south-east, south, south-west, ending at north-west, and frequently is succeeded, on the following day, (if in middle latitude, ) by a moderate breeze from the northward. Now, if the north-east gale spoken of above, was the outer limits of anatmospheric vortex, a vessel sailing west ought not to meet thehurricane, as a north-east wind is indicative of being already on thewest side, or behind the storm. 

Again, the characters of the winds, and appearances at the differentchanges, are opposed to the circular theory. At a distance of fiftymiles from the centre of a storm, the wind which passes over a ship as asoutherly wind, will have made a rotation and a half, with the hurricanevelocity, before the same wind can again pass the ship as a northerlywind, (supposing the progress eastward, and the ship lying to, ) that is, the same wind which in another place was a south wind two hours before, and after only going one degree north, becomes a northerlywind, --changed in character and temperature, as every seaman is wellaware. In a storm, if the circular theory be true, the character andtemperature should be the same, no matter from what point the wind isblowing. This should be a conclusive argument. 

Mr.  Espy has also changed his ground on the storms of the United States;he does not now contend that the winds blow inwards to a centre, but toa line either directly or obliquely. Thus we see that while Mr.  Redfieldconcedes to Mr.  Espy a spirally inward current, the latter also gives upa direct current to the centre, to Mr.  Redfield. This shows at least anapproximation to the truth. 

It is not necessary for the support of this theory, that we shouldderive any materials from the ruins of others; we shall therefore notavail ourselves of certain discrepant results, which can be found inmany of the storms cited by Colonel Reid. With respect to Mr.  Espy's_cause_ of storms, the experiments of Regnault may be considered asdecisive of the question:--1st, because the specific heat of vapor is somuch less than Espy assumed it to be; and 2d, because the expansion ofair in a free space does not suffer any change of volume by ascending, except what is due to diminished pressure, and the natural temperatureof that elevation. 

INDICATIONS OF A STORM. 

In accordance with our theory, the direction and force of the wind in astorm are due to ascending columns of air, supplied from the upperportion of the atmospheric stratum beneath the clouds. The commotionbegins at the highest limits of the cirri, and even at greaterelevations. Hence, the hazy appearance of the sky is a legitimateprecursor of the coming gale. As a general thing, the wind will blow (atthe surface) towards the centre of greatest commotion, but it is toodependent on the ever-varying position and power of temporary nuclei ofdisturbance, to be long steady, except when the disturbance is so remotethat its different centres of induction are, as it were, merged into onecommon focus. When a vortex is descending, or passing from north tosouth, and withal very energetic at the time, the southerly wind (whichmay always be considered the principal wind of the storm in thishemisphere) may blow steadily towards the vortex for three or even fourdays. When a vortex is ascending, the induced northerly current will becomparatively moderate, and be frequently checked by the southerly windoverblowing the storm, and arriving the day before the vortex whichproduced it. 

The important point for the navigator, is to know the time of meridianpassage of the vortex, and its latitude at the time of the passage, andthen be guided by the indications of the weather and the state ofbarometer. If it commences storming the day before the passage, he mayexpect it much worse soon after the passage; and again, if the weatherlooks bad when no vortex is near, he may have a steady gale settingtowards a storm, but no storm until the arrival of a vortex. Again, ifthe barometer is low the day before the vortex passes, there may be highbarometer to the west, and the passage be attended by no greatcommotion, as it requires time for the storm to mature, and consequentlyits greatest violence will be to the east. If at the ship the barometeris high, the vortex may still produce a storm on a line of low barometerto the west, and this line may reach the ship at the time of thepassage. In tropical climates the trouble must be looked for to theeastward; as a storm, once excited, will travel westward with thatstratum of atmosphere in which the great mass of vapor is lodged, and inwhich, of course, the greatest derangement of electric tension isproduced. 

It will now be seen that we do not admit, with Col.  Reid, that a stormcontinues in existence for a week together. Suppose a hurricane tooriginate in the Antilles at the southern limits of a vortex, thehurricane would die away, according to our theory, if the vortex did notcome round again and take up the same nucleus of disturbance. On thethird day the vortex is found still further north, and the apparent pathof the hurricane becomes more curved. In latitude 30° the vortex passesover 3° or 5° of latitude in a day; and here being the latitude wherethe lower atmospheric current changes its course, the storm passes duenorth, and afterwards north-east. Now, each day of the series there is adistinct hurricane, (caused by an increase of energy in a particularvortex, as we have before hinted, ) each one overlapping on the remainsof the preceding; but in each the same changes of the wind are gonethrough, and the same general features preserved, as if it were truly aprogressive whirlwind, except that each vessel has the violent part ofit, as if she was in the southern half of the whirl. The apparentregularity of the Atlantic storms in direction, as exhibited by Col. Reid, are owing in a great degree to the course of the Gulf Stream, inwhich a vortex, in its successive passages in different latitudes, findsmore favorable conditions for the development of its power, than inother parts of the same ocean; thus showing the importance of regardingthe established character of storms in each locality, as determined byobservation. In this connection, also, we may remark, that the meridiansof greatest magnetic intensity are, _ceteris paribus_, also themeridians of greatest atmospheric commotion. The discovery of this factis due to Capt.  Sabine. The cause is explained by the theory. 

As it is the author's intention to embody the practical application ofthis theory to navigation, with the necessary rules and tables, in aseparate work, sufficient has been said to familiarize the reader withthe general idea of a cause external to the earth, as the active motorin all atmospheric phenomena. We will therefore only allude in a generalway to the principal distinguishing feature of the theory. We say, then, that the wind in a storm is not in rotation, and it is a dangerousdoctrine to teach the navigator. We also assert as distinctly, that thewind _in_ a storm does not blow from all sides towards the centre, whichis just as dangerous to believe. If it were wise to pin our faith to anyProcrustean formula, we might endorse the following propositions: Thatat the beginning of a storm the wind is from the equator towards thepoles in every part of the storm; that, at a later date, another current(really a polar current deflected by convection) sets in at right anglesto the first one; and that at the end of the storm there is only _one_wind blowing at right angles to the direction at the beginning. Outsidethe storm, considered as a hundred, or two or three hundred miles indiameter, there is, under certain limitations, a surface wind settingtowards the general focus of motion and condensation, and this surfacewind will be strongest from the westward, on account of the motion ofthe whole atmosphere in which these other motions are performed being tothe eastward. [9] The whole phenomenon is electrical or magnetic, orelectro-magnetic or ethereal, whichever name pleases best. The vortex, by its action, causes a current of induction below, from the equator, asmay be understood by inspecting Fig.  2, which in the northern hemispherebrings in a southerly current by convection: the regular circularcurrent, however, finally penetrates below, as soon as the process ofinduction has ceased; and thus the polar current of the atmosphere atlast overcomes the equatorial current in a furious squall, which ceasesby degrees, and the equilibrium is restored. 

Every locality will have its peculiar features; in each, the prevailingwind will be at right angles to the magnetic meridian, and the progressof the storm will tend to follow the magnetic parallel, which is onereason why the Atlantic and Indian Ocean storms have been mistaken forprogressive whirlwinds. When these views are developed in full, themariner can pretty certainly decide his position in the storm, thedirection of its progress, and its probable duration. 

FOOTNOTES:

[3] The specific heat of the ether being a constant factor, it may bedivided out. 

[4] A term adopted by Prof. Faraday to denote the mode in which bodiesare carried along by an electrical current. 

[5] Ottawa, Ill. 

[6] The principal cause of these waves is, no doubt, due to thevortices, and the eastern progress of the waves due to the rotatingether; but, at present, it will not be necessary to separate theseeffects. 

[7] The inner vortex may reach as high as 83° when the moon's orbit isfavorably situated. 

[8] The curvature of the earth is more than 10 miles in a distance of300 miles. 

[9] In middle latitudes. 

SECTION SECOND. 

MECHANICAL ACTION OF THE MOON. 

We will now proceed to give the method of determining the latitude ofthe axis of the vortex, at the time of its passage over any givenmeridian, and at any given time. And afterwards we will give a briefabstract from the record of the weather, for one sidereal period of themoon, in order to compare the theory with observation. 

[Illustration: Fig. 4]

In the above figure, the circle PER represents the earth, E the equator, PP′ the poles, T the centre of the earth, C the mechanical centre of theterral vortex, M the moon, XX′ the axis of the vortex, and A the pointwhere the radius vector of the moon pierces the surface of the earth. Ifwe consider the axis of the vortex to be the axis of equilibrium in thesystem, it is evident that TC will be to CM, as the mass of the moon tothe mass of the earth. Now, if we take these masses respectively as 1 to72. 3, and the moon's mean distance at 238, 650 miles, the mean value ofTC is equal to this number, divided by the sum of these masses, --_i. E. _the mean radius vector of the little orbit, described by the earth'scentre around the centre of gravity of the earth and moon, is equal238650/(72. 3+1) = 3, 256 miles; and at any other distance of the moon, isequal to that distance, divided by the same sum. Therefore, by taking CTin the inverse ratio of the mean semi-diameter of the moon to the truesemi-diameter, we shall have the value of CT at that time. But TA is toTC as radius to the cosine of the arc AR, and RR′ are the points on theearth's surface pierced by the axis of the vortex, supposing this axiscoincident with the pole of the lunar orbit. If this were so, thecalculation would be very short and simple; and it will, perhaps, facilitate the investigation, by considering, for the present, that thetwo axes do coincide. 

In order, also, to simplify the question, we will consider the earth aperfect sphere, having a diameter of 7, 900 miles, equal to the actualpolar diameter, and therefore TA is equal to 3, 950 miles. 

In the spherical triangle given on next page, we have given the point A, being the position of the moon in right ascension and declination in theheavens, and considered as terrestrial latitude and longitude. 

Therefore, PA is equal to the complement of the moon's declination, Pbeing the pole of the earth, and L being the pole of the lunar orbit; PLis equal to the obliquity of the lunar orbit, with respect to the earth, and is therefore given by finding the true inclination of the lunarorbit at the time, equal EL, (E being the pole of the ecliptic, ) alsothe true longitude of the ascending node, and the obliquity of theecliptic PE. Now, as we are supposing the axis of the vortex parallelto the pole of the lunar orbit, and to pierce the earth's surface at R, ARL will evidently all be in the same plane; and, as in the case of Aand L, this plane passes through the earth's centre, ARL must all lie inthe same great circle. Having, therefore, the right ascension of A, andthe right ascension of L, we have the angle P. This gives us two sides, and the included angle, to find the side LA. But we have before foundthe arc AR; we therefore know LR. But in finding LA, we found both theangles L and A, and therefore can find PR, which is equal to thecomplement of the latitude sought. 

[Illustration: Fig. 5]

We have thus indicated briefly the simple process by which we could findthe latitude of the axis of the central vortex, supposing it to bealways coincident with the pole of the lunar orbit. The true problem ismore complicated, and the principal modifications, indicated by thetheory, are abundantly confirmed by observation. The determination ofthe inclination of the axis of the vortex, its position in space at agiven time, and the law of its motion, was a work of cheerless labor fora long time. He that has been tantalized by hope for years, and ever onthe eve of realization, has found the vision vanish, can understand thefeeling which proceeds from frequent disappointment in not finding that, whose existence is almost demonstrated; and more especially when theapproximation differs but slightly from the actual phenomena. 

The chief difficulty at the outset of these investigations, arose fromthe conflicting authority of astronomers in relation to the mass of themoon. We are too apt to confound the precision of the laws of nature, with the perfection of human theories. Man observes the phenomena of theheavens, and derives his means of predicting what will be, from what hasbeen. Hence the motions of the heavenly bodies are known to within atrifling amount of the truth; but it does not follow that the trueexplanation is always given by theory. If this were so, the mass of themoon (for instance) ought to be the same, whether deduced from theprinciple of gravitation or from some other source. This is not so. Newton found it 1/40 of that of the earth. La Place, from a profoundtheoretical discussion of the tides, gave it as 1/58. 6, while from othersources he found a necessity of diminishing it still more, to 1/68, andfinally as low as 1/75. Bailly, Herschel, and others, from the nutationof the earth's axis, only found 1/80, and the Baron Lindenau deduced themass from the same phenomenon 1/88. In a very recent work by Mr.  Hind, he uses this last value in certain computations, and remarks, that weshall not be very far wrong in considering it as 1/80 of the mass of theearth. This shows the uncertainty of the matter in 1852. If astronomy isso perfect as to determine the parallax of a fixed star, which is almostalways less than one second, why is it that the mass of the moon is notmore nearly approximated? Every two weeks the sun's longitude isaffected by the position of the moon, alternately increasing anddiminishing it, by a quantity depending solely upon the relative mass ofthe earth and moon, and is a gross quantity compared to the parallax ofa star. So, also, the horizontal parallax--the most palpable of allmethods--taken by different observers at Berlin, and the Cape of GoodHope, (a very respectable base line, one would suppose, ) makes the massof the moon greater than its value derived from nutation; the firstgiving about 1/70, the last about 1/74. 2. Does not this declare that itis unsafe to depend too absolutely on the strict wording of theNewtonian law of gravitation. Happily our theory furnishes us with thecorrect value of the moon's mass, written legibly on the surface of theearth; and it comes out nearly what these two phenomena always gave it, viz. : 1/72. 3 of that of the earth. In another place we shall inquireinto the cause of the discrepancy as given by the nutation of the earth. 

MOTION OF THE AXIS OF THE VORTEX. 

If the axis of the terral vortex does not coincide with the axis of thelunar orbit, we must derive this position from observation, which canonly be done by long and careful attention. This difficulty is increasedby the uncertainty about the mass of the moon, already alluded to, andby the fact that there are three vortices in each hemisphere which passover _twice_ in each month, and it is not _always_ possible to decide byobservation, whether a vortex is ascending or descending, or even todiscriminate between them, so as to be assured that this is the centraldescending, and that the outer vortex ascending. A better acquaintance, however, with the phenomenon, at last dissipates this uncertainty, andthe vortices are then found to pursue their course with that regularitywhich varies only according to law. The position of the vortex (thecentral vortex is the one under consideration) then depends on theinclination of its axis to the axis of the earth, and the rightascension of that axis at the given time. For we shall see that anassumed immobility of the axis of the vortex, would be in directcollision with the principles of the theory. 

Let the following figure represent a globe of wood of uniform densitythroughout. Let this globe be rotated round the axis. It is evident thatno change of position of the axis would be produced by the rotation. Ifwe add two equal masses of lead at m and m′, on opposite sides of theaxis, the globe is still in equilibrium, as far as gravity is concerned, and if perfectly spherical and homogeneous it might be suspended fromits centre in any position, or assume indifferently any position in avessel of water. If, however, the globe is now put into a state of rapidrotation round the axis, and then allowed to float freely in the water, we perceive that it is no longer in a state of equilibrium. The mass mbeing more dense than its antagonist particle at n, and having equalvelocity, its momentum is greater, and it now tends continually to pullthe pole from its perpendicular, without affecting the position of thecentre. The same effect is produced by m′, and consequently the axisdescribes the surface of a double cone, whose vertices are at the centreof the globe. If these masses of lead had been placed at opposite sidesof the axis on the _equator_ of the globe, no such motion would beproduced; for we are supposing the globe formed of a hard and unyieldingmaterial. In the case of the ethereal vortex of the earth, we mustremember there are two different kinds of matter, --one ponderable, theother not ponderable; yet both subject to the same dynamical laws. If weconsider the axis of the terral vortex to coincide with the axis of thelunar orbit, the moon and earth are placed in the equatorial plane ofthe vortex, and consequently there can be no derangement of theequilibrium of the vortex by its own rotation. But even in this case, seeing that the moon's orbit is inclined to the ecliptic, thegravitating power of the sun is exerted on the moon, and of necessityshe must quit the equatorial plane of the vortex; for the sun can exertno influence on the _matter_ of the vortex by his attracting power. Themoment, however, the moon has left the equatorial plane of the vortex, the principle of momentum comes into play, and a conical motion of theaxis of the vortex is produced, by its seeking to follow the moon in hermonthly revolution. This case is, however, very different to theillustration we gave. The vortex is a fluid, through which the moonfreely wends her way, passing through the equatorial plane of the vortextwice in each revolution. These points constitute the moon's nodes onthe plane of the vortex, and, from the principles laid down, the forceof the moon to disturb the equilibrium of the axis of the vortex, vanishes at these points, and attains a maximum 90° from them. And theeffect produced, in passing from her ascending to her descending node, is equal and contrary to the effect produced in passing from herdescending to her ascending node, --reckoning these points on the planeof the vortex. 

[Illustration: Fig. 6]

INCLINATION OF THE AXIS. 

By whatever means the two planes first became permanently inclined, wesee that it is a necessary consequence of the admission of theseprinciples, not only that the axis of the vortex should be drawn asideby the momentum of the earth and moon, ever striving, as it were, tomaintain a dynamical balance in the system, in accordance with thesimple laws of motion, and ever disturbed by the action of gravitationexerted on the grosser matter of the system; but also, that this axisshould follow, the axis of the lunar orbit, at the same meaninclination, during the complete revolution of the node. The meaninclination of the two axes, determined by observation, is 2° 45′, andthe monthly equation, at a maximum, is about 15′, being a pluscorrection in the northern hemisphere, where the moon is between herdescending and ascending node, reckoned on the plane of the vortex, anda minus correction, when between her ascending and descending node. Andthe mean longitude of the node will be the same as the true longitude ofthe moon's orbit node, --the maximum correction for the true longitudebeing only about 5° ±. 

[Illustration: Fig. 7]

In the following figure, P is the pole of the earth; E the pole of theecliptic; L the pole of the lunar orbit; V the mean position of the poleof the vortex at the time; the angle ♈EL the true longitude of the poleof the lunar orbit, equal to the _true_ longitude of the ascending node± 90°. VL is therefore the mean inclination ± 2° 45′; and the littlecircle, the orbit described by the pole of the vortex _twice_ in eachsidereal revolution of the moon. The distance of the pole of the vortexfrom the mean position V, may be approximately estimated, by multiplyingthe maximum value 15′ by the sine of twice the moon's distance from thenode of the vortex, or from its mean position, viz. : the true longitudeof the ascending node of the moon on the ecliptic. From this we maycalculate the true place of the node, the true obliquity, and the trueinclination to the lunar orbit. Having indicated the necessity for thiscorrection, and its numerical coefficient, we shall no longer embarrassthe computation by such minutiæ, but consider the mean inclination asthe true inclination, and the mean place of the node as the true placeof the node, and coincident with the ascending node of the moon's orbiton the ecliptic. 

POSITION OF THE AXIS OF THE VORTEX. 

It is now necessary to prove that the axis of the vortex will still passthrough the centre of gravity of the earth and moon. 

[Illustration: Fig. 8]

Let XX now represent the axis of the lunar orbit, and C the centre ofgravity of the earth and moon, X′X′ the axis of the vortex, and KCR theinclination of this axis. Then from

 similarity Ct : Tt :: Cm : Mm but Tt : Mm :: Moon's mass : Earth's mass. That is Tt : Mm :: TC : MC. 

Therefore the system is still balanced; and in no other point but thepoint C, can the intersection of the axes be made without destroyingthis balance. 

It will be observed by inspecting the figure, that the arc R′K′ isgreater than the arc RK. That the first increases the arc AR, and thesecond diminishes that arc. The arc R′K′ is a plus correction therefore, and the smaller arc RK a minus correction. If the moon is between herdescending and ascending node, (taking now the node on the ecliptic, )the correction is negative, and we take the smaller arc. If the moon isbetween her ascending and descending node, the correction is positive, and we take the larger arc. If the moon is 90° from the node, thecorrection is a maximum. If the moon is at the node, the correction isnull. In all other positions it is as the sine of the moon's distancefrom the nodes. We must now find the maximum value of these arcs ofcorrection corresponding to the mean inclination of 2° 45′. 

To do this we may reduce TC to Tt in the ratio of radius to cosine ofthe inclination, and taking TS for radius. 

[Illustration: Fig. 9]

{TC × Cos &c. (inclination 2° 45′)}/R is equal the cosine of the arc SK′and SK′ + AS = AK′ and AK′ + AR′ = R′K′. But from the nature of thecircle, arc RK + arc R′K′ = angle RCK + angle R′CK′, or equal to doublethe inclination; and therefore, by subtracting either arc from doublethe inclination, we may get the other arc. 

The maximum value of these arcs can, however, be found by a simpleproportion, by saying; as the arc AR, plus the inclination, is to theinclination, so is the inclination to the difference between them; andtherefore, the inclination, plus half the difference, is equal thegreater arc, and the inclination, minus half the difference, is equalthe lesser; the greater being positive, and the lesser negative. 

Having found the arc AR, and knowing the moon's distance from eithernode, we must reduce these values of the arcs RK and R′K′ just found, inthe ratio of radius to the sine of that distance, and apply it to thearc AR or A′R′, and we shall get the first correction equal to thearc AK or AK′. 

 Call the arc AR = a " inclination = n " distance from the node = d " arc AK = k

and supposing the value of AK be wanted for the northern hemisphere whenthe moon is between her descending and ascending node, we have

 n² ------- a + n (n - ------- ) sin d. 2 k = a - ---------------------- R

If the moon is between her ascending and descending node, then

 n² ------- a + n (n - ------- ) sin d. 2 k = a + ---------------------- R

The computation will be shorter, however, if we merely reduce theinclination to the sine of the distance from the node for the firstcorrection of the arc AR, if we neglect the semi-monthly motion of theaxis; for this last correction diminishes the plus corrections, and thefirst one increases it. If, therefore, one is neglected, it is better toneglect the other also; especially as it might be deemed affectation tonotice trifling inequalities in the present state of the elements of thequestion. 

There is one inequality, however, which it will not do to neglect. Thisarises from the displacement of the axis of the vortex. 

DISPLACEMENT OF THE AXIS. 

We have represented the axis of the terral vortex as continually passingthrough the centre of gravity of the earth and moon. Now, by followingout the principles of the theory, we shall see that this cannot be thecase, except when the moon is in quadrature with the sun. To explainthis:

[Illustration: Fig. 10]

Let the curve passing through C represent a portion of the orbit of theearth, and S the sun. From the principles laid down, the density of theethereal medium increases outward as the square roots of the distancesfrom the sun. Now, if we consider the circle whose centre is C torepresent the whole terral vortex, it must be that the medium composingit varies also in density at different distances from the sun, and atthe same time is rotating round the centre. That half of the vortexwhich is exterior to the orbit of the earth, being most dense, hasconsequently most inertia, and if we conceive the centre of gravity ofthe earth and moon to be in the orbit (as it must be) at C, there willnot be dynamical balance in the terral system, if the centre of thevortex is also found at C. To preserve the equilibrium the centre of thevortex will necessarily come nearer the sun, and thus be found between Tand C, T representing the earth, and ☾ the moon, and C the centre ofgravity of the two bodies. If the moon is in opposition, the centre ofthe vortex will fall between the centre of gravity and the centre of theearth, and have the apparent effect of diminishing the mass of the moon. If, on the other hand, the moon is in conjunction, the centre of thevortex will fall between the centre of gravity and the moon, and havethe apparent effect of increasing the mass of the moon. If the moon isin quadrature, the effect will be null. The coefficient of thisinequality is 90′, and depends on the sun's distance from the moon. Whenthe moon is more than 90° from the sun, this correction is positive, andwhen less than 90° from the sun, it is negative. If we call this secondcorrection C, and the moon's distance from her quadratures Q, we havethe value of C = ±(90′ × sin Q)/R. 

[Illustration: Fig. 11]

This correction, however, does not affect the inclination of the axis ofthe vortex, as will be understood by the subjoined figure. If the moonis in opposition, the axis of the vortex will not pass through C, butthrough C′, and QQ′ will be parallel to KK′. If the moon is inconjunction, the axis will be still parallel to KK′, as represented bythe dotted line qq′. The correction, therefore, for displacement, isequal to the arc KQ or Kq, and the correct position of the vortex on thesurface of the earth at a given time will be at the points Q or q and Q′or q′, considering the earth as a sphere. 

[Illustration: Fig. 12]

In the spherical triangle APV, P is the pole of the earth, V the pole ofthe vortex, A the point of the earth's surface pierced by the radiusvector of the moon, AQ is the corrected arc, and PV is the obliquity ofthe vortex. Now, as the axis of the vortex is parallel to the pole V, and the earth's centre, and the line MA also passes through the earth'scentre, consequently AQV will all lie in the same great circle, and asPV is known, and PA is equal to the complement of the moon's declinationat the time, and the right, ascensions of A and V give the angle P, wehave two sides and the included angle to find the rest, PQ being thecomplement of the latitude sought. 

We will now give an example of the application of these principles. 

_Example. _[10] Required the latitude of the central vortex at the timeof its meridian passage in longitude 88° 50′ west, July 2d, 1853. 

CENTRAL VORTEX ASCENDING. 

 Greenwich time of passage 2d. 3h. 1m. Mean longitude of moon's node 78° 29′ True " " 79 32 Mean inclination of lunar orbit 5 9 True " " 5 13 Obliquity of ecliptic 23 27 32″ Mean inclination of vortex 2 45 0

Then in the spherical triangle PEV, PE is equal 23° 27′ 32″ EV " 7 58 0 E " 100 28 0 P " 18 5 7 PV " 26 2 32

Calling P the polar angle and PV the obliquity of vortex. 

[Illustration: Fig. 13]

To find the arc AR. 

By combining the two proportions already given, we have by logarithms:

 M. R. V. Minor = 3256 Log. 3. 512683 M. S. D. Of moon = 940″ " 2. 973128 P. S. D. Of earth = 3950 A.  C. 6. 403403 Radius 10. 000000 T. S. D. Of moon 885″. 5 A.  C. 7. 052811 Log. Cosine arc AR = 28° 57′ 3″ 9. 942025 ---------

As the only variable quantity in the above formula is the "True"semi-diameter of the moon at the time, we may add the Constant logarithm2. 889214 to the arithmetical complement of the logarithm of the truesemi-diameter, and we have in two lines the log. Cosine of the arc AR. 

We must now find the arc RK equal at a maximum to 2° 45′. The truelongitude of the moon's node being 79° 32′, and the moon's longitude, per Nautical Almanac, being 58° 30′, the distance from the node is 21°2′, therefore, the correction is

 -2° 45′ × sin 21° 2′ -arc RK = --------------------- = -59′ 13″ R

To find the correction for displacement. 

 True longitude of sun at date 100° 30′ " of moon " 58 30 Moon's distance from quadrature 48 0

As the moon is less than 90° from the sun this correction is alsonegative, or

 -90′ × sin 48° Arc Kq = --------------- = -1° 6′ 46″. R

 Arc AR = 28° 57′ 3″ RK = - 0° 39′ 13″ Kq = - 1° 6′ 46″ Sum = 26° 51′ 4″ = corrected arc AQ. 

We have now the necessary elements in the Nautical Almanac, which wemust reduce for the instant of the vortex passing the meridian inGreenwich time. 

 July 2d. Meridian passage, local time, at 9h. 5m. A. M. " in Greenwich time 2d. 3h. 1m. Right ascension same time 56° 42′ 45″ Declination north " 18 00 1 Obliquity of the vortex " 26 2 32 Polar angle " 18 5 7 Arc AQ " 26 51 4

[Illustration: Fig. 14]

 PA = 17° 59′ 59″ } P = 128° 37′ 38″ PV = 26 2 32 } VA = 89 3 0 V = 47 59 44 VQ = 62 11 56 A = 20 3 42 PQ = 47 14 22 Q = 26 22 55 Latitude of Q on the sphere = 42° 45′ 38″

CORRECTION FOR PROTUBERANCE. 

We have hitherto considered the earth a perfect sphere with a diameterof 7, 900 miles. It is convenient to regard it thus, and afterwards makethe correction for protuberance. We will now indicate the process forobtaining this correction by the aid of the following diagram. 

[Illustration: Fig. 15]

Let B bisect the chord ZZ′. Then, by geometry, the angle FQY is equal tothe angle BTF, and the protuberance FY is equal the sine of that angle, making QF radius. This angle, made by the axis of the vortex and thesurface of the sphere, is commonly between 30° and 40°, according as themoon is near her apogee or perigee; and the correction will be greatestwhen the angle is least, as at the apogee. At the equator, the wholeprotuberance of the earth is about 13 miles. Multiply this by the cosineof the angle and divide by the sine, and we shall get the value of thearc QY for the equator. For the smallest angle, when the correction is amaximum, this correction will be about 20′ of latitude at the equator;for other latitudes it is diminished as the squares of the cosines ofthe latitude. Then add this amount to the latitude EQ, equal thelatitude EY. This, however, is only correct when the axis of the vortexis in the same plane as the axis of the earth; it is, therefore, subjectto a minus correction, which can be found by saying, as radius to cosineof obliquity so is the correction to a fourth--the difference of thesecorrections is the maximum minus correction, and needs reducing in theratio of radius to the cosine of the angle of the moon's distance fromthe node; but as it can only amount to about 2′ at a maximum under themost favorable circumstances, it is not necessary to notice it. Thecorrection previously noticed is on the supposition that the earth islike a sphere having TF for radius; as it is a spheroid, we must correctagain. From the evolute, draw the line SF, and parallel to it, draw TW;then EW is the latitude of the point F on the surface of the spheroid. This second correction is also a plus correction, subject to the sameerror as the first on account of the obliquity, its maximum value for anangle of 30° is about 6′, and is greatest in latitude 45°; for otherlatitudes, it is equal {6′ × sin(double the lat. )}/R. 

The three principal corrections for protuberance may be _estimated_ fromthe following table, calculated for every 15° of latitude for an angleof 30°, or when the correction is greatest. 

 Latitude. 1st Corr. 2d Corr. 3d Corr. 0 + 20′ + 0 - 2 15 + 19 + 3 - 1. 5 30 + 15 + 5 - 1. 5 45 + 10 + 6 - 1. 60 + 5 + 5 - 1 70 + 1 + 3 - 0. 5

We can now apply this correction to the latitude of the vortex justfound:

 Latitude on the sphere 42° 45′ 38″ n. Correction for protuberance + 14 22 ---------- Correct latitude 43 00 00

MILWAUKIE STORM, JULY 2. 

As this example was calculated about ten days before the actual date, wehave appended an extract from the Milwaukie papers, which is in the samelongitude as Ottawa, in which place the calculation was made. It isneedless to remark that the latitude of Milwaukie corresponds to thecalculated latitude of the centre of the vortex. It is not intended, however, to convey the idea that the central line is always the mostsubject to the greatest violence--a storm may have several centres ornuclei of disturbance, which are frequently waning and reviving as thestorm progresses. Generally speaking, however, the greatest action isdeveloped along the line previously passed over by the axis of thevortex. 

 "SUMMIT, Waukesha Co. , Wis. , July 4, 1853. 

 "Our town, on Saturday, the 2d, was visited by a terrible storm, which will long be remembered by those who witnessed its effects and suffered from its fury. It arose in the south-west, and came scowling in blackness, sufficient to indicate its anger, for the space of eighty or a hundred rods in _width_, covering our usually quiet village; and for nearly half an hour's duration, the rain fell in torrents, the heavens blazed with the lightning's flashes, trees fell and were uprooted by the fury of the blast, fragments of gates and of buildings, shingles, roof-boards, rafters, circled through the air, the playthings of the wind--and buildings themselves were moved entire from their foundations, and deposited at different distances from their original positions. A barn, fifty-five feet square on the ground, owned by Mr.  B.  R. Hinckley, is moved from its position some ten feet to the eastward; and a house, some fifteen by eighteen feet on the ground, owned by the same person, fronting the east, was driven by the wind to the opposite side of the street, and now fronts nearly west; and what is most strange, is that the grass, in the route the house must have passed over, stands straight as usual, and gives no evidence that the building was pushed along on the ground. A lady running from a house unroofed by the storm, took an aërial flight over two fences, and finally caught against a tree, which arrested her passage for a moment only, when, giving way, she renewed her journey for a few rods, and was set down unhurt in Mr.  O.  Reed's wheat field, where, clinging to the growing grain, she remained till the gale went by. "[11]

The weather at this place is briefly recorded in the accompanyingabstract from the journal, as well as in an extract from a note toProfessor Henry, of the Smithsonian Institution, from a friend of theauthors, who has long occupied a high official station in Illinois. Butsuch coincidences are of no value in deciding on the merits of such atheory, it must be tried before the tribunal of the world, and appliedto phenomena in other countries with success, before its merits can befully appreciated. The accompanying record, therefore, is only given toshow how these vortices render themselves apparent, and what ought to beobserved, and also to exhibit the order of their recurrence and theirpositions at a given time. 

_Extract of a note addressed to the Secretary of the SmithsonianInstitution, by Hon. John Dean Caton, on this subject. _

 "As a striking instance of the remarkable coincidences confirmatory of these calculations, I will state, that on Friday, the first of July last, this gentleman[12] stated that on the next day a storm would pass north of us, being central a little south of Milwaukie, and that he thought, from the state of the atmosphere, the storm would be severe, and that its greatest violence would be felt on the afternoon or night of the next day. At this time the weather was fine, without any indications of a storm, so far as I could judge. At noon on the following day he pointed out the indications of a storm at the north and north-west, consisting of a dark, hazy belt in that direction, extending up a few degrees above the horizon, although so indistinct as to have escaped my observation. At five o'clock a violent storm visited us, which lasted half an hour, although a clear sky was visible at the south the whole time. On Monday morning I learned, from the telegraph office at Chicago, that early on Saturday afternoon communication with Milwaukie had been interrupted by atmospheric electricity, and that the line had been broken by a storm. "

NEW YORK STORM. 

After this was written, the author discovered that the vortex wasequally violent the day before at New York, July 1st, 1853. An accountof this storm follows. The calculation has not been made, but it is easyto perceive that the latitude of the vortex, on July 1st, must be verynearly that of New York--being in latitude 43° next day and ascending. 

"At a meeting of the American Association, convened at Cleveland, Professor Loomis presented a long notice of the terrible hail storm inNew York on the 1st of July. He traced its course, and minutely examinedall the phenomena relating to it, from a mile and a half south-east ofPaterson, N. J. , to the east side of Long Island, where it appearednearly to have spent its force. It passed over the village of Aqueenac, striking the Island of New York in the vicinity of the Crystal Palace. It was not much more than half a mile wide. The size of the hail-stoneswas almost incredibly large, many of them being as large as a hen's egg, and the Professor saw several which he thought as large as his fist. Some of them weighed nearly half a pound. The principal facts inrelation to this storm were published at the time, and need not berepeated. The discussions arising among the members as to the origin andthe size of these hail-stones, and the phenomena of the storm, wereexceedingly interesting. They were participated in by Professors Heustusand Hosford, of Cambridge University, Professor Loomis, and ProfessorsBache and Redfield. The latter two gentlemen differ somewhat, we shouldsuppose radically, in their meteorological theories, and had some verysharp but very pleasant "shooting" between them. "[13]

CENTRAL VORTEX DESCENDING. 

We will now make the calculation for the central vortex _descending_, for longitude 88° 50′ west, August 7, 1853, --putting down the necessaryelements for the time of the meridian passage in order:

 Meridian passage in local time at 2h. 25m. P. M. " " in Greenwich time 7d. 8h. 18m. Mass of the moon 1/12. 3 M.  R.  V. Minor 3, 256 miles. Obliquity of the vortex, same time 26° 5′ 0″ Polar angle of " " 17 41 47 True longitude of moon's node " 78 42 0 " inclination of orbit " 5 5 0 " longitude of the sun " 135 20 0 Moon's longitude " 169 44 0 " distance from node " 91 2 0 " distance from quadrature " 55 36 0 " true semi-diameter " 943 " right ascension " 172 30 0 " declination north " 8 42 20 Constant logarithm 2. 889214 Arith. Comp. Of log. Of 943 7. 025488 Log. Cos. Arc. AR 9. 914702 = 34° 44′ 48″ 1st. Correction, + 2 45 0 2d. Correction, - 1 14 15 -------------- Corrected arc AQ = 36 15 33 PA = 81° 17′ 40″ PV = 26 5 0 P = 115 11 47 V = 63 34 26 A = 23 28 24 AV = 92 48 39 Q = 31 32 18 Complement of lat.  = PQ = 48° 49′ 41″ The latitude is therefore for the earth, as a sphere 41 10 18 Correction for protuberance + 0 16 0 ------------ True latitude of centre 41 26 18 north. ------------ Latitude of Ottowa 41 20 0 " ------------ Vortex passed 6 18 north of Ottowa. 

[Illustration: Fig. 16]

As this was nearly a central passage, and as the influence was lessextensive than usual, on account of great atmospheric pressure with alow dew point, the central disturbance could the more readily belocated, and was certainly to the north, and but a few miles. Thefollowing is from the record of the weather:

_August_ 6th. Very fine and clear all day; wind from S. -W. ; a lightbreeze; 8 P. M. Frequent flashes of lightning in the northern sky;10 P. M. A _low bank of dense clouds in north_, fringed with cirri, visible during the flash of the lightning; 12 P. M. Same continues. 

7th. Very line and clear morning; wind S. -W. Moderate; noon, cloudsaccumulating in the northern half of the sky; wind fresher S. -W. ; 3 P. M. A clap of thunder overhead, and black cumuli in west, north, and east;4 P. M. Much thunder, and scattered showers; six miles west rained veryheavily; 6 P. M. The heavy clouds passing over to the south; 10 P. M. Clear again in north. 

_August_ 8th. Clear all day; wind the same (S. -W. ); a hazy bank visibleall along on _southern horizon_. 

This was not a storm, in the ordinary acceptation of the term; but thesame cause, under other circumstances, would have produced one; and letit be borne in mind, that although the moon is the chief disturbingcause, and the passages of the vortices are the periods of greatestcommotion in both settled and unsettled weather, still the sun ispowerful in predisposing the circumstances, whether favorable orunfavorable; and as there is no periodic connection between the passageof a vortex and the concurrence of the great atmospheric waves, it will, of course, happen only occasionally that all the circumstances willconspire to make a storm. There are also other modifying causes, towhich we have not yet alluded, which influence the storms at differentseasons of the year, --exaggerating their activity in some latitudes, anddiminishing it in other latitudes. In this latitude, the months of May, June, and July are marked by more energetic action than August, September, and October. The activity of one vortex also, in one place, seems to modify the activity of another vortex in another place. But thegreat question to decide is: Do these vortices really exist? Do theyfollow each other in the _order_ indicated by the theory? Do they passfrom south to north, and from north to south, at the _times_ indicatedby the theory? Do they obey, in their monthly revolutions, amathematical law connecting them with the motions of the moon? We answeremphatically, Yes! And the non-discovery of these facts, is one of themost humiliating features of the present age. 

OTTOWA STORM, DECEMBER 22, 1852. 

To show that the same calculations are applicable for other times, wewill make the calculation for the _centre ascending_, for the 22dDecember, 1852, taking the following elements:

 Moon's mer. Passage, Dec. 22d 15h. 16m. G. Time. " right ascension, same time 51° 57′ " declination north 15 42 " true S. Diameter 886. 6″ " distance from node 37 " " " quadrature 52 -------- Which gives the arc AR 29 5 1st correction -1 51 2d +1 11 -------- Corrected arc AQ 28 25 --------

And the latitude at the time of the meridian passage = 42° north, orabout forty miles north of Ottawa. 

Abstract from the record:--

[14]_Dec. _ 21st, 1852. Wind N. -E. , fineweather. 

_Dec. _ 22d. Thick, hazy morning, wind east, much lighter in S. -E. Thanin N. -W. ; 8 A. M. , a clear arch in S. -E. Getting more to south; noon, very black in W.  N. -W. ; above, a broken layer of cir. Cumulus, the sunvisible sometimes through the waves; wind round to S. -E. , and fresher;getting thicker all day; 10 P. M. , wind south, strong; thunder, lightning, and heavy rain all night, with strong squalls from south. 

_Dec. _ 23d. Wind S. -W. , moderate, drizzly day; 10 P. M. , wind west, andgetting clearer. 

The next day the vortex passed the latitude of Montreal (the moon beingon the meridian about 10 P. M. )

MAGNETIC STORM, DECEMBER 23, 1852. 

In the July number of Vol.  XVI. Of Silliman's Journal, we find certainnotices of the weather in 1852, by Charles Smallwood, of St. Martins, nine miles east of Montreal. He mentions "two remarkable electricalstorms (which) occurred on the 23d and 31st of December, (in which)sparks 5/40 of an inch were constantly passing from the conductor to thedischarger for several hours each day. " At 10 P. M. (23d) the vortexpassed over Montreal, and again descending on the 31st North, and wasvisible at Ottowa on the morning of the 1st of January, with southerlywind setting towards it. On the 29th of December, Mr.  Smallwood records"a low auroral arch, sky clear. " On the 20th, the vortex was 5° to thenorthward of Montreal, and the aurora was consequently low--thebrightest auroras being when the vortex is immediately north withoutstorm, or one day to the northward, although we have seen it _very low_when the vortex was three days to the north, and no other vortex near. 

LIVERPOOL STORM. 

On the night of the 24th of December, the same central vortex ascendingpassed between Cape Clear and Liverpool. 

On the 25th, at midnight, the vortex passed to the north of Liverpool:its northerly progress being very slow, being confined for three daysbetween the parallel of Liverpool and its extreme northern limit inlatitude about 57°. The accompanying account of the weather will showthe result of a long-continued disturbance near the same latitude:

The Baltic, three days out from Liverpool, encountered the vortex on thenight of the 23d. On the morning of the 25th, very early, the galecommenced at Liverpool, and did much damage. On the 26th, the vortexattained its northern limit; but we have not been able to procure anyaccount of its effects to the northward of Liverpool, although there canbe but little doubt that it was violent on the coast of Scotland on the26th; for the next day (27th) the vortex having made the turn, was nearthe latitude of Liverpool, and caused a _tremendous_ storm, thus showinga continued state of activity for several days, or a peculiarlyfavorable local atmosphere in those parts. It is very probable, also, that there was a conjunction of the central and inner vortex on the27th. The inner vortex precedes the central in passing latitude 41°; butas the mean radius of its orbit is less than that of the central, itattains to a higher latitude, and has, consequently, to cross the pathof the central, in order again to precede it descending in latitude 41°. As a very trifling change in the elements of the problem will causegreat changes in the positions of the vortices on the surface of theearth, it cannot now be asserted that such a conjunction did positivelyoccur at that time; but, it maybe suspected, that a double disturbancewould produce a greater commotion, or, in other words, a more violent, storm. 

It is on this account, combined with other auxiliary causes, that thevicinity of Cape Horn is so proverbially stormy, as well as for the lowstandard of the barometer in that latitude, it is the stationary pointof the vortices in ordinary positions of the nodes and perigee of themoon. We have already alluded to the fact, that none of the vorticesscarcely ever pass much beyond latitude 80°, and then only underfavorable circumstances, so that we ought to infer, that gales in highlatitudes should set from the poles towards the storms in lowerlatitudes. This is, no doubt, the fact, but, nevertheless, a hardsoutherly blow _may possibly_ occur in high northern latitudes, if astorm should be raging very violently in a lower latitude on theopposite side of the pole, the distance across the circle of 80° beingonly about 1, 400 miles. As the different vortices have a different limitin latitude every year, the determination of this turning point isobviously of great practical utility, as the fact may yet be connectedwith other phenomena, so as to give us the probable character of thepolar ice at any assigned time. On this point we have more to say. 

PASSAGES OF ALL THE VORTICES. 

Our remarks have hitherto been confined to the central vortex. We shallnow show from the record, that the other vortices are as effective inderanging the equilibrium of our atmosphere. In the following table wehave given the passages of the different vortices, which will serve astheir true positions within moderate limits, to calculate from, for allfuture time. 

PASSAGES OF THE CENTRAL AND LATERAL VORTICES, OBSERVED IN JUNE AND JULY, 1853, IN LATITUDE 41° 20′ NORTH. 

I signifying Inner; O, outer; C, central; A, ascending; D, descending. 

 ____________________________________________________________________ | | | | | | | | Order. |Vortex. | Date. | Meridian |Passage. | Calculated latitude | | | | | Passage. | | and Remarks. | |_______|_______|_________|__________|________|______________________| | | | | | | | | 1st | I.  A. | June 22 | 7 A. M. | south | Centre. About 40°. | | | | 23 | 8 A. M. | north | Warsaw. Storm. | | 2d | O.  D. | 27 | 0 noon | north | | | | | 28 | 1 A. M. | south | See record. | | 3d | C.  A. | July 1 | 9 A. M. | south | | | | | 2 | 10 A. M. | north | Lat. 43°. Storm. | | 4th | I.  D. | 7 | 5 P. M. | north | | | | | 8 | 6 P. M. | south | Lat. New York. Storm. | | 5th | C.  D. | 12 | 5 P. M. | north | Aurora. | | | | 13 | 6 P. M. | south | Stormy, very. | | 6th | O.  A. | 14 | 10 A. M. | south | | | | | 15 | 11 A. M. | north | See Record. | |_______|_______|_________|__________|________|______________________|

The intervals between the ascending and descending passages of thedifferent vortices, are

 Between I.  A. And I.  D. From 11 to 14 days. " O.  A. " O.  D. " 10 " 12 " " C.  A. " C.  D. " 9 " 11 "

and the effect is greatest when the vortex comes to the meridian beforethe sun, and least when after the sun; in which case the full effect isnot developed, sometimes until the following day. 

A brief abstract from a journal of the weather for one sidereal periodof the moon, in 1853. 

_June_ 21st. Fine clear morning (S. Fresh)[15]: noon very warm 88°;4 P. M. Plumous _cirri in south_; ends clear. 

22d. Hazy morning (S. Very fresh) arch of cirrus in west; 2 P. M. , blackin W. -N. -W. ; 3 P. M. , overcast and rainy; 4 P. M. , a heavy gust fromsouth; 4. 30 P. M. , blowing furiously (S. By W. ); 5 P. M. , tremendoussquall, uprooting trees and scattering chimneys; 6 P. M. , more moderate(W. )

23d. Clearing up (N. -W. ); 8 A. M. , quite clear; 11 A. M. , bands of mottledcirri pointing N. -E. And S. -W. ; ends cold (W.  N. -W. ); the cirri seem torotate from left to right, or with the sun. 

24th. Fine clear cool day, begins and ends (N. -W. )

25th. Clear morning (N. -W, light); 2 P. M. (E. ) calm; tufts of tangledcirri in north intermixed with radiating streaks, all passing eastward;ends clear. 

26th. Hazy morning (S. -E) cloudy; noon, a heavy windy looking bank innorth (S. Fresh), with dense cirrus fringe above on its upper edge;clear in S. 

27th. Clear, warm, (W. ); bank in north; noon bank covered all thenorthern sky, and fresh breeze; 10 P. M. , a few flashes to the northward. 

28th. Uniform dense cirro-stratus, (S. Fresh); noon showers all round;2 P. M. , a heavy squall of wind, with thunder and rain (S. -W. To N. -W. );8 P. M. , a line of heavy cumuli in south; 8. 30 P. M. , a very bright andhigh cumulus in S. -W. , protruding through a layer of dark stratus;8. 50 P. M. , the cloud bearing E. By S. , with three rays of electriclight. [16]

[Illustration: Fig. 17]

_June_ 29th. A stationary stratus over all, (S. -W. Light); clear atnight, but distant lightning in S. 

30th. Stratus clouds (N. -E. Almost calm); 8 A. M. , raining gently;3 P. M. , stratus passing off to S; 8 P. M. , clear, pleasant. 

_July_ 1st. Fine and clear; 8 A. M. , cirrus in sheets, curls, wisps, andgauzy wreathes, with patches beneath of darker shade, all nearlymotionless; close and warm (N. -E. ); a long, low bank of haze in S. , withone large cumulus in S. -W. , but very distant. 

_July_ 2d. At 5 A. M. , overcast generally with hazy clouds and fog ofprismatic shades, chiefly greenish-yellow; 7 A. M. , (S. -S. -E. Freshening, ) thick in W; 8 A. M. , (S. Fresh) much cirrus, thick andgloomy; 9 A. M. , a clap of thunder, and clouds hurrying to N. ; a reddishhaze all around; at noon the margin of a line of yellowish-red cumulijust visible above a gloomy-looking bank of haze in N. -N. -W. , (S. Veryfresh;) warm, 86°; more cumuli in N. -W. --the whole line of cumuli N. Areseparated from the clouds south by a clear space. These clouds are bornerapidly past the zenith, but never get into the clear space--they seemto melt or to be turned off N. -E. The cumuli in N. And N. -W. , slowlyspreading E. And S. ; 3 P. M. , the bank hidden by small cumuli; 4 P. M. , very thick in north, magnificent cumuli visible sometimes through thebreaks, and beyond them a dark, watery back-ground, (S. Strong);4. 30 P. M. , wind round to N. -W. In a severe squall; 5 P. M. , heavy rain, with thunder, &c. --all this time there is a bright sky in the southvisible through the rain 15° high; 7 P. M. , clearing, (S. -W. Mod. )

_July_ 3d. Very fine and clear, (N. -W. ); noon, a line of large cumuli inN. , and dark lines of stratus below, the cumuli moving eastward; 6 P. M. , their altitude 2° 40′. Velocity 1° per minute; 9 P. M. , much lightning inthe bank north. [17]

_July_ 4th. 6 A. M. , a line of small cumulo-stratus, extending east andwest, with a clear horizon north and south 10° high. This band[18] seemsto have been thrown off by the central yesterday, as it moves slowlysouth, preserving its parallelism, although the clouds composing it moveeastward. Fine and cool all day--(N. -W. Mod. )--Lightning in N. 

_July_ 5th. Cloudy (N. Almost calm), thick in E. , clear in W. ; same allday. 

6th. Fine and clear (E. Light); small cumuli at noon; clear night. 

7th. Warm (S.  E. Light); cirrus bank N.  W. ; noon (S. ) thickening in N. ;6 P. M. , hazy but fine; 8 P. M. , lightning in N. ; 10 P. M. , the lightningshows a heavy line of cumuli along the northern horizon; calm and verydark and incessant lightning in N. 

8th. Last night after midnight commencing raining, slowly and steadily, but leaving a line of lighter sky south; much lightning all night, butlittle thunder. 

8th. 6 A. M. Very low scud (500 feet high) driving south, still calmbelow, (N. Light); 10 A. M. , clearing a little; a bank north with cirrusspreading south; same all day; 9 P. M. , wind freshening (N. Stormy);heavy cumuli visible in S. ; 10. 30 P. M. , quite clear, but a dense wateryhaze obscuring the stars; 12 P. M. , again overcast: much lightning in S. And N. -W. 

9th. Last night (2 A. M. Of 9th) squall from N. -W. Very black; 4 A. M. , still raining and blowing hard, the sky a perfect blaze, but very fewflashes reach the ground; 7 A. M. , raining hard; 8 A. M. (N. -W. Strong); aconstant roll of thunder; noon (N. -E. ); 2 P. M. (N. ); 4 P. M. Clearing;8 P. M. , a line of heavy cumuli in S. , but clear in N-W. , N. , andN. -E. [19]

NEW YORK STORM, JULY 8, 1853. 

"At 5 o'clock Friday afternoon, a terrible storm of rain, hail, andlightning, rose suddenly from the north-west, and passed over the upperpart of the city and neighborhood. It was quite moderate in the lowerpart of the town, and probably scarcely felt on Staten Island. The wholeaffair lasted not more than a quarter of an hour, yet the results weremost disastrous, as will be seen by the following accounts from ourreporters:

"Happening to be in the neighborhood of the Palace about 5 o'clockFriday evening, we sought shelter under its ample roof from an impendingthunder storm, of very threatening appearance, rapidly approaching fromthe west. We had scarcely passed the northern entrance, and reached thegallery by the nearest flight of steps, when the torrent--it was notrain, but an avalanche of water--struck the building; the gutters werefilled on the windward side in a moment, and poured over an almostunbroken sheet of water, which was driven through the Venetian blindventilators, into and half way across the north-west gallery, and alsothrough the upper ventilators, falling upon the main floor of the northtransept. Workmen hastened to close the blinds, but that did not preventthe deluge. The tinning of the dome being unfinished, the water, ofcourse, came down in showers all over the centre. Many workmen wereengaged on the dome when the shower struck it; several of them, in theirhaste to escape such dangerous proximity to the terrific lightning, camedown single ropes, hand over hand. Large number of workmen were engagedall over the exterior, and such a scampering will rarely be witnessedbut once in a lifetime. It was found impossible to close a north window, used for ingress and egress of workmen upon the rod, and the water camein, in almost solid columns. For a time the water was nearly two inchesdeep on the gallery floor, and poured down the stairs in miniaturecascades. 

"A great number of boxes, bales, and packages of goods lay upon the mainfloor, among which the water poured down from the edge of the galleryfloor in destructive quantities; Fortunately but few goods were opened, and were upon the tables, or the damage would have been irreparable. Asit is, we fear some of the goods are injured. In the height of thestorm, the centre portion of the fanlight over the western entranceburst in, and several single lights were broken, by staging orotherwise. 

"About ten minutes after the storm burst, the most terrific hailstorm weever saw began to rattle, like discharges of musketry, upon the tin roofand glass sides. Some of the masses of ice were as large as hen's eggs. There were probably a thousand excited workmen in the building, and agood many exhibitors and visitors, among whom there were some twentyladies, some of whom appeared a good deal alarmed at the awful din. Aportion of the frame-work of the addition next to 42d street, went downwith a terrible crash, and a part of the brick wall of the engine-houseon the opposite side of the street, was blown over, crushing two orthree shanties, fortunately without any other injury than driving theoccupants out into the storm. But an awful scene occurred on the northside of 43d street, directly opposite the Latting Tower. Here two largeunfinished frame buildings were blown, or rather, we should judge fromappearances, were crushed down into a mass of ruins, such as may beimagined by supposing a great weight had fallen, with a circular, grinding motion, upon the first fine fabrics. One of them was partlysided, and had the rafters up, but no roof; the other was sided androoted with tin, and was being plastered. We were told it was threestories high, 50 by 98 feet. 

"We reached the ruins among the first, after the burst of the stormsubsided a little. The scene was such as we pray God we may neverwitness again. A small portion of the roof and upper part of the frontof the building stood or rather partly hung over the side-walk. Thechamber and lower floor of the front rooms lay flat together. The sideswere standing. In the rear all were down. In this building, besides theworkmen, there were numerous laborers who had taken shelter under itsroof when the storm drove them hurriedly from their work. How so manypersons escaped death is truly wonderful. It can only be accounted forby supposing that they had a moment's warning, and rushed into thestreet. The first alarm was from the tearing off a portion of the tinroof, which was carried high over another building, and fell in thestreet. A horse and cart barely escaped being buried under this. Itseems the frame of the other building came down with a deafening crashat the same time, confusing instead of warning those in danger. At anyrate, before they could escape, they were buried in a mass of timber, and three of them instantly killed, and four or five dangerouslywounded; and others slightly bruised and badly frightened. Several wouldhave perished but for timely assistance to extricate them. In this theywere greatly assisted by Jacob Steinant, boss carpenter of the Tower, who with his men rushed to the rescue, notwithstanding the pouring downtorrents. 

"In Williamsburgh, the storm lasted about fifteen minutes, doing anincalculable amount of damage to dwellings, foliage, &c. Hailstones camedown in sizes from that of a hickory-nut to a large apple, some withsuch force as to drive them through the cloth awnings. 

"The storm passed over Brooklyn lightly, in comparison with the effectsacross the Williamsburgh line. On Flushing avenue, beyond the NavalHospital, a number of trees were uprooted, and the window-panes of thehouses shattered. On the corner of Fulton and Portland avenues, threebuildings were unroofed, and the walls of the houses were sprung to thefoundation. 

"On Spencer street, a new frame building was levelled with the ground. Along Myrtle, Classon, and other streets and avenues of East Brooklyn, many of the shade trees were uprooted, and the windows smashed. In Jaystreet, two trees were struck by lightning, but no other damage ensued. 

"Several schooners at the foot of Jay street were forced from theirmoorings, but were soon after secured. A small frame house in Spencerstreet, just put under roof, was prostrated to the ground. 

"We understand that a large barn filled with hay, situated on the roadbetween Bushwick and Flushing, was struck by lightning and destroyedwith its contents, embracing several head of live stock. "[20]

_July_ 10th, 3 A. M. Overcast and much lightning in south (N. Mod. );7 A. M. , clear except in south; 6 P. M. (E. ); 10 P. M. , lightning south;11 P. M. , auroral rays long but faint, converging to a point betweenEpsilon Virginis and Denebola, in west; low down in west thick withhaze; on the north the rays converged to a point still lower; lightningstill visible in south. This is an aurora in the west. 

11th. Fine clear morning (N. -E. ); same all day; no lightning visibleto-night, but a bank of clouds low down in south, 2° high, and streaksof dark stratus below the upper margin. 

12th. Fine and clear (N. -E. ); noon, a well defined arch in S. -W. , risingslowly; the bank yellowish, with prismatic shades of greenish yellow onits borders. This is the O.  A. At 6 P. M. , the bank spreading to thenorthward. At 9 P. M. , thick bank of haze in north, with bright auroralmargin; one heavy pyramid of light passed through Cassiopæa, travelling_westward_ 1½° per minute. This moves to the other side of the pole, but not more inclined towards it than is due to prospective, if theshaft is very long; 11. 10 P. M. , saw a mass of light more diffuse dueeast, reaching to _Markab_, then on the prime vertical. It appearsevident this is seen in profile, as it inclines downwards at an angle of10° or 12° from the perpendicular. It does not seem very distant. 12 P. M. , the aurora still bright, but the brightest part is now west ofthe pole, before it was east. 

13th, 6 A. M. Clear, east and north; bank of cirrus in N. -W. , _i. E. _, from N. -N. -E. To W. By S. ; irregular branches of cirrus clouds, reachingalmost to south-eastern horizon; wind changed (S. -E. Fresh); 8 A. M. , thesky a perfect picture; heavy regular shafts of dense cirrus radiatingall around, and diverging from a thick nucleus in north-west, the spacesbetween being of clear blue sky. The shafts are rotating from north tosouth, the nucleus advancing eastward. 

Appearance of the central vortex descending at 8 A. M. , July 13th, 1853:

In Fig.  18, the circle represents the whole sky from the zenith to thehorizon, yet it can convey but a very faint idea of the regularity andvividness of this display. The reflected image of the sky was receivedfrom a vessel of turbid water, which will be found better than a mirror, when the wind will permit. 

[Illustration: Fig. 18]

At noon (same day) getting thicker (S. -E. Very fresh); 6 P. M. , moon onmeridian, a prismatic gloom in south, and very thick stratus of allshades; 9 P. M. , very gloomy; wind stronger (S. -E. ): 10 P. M. , very blackin south, and overcast generally. 

14th. Last night about 12 P. M. Commenced raining; 3 A. M. , rainedsteadily; 7 A. M. , same weather; 8. 20 A. M. , a line of low storm-cloud, orseud, showing very sharp and white on the dark back ground all along thesouthern sky. This line continues until noon about 10° at the highest, showing the northern boundary of the storm to the southward; 8 P. M. , same bank visible, although in rapid motion eastward; same time clearoverhead, with cirrus fringe pointing north from the bank; muchlightning in south (W. Fresh); so ends. 

15th. Last night a black squall from N. -W. Passed south without rain; at3 A. M. Clear above, but very black in south (calm below all the time);9 A. M. , the bank in south again throwing off rays of cirri in awell-defined arch, whose vortex is south: these pass east, but continueto form and preserve their linear direction to the north; no lightningin south to-night. 

16th. Clear all day, without a stain, and calm. 

17th. Fine and clear (N. -E. Light); 6 P. M. , calm. 

18th. Fair and cloudy (N. -E. Light); 6 P. M. , calm. 

19th. Fine and clear (N. Fresh); I.  V. Visible in S. -W. 

20th. 8 A. M. , bank in N. -W. With beautiful cirrus radiations; 10 A. M. , getting thick with dense plates of cream-colored cirrus visible throughthe breaks; gloomy looking all day (N. -E. Light). [21]

Appearance of the Inner Vortex at 8 A. M. , July 20th, 1853, including thewhole sky. (See Fig.  19. )

[Illustration: Fig. 19]

This was a different passage of the Inner Vortex ascending as comparedwith the same 28 days before. At that date (June 22) it did great damagein the central parts of Illinois. Still this last passage was verypalpable--the clouds were very irregularly assorted--plates of cirrusabove and beneath cumulus--various kinds of cirrus clouds, and thatpeculiar prismatic haze which is a common sign of the passage of avortex. The appearance depicted above is a very common, although a veryevanescent appearance. When the sky appears of a clear blue through thecirri, there will be generally fresh gales without any great electricalderangement; but if the clear spaces are hazy, gradually thickeningtowards the nucleus, a storm may be expected. Any one who wishes tounderstand the indications of the clouds, must watch them closely formany years, before he can place much reliance upon them. But we shallagain advert to this point. 

We have now passed through one sidereal period of the moon. We mightcontinue the record, but it would be tedious. The passages of thesevortices vary in violence at different times, as we might expect; butthey never cease to circulate, and never will as long as the moonremains a satellite to the earth; and if we take the passage of any ofthese vortices, and add thereto the time of one sidereal period of themoon, we get approximately the time of the next passage. When theelements of the lunar orbit tend to accelerate the passages, they maycome in 26 days; and when to retard, in 28 days; and these are about thelimits of the theory. 

Having begun and ended this record of the weather with the passage ofthe Inner vortex ascending, it may not be amiss to notice one more, (theAugust passage, ) as it offers a peculiarity not often so distinctlymarked. We have alluded to the greater force of the storms when thepassage of the vortex corresponds to the passage of the line of lowbarometer or the depression point of a great atmospheric wave, which isalso due to the action of the ether. In consequence of these wavespassing from west to east, the storm will only be violent when formed alittle to the westward. If the storm forms to the eastward, we neithersee it nor feel it, as it requires time to develop its strength, andalways in this latitude travels eastward; so that storms may generallybe said to come from the west, although the exciting cause travels fromeast to west. In the case now alluded to, the weather indicated a highbarometer, and the storm formed immediately to the eastward, evenshowing a distinct circular outline. We subjoin a description. 

_August_ 15th. Clear morning (N. -E. ), a bank of cumuli in south: noonquite cloudy in S. And clear in north. (N. -E. )

16th. Clear morning (N. -E. ); 3 P. M. , getting very black in E. And S. -E. , very _clear_ to the _westward_; 4 P. M. , much thunder and lightning ineast, and evidently raining hard; 5 P. M. , a violent squall from _east_for 10 minutes; tore up several trees; 6 P. M. , the storm passingeastward, clear in west all this time; 6. 30 P. M. , the storm forming aregular arch, the vertex being in _S. -E. _; the arch of hazy cirrus andheavy cumulus much lower in S. -E. , wind still moderate from east;10 P. M. , clear all around, but lightning in S. -E. And E. 

17th. Fine clear morning (W. ); noon, scattered cumuli in north; 6 P. M. , a beautifully regular arch of dense cumuli and cirrus margin in _N. -E. _, with a constant glimmer of lightning; 7 P. M. , very clear to the west, and north-west, and south; along the northern horizon a line of highpeaked cumuli terminating in N. -N. -W. ; a continued roll of distantthunder in the circular bank in N. -E. , and not a moment's cessation tothe lightning; the electric excitement advancing westward along thelines of cumuli; the cirrus haze also rising and passing towards S. -W. ;8 P. M. , the sky alive with lightning, the cirrus now reaches the zenith;no streaks of lightning coming to the earth; they seem to radiate fromthe heaviest mass of cumuli, and spread slowly (sufficiently so tofollow them) in innumerable fibres over the cloudy cirrus portion of thesky; every flash seems to originate in the same cloud; 8. 30 P. M. , onebranching flash covered the whole north-eastern half of the sky, noleafless tree of the forest could show so many branches; 9. 30 P. M. , allpassed to S. -W. Without rain, leaving behind a large cumulus, as if itlagged behind. From this cumulus a straight line of lightning shot up10° above the cloud into a perfectly clear sky, and terminated abruptlywithout branching. 

We have been thus particular in giving these details, as this was aclear case confirming the principles advanced, that the vortices do notform a continuous line of disturbance, in their daily passage around theearth. It shows also that the barometer, in connection with theseprinciples, will be a far more useful instrument than it has yet proveditself, for practical service as an indicator of the weather. 

FOOTNOTES:

[10] For convenience to those wishing to verify the calculation of thesetriangles, we have put down each side and angle as found. Also, as anaid to the navigator. 

[11] Daily Wisconsin, July 7. 

[12] The author. 

[13] Chicago Democrat. 

[14] This was also calculated before the event. 

[15] The letters in a parenthesis signify the direction of the wind. 

[16] Giving this cloud the average velocity of thirty miles per hour, its altitude was determined by the sextant at twelve miles, and we thinkunder-estimated. While measuring, the author's attention was drawn tothe fact, that although it appeared equally dense above and below, yetits middle part was the brightest, and as there was only a faint glimmerof twilight in the N. -W. , he concluded that the cloud was self-luminous;for when the smallest stars were visible, it glowed about as bright asthe milky-way in Sagittarius. Occasionally the whole cloud was lit upinternally by the lightning, and about this time it sent off three rays:one horizontally, westward, which was the faintest; one about N. -W. , towards Jupiter, and the brightest of the three; and another towards thenorth. These were not cirrus streaks, but veritable streams of electricmatter, and had a very decided rotation from left to right, andcontinued visible about twenty minutes, as represented above. 

[17] This day the central vortex passed in about latitude 47° N. --thesouthern margin cannot be nearer than 250 miles, throwing off the 40′for the horizontal refraction, would give eight miles of altitude abovea tangential plane. Then another seven miles, for curvature, will givean altitude of fifteen miles for the cumuli. The height of thesethunder-clouds has been much under-estimated. They seem to rise inunbroken folds to a height of ten and twelve miles frequently; from thedata afforded by the theory, we believe they will be found much highersometimes--even as much as sixteen miles. 

[18] These parallel bands, and bands lying east and west, are frequentin fine weather between two vortices. Sailors consider them a sign ofsettled weather. After dark there was frequently seen along the northernhorizon flashes of lightning in a perfectly clear sky. But they wereboth faint and low, not reaching more than 4° or 5° above the horizon. After sunset there were very distinct rays proceeding from the sun, butthey were shorter than on the evening of the 3d. These are caused by thetops of the great cumuli of the storm, when sunk below the horizon, intercepting the sun's rays, which still shine on the upper atmosphere. The gradation was very marked, and accorded with the different distancesof the central vortex on the 3d and 4th--although, on the 4th, thenearest distance must have been over four hundred miles to the southernboundary of the storm. 

[19] It is worthy of notice here, that New York, which only differs byabout 40 miles of latitude and 800 in longitude, had the storm earlier, near the time of the passage, as appears by the appended account of it. This proves, that a storm affects a particular latitude simultaneously, or approximately so. If this had to travel eastward to reach New York, it would have been the 10th instead of the 8th. The principal troublewas, however, in the early part of the evening of the 8th, to the southof Ottawa, where the strong wind was drawn in from the northward. If avortex passes from north to south, leaving the observer between thepassages, there must, nearly always, be a winding up squall from thenorth to clear away the vapory atmosphere. 

[20] From the _New York Tribune_, July 9, 1853. 

[21] These pages are now in the compositors' hands, (Nov. 21st, ) and upto the last moment the Author has observed carefully in New York thepassages of these vortices. October 24th, in the inner vortex descendingproduced a violent storm on the coast, and much damage ensued. November7th, the same vortex ascending was also severe. And on November 13th, early, the passage of the central vortex ascending, caused a flood inConnecticut of a very disastrous nature. Would it not pay the insuranceoffices to patronize such investigations in view of such palpable factsas these?

SECTION THIRD. 

OBJECTIONS TO LUNAR INFLUENCE. 

We have now presented a theory of the weather, which accounts for manyprominent phenomena, a few of which we shall enumerate. It is anobserved fact, that in all great storms electrical action is more orless violent, and that without this element it seems impossible toexplain the velocity of the wind in the tornado, its limited track, andthe formation of large masses of ice or hail in the upper regions of theatmosphere. It is also an observed fact, that the barometer is incontinued motion, which can only be legitimately referred to a change inthe weight of the atmospheric column. This we have explained as due toatmospheric waves, caused by the greater velocity of rotation of theexternal ether, as well as to the action of the three great vortices. These causes, however, only partially produce the effect--the greaterportion of the daily oscillations is produced by the action of the greatradial stream of the solar vortex, as we shall presently explain. It isan observed fact, that, although the storm is frequently violent, according to the depression of the barometer, it is not always so. According to the theory, the storm will be violent, _ceteris paribus_, on a line of low barometer, but may still be violent, when the contraryobtains. Another fact is the disturbance of the magnetic needle during astorm. Storms are also preceded generally by a rise in the thermometer, and succeeded by a fall; also by a fall in the barometer, and succededby a rise. It is also well known, that hurricanes are unknown at theequator, and probably at the poles also. At all events, they are rare inlat.  80°, and, according to Capt.  Scoresby, storms are there frequentlyraging to the south, while above, there is clear sky and fine weather, with a stiff breeze from the northward. The greater violence of stormsin those regions where the magnetic intensity is greater in the samelatitude, the probable connection of peculiarities in the electric stateof the atmosphere with earthquakes, and the indications of the latterafforded by the magnet; the preponderance of westerly winds at a greatelevation in every latitude on the globe visited by man; and thefrequent superposition of warm layers of air above cold ones at thoseelevations, are all facts worthy of note. And the connection of cirrusclouds with storms, as well as with the aurora, indicates that theproducing cause is external to the atmosphere, and gradually penetratesbelow. The theory fully explains this, and is confirmed by the fantasticwreathings and rapid formation of these clouds in straight lines of ahundred miles and upwards. But time would fail us in pointing out atithe of the phenomena, traceable to the same cause, which keeps ouratmosphere in a perpetual state of change, and we shall only advert toone more peculiarity of the theory. It places meteorology on amathematical basis, and explains why it is that a storm may be raging atone place, while in another, not very remote, the weather may be fine, and yet be dependent on the position of the moon. 

That the moon has exerted an influence on the weather has been thepopular creed from time immemorial; but, ignorant of the mode in whichthis influence was exerted, men have often been found who have fosteredthe popular belief for their own vanity or advantage; and, on the otherhand, philosophers have assailed it more by ridicule than by argument, as a relic of a barbarian age. Not so with all; for we believe we arenot wrong in stating, that the celebrated Olbers compared the moon'spositions with the weather for fifty years, before he gave his verdictagainst it. He found the average amount of rain at the perigee aboutequal to the amount at the apogee, as much at the full as at the change, and no difference at the quadratures. But this fact does not throw afeather in the scale by which this theory is weighed. Popular opinions, of remote origin, have almost always some foundation in fact, and it isnot much more wise to reject them, than to receive them. The Baron VonHumboldt--a man possessing that rare ingredient of learning, a practicalcommon sense--observes: "That arrogant spirit of incredulity whichrejects facts, without attempting to investigate them, is, in somecases, more injurious than an unquestioning credulity. "[22] If a popularbelief or prejudice be absurd, its traditional preservation for athousand years or more may very well account for the absurdity. 

The present system of astronomy still retains the motley garniture ofthe celestial sphere, as handed down from the most remote antiquity; andgranting that ages of ignorance and superstition have involved thehistory of the different constellations in a chaos of contradictorytraditions, there is no doubt at the foundation some seeds of truthwhich may even yet emerge from the rubbish of fable, and bear fruit mostprecious. That the zodial[23] signs are significant records of somethingworthy of being preserved, is prejudice to deny; and we must be allowedto regard the Gorgons and Hydras of the skies as interesting problemsyet unsolved, as well as to consider that the belief in lunar influenceis a fragment of a true system of natural philosophy which has becomemore and more debased in postdiluvian times. Amongst those who have notsummarily ignored the influence of the moon, is Toaldo, a Spanishphysicist, who endeavored to show the connection between the recurrenceof warm and cold seasons, and the semi-revolution of the lunar nodes andapogee, and proposed six of those periods, or about fifty-four years, asthe cycle in which the changes of the weather would run through theircourse. According to the present theory, it is not likely such a cyclewill ever be discovered. There are too many secular, as well as periodicinfluences combining, to produce the effect; and the times are tooincommensurable. Lately, Mr.  Glaisher has presented a paper to the RoyalSociety, giving about fourteen years from observation. Others havelately attempted to connect the changes of the seasons with the solarspots, as well as with the variations of the magnetism of the earth, butwithout any marked result. 

It may, however, be urged, that if the sidereal period of the moon beapproximately a cycle of change, it would have been detected long ago. One reason why this has been so long concealed, is the high latitude ofthe observers. Spain, Italy, and Turkey, are better situated than otherEuropean countries; but the scientific nations lie further north; andfrom these the law has gone forth to regulate more southern lands. Inthe United States, particularly in the great plains of the west, theweather can be better compared; not only on account of the latitudebeing more favorable, but also on account of the greater magneticintensity of the western hemisphere. 

It must also be remembered that there are in latitude 40°, five or sixdistinct passages of the disturbing cause in one sidereal period of themoon. If two of these periods are drawn closer together by the change ofthe elements, the interval between two others must necessarily beincreased. Besides, the effect produced is not always the same, forreasons already adverted to. One vortex may be more violent one month, or for a few days in one month, while another may be more active thenext. It may also happen that for several successive passages, thepassage shall be central in one latitude, while two or three degreesnorth or south, another place shall be passed by. In different monthsand in different years, as well as in different seasons of the year, theenergy of the ether may be augmented or diminished. But it may be said, that, supposing the theory true, if its indications are so uncertain, itis of little value. By no means. It is true there are many things to beinquired into; but it is a great thing in this science to be able totake the first step in the right direction, --to find even the _key_ ofthe portal. It is a great stride to be able to say, a storm may happenat such a time, but cannot happen at another; that a storm, when raging, will go in this direction, rather than in that; that it will be centralhere, and less violent yonder; and when we consider its bearing onastronomical and other science, it is difficult to exaggerate its valueto the world at large. 

Again, it may be said that rain, and cloudy days, and fresh breezes, andeven strong winds, sometimes occur, when the vortices do not passcentrally. This is true; yet only indicating that where the vortices arecentral, an unusual disturbance is taking place. But there is anothercause, which was purposely omitted in considering the prominent featuresof the theory, in order not to encumber the question with secondaryinfluences. By referring to Fig.  3, section 1, we see that the lateralvortices of the globe are continually passing off to the southward, inthe northern hemisphere, in a succession of dimples, and continuallyreforming. We will now represent this mode of action in profile, as itactually occurs in the illustration we have used. 

The vortex passing off from O, (Fig.  20, ) although it does not actuallyreach the surface of the atmosphere, affects the equilibrium of theether, and, for a short distance from the parent vortex, may cause anascensional movement of the air. If to this is conjoined a northerlywind from the vortex, a band of clouds will be produced, and perhapsrain; but violent storms never occur in the intervals, except as asteady gale, caused by the violence of a distant storm. Thus, it willfrequently be noticed that these vortices are flanked by bands ofclouds, which pass southward, although the individual clouds may bemoving eastward. Hence, instead of disproving the theory, they offerstrong evidence of its truth; and could we view the earth from the moonwith a telescope, we should no doubt see her beautifully belted. 

[Illustration: Fig. 20]

But it may be again asked, why should not the weather be the samegenerally, in the same latitude, if this theory be true? If the earthwere a globe of level land, or altogether of water, no doubt it would besimilar; but it must be remembered, that both land and water are veryunequally distributed: that the land is of varying extent andelevation--here a vast plain, far removed from the ocean, and there amountain chain, interposing a barrier to the free course of theatmospheric currents; sometimes penetrating in full width into thefrigid zone, and again dwindling to a few miles under the equator. Onevery important distinction is also to be remarked, in the superficialarea of the different zones, reckoning from the equator, and taking thehemisphere as 100 parts:

 Frigid zone 8 parts. Temperate " 52 " Torrid " 40 "

For as the time of rotation in every latitude is the same, the area tobe disturbed in the same time, is less in high latitudes, and there agreater similarity will obtain, _ceteris paribus_. In lower latitudes, where both land and water stretch away for thousands of miles, it is notwonderful that great differences should exist in the electrical andhygrometric state of the air. 

The summer of many countries is always dry--California for instance. Inwinter, in the same country, the rains are apparently incessant. This ofcourse depends on the power of the sun, in diverting the great annualcurrents of the atmosphere. As long as the dry north-west trade setsdown the coast of California, the circumstances are not favorable forgiving full development to the action of the vortices. When the tradewind ceases, and the prevailing winds come from the south, loaded withvapor, the vortices produce storms of any magnitude; but (and we speakfrom two years' observation) the passages of the vortices are asdistinctly marked there in winter time, as they are in the easternStates; and in summer time, also, they are very perceptible. The sameremark applies to Mediterranean countries, particularly to Syria andAsia Minor; although the author's opportunity for observing lasted onlyfrom April to December, during one season. If we are told it never rainson the coast of Peru, or in Upper Egypt, it does not seriously militateagainst the theory. The cause is local, and the Samiel and the sandstorm of the desert, is but another phase of the question, explicable onthe same general principles. From the preceding remarks it will be seen, that in order to foretell the character of particular days, a previousknowledge of the weather at that particular place, and for someconsiderable time, is requisite; and hence the difficulty of laying downgeneral rules, until the theory is more fully understood. 

MODIFYING CAUSES. 

We now come to the causes which are auxiliary and interfering. It isnatural that we should regard the sun as the first and most influentialof these causes, as being the source of that variation in thetemperature of the globe, which alternately clothes the colder regionsin snow and verdure. The heat of the sun undoubtedly causes the ether ofthe lower atmosphere to ascend, not by diminution of its specificgravity; for it has no ponderosity; but precisely by increase oftension, due to increase of motion. This aids the ascensional movementof the air, and therefore, when a vortex is in conjunction with the sun, its action is increased--the greatest effect being produced when thevortex comes to the meridian a little before the sun. This has atendency to make the period of action to appear dependent on the phasesof the moon, which being the most palpable of all the moon's variations, has been naturally regarded by mankind as the true _cause_ of thechanges of the weather. Thus Virgil in his Georgics, speaking of themoon's influence and its signs:

 "Sin ortu in quarto (Namque is certissimus auctor) Pura, nec obtusis per cœlum cornibus ibit; Totus et ille dies, et qui nascentur ab illo, Exactum ad mensem, pluviâ ventisque carebunt. "

Hence, also, in the present day we hear sailors speak of the full andchange, or the quartering of the moon, in connection with a gale at sea;thus showing, at least, their faith in the influence of the phenomenon. Yet it is actually the case, at certain times, that in about latitude40° and 41°, the storms appear about a week apart. 

There is some reason, also, to suspect, that there is a difference oftemperature on opposite sides of the sun. As the synodical rotation isnearly identical with the siderent period of the moon, this wouldrequire about forty-four years to run its course, so as to bring thephenomena to exact coincidence again. Since these observations weremade, it is understood that Sig. Secchi has determined that theequatorial regions of the sun are hotter than his polar regions. It maybe owing to this fact, that we have inferred a necessity for a change, whose period is a multiple of the sun's synodical rotation, but it isworthy of examination by those who possess the necessary conveniences. 

Another period which must influence the character of different years, depends on the conjunction of the perigee of the lunar orbit with thenode. Taking the mean direct motion of the moon's perigee, and the meanretrograde motion of the node, we find that it takes six years and oneday nearly from conjunction to conjunction. Now, from the principleslaid down, it follows, that when the perigee of the orbit is due north, and the ascending node in Aries, that the vortices of the earth willattain their greatest north latitude; and when these conditions arereversed, the vortices will reach their highest limit in the lowestlatitude. This will materially affect the temperature of the polarregions. In the following table, we have calculated the times of theconjunctions of the apogee and pole of the orbit, taking the meanmotions. It may be convenient to refer to by-and-bye, remembering thatwhen the conjunction takes place due south, the vortices reach thehighest, but when due north, the vortices in the northern hemispherehave their lowest upper limit:

 CONJUNCTION OF APOGEE AND POLE OF ORBIT. [24]

 Year. Month and Day. Longitude. 1804, April 18th, 220° 1810, " 17th, 104 1816, " 16th, 348° 1822, " 15th, 232 1828, " 14th, 116 1834, " 12th, 360 1840, " 11th, 244 1846, " 10th, 128 1852, " 9th, 12 1858, " 8th, 255 1864, " 7th, 139 1870, " 6th, 23 1876, " 5th, 267

By this we see that the vortices have never attained their highest limitduring the present century, but that in 1858 their range will be in atolerable high latitude, and still higher in 1876--neglecting theeccentricity of the orbit. 

A very potent influence is also due to the heliocentric longitude of thesun, in determining the character of any given year. Let us explain:

The moon's inertia forces the earth from the mechanical centre of theterral system, but is never able to force her clear from the centralaxis. With the sun it is different. He possesses many satellites(planets). Jupiter alone, from his great mass and distance, is able todisplace the whole body of the sun. If other planets conspire at thesame side, the centre of the sun may be displaced a million of milesfrom the mechanical centre of the solar system. Considering this centre, therefore, as the centre of an imaginary sun, from which heliocentriclongitudes are reckoned, the longitude of the real sun will vary withthe positions of the great planets of the system. Now, although this_systematic_ longitude will not be exactly similar to the heliocentriclongitude reckoned from the sun's centre, yet, for the purposesintended, it will correspond sufficiently, and we shall speak of thelongitude of the sun as if we reckoned heliocentric longitudes from themechanical centre of the system. When we come to consider the solarspots, we shall enter into this more fully. In the following diagram weshall be able to perceive a cause for variation of seasons in a givenyear, as well as for the general character of that year. 

[Illustration: Fig. 21]

Let S represent the centre of the sun, and the circle a vertical sectionof the sun, cutting; through the centre, --SJ being in the equatorialplane of the vortex, of which ZZ′ represents the axis. As the etherdescends the poles or axis at Z, it is met by the current down theopposite pole, and is thence deflected in radii along the equatorialplane to J. But on the side S, the ether is opposed by the body of thesun; its direction is consequently changed, and cross currents areproduced, assuming it as a principle, that the ethereal fluid ispermeable by other currents of similar matter, and that it tends alwaysto move in right lines. This granted, it is evident that, in passing thesun, the quick moving ether forms a conical shell, (the sun being at theapex, ) so that the strongest current of ether is in this conical shell, or at the surface of this conical space. As the plane of the ecliptic isnot much inclined to the sun's equator, and this last probably not muchinclined to the plane of the vortex, should the earth have the same_heliocentric_ longitude at the time, (or nearly the same, ) she wouldbe in an eddy, as respects the radial stream, and be protected from itsfull force by the body of the sun. 

Now, the ether comes down the axis with the temperature of space, andmay possibly derive a _little_ additional temperature in passing overthe body of the sun; so that in this position the earth is protectedfrom the chilling influence of the radial stream, by being protected bythe body of the sun. And although, from the immense velocity of theether, it cannot derive much additional temperature, there may still bean appreciable difference, due to this cause. 

It is the chilling influence of the ethereal stream which originated theidea among philosophers, of _frigorific impressions, darted from a clearsky_. In some years the sun will be nearly in the centre of the system;in other years the axis of the vortex will not come near the sun. And asthe sun's longitude may vary through the entire circle, it may happenthat the earth's longitude shall coincide in winter or summer, or springor autumn. When, however, the earth emerges from the protection of thesun, and enters the conical shell, considered as a space of considerabledepth, she will again be exposed to the full force of the radial stream, rendered more active by the previous deflection, and by the numerouscross currents pervading it; so that a mild and calm winter may besucceeded by a cold and stormy spring. The present season, (1853) theearth's longitude coincided with the sun's longitude in about 135°, andconsequently was in the conical space spoken of, during February andMarch; but the radius vector of the sun's centre, being then lessthan 300, 000 miles, the protection was not as complete as it issometimes. Still, the general fineness of these months was remarkable;yet in April and May, when the earth became again exposed to the actionof the solar stream, the effect was to retard the spring, and disappointthe prognostications of the weather-wise. In applying these principles, we must consider the effect in those latitudes which are more readilyaffected, --that is, in the temperate zone, midway between the twoextreme zones of heat and cold. 

In 1837 and 1838, the longitude of the sun's centre corresponded withthe earth's, in August and September, when there was neither rain norelectrical excitement; and consequently those seasons were sickly overthe whole country. Now, there is another cause which renders the monthsof August, September, and October, deficient in electrical energy, andconsequently more prone to be sickly. If, therefore, the two causesunite their influence, the autumnal months will be more sickly at thosetimes. This last cause, however, only affects the _northern latitudes_in autumn, and consequently, _ceteris paribus_, the autumnal monthsshould not be so proverbially sickly in the southern hemisphere. Thisis, however, only suggestive. 

Again, in 1843, the winter was very mild in January and February; but inMarch it turned cold and stormy, and continued through April. In thisyear the longitude of the sun was nearly the same as in 1853, --the twolongitudes of the earth and sun corresponding about the last of January;but in March, the earth forsook the comparative calm produced by thesun's position, and hence the greater cold. [25]

Thus it appears at every step we take, that the different members of thesolar system do indeed belong to the same family, whose least motionshave their influence on the rest. Who could have anticipated that theposition of Jupiter in his orbit had anything to do with the health ofthis remote planet, or with the mildness of its seasons? In this we havea clue to the origin of that astrological jargon about planetary aspectsbeing propitious or malign. Philosophers are even yet too prone to wrapthemselves in their mantle of academic lore, and despise the knowledgeof the ancients, while there is reason to believe that the world oncepossessed a true insight into the structure of the solar system. As warbecame the occupation of mankind, under the despotic rule of ambition, so truth retired, and ignorance seizing upon her treasures, has somutilated and defaced them, that their original beauty no longerappears. Let us hope that the dawn of a better day is approaching. 

There is yet another cause (just alluded to) which modifies the actionof the vortices. 

We have shown that, if the periodic times of the planets areapproximately equal to the periodic times of the contiguous parts of thesolar vortex, the density of the ether is directly as the square rootsof the distances from the centre. As the earth is at her perihelionabout the first of January, the density of the surrounding ether is thenless than in other parts of the orbit; consequently, if we suppose thatthere is a continual tendency to equilibrium, the ether of space mustpress inwards, during the time between the perihelion and aphelion, (_i. E. _ from January to July, ) lowering the temperature and increasingthe electrical action of those months. As the distance from the sun ismost rapidly augmenting about the first of April, and the effectivepower of the sun's radiation is most rapidly increasing in May; bycombining the two we shall find, that about the first of May we shallhave considerable electrical action, and cold weather. This explainsalso, in part, the prevalent tradition of certain days in May being verycold. [26] When the earth leaves the aphelion, a reaction takes place, being most rapid in September. There is then an _escape_ of ether fromthe earth, which keeps up the temperature, and causes these months to besickly, from the negative electrical state of the atmosphere. In thesouthern hemisphere, the effects in the same season will be reversed, which may partly account for the greater degree of cold in thathemisphere, and for accelerating the approach of both summer and winter, while in the north they were both retarded. 

We must now advert to another cause, which of all others is probably themost important, at least to the other members of the solar system. 

In every part of the solar vortex the ether is continually pressingoutwards. We are not now speaking of the radial stream, but of theslower spiral motion of the ether around the axis of the vortex, whosecentrifugal force is bearing the whole body of the ether outwards, thusrarefying the central parts, and thus giving rise to the polar influx, from which arises the radial stream. This may be made more intelligible, by reflecting that the polar current is comparatively dense ether, andthat the length of the axis of the vortex prevents this influx currentcoming in sufficient quantities to restore an equilibrium in the densityof the medium. Yet, what does come down the poles, is distributedrapidly along the equatorial plane, leaving the space still rarefied. Now we perceive, that in order for the radial stream to continue inaction, requires the whole medium of the vortex to be also movingoutward; it is therefore continually condensed as it proceeds. Thiscondensation necessarily converts much of the specific heat of the etherinto sensible heat; so that the _temperature_ of the medium iscontinually increasing, as the distance from the sun increases. 

When we contemplate the solar system as the emanation of one Great Mind, we naturally seek for evidence of the wisdom of a supreme intelligencein _all_ the arrangements of that system. But, however humbly andreverently we may speak of these arrangements, we can scarcely avoid thewish, that the planetary distances had been differently arranged, ifNewton's doctrine be true, that space is a vacuum, and that the heat ofa planet, is inversely as the squares of the distances from the sun. For, to speak of the temperature of space, except as dependent on thislaw, is one of those many incomprehensible inconsistencies with whichphilosophers are chargeable. If the Newtonian philosophy is literallytrue, space has _no temperature_, and the surface heat of the planetNeptune is nearly 1, 000 times less than on our own globe. Again, onMercury it is seven times greater, which heat would scorch and consumeevery organic substance on the earth, and speedily envelope the boilingocean in a shroud of impermeable vapor. Granting even that space may notbe a vacuum, and yet the law of gravitation be true, we may still beallowed to consider both Saturn and Uranus and Neptune, as inhospitableabodes for intelligent creatures; and, seeing the immensity of room inthe system, there is no reason why these planets might not have beenpermitted to revolve nearer the great source of light and life andcheering emanations. To suggest the resources of Omnipotence is noargument. He has surrounded us with analogies which are seen, by whichwe may attain a knowledge of those which are not seen; and we have everyreason to suppose that the great Author of nature is not indifferent tothe aspects under which his works reveal him unto his creatures. Yetthere is (on the above hypothesis) an apparent want of harmony in theplanetary distances; and if frail mortality may be permitted to speakout, an explanation is needed to obviate this seeming anomaly in theeconomy of the world. The more we learn of the physical arrangements ofthe universe, the more do they correspond with our experience of thenice adaptation of the means to the end which obtains in our own globe, and we can only judge of other planets by the analogies around us. Here, there, are extremes of temperature it is true: it is necessary thereshould be, and we can see and understand the necessity in all suchcases, and how they conduce to the general average of good. But, astronomers can give no reason why it is necessary that some planets ofour system should be placed so remote that the sun is frittered down toa star, whose heatless light is but a mockery to those frigid realms. 

Now, according to this theory, the temperature of Neptune may be farmore uniform and conducive to life than that of our own globe. Thechilling influence of the solar stream at that planet being nearly null, and the temperature of the surrounding space far greater. So alsoMercury, instead of being the burning planet of the schools, may sufferthe most from cold. 

The planet Mars is generally considered, of all the members of thesystem, most nearly to resemble our own world. The telescope not onlyreveals seas and continents, but the snowy circles round his poles, which appear to increase and diminish, as his winter is beginning orending. This planet's ecliptic is similar to our own in inclination orobliquity, his distance, also, is far greater, and his winter longer;yet, for all this, his snow zones are less than on our own globe. Thisanomalous fact has, we believe, never been noticed before; but it isexplicable on the theory, and therefore confirms it. Mars has nosatellite, and therefore his centre will be coincident with the centreof the marsial vortex. There will be no _lateral vortices_ to derangehis atmosphere, and if the axis of his vortex coincides also with theaxis of the planet, the central vortex will be continually over thepoles, _and there will be no storms on the planet Mars_. A capital factconnected with this, is the want of belts, as in Jupiter and Saturn; forthese planets have satellites, and if _they_ are not massive enough, thebelts may be produced by an obliquity in the axis of the Jovial andSaturnial vortices. If Mars had an aurora like the earth, it is fair topresume the telescope would ere this have shown it. He is, therefore, inequilibrium. In applying this reasoning to the earth, we perceive that acertain influence is due to the difference of temperature of theethereal medium surrounding the earth, at perihelion and aphelion, beingleast at the former, and greatest at the latter. 

As a modifying and interfering cause in the action of the vortices, wemust mention the great natural currents of the atmosphere, due to theearth's rotation. 

It is considered that the sun is the principal cause of these greatcurrents. By elevating the surface atmosphere of the equator, a lateralcurrent is induced from the north and south; but on account of theenlarging circles of latitude, their direction tends more from thenorth-east and south-east. These currents are usually called the trades. Without disputing the correctness of this, it may be doubted whether thewhole effect is due to the sun. As this principle affects the oceanlikewise, it is necessary to look into it; and in order to simplify thequestion, we will first suppose our globe covered entirely by the ocean, without any protuberant land. 

Let us assign a uniform depth of ten miles to this ocean. In the Fig. Following, the two circles will represent the surface and bottom of theocean respectively. The axis of rotation is thus represented by the linePP′. Let us consider two particles of water at m and n, as feeling theinfluence of this rotation; they will, of course, be both urged towardsthe equator by the axifugal force. Now, every particle in the oceanbeing also urged by the same force, it might be supposed that after aprotuberant mass of water had accumulated at the equator EE′, the wholeocean would be in equilibrium. This would not follow. The particle at mis urged by a greater force than n; consequently the particle at n isoverborne by the pressure at m. Considering both in the same direction, yet the particle at n must give way, and move in the opposite direction. Just as the heaviest scale of the balance bears up the lightest, although both gravitate towards the same point. This is so self-evidentthat it would seem unnecessary to dwell upon it, had not the scientificworld decided that the rotation of the earth can cause no currentseither in the atmosphere or in the ocean. 

[Illustration: Fig. 22]

The axifugal forces of the two particles m and n are directly as thelines Mm and Nn, and if the gravitating forces were also as the radii Tmand Tn, no motion would be produced. Admitting even the Newtonian law tobe rigidly exact, the earth cannot be considered a homogeneous globe, but, on the contrary, the density of the central parts must be nearlythirty times greater than the density of the surface of the ocean. Theratio of the gravitating forces of these two particles is, therefore, less than the ratio of their respective radii, and the axifugal tendencyof the particle at n is more than proportionally restrained by thecentral gravitation; and hence m will move towards the equator, and ntowards the poles, as represented in the Fig. 

It is on account of the overwhelming momentum of the surface waters ofthe South Pacific over the North, that the Pacific, at Panama, standssix or seven feet higher than the Atlantic. We shall again allude tothis interesting fact. 

According to newspaper reports of a lecture, delivered in New York, byLieut. Maury, U.  S.  N. , this gentleman endeavors to explain the currentsof the ocean, by referring them to evaporation in the tropics. The vaporleaves the salt of the water behind, and thus, by continualaccumulation, the specific gravity of the tropical waters is greaterthan that of the superficial waters nearer the poles; the lighterwater, therefore, passes towards the equator, and the heavier waterbelow, towards the poles. If this be a correct statement of thatgentleman's theory, fidelity to our standards compels us to question thesoundness of the conclusion. The mere fact of the surface water of theocean being lighter than that of the bottom, cannot on any knownprinciples of science cause any movement of the surface waters towardsthe equator. When such an acute and practical physicist is driven, bythe palpability of the fact that the polar waters are continuallytending towards the equator, to seek the cause in the tropicalevaporation, it shows that the dogma, which teaches that rotation canproduce no motion, is unsound. 

Sir John Herschel, in speaking of the solar spots, says: "We may alsoobserve that the tranquillity of the sun's polar, as compared with hisequatorial regions (if his spots be really atmospheric), cannot beaccounted for by its rotation on its axis only, but must arise from somecause external to the sun, as we see the belts of Jupiter and Saturn andour trade winds arise from a cause external to these planets combiningitself with their rotations, which _alone_ (and he lays an emphasis onthe word) can produce no motions when once the form of equilibrium isattained. "

With respect to the origin of the solar spots, we have no disposition toquestion the conclusion; but, as regards the _principle_ laid down, thatrotation can produce no motions when once the form of equilibrium isattained, we must unequivocally dispute it. If our atmosphere were ofuniform density, the rotation of the earth would cause no current suchas we have described; with our atmosphere as it is, the result will bedifferent. The momenta of two portions of matter are the products oftheir inertiæ by their motions, and, in the present case, we must takethe inertiæ of equal spaces. A cubic inch of air at the surface, and atthree miles above the surface, is as 2 to 1; but their centrifugalvelocity varies only as the radii of the respective spheres, or as 1320to 1321. In the polar regions, therefore, the momentum of the surfaceair preponderates, and, in this case, the _surface_ current is towardsthe equator, and the upper current towards the poles. When, however, thecentrifugal velocity is considerably increased in a lower latitude, andthe curvature of the surface becomes more and more inclined to thedirection of that resolved part of the centrifugal force, which isalways _from_ the axis, the surface layers will evince a tendency toleave the surface, and an intermingling will then take place in thespace between latitude 70° and 50°, or in latitude 60°. As this layer iscontinually urged on in the same direction by the surface layer oflatitudes above 60°, the upper layer now becomes a current setting_towards_ the equator, and, consequently, the back current occupies thesurface. Now, considering that the rarefying action of the sun iselevating the air under the equator, there must necessarily be an uppercurrent from the equator to the poles; so that if we conceive the twocurrents to meet about latitude 30°, there will be a secondintermingling, and the current from the poles will again occupy thesurface. Thus, we regard a part of the effect of the trades to therotation of the earth, which is the chief impelling power at the poles, as the sun is at the equator; and the latitudes 60° and 30° will bemarked by some especial phenomena of temperature, and othermeteorological features which do actually obtain. These would be muchmore marked if the irregular configuration of land and sea, theexistence of mountain chains, and the different heating power ofdifferent latitudes, owing to the unequal distribution of the land, didnot interfere; and the currents of the air (disregarding the deflectioneast and west) might then be represented by a treble link or loop, whosenodes would vary but little from latitudes 30° and 60°. As it is, ithas, no doubt, its influence, although unimportant, when compared withthe disturbing action of the ethereal vortices. 

There is another phenomenon due to the action of the radial stream, which has given much trouble to the physicist, and which has yet neverbeen explained. This is the horary oscillations of the atmosphericpressure which, in some countries are so regular that the time of daymay be ascertained by the height of the barometer. According toHumboldt, the regularity of the ebb and flow in the torrid regions ofAmerica, is undisturbed by storms or earthquake. It is supposed that themaxima occur at 9 A. M. And 10½ P. M. , and the minima at 4 A. M. And4¼ P. M. From the morning minimum to the morning maximum is, therefore, five hours; from the evening minimum to the evening maximumis 6¼ hours; from the evening maximum to the morning minimum is 5½hours, and from the morning maximum to the evening minimum is 7¼hours. Again, these oscillations are greatest at the equator, anddiminish with the increase of latitude. 

[Illustration: Fig. 23]

If we suppose the earth's axis perpendicular to the plane of the vortex, and P the pole in the above figure, and SP the line joining the centreof the earth and sun, M and m will represent the points in the earth'sequator where it is midday and midnight respectively. The solar streampenetrates the terral vortex; and strikes the earth's atmosphere alongthe lines parallel to SP. The direct effect would be to pile up theatmosphere at N and n; and therefore, were the earth at rest, themaximum would be at 6 A. M. And 6 P. M. , and the minimum at midday andmidnight; but the earth rotating from N towards M, carries along theaccumulated atmosphere, being more sluggish in its motions than theproducing cause, which cause is still exercised to force it back to N. From this cause the maximum is now found at K. For a like reason theminimum at M would be found at L, but on account of the motion of theearth being now in the same direction as the solar stream, the minimumis found still more in advance at k; so that, according to the theory, the interval between the morning maximum and the evening maximum, shouldbe greater than the interval between the evening maximum and the morningmaximum; and so it is, the first being 13½ hours and the last 10½hours. The morning minimum should also be less marked than the eveningminimum, and this also is a fact. The effect also should be greater inthe tropics than in high latitudes, which again also obtains; being 1. 32French lines at the equator, and only 0. 18 at latitude 70°. Had theearth no obliquity, the effect would be as the squares of the cosines ofthe latitude; but the ratio is diminished by the inclination of theaxis. But there are other variations of the barometer of longer period, apparently depending on the phases of the moon, but which cannot bereconciled to the attracting power of the moon as an atmospheric tide;and Arago concluded that they were due to some _special cause_, of whichthe nature and mode of action are unknown. Perhaps this theory willobviate the difficulty, as although the central vortex comes to themeridian at the same time as the moon, its effect will be different onthe inferior meridian to what it is on the superior one; whereas themoon's attraction should be the same on both. That the passage of avortex over or near a particular place should affect the barometer, istoo obvious to need explanation, and therefore we may say that thetheory will explain all those varieties both small and great, which havecaused so much speculation for the last fifty years. 

TERRESTRIAL MAGNETISM. 

In applying the theory to the magnetism of the earth, we must bear inmind that the earth is probably magnetic by induction, and not in virtueof its own specific action. The rotation of the surrounding ether, andthe consequent production of a radial stream, calls the ether intomotion within the earth's interior, as well as on the surface; but itdoes not follow that the ether shall also enter the earth at its polesand escape at its equator, for the obliquity of the vortex wouldinterfere with this result. It is sufficient that this does occur in theterral vortex immediately surrounding the earth. From late experimentsit is pretty well established that the axial direction of the needle, (and of other bodies also, ) is due to peculiar internal arrangement inlaminæ or layers, the existence of which is favorable to the passage ofthe magnetic current. 

According to the experiments[27] of Dr. Tyndal, it is found that themagnetism of a body is strongest along the line of greatest density. As, therefore, the laminæ of bodies may be considered planes of pressure, when these planes are suspended horizontally, the directive force isgreatest, and the longest diameter of the body sets axial. On the otherhand, when the body was suspended so that the laminæ were vertical, thelongest diameter set equatorial. Now, we know that the crust of theearth is composed of laminæ, just as the piece of shale in DoctorTyndal's experiments, and that these layers are disposed horizontally. And whatever force originally arranged the land and water on our globe, it is evident that the continents are longest from north to south, andtherefore correspond to the natural direction of the magnetic force. 

In consequence of the intrinsic difficulties of this question, and themystery yet attaching to it, we may be permitted to enter a little moreminutely into it, and jointly consider other questions of interest, thatwill enable us to refer the principal phenomena of terrestrial magnetismto our theory. 

We have before adverted to the discrepancies in the earth's compression, as determined by the pendulum, and also to the uncertainty of the moon'smass, as deduced from the nutation of the earth's axis. It is alsosuspected that the southern hemisphere is more compressed than thenorthern; and other phenomena also point out the inadequacy of the lawof gravitation, to account for the figure of the earth. 

From the invariability of the axis of rotation, we must conclude thatwhatever form is the true form, it is one of equilibrium. In casting oureyes over the map of the world, we perceive that the surface is veryunequally divided into land and sea; and that the land is very unequallyarranged, both north and south, and east and west. If we compare thenorthern and southern hemisphere, we find the land to the water about 3to 1. If we take the Pacific portion, and consider the north end of NewZealand as a centre, we can describe a great circle taking in one halfthe globe, which shall not include one-tenth of the whole land. Yet theaverage height of the remaining nine-tenths, above the level of the sea, is nearly 1, 000 feet. Call this nine-tenths nearly equal to one-fourthof the whole surface, and the protuberant land in the hemisphere, opposite the South Pacific, amounts to 1/30, 000 part of the whole massof the earth, or about 1/700 of the mass of the moon. Again, the meandensity of the earth is about 5½--water being unity, --and the meandensity of the surface land is only about half this: but three-fourthsof the whole surface is water. Hence, we see that the materials of theinterior of the earth must be either metallic or very compressible. Toassign a metallic nucleus to the earth, is repugnant to analogy; and itis not rendered even probable by facts, as we find volcanic emissions tocontain no heavier elements than the sedimentary layers. Besides, thereare indications of a gradual increase of density downwards, such aswould arise from the compressibility of the layers. Seeing, therefore, the equilibrium of the whole mass, and the consequent hydrostaticbalance of the land in the sea, --seeing also the small compressibilityof the solid portions, and the great compressibility of the fluid, theinference is legitimate that the whole is hydrostatically balanced, andthat our globe is a globe of water, with an intermediate shell of land, specifically lighter than the fluid in which it is suspended. Where thisshell is of great thickness, it penetrates to greater depths, andattains to greater elevations above the surface of the aqueous globe;where it is less thick, it is found below the surface, and forms thebottom of the upper ocean. Recent soundings give much greater depths tosome parts of the ocean, than the most elevated land upon the globe. Captain Denham, of H.  B.  M. Ship Herald, lately sounded in 37° south and37° west, and found bottom at 7, 706 fathoms, or about nine Englishmiles. 

As the interior portions of our globe are totally unknown, and thecompressibility of water is well established, it is just as sane toconsider water the most abundant element of nature, as solid land. Thegreat question to ask is, whether there may not be other phenomenaincompatible with this supposition? It is plain that the permanency ofterrestrial latitudes and longitudes would be unaffected by theconditions we have supposed. Would the precession of the equinoxes bealso unaffected? Mr. Hopkins has entered into such an investigation, andconcludes: "Upon the whole, then, we may venture to assert that theminimum thickness of the crust of the globe, which can be deemedconsistent with the observed amount of precession, cannot be less thanone-fourth or one-fifth of the radius of the earth. " Theseinvestigations were made on the hypothesis of the interior fluiditybeing caused by the fusion of the central portions of a solid globe; butit is evident that the analytical result would be the same if thesecentral parts were water, inclosed by an irregularly-spherical shell ofland. Nor would the result be affected, if we considered certainportions of the interior of this solid shell to be in a state of fusion, as no doubt is the case. 

May not the uncertainty of the mass of the moon, be owing to the factthat this shell is not so rigidly compacted but that it may yield alittle to external force, and thus also account for the tides in thePacific groups, rather obeying the centrifugal force due to the orbitvelocity of the earth, than the attraction of the moon?

Since the days of Hipparchus the sidereal day has not diminished by thehundredth part of a second; and, consequently, seeing that thecontraction of the mass must be limited by the time of rotation, it isinferred that the earth has not lost 1/508th of one degree of heat sincethat time. This conclusion, sound as it is, is scarcely credible, whenwe reflect on the constant radiation into a space 60° below zero. Admitthat the globe is a globe of water, whose average temperature is thetemperature it receives from the sun, and the difficulty vanishes atonce. Its diameter will be invariable, and the only effect of thecooling of the solid parts will be to immerse them deeper in the water, to change the _relative_ level of the sea without changing its volume. This is no puerile argument when rightly considered; but there isanother phenomenon which, if fairly weighed, will also conduct us to thesame views. 

It is now a fact uncontroverted, that the sea does actually change itslevel, or rather, that the elevation of continents is not only apparentbut real. The whole coast of Sweden and Finland is rising at the presentday at the rate of four feet in a century, while on the south a contraryeffect is produced. Various hypotheses have been formed concerning thisinteresting fact. Yet from the indications of geology, it must have beenan universal phenomenon in the early ages of the world, in order toaccount for the emersion of sedimentary deposits from the fluid whichdeposited them. May not internal fires be yet spreading, and thecontinents expanding instead of contracting? And may there not be aninequality in this process, so as necessarily to immerse in onedirection nearly as much as to elevate in another? One fact is certain, the elements are scattering the materials of the land along its Oceaniccoasts, which of itself must produce a very minute effect in disturbingthe hydrostatic balance; but a more efficient agent is the earthquakeand volcano. 

The upheaving of tracts of land by earthquakes, as on the coast of Chiliwould thus be satisfactorily explained, by attributing a certainresistance due to cohesion or friction preventing a _gradual_ change oflevel, but producing it suddenly by the jar of the earthquakes. May wenot inquire also, whether the facility with which the earth seems movedby this destructive agent, does not point to the same solution as theirregularity of the figure of the earth?

This is a subject on which it is allowable to speculate, especially ifany light can be thereby thrown on the still more mysterious source ofterrestrial magnetism. It is for such a purpose that we have permittedourselves to digress from that subject. In this connection we also mayacknowledge our indebtedness to the sacred volume for the first germ ofthis theory of the weather. 

Believing in the authenticity of the Mosaic history of the deluge, theauthor found it difficult to refer that event to other than naturalcauses, called into action by the operation of other causes, and allsimultaneous with the going forth of the fiat of Omnipotence. Thusreasoning, he was led to regard the deluge as a physical phenomenoninviting solution, and as a promising exponent to the climatology ofthe early world. He looked upon the bow of promise, as the autograph ofthe Creator, the signature to a solemn bond, upon which the eye of manhad never before rested. But if there was no rainbow before the deluge, there was no rain; and following up this clue, he was not only enabledto solve the problem, but also led to the true cause, which produces theprincipal commotions in our atmosphere. 

Science boasts of being the handmaid of religion; yet there are names ofnote in her ranks who have labored rather to invest this phenomenon withthe mantle of fable, and to force it into collision with the recordsgraven on the rocky pages of geognosy. But the world is ever prone to becaptivated by the brilliancy of misapplied talents, instead of weighingmerit by its zeal in reconciling the teachings of those things which areseen, with those which are revealed. 

If our globe be constituted as we suppose, the land might experiencerepeated submersions, without involving the necessity of any greatdeparture from established laws. And we might refer to the historicalrecord of one of these, with all the minute particulars as positivedata, imposing on us the necessity of admitting that the solid parts ofthe globe are hydrostatically balanced in the sea. But, modern scienceis not always correctly defined when called the pursuit of truth, norhuman learning the means of discovering it. 

If we could divest ourselves of this prejudice, we should have a readysolution of the difficulty presented by the earth having two northmagnetic poles, and probably two also in the south. For, by regardingthe old and new continents as two distinct masses of land whose basesare separated by 6, 000 miles of water, we recognize two great magnets, dependent, however, for their magnetism, on the rotation of the terralvortex. 

This is no place to enter into a lengthy discussion of such a difficultsubject as magnetism, but we may be allowed to enter a protest againstthe current theory of electro-magnetism, viz. : that a force is generatedby a galvanic current at right angles to the producing cause, which iscontrary to the fundamental principles of mechanics. We may conceivethat a current is induced from or to the surrounding space by therarefaction or condensation attending the transmission of such a currentalong a wire, and that rotation should follow, just as a bent pipe fullof small holes at the lower end, and immersed in water as a syphon, willgenerate a vorticose motion in the water; but mere juxtaposition, without participation and communication with the general current, isirrational, and, therefore, not true. 

We have always regarded a magnetic needle as a part of the great naturalmagnet, the earth; that its north pole actually points to the north, andits south pole to the south; and, being free to move, it is affected bythe circular motion of the surrounding ether, and by every motion bywhich the ether is directed. If there was any attraction between theearth and the needle, opposite poles would be presented, but it is notso--the force is merely directive. 

MAGNETIC VARIATIONS. 

Let us now see whether we cannot assign an adequate cause for thesecular and periodic variations in the inclination and declination ofthe needle. These have been generally referred to changes oftemperature, as in fact, also, the magnetism of the earth is sometimesascribed to galvanic or electric currents, called forth by a dailychange of temperature. Our theory gives a totally different explanationof these variations. 

In the northern hemisphere, the north point of the needle moves fromeast to west in the morning from about 8½ A. M. To 1½ P. M. , andreturns to its mean position about 10 P. M. It then passes over to theeast, and again returns to its mean position about 8 or 9 A. M. Theanalogy of this motion, with the horary changes in the barometer, indicate a common origin. Humboldt, in the instructions he drew up forthe Antarctic Expedition under Sir James Ross, says: "The phenomenaof periodical variations depend manifestly on the action of _solarheat_, operating probably through the medium of thermo electric currentsinduced on the earth's surface. Beyond this rude guess, however, _nothing is yet known of their physical cause_. It is even still amatter of speculation whether the solar influence be a principal or onlya subordinate cause. " That the sun may exert a modifying influence onthe phenomenon is not unlikely, but that he cannot be the principalcause, is evident from the following considerations. These horaryvariations of the magnetic needle are as great at the bottom of deepmines far removed from solar influence, as on the surface. They are asgreat, _ceteris paribus_ on a small island in the midst of the ocean, asin the interior of continents, where the heating power of the surface isvastly greater. They are extremely regular, so that between the tropics, according to the sagacious Humboldt, "the time of the day may be knownby the direction of the needle, as well as by the height of thebarometer. "

But what is the cause of these variations? This question is the mostdifficult of all physical problems, and we shall only aim at indicatingthe causes which are yet perhaps too intricately involved to afford apositive numerical determination. Admitting the existence of twoprincipal solid masses whose general direction is from south to north, and that these masses are more susceptible of permeation by the etherealfluid than the waters in which they are suspended, we have a generalsolution of the position of the magnetic poles, and of the isogonic, isoclinic, and isodynamic lines. Considering, too, that the southernpoles of these masses are the points of ingress, and the northern polesthe points of egress, it is easily understood that the ethereal mediumhaving the temperature of space, will cause the southern hemisphere tobe colder than the northern, and also that the magnetic poles will bethe poles of maximum cold, and the centres respected by the isothermaland isogeothermal lines. 

The general direction of the magnetism of the earth may be considered asthe controlling influence, therefore, in determining the position of themagnetic needle; but there are other causes which, to some extent, willmodify the result. That half of the globe turned away from the sun willpartake of the density of the ether at that distance, which is greaterthan on the side next the sun; the magnetic intensity ought, therefore, to be greater in the night than in the day. The poles of the greatterrestrial magnets, or even the position of a magnetic needle on thesurface, are continually placed by the earth's rotation in a differentrelation to the axes of the terral vortex, and the tangential current, which is continually circulating around the globe, has its inclinationto a given meridian in a perpetual state of change. If we conceive thatthere is a tendency to force the needle at right angles to this current, we shall have an influence which varies during the day, during the year, and during the time occupied by a complete revolution of the node. Theprincipal effect, however, of the horary variation of the needle is dueto the radial stream of the sun, which not only penetrates theatmosphere, but also the solid crust of the earth. Its principalinfluence is, however, an indirect influence, as we shall endeavor toexplain. 

No fact in the science of electro-magnetism is, perhaps, betterestablished than the disposition of an ethereal current to place itselfat right angles to the magnetic meridian, and conversely, when thecurrent is not free to move, to place the needle at right angles to thecurrent. Now, the terrestrial magnet or magnets, may be considered to besurrounded by a body of ether in rotation, which, in the earth, on itssurface, and for some distance from the surface, is made to conform tothe general rule, that is, to circulate at right angles to the magneticmeridian. Outside this again, the ether more and more conforms to theposition of the axis of the vortex, and this position varying, it mustexert _some_ influence on the surface currents, and, therefore, changein some degree the position of the magnetic meridian. The radial streamcomes from the sun in parallel lines, and strikes the globe and itssuperficial ethereal envelope just as we have shown its action on theatmosphere; but in this last case the magnetic equator is not a greatcircle, neither can we suppose its effects to be an accumulation of afluid which is imponderable at points 90° from the plane passing throughthe centre of the earth and sun, and coincident with the plane of thecentral meridian, and a depressing effect on that meridian. Its preciseinfluence must be, from the nature of the cause, to deflect the circularcurrent towards the poles, in places less than 90° from the meridian, and a contrary effect must be produced in places greater than 90° fromthe meridian. Let us assume, for argument's sake, that the magneticpoles of the earth correspond to the poles of rotation, the parallels oflatitude will, therefore, represent the ethereal currents circulatingaround the globe. Now, at sunrise, the radial stream of the solar vortexis tangential to the surface, and, therefore, can produce no change inthese currents. As the sun ascends say about 8 or 9 A. M. , the radialstream striking only the surface of the earth perpendicularly in thatplace where the sun is vertical (which we will suppose at the equator), streams off on every side, as the meridians do from the pole, and thecircles of latitude (that is the ethereal currents) being parallel tothe equator, they are met by the radial stream obliquely, and deflectedtowards either pole. By this deflection they are no longer at rightangles to the meridians. But, from the principle of reaction abovenoticed, the magnetic meridians will place themselves at right angles tothe current, or, in other words, the magnetic pole will change itsposition on the surface of the earth with respect to that particularplace. But, in other parts of the world, the meridians are in oppositephases at the same instant of absolute time; therefore, the magneticpoles are not points, but wide areas enclosing the magnetic poles of allthe countries under the sun. As this conforms to observation, it isworthy our especial attention, and may be understood by the subjoinedfigure, in which the oblique curves represent the course of thetangential current in the different positions of the sun, the parallellines representing the solar radial stream. 

[Illustration: Fig. 24]

As the sun gains altitude the action of the radial stream is at agreater and greater angle to the circular currents, and attains itsmaximum at noon, still acting, however, after noon; but seeing that thecircular current possesses a force of re-action, that is, that themagnetism of the earth is ever striving to bring these currents to theirnatural direction, an hour or two after noon, the currents tend again tothe equator, and the maximum deflection is passed, and finally ceases afew hours after sunset. Now let us attend to what is going on on theopposite side of the world. The radial stream passing over the polarregions, now produces a contrary effect; the ethereal atmosphere of thegreat magnet is accumulated on the farthest side from the sun, by theaction of the radial stream passing over the polar region, the parallelcurrents are now bent towards the equator, being at a maximum in placeswhere it is an hour or two past midnight. Before they were concave tothe equator, and now they are convex; the magnetic meridian is thereforedeflected the contrary way to what it was in the day time, by the sameprinciple of reaction. After the maximum, say at 4 A. M. , the deflectiongradually ceases, and the magnetic meridian returns to its mean positionat 8 or 9 A. M. These times, however, of maximum and minimum, must varywith the time of the year, or with the declination of the sun, with theposition of the moon in her orbit, with the perigee of the orbit, andwith the place of the ascending node; there are also minor influenceswhich have an effect, which present instrumental means cannot renderappreciable. 

What says observation? The needle declines from its mean position in thewhole northern hemisphere to the westward, from about 8. 30 A. M. , until1. 30 P. M. ; it then gradually returns to its mean position by 10 A. M. After 10 P. M. , it passes over to the eastward, and attains its maximumdeflection about three or four hours after midnight, and is found againat its mean position about 9 A. M. Now, this is precisely the directionof the deviation of the magnetic meridian, the needle therefore onlyfollows the meridian, or still continues to point to the temporarymagnetic pole. And although we have assumed, for the sake of simplicity, that the mean magnetic pole corresponds to the pole of rotation; intruth there are two magnetic poles, neither of which correspond; yetstill the general effect will be the same, although the numericalverification will be rendered more difficult. 

In the southern hemisphere the effect is the reverse, (this southernhemisphere, however, must be considered separated from the northern bythe magnetic equator, and not by the geographical one, ) the needledeclines to the eastward in the morning, and goes through the samechanges, substituting east for west, and west for east. Does observationdecide this to be to be a fact also? Most decidedly it does; and thisalone may be considered a positive demonstration, that the theory whichexplains it is true. The contrary deflection of the needle in thenorthern and southern hemisphere may be formally proclaimed as utterlybeyond the reach of the common theory of magnetism to explain. Thisdifficulty arises from considering the needle as the disturbed bodyinstead of the earth; and also from the fact that the effect of solarheat must be common to needles in both hemispheres, and act upon similarpoles, and consequently the deflection must be in the same direction. 

But a still more capital feature is presented by the discovery ofColonel Sabine, that the deflection is in contrary directions at theCape of Good Hope, at the epoch of the two equinoxes. This arises fromthe great angle made by the magnetic meridian at this place, with theterrestrial meridian--the variation being by Barlow's tables, 30° to thewestward. The sun varies in declination 47° throughout the year. At thesouthern solstice, therefore the radial stream strikes the circularcurrent on the southern side, and deflects it towards the equator, rendering the declination to the westward in the morning; but at thenorthern solstice the radial stream strikes the current on its northernside, and the deflection is eastward in the morning. And the vicinity ofthe Cape of Good Hope is, perhaps, the only part of the world where thisanomaly will obtain; as it is necessary not only that the declinationshall be considerable, but also that the latitude shall not be verygreat. 

Observation also determines that the amount of the horary variationincreases with the latitude. Near the equator, according to Humboldt, itscarcely amounts to three or four minutes, whilst it is from thirteen tofourteen minutes in the middle of Europe. The theory explains this also;for as the circles recede from the equator, the angles made by theirplanes with the direction of the radial stream increases, and hence theforce of deflection is greater, and the effect is proportioned to thecause. We have also a satisfactory explanation of the fact that therehas not yet been discovered a line of _no variation of horarydeclination_ as we might reasonably anticipate from the fact that thedeclinations are in _contrary directions_ in the northern and southernhemisphere. This is owing to the ever-varying declination of the sun. There would be such a line, no doubt, if the axis of the earth wereperpendicular to the plane of the orbit, and the magnetic pole coincidedwith the pole of rotation: for then the equator would be such a line. 

MAGNETIC STORMS. 

But there are also irregular fluctuations in the direction of themagnetic needle. These depend on the moon, and are caused by the passageof the vortices over or near to the place of observation. The action ofthese vortices is proved to be of variable force, whether arising fromatmospheric conditions, or due to an increased activity of the etherealmedium throughout the whole system, is at present immaterial. They dovary, and sometimes the passage of a vortex will deflect the needle awhole degree. At other times, there are magnetic storms extending over agreat part of the earth's surface; but there is reason to suppose, thatthe extent of these storms has been over estimated. Thus, on the 25th ofSeptember, 1841, a magnetic storm was observed in Toronto, and at thesame time there was one felt at the Cape of Good Hope. There is no greatmystery in this. If we suppose the axis of the central vortex, forinstance, to have passed Toronto in latitude 43° 33′ north, in ordinarypositions of the moon, in her orbit, the southern portion of the axiswould be in 33° or 34° south latitude, and consequently would havepassed near the Cape of Good Hope on the same night. Now, we certainlycould not expect the northern portion of the vortex to be intenselyactive, without the southern portion being in the same state ofactivity. That this is the true explanation is proved by magnetic stormsin the same hemisphere being comparatively limited in extent; as, according to Gauss and Weber, magnetic storms which were simultaneouslyfelt from Sicily to Upsala, did not extend from Upsala to Alten. Stillit would not be wonderful if they were felt over a vast area ofthousands of miles as a consequence of _great_ disturbance in theelasticity of the ether in the terral vortex; as the solid earth must bepermeable to all its motions, and thus be explicable on the generalprinciples we have advanced. 

But besides these variations which we have mentioned, there are changessteadily going on, by which the isodynamic, isogonic and isoclinic linesare permanently displaced on the surface of our planet. These must beattributed to changes of temperature in the interior of the globe, andto the direction in the progress of subterranean fires, which it mayalso be expected will change the isogeothermal lines. But there arechanges, which although of long period, are yet periodic, one of whichis obviously due to the revolution of the lunar nodes in eighteen and ahalf years, and the revolution of the apogee in nine years. The first iscontinually changing the obliquity of the axis of the vortex, and theyboth tend to limit the vortices in their extreme latitudes; but theplanet Jupiter has an indirect influence, which is probably equal, ifnot greater, than the action of the moon, in changing the magneticdeclination. 

From the investigations of Lamont, it would appear, that the period ofthe variations of magnetic declination is about 10⅓ years, while, more recently, R. Wolfe has suggested the connection between thisvariation and the solar spots, and assigns a period of 11. 11 years, andremarks, that it "corresponds more exactly with the variations inmagnetic declination than the period of 10⅓ years established byLamont. The magnetic variations accompany the solar spots, not only intheir regular changes, but even in their minor irregularities: thislatter fact is itself sufficient to prove definitely the importantrelations between them. "[28]

As the planet Jupiter exerts the greatest influence on the sun, inforcing the centre from the mechanical centre of the system, thelongitude of the sun will in a great measure depend on the position ofthis planet; and, in consequence, the sun will generally revolve aroundthis centre in a period nearly equal to the period of Jupiter. Thesidereal period of Jupiter is about twelve years, but the action of theother planets tend to shorten this period (at least, that has been theeffect for the last twenty or thirty years), and bring it nearly to theperiod assigned by M. Wolfe to the variations in the magneticdeclinations. As this has its influence on the radial stream, and theradial stream on the declination, we see at once the connection betweenthem. When we come to a consideration of the solar spots, we shallexhibit this influence more fully. 

AURORA BOREALIS. 

Let us now examine another phenomenon. The Aurora Borealis has beengenerally considered to be in some way connected with the magnetism ofthe earth, and with the position of the magnetic pole. It is certainthat the appearance of this meteor does affect the needle in a way notto be mistaken, and (although not invariably) the vertex of the luminousarch will usually conform to the magnetic meridian. Yet (and this isworthy of attention), the observations made in the North PolarExpeditions[29] "appear to prove, that in the immediate vicinity of themagnetic pole the development of light is not in the least degree moreintense or frequent than at some distance from it. " In fact, as theAmerican magnetic pole is, as stated, in latitude 73°, the centralvortex will seldom reach so high, and, consequently, the aurora oughtat such times to be more frequent in a lower latitude. In a late work byM. De la Rive, this gentleman expresses the opinion, that the cause ofthe aurora is not due to a radiation of polar magnetism, but to a purelyelectrical action. [30] His explanation, however, is not so satisfactoryas his opinion. Now, we have examined numerous cases of auroraldisplays, and never yet found one which could not be legitimatelyreferred to the action of ethereal vortices. Generally, the aurora willnot be visible, when the upper surface of the atmosphere of thatlatitude in which the vortex is known to be (reckoning in the directionof the magnetic meridian) is below the horizon, which shows that thebrightest portion is in the atmosphere. In latitude 41° even, it mayshow itself when the vortex is three days north, more frequently whenone or two days north; but when the vortex passes centrally, or south, it rarely is seen, and this is the only difficulty in explaining it bythe theory. But, when we reflect that the ether shoots out in straightlines, and at an angle corresponding to the magnetic dip, we are at noloss to perceive the reason of this. If each minute line composing thelight were seen endwise, it would be invisible; if there were millionssuch in the same position, they could add nothing to the general effect;but, when viewed sideways, the case would be different, there would be acontinued reduplication of ray upon ray, until in the range of somehundreds of miles an effect might be produced amounting to any degree ofintensity on record. Now, this is the case when the aurora isimmediately overhead, it will be invisible to those below, but may beseen by persons a hundred miles south; so, also, when it is to thesouth, it is too oblique to the line of vision to be seen, especially asall the rays to the northward of the observer can contribute nothing toincrease the effect. That it is of the nature of rays very muchdiffused, can hardly be doubted; and, therefore, if only of a few milesin depth, its impressions are too faint to be sensible. By referring tothe record of the weather in the second section of this work, an auroraldisplay will be found on July 12th, the central vortex having passed alittle to the northward the same evening, and the next day passing south_descending_. On that occasion the author saw an inclined column, inprofile, due east, and between himself and a line of bluffs and timber, about eight miles distant; And, he has not any doubt that the mass ofrays began where he stood. As in a shower, every drop, passing through aconical surface, whose axis passes through the sun and through the eye, contributes to form the apparently distant rainbow. 

The altitude of this meteor has been much exaggerated, especially ofthose rings or luminous arches, which are often detached completely fromthe luminous bank. On the 24th of May, a bright aurora was visible atOttawa, but the author's attention was engrossed by the most brilliantarch of light he had ever seen. It was all the time south of the zenith, and had no visible connection with the aurora north. At 9 hours, 59minutes, 30 seconds mean solar time, Arcturus was in the exact centre ofthe band, at which time it was very bright, and full 7° wide. At thesame time, Prof. G. W. Wheeler observed the aurora in Perryville, in theState of Missouri, only 1° of longitude to the westward, but did not seethe arch. [31] The difference of latitude between the two places being 3°30′, and the weather, as he states, clear and still, there is only onereason why he did not see the arch: it must have been too _low_, and hadbecome merged in the bank of light. At the time mentioned, the altitudeof Arcturus was 68° 30′, and, as Prof. Wheeler assigns only 10° as thealtitude of the bank, the maximum elevation of the arch, on thesupposition of its composing a part of the bank, was 43 miles. AtPerryville, the bank and streamers had disappeared at 10 o'clock. AtOttawa, the arch or bow disappeared at 10 h. 5 m. , differing only thefraction of a minute from the time at Perryville; but, the bank wasstill visible, but low and faint, the greatest altitude having been over30°. To show the rapid fluctuations in width and position of this bow, we will add a few of the minutes taken at the time with great care, inhopes some other observer had been equally precise. When first seen, there were three luminous patches, or elongated clouds of light; one inLeo, one in Bootes, and another in Ophinchus, all in line. This wasabout 9h. 15m. The times following are correct to 30 seconds:

 9h. 42m. 30s. Bow complete; south edge 2° north of Arcturus. 

 9 45 30 Northern edge diffuse south; edge bright, and well defined; 10° wide in zenith; north edge on Alphacca. 

 9 47 30 South edge 5° north of Arcturus; north edge close to Cor. Caroli. 

 9 53 30 Eastern half composed of four detached bands _shingling_ over each other. 

 58 30 Arcturus on south; bow narrower. 

 9 59 30 Arcturus in the middle of the band; very bright and regular in outline, and widest at the zenith. 

 10 0 30 Arcturus on northern edge; north side better defined than the southern. 

 10 2 0 Arcturus 1° north; very bright. 

 10 2 30 Gamma and Delta Leonis, northern edge. 

 10 3 Regulus on southern age; getting faint. 

 10 5 Fast fading away. 

 10 5 30 Scarcely visible; bank in north faint. 

This aurora was due to the _inner vortex ascending_, whose period was atthis time 28 days. 

There are several circumstances to be observed in this case. The bowbrightened and faded simultaneously with the aurora, and respected thevertex of the auroral bank, being apparently concentric with it. Thebow, therefore, depends on the same cause, but differs from the aurorain being limited to the _surface_ of the atmosphere in which the vortexhas produced a wave to the southward of its central path, as may beunderstood by inspecting Fig.  2, Sec.  1, --the figure representing thepolar current of the central vortex. On the 29th of May, 1840, [32] theauthor saw a similar phenomenon, at the same time of night, and passingover the same stars southward until it reached within 5° of Jupiter andSaturn, to which it was parallel. This atmospheric wave offers a greaterresistance to the passage of the ether: hence the light. On this accountit is, also, that when the passage of a vortex is attended by an auroraldisplay there will be no thunder-storm. There may be an increase ofwind; but the atmosphere at such times is too dry to make a violentstorm, and there is a silent restoration of the equilibrium, by theether passing through the dry atmosphere, without meeting anycondensable vapor, and becoming luminous on account of the greaterresistance of the air when unmixed with vapor. We thus see also theconnection between the aurora and the linear cirri, and we have atriumphant explanation of the fact, that when the observer is north ofthe northern limit of the vortices, he sees the aurora to the south andnot to the north; for, to see it to the northward, he would have to seeit in the same latitude as it appears in the south, and, consequently, have to see across twice the complement of the latitude. We thus see, also, why the temperature falls after an aurora; for, the passage ofelectricity in any shape, must have this effect on account of the greatspecific caloric of this fluid. We see, also, why the aurora should bemore frequent where the magnetic intensity is greatest and beconsequently invisible at the equator, and why the magnetic needle is sosensibly affected at the time of its occurrence. We may, perhaps, herebe allowed to allude to another phenomenon connected with terrestrialmagnetism and electricity. 

EARTHQUAKES. 

The awful and destructive concussions which sometimes are produced atgreat depths beneath the surface of the soil, would seem to indicatethat no force but that of electricity is adequate to account for thealmost instantaneous desolation of wide tracts of the earth's surface. But we do not mean to say that the action of the terral vortices, combined with the internal conditions of our planet, is the only cause;although it is far from improbable that the same activity of the ether, which generates through these vortices, the full fury of the hurricanein the tropics, may be simultaneously accompanied by a _subterranean_storm. And physicists are too rash to reject the evidence on which theconnection of the phenomena rests. 

In the extract given by Colonel Reid, in his "Law of Storms, " from SirGeorge Rodney's official report of the great hurricane of 1780, it isstated, that, "Nothing but an earthquake could have occasioned the_foundations_ of the strongest buildings to be rent; and I am convincedthat the violence of the wind must have prevented the inhabitants fromfeeling the earthquake which certainly attended the storm. "[33] Again, in the Savannah-la-Mar hurricane, which occurred the same year andmonth, the Annual Register, published at Jamaica, states, that at thesame time, "a smart shock of an earthquake was felt. " The generalserenity of equatorial regions is due to the fact that they are beyondthe limit of the vortices, as in Peru, where neither rain nor lightningnor storm is ever seen. Thunder and rain, without storms, however, arecommon in other tropical countries, also out of the reach of thevortices. But even in those parts, (as the Antilles, ) lying in the trackof these vortices, the weather is not as _frequently_ disturbed as inhigher latitudes. The storms of the Antilles, when they do occur, however, are fearful beyond any conception, showing the presence of somecause, auxiliary to the ordinary disturbing action of the vortices, which, when simultaneously occurring, adds tremendously to their force. 

That earthquakes are preceded _sometimes_ by a peculiar haziness andoppressiveness, similar to that which sometimes precedes a storm, is acurrent opinion in volcanic countries. And Humboldt, who doubts theconnection, has to confess that sudden changes of weather have_succeeded_ violent earthquakes, and that "during the great earthquakeof Cumana, he found the inclination of the needle was diminished 48′. "He also mentions the simultaneous occurrence of shocks, fromearthquakes, and a clap of thunder, and the agitation of theelectrometer during the earthquake, which lasted from the 2d of April tothe 17th of May, 1808; but concluding that "these indications presentedby clouds, by modifications of atmospheric electricity, or by calms, cannot be regarded as _generally_ or _necessarily_ connected withearthquakes, since in Peru, Canada, and Italy, earthquakes are observed, along with the purest and clearest skies, and with the freshest land andsea breezes. But if no meteorological phenomena indicates the comingearthquake, either on the morning of the shock or a few days previously, the influence of certain periods of the year, (the vernal and autumnalequinoxes, ) the commencement of the rainy season in the tropics, afterlong drought, cannot be overlooked, even though the genetic connectionof meteorological processes, with those going on in the interior of ourglobe, is still enveloped in obscurity. "[34]

It is at the equinoxes that the earth changes her distances from the sunmost rapidly, and whether she is passing from her perihelion or fromher aphelion, the density of the ether externally is changing in thesubduplicate ratio of these distances and consequently at these timesthere will be the greatest disturbance of the electric equilibrium. Howfar our views of the internal structure of our globe, (considered alonga diameter as a solid crust, then a fused mass separated from the lowerocean by another solid crust, and separated from a similar arrangementon the opposite side by an interposed mass of water, perhaps alsopossessing a solid nucleus, ) may affect this question, is difficult tosay; but that the agent is electric, appears highly probable; and veryrecently it has been discovered, by M. Ratio Menton, that a piece ofiron, suspended by attraction to a magnet, will fall on the approach ofan earthquake; thus indicating that the power of the magnet istemporarily weakened by the action of some disturbing force. 

FOOTNOTES:

[22] Hum. Cosmos, art Aerolites. 

[23] We shall in all cases use this abbreviation for the extremelyawkward word zodiacal. 

[24] It is here assumed, that all the vortices are at their apogee atthe same time, and, consequently, they lie in different longitudes, butthe central being between, its position is taken for the averageposition of the three. 

[25] It is far from improbable that the effect produced in one zone ofclimate, may be reversed in another, from the nature of the cause. 

[26] That the 11th, 12th, and 13th of May should recede 2° intemperature as determined by Mædler from observations of 86 years, at atime when the power of the sun so rapidly augments, is stronglyconfirmatory of the theory. See _Cosmos_, p.  121. 

[27] Plucker first discovered that a plate of tourmaline suspended withits axis vertical, set axial. 

[28] Silliman's Journal for March and April, 1853. 

[29] Humboldt, _Cosmos_ p.  193, London ed. 

[30] See Silliman's Journal for September, 1853. 

[31] See Silliman's Journal for September, 1853. 

[32] This was the central vortex ascending. 

[33] Reid's Law of Storms, p.  350. 

[34] Humboldt, _Cosmos_, p.  203. 

SECTION FOURTH. 

THE SOLAR SPOTS. 

We have yet many phenomena to investigate by the aid of the theory, andwe will develop them in that order which will best exhibit their mutualdependence. The solar spots have long troubled astronomers, and to thisday no satisfactory solution of the question has been proposed; but weshall not examine theories. It is sufficient that we can explain them onthe same general principles that we have applied to terrestrialphenomena. There can be but little doubt about the existence of a solaratmosphere, and, reasoning from analogy, the constituent elements of thesun must partake of the nature of other planetary matter. That there arebodies in our system possessing the same elements as our earth, isproved by the composition of meteoric masses, which, whether they areindependent bodies of the system, or fragments of an exploded planet, orprojected from lunar volcanoes, is of little consequence; they show thatthe same elements are distributed to other bodies of the system, although not necessarily in the same proportions. The gaseous matter ofthe sun's atmosphere may, therefore, be safely considered as vaporscondensable by cold, and the formation of vortices over the surface ofthis atmosphere, brings down the ether, and causes it to interminglewith this atmosphere. But, from the immensely rapid motion of the polarcurrent of the solar vortex, this ether may be considered to enter theatmosphere of the sun with the temperature of space. 

Sir John Herschel, in commenting on the theory of Mr. Redfield beforethe British Association, convened at Newcastle in 1838, [35] suggested ananalogy to terrestrial hurricanes, from a suspected rotation andprogressive motion in these spots. From their rapid formation, change ofshape, and diameter, this view is allowable, and, taken in conjunctionwith the action of the ethereal currents, will account for all thephenomena. The nucleus of the spot is dense, like the nucleus of a stormon the earth, and surrounded by a penumbon precisely as our storms arefringed with lighter clouds, permitting the light of the sun topenetrate. And, it has been observed, that these spots seem to followone another in lines on the same parallel of solar latitude (or nearlythe same), exactly as we have determined the action of the vortices onthe surface of the earth from observation. These spots are never foundin very high latitudes--not much above 30° from the solar equator. If weconsider this equator to be but slightly inclined to the plane of thevortex, this latitude would be the general position of the lateral solarvortices, and, in fact, be confined principally to a belt on each sideof the equator, between 15° and 30° of solar latitude, rather than atthe equator itself. This, it is needless to say, is actually the case. But, a more capital feature still has been more recently brought tolight by observation, although previously familiar to the author, who, in endeavoring to verify the theory, seriously injured his sight, byobserving with inadequate instrumental means. This is the periodicity ofthe spots. 

We have already observed, that there is reason to suppose that theaction of the inner vortex of the earth is probably greater than that ofthe outer vortex, on account of the conflicting currents by which it iscaused. And the full development of this vortex requires, that thecentral vortex or mechanical axis of the system shall be nearlytangential to the surface. In this position, the action of the centralvortex is itself at a maximum; and, when the planets of the system areso arranged as to produce this result, we may expect the greatest numberof spots. If the axis or central vortex approaches to coincidence withthe axis of the sun, the lateral vortices disappear, and the centralvortex being then perpendicular to the surface, is rendered ineffective. Under these circumstances, there will be no spots on the sun's disc. When, on the other hand, all the planets conspire at the same side toforce the sun out from the mechanical centre of the system, the surfaceis too distant to be acted on by the central vortex, and the lateralvortices are also thrown clear of the sun's surface, on account of thegreater velocity of the parts of the vortex, in sweeping past the bodyof the sun. In this case, there will be but few spots. The case in whichthe axis of the vortex coincides with the axis of the sun, is much moretransient than the first position, and hence, although the intervalbetween the maxima will be tolerably uniform, there will be anirregularity between a particular maximum, and the preceding andsubsequent minimum. 

The following table exhibits the solar spots, as determined by Schwabe, of Dessau:

 Year of observation. Groups of spots observed. Number of days. 1826 118 277 1827 161 273 1828 225 282 1829 199 244 1830 190 217 1831 149 239 1832 84 270 1833 33 267 1834 51 273 1835 173 244 1836 272 200 1837 333 168 1838 282 202 1839 162 205 1840 152 263 1841 102 283 1842 68 307 1843 34 324

Previous to the publication of this table, the author had inferred thenecessity of admitting the existence of another planet in the solarsystem, from the phenomenon of which we are speaking. He found asufficient correspondence between the minima of spots to confirm theexplanation given by the theory, and this was still more confirmed bythe more exact determination of Schwabe; yet there was a littlediscrepancy in the synchronous values of the ordinates, when the theorywas graphically compared with the table. Previous to the discovery ofNeptune, the theory corresponded much better than afterwards, and as nodoubt could be entertained that the anomalous movements of Uranus werecaused by an exterior planet, he adopted the notion that there were twoplanets exterior to Uranus, whose positions at the time were such, thattheir mechanical affects on the system were about equal and contrary. Consequently, when Neptune became known, the existence of another planetseemed a conclusion necessary to adopt. Accordingly, he calculated theheliocentric longitudes and true anomalies, and the values of radiusvector, for all the planets during the present century, but not havingany planetary tables, he contented himself with computing for thenearest degree of true anomaly, and the nearest thousand miles ofdistance. Then by a composition and resolution of all the forces, hededuced the radius vector of the sun, and the longitude of his centre, for each past year of the century. It was in view of a littleoutstanding discrepancy in the times of the minima, as determined bytheory and observation, that he was induced to consider as almostcertain the existence of a theoretical planet, whose longitude, in 1828, was about 90°, and whose period is from the theory about double that ofNeptune. And for convenience of computation and reference, he has beenin the habit of symbolizing it by a volcano. The following table of theradii vectores of the sun, and the longitude of his centre, for theyears designated in Schwabe's table, is calculated from the followingdata for each planet:

 Long. Of Planets. Masses. Mean distances. Eccentricities. Perihelion. ♃ 1/1648 494. 800. 000 0. 0481 11° ♄ 1/3310 907. 162. 000 0. 0561 89 ♅ 1/23000 1824. 290. 000 0. 0166 167 ♆ 1/20000 2854. 000. 000 0. 0088 0 ⊿ 1/28000 4464. 000. 000

 No. Of spots in Dates. Rad. Vector. Sun's long. Ordinates. Schwabe's table. Jan. 1, 1826 528, 000 320° +  84 118 " 1827 480, 000 339 +  36 161 " 1828 432, 000 352 -  12 Max. 225 Max. " 1829 397, 000 38 -  47 199 " 1830 858, 000 71 -  86 190 " 1831 324, 000 104 - 120 149 " 1832 311, 000 144 - 133 84 " 1833 300, 000 183 - 144 Min. 33 Min. " 1834 307, 000 220 - 137 51 " 1835 338, 000 263 - 106 173 " 1836 380, 000 302 -  55 272 " 1837 419, 000 337 +  25 Max. 333 Max. " 1838 488, 000 3 +  44 282 " 1839 651, 000 29 + 107 162 " 1840 632, 000 51 + 188 152 " 1841 680, 000 80 + 236 102 " 1842 730, 000 105 + 286 68 " 1843 160, 000 128 + 322 34 Min. " 1844 188, 000 152 + 339 Min. 52 " 1845 772, 000 174 + 328 114 " 1846 728, 000 196 + 284 157 " 1847 660, 000 218 + 216 " 1848 563, 000 240 + 119 Observed. Max. " 1849 447, 000 261 +  3 Max. " 1850 309, 000 283 - 135 " 1851 170, 000 323 - 274 " 1852 53, 000 41 - 391 Min. " 1853 167, 000 133 - 277 " 1854 315, 000 160 - 129 " 1855 475, 000 183 +  31 Max. " 1856 611, 000 203 + 167 " 1857 720, 000 225 + 276

It is necessary to observe here, that the values of the numbers inSchwabe's table are the numbers for the whole year, and, therefore, the1st of July would have been a better date for the comparison; but, asthe table was calculated before the author was cognizant of the fact, and being somewhat tedious to calculate, he has left it as it was, viz. , for January 1st of each year. Hence, the minimum for 1843 appears aspertaining to 1844. The number of spots ought to be inversely as theordinates approximately--these last being derived from the RadiiVectores minus, the semi-diameter of the sun = 444, 000 miles. 

In passing judgment on this relation, it must also be borne in mind, that the recognized masses of the planets cannot be the true masses, ifthe theory be true. Both sun and planets are under-estimated, yet, asthey are, probably, all to a certain degree proportionally undervalued, it will not vitiate the above calculation much. 

The spots being considered as solar storms, they ought also to vary innumber at different times of the year, according to the longitude of theearth and sun, and from their transient character, and the slow rotationof the sun, they ought, _ceteris paribus_, to be more numerous when theproducing vortex is over a visible portion of the sun's surface. 

The difficulty of reconciling the solar spots, and their periodicity toany known principle of physics, ought to produce a more tolerant spiritamongst the scientific for speculations even which may afford theslightest promise of a solution, although emanating from the humblestinquirer after truth. The hypothesis of an undiscovered planet, exteriorto Neptune, is of a nature to startle the cautions timidity of many;but, if the general theory be true, this hypothesis becomes extremelyprobable. We may not have located it exactly. There may be even two suchplanets, whose joint effect shall be equivalent to one in the positionwe have assigned. There may even be a comet of great mass, capable ofproducing an effect on the position of the sun's centre (although itfollows from the theory that comets have very little mass). Yet, in viewof all these suppositions, there can be but little doubt that the solarspots are caused by the solar vortices, and these last made effective onthe sun by the positions of the great planets, and, therefore, we haveindicated a new method of determining the existence and position of allthe planets exterior to Neptune. On the supposition that there is onlyone more in the system, from its deduced distance and mass, it willappear only as a star of the eleventh magnitude, and, consequently, willonly be recognizable by its motion, which, at the greatest, will only beten or eleven seconds per day. 

MASSES OF THE SUN AND PLANETS. 

We have alluded to the fact of the radial stream of the sun necessarilydiminishing the sun's power, and, consequently, diminishing his apparentmass. The radial stream of all the planets will do the same, so thateach planet whose mass is derived from the periodic times of thesatellites, will also appear too small. But, there is also a greatprobability that some modification must be made in the wording of theNewtonian law. The experiments of Newton on the pendulum, with everyvariety of substance, was sufficient justification to entitle him toinfer, that inertia was as the weight of matter universally. But, therewas one condition which could not be observed in experimenting on thesesubstances, viz. , the difference of temperature existing between theinterior and surface of a planet. 

We have already expressed the idea, that the cause of gravity has nosuch mysterious origin as to transcend the power of man to determine it. But that, on the contrary, we are taught by every analogy around us, aswell as by divine precept, to use the visible things of creation asstepping stones to the attainment of what is not so apparent. That wehave the volume of nature spread out in tempting characters, inviting usto read, and, assuredly, it is not so spread in mockery of man's limitedpowers. As science advances, strange things, it is true, are brought tolight, but the more _rational_ the queries we propound, in every casethe more satisfactory are the answers. It is only when man consults theoracle in irrational terms that the response is ambiguous. Alchemy, withits unnatural transmutations, has long since vanished before theincreasing light. Why should not attraction also? Experience andexperiment, if men would only follow their indications, are consistentlyenforcing the necessity of erasing these antiquated chimeras from thebook of knowledge; and inculcating the great truth, that the physicaluniverse owes all its endless variety to differences in the form, size, and density of planetary atoms in motion, according to simple mechanicalprinciples. These, combined with the existence of an all-pervadingmedium filling space, between which and planetary matter no bond ofunion subsists, other than that which arises from a continualinterchange of motion, are the materials from which the gems of natureare elaborated. But, simplicity of means is what philosophy has everbeen reluctant to admit, preferring rather the occult and obscure. 

If action be equal to reaction, and all nature be vibrating with motion, these motions must necessarily interfere, and some effect should beproduced. A body radiating its motion on every side into a physicalmedium, produces waves. These waves are a mechanical effect, and thebody parts with some of its motion in producing them; but, shouldanother body be placed in juxtaposition, having the same motion, theopposing waves neutralize each other, and the bodies lose no motion fromtheir contiguous sides, and, therefore, the reaction from the oppositesides acts as a propelling power, and the bodies approach, or tend toapproach each other. If one body be of double the inertia, it moves onlyhalf as far as the first; then, seeing that this atomic motion isradiated, the law of force must be directly as the mass, and inverselyas the squares of the distances. There may be other atomic vibrationsbesides those which we call light, heat, and chemical action, yet thejoint effect of all is infinitesimally small, when we disregard theunited _attraction_ of all the atoms of which the earth is composed. The_attraction_ of the whole earth at the surface causes bodies to fall 16feet the first second of time; but, if two spheres of ice of one footdiameter, were placed in an infinite space, uninfluenced by othermatter, and only 16 feet apart, they would require nearly 10, 000 yearsto fall together by virtue of their mutual attraction. Our conceptions, or, rather, our misconceptions, concerning the force of gravity, arisesfrom our forgetting that every pound of matter on the earth contributesits share of the force which, in the aggregate, is so powerful. Hence, the cause we have suggested, is fully adequate to account for thephenomena. Whether the harmony of vibrations between two bodies may nothave an influence in determining the amount of interference, and, consequently, produce _some_ difference between the gravitating massand its inertia, is a question which, no doubt, will ultimately besolved; but this harmony of vibrations must depend, in some degree, onthe atomic weight, temperature, and intensity of atomic motion. 

That a part of the mass of the earth is _latent_ may be inferred fromcertain considerations: 1st, from the discrepancies existing in theresults obtained for the earth's compression by the pendulum and byactual measurement; and, 2d, from the irregularity of that compressionin particular latitudes and longitudes. The same may also be deducedfrom the different values of the moon's mass as derived from differentphenomena, dependent on the law of gravitation. Astronomers havehitherto covered themselves with the very convenient shield of errors ofobservation; but, the perfection of modern instruments now demand abetter account of all outstanding discrepancies. The world requires itof them. 

The mass of the moon comes out much greater by our theory than nutationgives. The mass deduced from the theory is only dependent on therelative inertiæ of the earth and moon. That given by nutation dependson gravity. If, then, a part of the mass be latent, nutation will givetoo small a value. But, in addition to this, we are justified indoubting the strict wording of the Newtonian law, deriving our authorityfrom the very foundation stone of the Newtonian theory. 

It is well known that Newton suspected that the moon was retained in herorbit by the same force which is usually called weight upon the surface, sixteen years before the fact was confirmed, by finding a correspondencein the fall of the moon and the fall of bodies on the earth. Usually, inall elementary works, this problem is considered accurately solved. Having formed a different idea of the mechanism of nature, this factpresented itself as a barrier beyond which it was impossible to pass, until suspicions, derived from other sources, induced the author toinquire: Whether the phenomenon did exactly accord with the theory? Weare aware that it is easy to place the moon at such a distance, that theresult shall strictly correspond with the fact; but, from the parallax, as derived from observation (and if this cannot be depended oncertainly, no magnitudes in astronomy can), we find, _that the moon doesnot fall from the tangent of her orbit, as much as the theory requires_. As this is of vital importance to the integrity of the theory we areadvocating, we have made the computation on Newton's own data, exceptsuch as were necessarily inaccurate at the time he wrote; and we havedone it arithmetically, without logarithmic tables, that, if possible, no error should creep in to vitiate the result. We take the moon'selements from no less an authority than Sir John Herschel, as well asthe value of the earth's diameter. 

 Mass of the moon 1/80 Mean distance in equatorial radii 59. 96435 Sidereal period in seconds 2360591

The vibrations of the pendulum give the force of gravity at the surfaceof the earth, and it is found to vary in different latitudes. Theintensity in any place being as the squares of the number of vibrationsin a given time. This inequality depends on the centrifugal force ofrotation, and on the spheroidal figure of the earth due to thatrotation. At the equator the fall of a heavy body is found to be16. 045223 feet, per second, and in that latitude the squares of whosesine is ⅓, it is 16. 0697 feet. The effect in this last-named latitudeis the same as if the earth were a perfect sphere. This does not, however, express the whole force of gravity, as the rotation of theearth causes a centrifugal tendency which is a maximum at the equator, and there amounts to 1/289 of the whole gravitating force. In otherlatitudes it is diminished in the ratio of the squares of the cosines ofthe latitude; it therefore becomes 1/434 in that latitude the square ofwhose sine is ⅓. Hence the fall per second becomes 16. 1067 feet forthe true gravitating force of the earth, or for that force which retainsthe moon in her orbit. 

The moon's mean distance is 59. 96435 equatorial radii of the earth, which radius is, according to Sir John Herschel, 20. 923. 713feet. Her mean distance as derived from the parallax is not to beconsidered the radius vector of the orbit, inasmuch as the earth alsodescribes a small orbit around the common centre of gravity of the earthand moon; neither is radius vector to be considered as her distance fromthis common centre; for the attracting power is in the centre of theearth. But the mean distance of the moon moving around a movable centre, is to the same mean distance when the centre of attraction is fixed, asthe sum of the masses of the two bodies, to the first of two meanproportionals between this sum and the largest of the two bodiesinversely. (Vid. Prin. Prop. 60 Lib. Prim. ) The ratio of the massesbeing as above 80 to 1 the mean proportional sought is 80. 666 and inthis ratio must the moon's mean distance be diminished to get the forceof gravity at the moon. Therefore as 81 is to 80. 666, so is 59. 96435 to59. 71657 for the moon's distance in equatorial radii of the earth. Multiply this last by 20. 923, 713 to bring the semi-diameter of the lunarorbit into feet = 1. 249. 492. 373, and this by 6. 283185, the ratio of thecircumference to the radius, gives 7. 850. 791. 736 feet, for the meancircumference of the lunar orbit. 

Further, the mean sidereal period of the moon is 2360591 seconds and the1/2360591th part of 7. 850. 791. 736 is the arc the moon describes in onesecond = 3325. 77381 feet, the square of which divided by the diameterof the orbit, gives the fall of the moon from the tangent or versedsize of that arc. 

 1106771. 36876644 = ---------------- = 0. 004426106 feet. 2498984746

This fraction is, however, too small, as the ablatitious action of thesun diminishes the attraction of the earth on the moon, in the ratio of178 29/40 to 177 29/40. So that we must increase the fall of the moonin the ratio of 711 to 715, and hence the true fall of the moon from thetangent of her orbit becomes 0. 00451 feet per second. 

We have found the fall of a body at the surface of the earth, consideredas a sphere, 16. 1067 feet per second, and the force of gravitydiminishes as the squares of the distances increases. The polar diameterof the earth is set down as 7899. 170 miles, and the equatorial diameter7925. 648 miles; therefore, the mean diameter is 7916. 189 miles. [36] Sothat, reckoning in mean radii of the earth, the moon's distance is59. 787925, which squared, is equal to 3574. 595975805625. At one meanradius distance, that is, at the surface, the force of gravity, or fallper second, is as above, 16. 1067 feet. Divide this by the square of thedistance, it is 16. 1067/3574. 595975805625 = 0. 0045058 feet for the forceof gravity at the moon. But, from the preceding calculation, it appears, that the moon only falls 0. 0044510 feet in a second, showing adeficiency of 1/82d part of the principal force that retains the moon inher orbit, being more than double the whole disturbing power of the sun, which is only 1/178th of the earth's gravity at the moon; yet, on this1/178th depends the revolution of the lunar apogee and nodes, and allthose variations which clothe the lunar theory with such formidabledifficulties. The moon's mass cannot be less than 1/80, and if weconsider it greater, as it no doubt is, the results obtained will bestill more discrepant. Much of this discrepancy is owing to theexpulsive power of the radial stream of the terral vortex; yet, it maybe suspected that the effect is too great to be attributed to this, and, for this reason, we have suggested that the fused matter of the moon'scentre may not gravitate with the same force as the exterior parts, andthus contribute to increase the discrepancy. 

As there must be a similar effect produced by the radial stream of everyvortex, the masses of all the planets will appear too small, as derivedfrom their gravitating force; and the inertia of the sun will also begreater than his apparent mass; and if, in addition to this, there be aportion of these masses latent, we shall have an ample explanation ofthe connection between the planetary densities and distances. We musttherefore inquire what is the particular law of force which governs theradial stream of the solar vortex. It will be necessary to enter intothis question a little more in detail than our limits will justify; butit is the resisting influence of the ether, and its consequences, whichwill appear to present a vulnerable point in the present theory, and tobe incompatible with the perfection of astronomical science. 

LAW OF DENSITY IN SOLAR VORTEX. 

Reverting to the dynamical principle, that the product of every particleof matter in a fluid vortex, moving around a given axis, by its distancefrom the centre and angular velocity, must ever be a constant quantity, it follows that if the ethereal medium be uniformly dense, the periodictimes of the parts of the vortex will be directly as the distances fromthe centre or axis; but the angular velocities being inversely as thetimes, the absolute velocities will be equal at all distances from thecentre. 

Newton, in examining the doctrine of the Cartesian vortices, supposesthe case of a globe in motion, gradually communicating that motion tothe surrounding fluid, and finds that the periodic times will be in theduplicate ratio of the distances from the centre of the globe. He andhis successors have always assumed that it was impossible for theprinciple of gravity to be true, and a Cartesian plenum also;consequently, the question has not been fairly treated. It is true thatDescartes sought to explain the motions of the planets, by themechanical action of a fluid vortex _solely_; and to Newton belongs theglorious honor of determining, the existence of a centripetal force, competent to explain these motions mathematically, (but not physically, )and rashly rejected an intelligible principle for a miraculous virtue. If our theory be true, the visible creation depends on the existence ofboth working together in harmony, and that a physical medium isabsolutely necessary to the existence of gravitation. 

If space be filled with a fluid medium, analogy would teach us that itis in motion, and that there must be inequalities in the direction andvelocity of that motion, and consequently there must be vortices. And ifwe ascend into the history of the past, we shall find ample testimonythat the planetary matter now composing the members of the solar system, was once one vast nebulous cloud of atoms, partaking of the vorticosemotion of the fluid involving them. Whether the gradual accumulation ofthese atoms round a central nucleus from the surrounding space, and thushaving their tangential motion of translation converted into vorticosemotion, first produced the vortex in the ether; or whether the vortexhad previously existed, in consequence of conflicting currents in theether, and the scattered atoms of space were drawn into the vortex bythe polar current, thus forming a nucleus at the centre, as a necessaryresult of the eddy which would obtain there, is of little consequence. The ultimate result would be the same. A nucleus, once formed, wouldgive rise to a central force, tending more and more to counteract thecentripulsive power of the radial stream; and in consequence of thiscontinually increasing central power, the heaviest atoms would be bestenabled to withstand the radial stream, while the lighter atoms might becarried away to the outer boundaries of the vortex, to congregate atleisure, and, after the lapse of a thousand years, to again face theradial stream in a more condensed mass, and to force a passage to thevery centre of the vortex, in an almost parabolic curve. That space isfilled with isolated atoms or planetary dust, is rendered very probableby a fact discovered by Struve, that there is a gradual extinction inthe light of the stars, amounting to a loss of 1/107 of the whole, inthe distance which separates Sirius from the sun. According to Struve, this can be accounted for, "by admitting as very probable that space isfilled with an _ether_, capable of intercepting in some degree thelight. " Is it not as probable that this extinction is due to planetarydust, scattered through the pure ether, whose vibrations convey thelight, --the material atoms of future worlds, --the debris of dilapidatedcomets? Does not the Scripture teach the same thing, in asserting thatthe heavens are not clean?

The theory of vortices has had many staunch supporters amongst thosedeeply versed in the science of the schools. The Bernoullis proposedseveral ingenious hypothesis, to free the Cartesian system from theobjections urged against it, viz. : that the velocities of the planets, in accordance with the three great laws of Kepler, cannot be made tocorrespond with the motion of a fluid vortex; but they, and all others, gave the vantage ground to the defenders of the Newtonian philosophy, byseeking to refer the principle of gravitation to conditions dependent onthe density and vorticose motion of the ether. When we admit that theether is imponderable and yet material, and planetary matter subject tothe law of gravitation, the objections urged against the theory ofvortices become comparatively trivial, and we shall not stop to refutethem, but proceed with the investigation, and consider that the ether isthe original source of the planetary motions and arrangements. 

On the supposition that the ether is uniformly dense, we have shown thatthe periodic times will be directly as the distances from the axis. Ifthe density be inversely as the distances, the periodic times will beequal. If the density be inversely as the square roots of the distances, the times will be directly in the same ratio. The celebrated J. Bernoulli assumed this last ratio; but seeking the source of motion inthe rotating central globe, he was led into a hypothesis at variancewith analogy. The ellipticity of the orbit, according to this view, was caused by the planet oscillating about a mean position, --sinkingfirst into the dense ether, --then, on account of superior buoyancy, rising into too light a medium. Even if no other objection could beurged to this view, the difficulty of explaining why the ether should bedenser near the sun, would still remain. We might make othersuppositions; for whatever ratio of the distances we assume for thedensity of the medium, the periodic times will be compounded of thosedistances and the assumed ratio. Seeing, therefore, that the periodictimes of the planets observe the direct ses-plicate ratio of thedistances, and that it is consonant to all analogy to suppose thecontiguous parts of the vortex to have the same ratio, we find that thedensity of the ethereal medium in the solar vortex, is directly as thesquare roots of the distances from the axis. 

Against this view, it may be urged that if the inertia of the medium isso small, as is supposed, and its elasticity so great, there can be nocondensation by centrifugal force of rotation. It is true that when wesay the ether is condensed by this force, we speak incorrectly. If in aninfinite space of imponderable fluid a vortex is generated, the centralparts are rarefied, and the exterior parts are unchanged. But in allfinite vortices there must be a limit, outside of which the motion isnull, or perhaps contrary. In this case there may be a cylindrical ring, where the medium will be somewhat denser than outside. Just as in water, every little vortex is surrounded by a circular wave, visible byreflection. As the density of the planet Neptune appears, from presentindications, to be a little denser than Uranus, and Uranus is denserthan Saturn, we may conceive that there is such a wave in the solarvortex, near which rides this last magnificent planet, whose ring wouldthus be an appropriate emblem of the peculiar position occupied bySaturn. This may be the case, although the probability is, that thedensity of Saturn is much greater than it appears, as we shall presentlyexplain. 

In order to show that there is nothing extravagant in the supposition ofthe density of the ether being directly as the square roots of thedistances from the axis, we will take a fluid whose law of density isknown, and calculate the effect of the centrifugal force, considered asa compressing power. Let us assume our atmosphere to be 47 miles high, and the compressing power of the earth's gravity to be 289 times greaterthan the centrifugal force of the equator, and the periodic time ofrotation necessary to give a centrifugal force at the equator equal tothe gravitating force to be 83 minutes. Now, considering the gravitatingforce to be uniform, from the surface of the earth upwards, and knowingfrom observation that at 18, 000 feet above the surface, the density ofthe air is only ½, it follows, (in accordance with the principle thatthe density is as the compressing force, ) that at 43½ miles high, or18, 000 feet _below_ the surface of the atmosphere, the density is only1/8000 part of the density at the surface of the earth. Let ustake this density as being near the limit of expansion, and conceive ahollow tube, reaching from the sun to the orbit of Neptune, and thatthis end of the tube is closed, and the end at the sun communicates withan inexhaustible reservoir of such an attenuated gas as composes theupper-layer of our atmosphere; and further, that the tube is infinitelystrong to resist pressure, without offering resistance to the passage ofthe air within the tube; then we say, that, if the air within the tubebe continually acted on by a force equal to the mean centrifugal forceof the solar vortex, reckoning from the sun to the orbit of Neptune, thedensity of the air at that extremity of the tube, would be greater thanthe density of a fluid formed by the compression of the ocean into onesingle drop. For the centrifugal force of the vortex at 2, 300, 000 milesfrom the centre of the sun, is equal to gravity at the surface of theearth, and taking the mean centrifugal force of the whole vortex asone-millionth of this last force; so that at 3, 500, 000 miles from thesurface of the sun, the density of the air in the tube (supposing itobstructed at that distance) would be double the density of theattenuated air in the reservoir. And the air at the extremity of thetube reaching to the orbit of Neptune, would be as much denser than theair we breathe, as a number expressed by 273 with 239 ciphers annexed, is greater than unity. This is on the supposition of infinitecompressibility. Now, in the solar vortex there is no physical barrierto oppose the passage of the ether from the centre to the circumference, and the density of the ethereal ocean must be considered uniform, exceptin the interior of the stellar vortices, where it will be rarefied; andthe rarefaction will depend on the centrifugal force and the length ofthe axis of the vortex. If this axis be very long, and the centrifugalvelocity very great, the polar influx will not be sufficient, and thecentral parts will be rarefied. We see, therefore, no reason why thedensity of the ether may not be three times greater at Saturn than atthe earth, or as the square roots of the distances directly. 

BODES' LAW OF PLANETARY DISTANCES. 

Thus, in the solar vortex, there will be two polar currents meeting atthe sun, and thence being deflected at right angles, in planes parallelto the central plane of the vortex, and strongest in that central plane. The velocity of expansion must, therefore, diminish from the divergenceof the radii, as the distances increase; but in advancing along theseplanes, the ether of the vortex is continually getting more dense, which operate by absorption or condensation on the radial stream; sothat the velocity is still more diminished, and this in the ratio of thesquare roots of the distances directly. By combining these two ratios, we find that the velocity of the radial stream will be in theses-plicate ratio of the distances inversely. But the force of thisstream is not as the velocity, but as the square of the velocity. The_force_ of the radial stream is consequently as the cubes of thedistances inversely, from the axis of the vortex, reckoned in the sameplane. If the ether, however, loses in velocity by the increasingdensity of the medium, it becomes also more dense; therefore the trueforce of the radial stream will be as its density and the square of itsvelocity, or directly as the square roots of the distances, andinversely as the cubes of the distances, or as the 2. 5 power of thedistances inversely. 

If we consider the central plane of the vortex as coincident with theplane of the ecliptic, and the planetary orbits, also, in the sameplane; and had the force of the radial stream been inversely as thesquare of the distances, there could be no disturbance produced by theaction of the radial stream. It would only counteract the gravitation ofthe central body by a certain amount, and would be exactly proportionedat all distances. As it is, there is an outstanding force as adisturbing force, which is in the inverse ratio of the square roots ofthe distances from the sun; and to this is, no doubt, owing, in part, the fact, that the planetary distances are arranged in the inverse orderof their densities. 

Suppose two planets to have the same diameter to be placed in the sameorbit, they will only be in equilibrium when their densities are equal. If their densities are unequal, the lighter planet will continuallyenlarge its orbit, until the force of the radial stream becomesproportional to the planets' resisting energy. This, however, is on thehypothesis that the planets are not permeable by the radial stream, which, perhaps, is more consistent with analogy than with the reality. And it is more probable that the mean atomic weight of a planet'selements tends more to fix the position of equilibrium for each. Underthe law of gravity, a planet may revolve at any distance from the sun, but if we superadd a centripulsive force, whose law is not that ofgravity, but yet in some inverse ratio of the distances, and this forceacts only superficially, it would be possible to make up in volume whatis wanted in density, and a lighter planet might thus be found occupyingthe position of a dense planet. So the planet Jupiter, respecting onlyhis resisting surface, is better able to withstand the force of theradial stream at the earth than the earth itself. To understand this, itis necessary to bear in mind, that, as far as planetary matter isconcerned, the earth would revolve in Jupiter's orbit in the sameperiodic time as Jupiter, under the law of gravity: but that, inreality, the whole of the gravitating force is not effective, and thatthe equilibrium of a planet is due to a nice balance of interferingforces arising from the planet's physical peculiarities. As in arefracting body, the density of the ether may be considered inversely asthe refraction, and this as the atomic weight of the refractingmaterial, so, also, in a planet, the density of the ether will beinversely in the same ratio of the density of the matter approximately. Hence, the density of the ether within the planet Jupiter is greaterthan that within the earth; and, on this ethereal matter, the sun has nopower to restrain it in its orbit, so that the centrifugal momentum ofJupiter would be relatively greater than the centrifugal momentum of theearth, were it also in Jupiter's orbit with the same periodic time. Hence, to make an equilibrium, the earth should revolve in a medium ofless density, that there may be the same proportion between the externalether, and the ether within the earth, as there is between the etheraround Jupiter and the ether within; so that the centrifugal tendency ofthe dense ether at Jupiter shall counteract the greater momentum of thedense ether within Jupiter; or, that the lack of centrifugal momentum inthe earth should be rendered equal to the centrifugal momentum ofJupiter, by the deficiency of the centrifugal momentum of the ether atthe distance of the earth. 

If then, the diameters of all the planets were the same (supposing theether to act only superficially), the densities would be as thedistances inversely;[37] for the force due to the radial stream is asthe square roots of the distance inversely, and the force due to themomentum, if the density of the ether within a planet be inversely asthe square root of a planet's distance, will also be inversely as thesquare roots of the distances approximately. We offer these views, however, only as suggestions to others more competent to grapple withthe question, as promising a satisfactory solution of Bode's empiricalformula. 

If there be a wave of denser ether cylindrically disposed around thevortex at the distance of Saturn, or between Saturn and Uranus, we seewhy the law of densities and distances is not continuous. For, if thelaw of density changes, it must be owing to such a ring or wave. Insidethis wave, the two forces will be inverse; but outside, one will beinverse, and the other direct: hence, there should also be a change inthe law of distances. As this change does not take place until we passUranus, it may be suspected that the great disparity in the density ofSaturn may be more apparent than real. The density of a planet is therelation between its mass and volume or extension, no matter what theform of the body may be. From certain observations of Sir Wm. Herschel--the Titan of practical astronomers--the figure of Saturn wassuspected to be that of a square figure, with the corners rounded off, so as to leave both the equatorial and polar zones flatter thanpertained to a true spheroidal figure. The existence of an unbroken ringaround Saturn, certainly attaches a peculiarity to this planet whichprepares us to meet other departures from the usual order. And when wereflect on the small density, and rapid rotation, the formation of thisring, and the figure suspected by Sir Wm. Herschel, it is neitherimpossible nor improbable, that there may be a cylindrical vacant spacesurrounding the axis of Saturn, or at least, that his solid parts may becylindrical, and his globular form be due to elastic gases and vapors, which effectually conceal his polar openings. And also, by dilating andcontracting at the poles, in consequence of inclination to the radialstream, (just as the earth's atmosphere is bulged out sufficiently toaffect the barometer at certain hours every day, ) give that peculiarityof form in certain positions of the planet in its orbit. Justice to SirWm. Herschel requires that _his_ observations shall not be attributed tooptical illusions. This view, however, which may be true in the case ofSaturn, would be absurd when applied to the earth, as has been donewithin the present century. From these considerations, it is at leastpossible, that the density of Saturn may be very little less, or evengreater than the density of Uranus, and be in harmony with the law ofdistances. 

It is now apparently satisfactorily determined, that Neptune is denserthan Uranus, and the law being changed, we must look for transneptuneanplanets at distances corresponding with the new law of arrangement. Butthere are other modifying causes which have an influence in fixing theprecise position of equilibrium of a planet. Each planet of the systempossessing rotation, is surrounded by an ethereal vortex, and eachvortex has its own radial stream, the force of which in opposing theradial stream of the sun, depends on the diameter and density of theplanet, on the velocity of rotation, on the inclination of its axis, andon the density of the ether at each particular vortex; but the numericalverification of the position of each planet with the forces we havementioned, cannot be made in the present state of the question. There isone fact worthy of note, as bearing on the theory of vortices inconnection with the rotation of the planets, viz. : that observation hasdetermined that the axial rotation and sidereal revolution of thesecondaries, are identical; thus showing that they are without vortices, and are motionless relative to the ether of the vortex to which theybelong. We may also advert to the theory of Doctor Olbers, that theasteroidal group, are the fragments of a larger planet which oncefilled the vacancy between Mars and Jupiter. Although this idea is notgenerally received, it is gathering strength every year by the discoveryof other _fragments_, whose number now amounts to twenty-six. If theidea be just, our theory offers an explanation of the great differencesobservable in the mean distances of these bodies, and which wouldotherwise form a strong objection against the hypothesis. For if theselittle planets be fragments, there will be differences of densityaccording as they belonged to the central or superficial parts of thequondam planet, and their mean distances must consequently vary also. 

There are some other peculiarities connecting the distances anddensities, to which we shall devote a few words. In the primordial stateof the system, when the nebulous masses agglomerated into spheres, thediameter of these nebulous spheres would be determined by the relationexisting between the rotation of the mass, and the gravitating force atthe centre; for as long as the centrifugal force at the equator exceededthe gravitating force, there would be a continual throwing off of matterfrom the equator, as fast as it was brought from the poles, until abalance was produced. It is also extremely probable, (especially if theelementary components of water are as abundant in other planets as wehave reason to suppose them to be on the earth, ) that the condensationof the gaseous planets into liquids and solids, was effected in a _briefperiod of time_, [38] leaving the lighter and more elastic substances asa nebulous atmosphere around globes of semi-fluid matter, whosediameters have never been much increased by the subsequent condensationof their gaseous envelopes. The extent of these atmospheres being (inthe way pointed out) determined by the rotation, their subsequentcondensation has not therefore changed the original rotation of thecentral globe by any appreciable quantity. The present rotation of theplanets, is therefore competent to determine the former diameters of thenebulous planets, _i. E. _, the limit where the present central forcewould be balanced by the centrifugal force of rotation. If we make thecalculation for the planets, and take for the unit of each planet itspresent diameter, we shall find that they have condensed from theiroriginal nebulous state, by a quantity dependent on the distance, fromthe centre of the system; and therefore on the original temperature ofthe nebulous mass at that particular distance. Let us make thecalculation for Jupiter and the earth, and call the original nebulousplanets the nucleus of the vortex. We find the Equatorial diameter ofJupiter's nucleus in equatorial diameters of Jupiter = 2. 21, and theequatorial diameter of the earth's nucleus, in equatorial diameters ofthe earth = 6. 59. Now, if we take the original temperature of thenebulous planets to be inversely, as the squares of the distances fromthe sun, and their volumes directly as the cubes of the diameters in theunit of each, we find that these cubes are to each other, in the inverseratio of the squares of the planet's distances; for, 2. 21³ : 6. 59³ :: 1² : 5. 2², showing that both planets have condensed equally, allowing for thedifference of temperature at the beginning. And we shall find, beginningat the sun, that the diameters of the nebulous planets, _ceterisparibus_, diminish outwards, giving for the nebulous sun a diameter of16, 000, 000 miles, [39] thus indicating his original great temperature. 

That the original nebulous planets did rotate in the same time as theydo at present, is proved by Saturn's ring; for if we make thecalculation, about twice the diameter of Saturn. Now, the diameter ofthe planet is about 80, 000 miles, which will also be the semi-diameterof the nebulous planet; and the middle of the outer ring has also asemi-diameter of 80, 000 miles; therefore, the ring is the equatorialportion of the original nebulous planet, and ought, on this theory, torotate in the same time as Saturn. According to Sir John Herschel, Saturn rotates in 10 hours, 29 minutes, and 17 seconds, and the ringrotates in 10 hours, 29 minutes, and 17 seconds: yet this is not theperiodic time of a satellite, at the distance of the middle of the ring;neither ought the rings to rotate in the same time; yet as far asobservation can be trusted, both the inner and outer ring do actuallyrotate in the same time. The truth is, the ring rotates too fast, if wederive its centrifugal force from the analogy of its satellites; but itis, no doubt, in equilibrium; and the effective mass of Saturn on thesatellites is less than the true mass, in consequence of his radialstream being immensely increased by the additional force impressed onthe ether, by the centrifugal velocity of the ring. If this be so, themass of Saturn, derived from one of the inner satellites, will be lessthan the same mass derived from the great satellite, whose orbit isconsiderably inclined. The analogy we have mentioned, between thediameters of the nebulous planets and their distances, does not holdgood in the case of Saturn, for the reason already assigned, viz. : thatthe nebulous planet was probably not a globe, but a cylindrical ring, vacant around the axis, as there is reason to suppose is the case atpresent. 

And now we have to ask the question, Did the ether involved in thenebulous planets rotate in the same time? This does not necessarilyfollow. The ether will undoubtedly tend to move with increasing velocityto the very centre of motion, obeying the great dynamical principle whenunresisted. If resisted, the law will perhaps be modified; but in thiscase, its motion of translation will be converted into atomic motion orheat, according to the motion lost by the resistance of atomic matter. This question has a bearing on many geological phenomena. As regards thegeneral effect, however, the present velocity of the ether circulatinground the planets, may be considered much greater than the velocities ofthe planets themselves. 

PERTURBATIONS DUE TO THE ETHER. 

In these investigations it is necessary to bear in mind that the wholeresisting power of the ether, in disturbing the planetary movements, isbut small, in comparison with gravitation. We will, however, show that, in the case of the planets, there is a compensation continually made bythis resistance, which leaves but a very small outstanding balance as adisturbing power. If we suppose all the planets to move in the centralplane of the vortex in circular orbits, and the force of the radialstream, (or that portion which is not in accordance with the law ofgravitation, ) to be inversely as the square roots of the distances fromthe sun, it is evident, from what has been advanced, that an equilibriumcould still obtain, by variations in the densities, distances anddiameter of the planets. Supposing, again, that the planets still movein the same plane, but in elliptical orbits, and that they are inequilibrium at their mean distances, under the influence or action ofthe tangential current, the radial stream, and the density of the ether;we see that the force of the radial stream is too great at theperihelion, and too small at the aphelion. At the perihelion the planetis urged from the sun and at the aphelion towards the sun. The densityand consequent momentum is also relatively too great at the perihelion, which also urges the planet from the sun, and at the aphelion, relatively too small, which urges the planet towards sun; and the law isthe same in both cases, being null at the mean distance of the planet, at a maximum at the apsides; it is, consequently, as the cosine of theplanet's eccentric anomaly at other distances, and is positive ornegative, according as the planet's distance is above or below the mean. 

At the planet's mean distance, the circular velocity of the vortex isequal to the circular velocity of the planet, and, at differentdistances, is inversely in the sub-duplicate ratio of those distances. But the circular velocity of a planet in the same orbit, is in thesimple ratio of the distances inversely. At the perihelion, the planettherefore moves faster than the ether of the vortex, and at theaphelion, slower; and the difference is as the square roots of thedistances; but the force of resistance is as the square of the velocity, and is therefore in the simple ratio of the distances, as we havealready found for the effect of the radial stream, and centrifugalmomentum of the internal ether. At the perihelion this excess oftangential velocity creates a resistance, which urges the planet towardsthe sun, and at the aphelion, the deficiency of tangential velocityurges the planet from the sun, --the maximum effect being at the apsidesof the orbit, and null at the mean distances. In other positions it is, therefore, as the cosines of the eccentric anomaly, as in the formercase; but in this last case it is an addititious force at theperihelion, and an ablatitious force at the aphelion, whereas the firstdisturbing force was an ablatitious force at the perihelion, and anaddititious force at the aphelion; therefore, as we must suppose theplanet to be in equilibrium at its mean distance, it is in equilibriumat all distances. Hence, a planet moving in the central plane of thevortex, experiences no disturbance from the resistance of the ether. 

As the eccentricities of the planetary orbits are continually changingunder the influence of the law of gravitation, we must inquire whether, under these circumstances, such a change would not produce a permanentderangement by a change in the mean force of the radial stream, so as toincrease or diminish the mean distance of the planet from the sun. Thelaw of force deduced from the theory for the radial stream is as the 2. 5power of the distances inversely. But, by dividing this ratio, we maymake the investigation easier; for it is equivalent to two forces, onebeing as the squares of the distances, and another as the square rootsof the distances. For the former force, we find that in orbits havingthe same major axis the mean effect will be as the minor axis of theellipse _inversely_, so that two planets moving in different orbits, butat the same mean distance, experience a less or greater amount ofcentripulsive force from this radial stream, according as their orbitsare of less or greater eccentricity, and this in the ratio of the minoraxis. On the other hand, under the influence of a force actingcentripulsively in the inverse ratio of the square roots of thedistances, we find the mean effect to be as the minor axis of theellipse _directly_, so that two planets in orbits of differenteccentricity, but having the same major axis, experience a differentamount from the action of this radial stream, the least eccentric orbitbeing that which receives the greatest mean effect. By combining thesetwo results, we get a ratio of equality; and, consequently, the actionof the radial stream will be the same for the same orbit, whateverchange may take place in the eccentricity, and the mean distance of theplanet will be unchanged. A little consideration will also show that theeffect of the centrifugal momentum due to the density of ether will alsobe the same by change of eccentricity; for the positive will alwaysbalance the negative effect at the greatest and least distances of theplanet. The same remark applies to the effect of the tangential current, so that no change can be produced in the major axes of the planetaryorbits by change of eccentricity, as an effect of the resistance of theether. 

We will now suppose a planet's orbit to be inclined to the central planeof the vortex, and in this case, also, we find, that the action of theradial stream tends to increase the inclination in one quadrant as muchas it diminishes it in the next quadrant, so that no change ofinclination will result. But, if the inclination of the orbit be changedby planetary perturbations, the mean effect of the radial stream willalso be changed, and this will tell on the major axis of the orbit, enlarging the orbit when the inclination diminishes, and contracting itwhen it increases. The change of inclination, however, must be referredto the central plane of the vortex. Notwithstanding the perfection ofmodern analysis, it is confessed that the recession of the moon's nodesdoes yet differ from the theory by its 350th part, and a similardiscrepancy is found for the advance of the perigee. [40] This theory isyet far too imperfect to say that the action of the ethereal medium willaccount for these discrepancies; but it certainly wears a promisingaspect, worthy the notice of astronomers. There are other minutediscordancies between theory and observation in many astronomicalphenomena, which theory _is_ competent to remove. Some of these we shallnotice presently; and, it may be remarked, that it is in those minutequantities which, in astronomy, are usually attributed to errors ofobservation, that this theory will eventually find the surest evidenceof its truth. 

KEPLER'S THIRD LAW ONLY APPROXIMATELY TRUE. 

But it may be asked: If there be a modifying force in astronomy derivedfrom another source than that of gravitation, why is it that theelements of the various members of the system derived solely fromgravitation should be so perfect? To this it may be answered, thatalthough astronomers have endeavored to derive every movement in theheavens from that great principle, they have but partially succeeded. Let us not surrender our right of examining Nature to the authority of agreat name, nor call any man master, either in moral or physicalscience. It is well known that Kepler's law of the planetary distancesand periods, is a direct consequence of the Newtonian Law ofgravitation, and that the squares of the periodic times ought to beproportional to the cubes of the mean distances. These times are givenaccurately by the planets themselves, by the interval elapsing betweentwo consecutive passages of the node, and as in the case of the ancientplanets we have observations for more than two thousand years past, these times are known to the fraction of the second. The determinationof the distances however, depends on the astronomer, and a tyro in thescience might suppose that these distances were actually measured; andso they are roughly; but the astronomer does not depend on hisinstruments, he trusts to _analogy_, and the mathematical perfection ofa law, which in the abstract is true; but which he does not know isrigidly exact when applied to physical phenomena. From the immensedistance of the planets and the smallness of the earth, man is unable tocommand a base line sufficiently long, to make the horizontal parallax asensible angle for the more distant planets; and there are difficultiesof no small magnitude to contend with, with those that are the nearest. In the occasional transit of Venus across the sun, however, he ispresented with a means of measuring on an enlarged scale, from which thedistance of the sun is determined; and by _analogy_ the distance of allthe planets. Even the parallax of the sun itself is only correct, bysupposing that the square of the periodic time of Venus is in the sameproportion to the square of the periodic time of the earth as the cubeof her distance is to the cube of the earth's distance. Our next nearestplanet is Mars, and observations on this planet at its opposition to thesun, invariably give a larger parallax for the sun--Venus giving 8. 5776″while Mars gives about 10″. It is true that the first is obtained undermore favorable circumstances; but this does not prove the last to beincorrect. It is well known that the British Nautical Almanac contains alist of stars lying in the path of the planet Mars about opposition, (for the very purpose of obtaining a correct parallax, ) that minutedifferences of declination may be detected by simultaneous observationsin places having great differences of latitude. Yet strange to say, theresult is discredited when not conformable to the parallax given byVenus. If then, we cannot trust the parallax of Mars, _à fortiori_, howcan we trust the parallax of Jupiter, and say that his mean distanceexactly corresponds to his periodic time? Let us suppose, for instance, that the radius vector of Jupiter fell short of that indicated byanalogy by 10, 000 miles, we say that it would be extremely difficult, nay, utterly impossible, to detect it by instrumental means. Let notastronomers, therefore, be too sure that there is not a modifying cause, independent of gravitation, which they will yet have to recognize. Themoon's distance is about one-fourth of a million of miles, and Neptune's2854 millions, or in the ratio of 10, 000 to 1; yet even the moon'sparallax is not trusted in determining her mass, how then shall wedetermine the parallax of Neptune? It is therefore _possible_ that theeffective action of the sun is in some small degree different, on thedifferent planets, whether due to the action of the ether, to thesimilarity or dissimilarity of material elements, to the temperature ofthe different bodies, or to all combined, is a question yet to beconsidered. 

As another evidence of the necessity of modifying the strict wording ofthe Newtonian law, it is found that the disturbing action of Jupiter ondifferent bodies, gives different values for the mass of Jupiter. Themass deduced from Jupiter's action on his satellites, is different fromthat derived from the perturbations of Saturn, and this last does notcorrespond with that given by Juno: Vesta also gives a different massfrom the comet of Encke, and both vary from the preceding values. [41]

In the analytical investigation of planetary disturbances, thedisturbing force is usually divided into a radial and tangential force;the first changing the law of gravitation, to which law the ellipticform of the orbit is due. The radial disturbing force, therefore, beingdirected to or from the centre, can have no influence over the first lawof Kepler, which teaches that the radius vector of each planet havingthe sun as the centre, describes equal areas in equal times. If theradial disturbing force be exterior to the disturbed body, it willdiminish the central force, and cause a progressive motion in theaphelion point of the orbit. In the case of the moon this motion is veryrapid, the apogee making an entire revolution in 3232 days. Does this, however, correspond with the law of gravitation? Sir Isaac Newton, incalculating the effect of the sun's disturbing force on the motion ofthe moon's apogee, candidly concludes thus: "Idoque apsis summa singulisrevolutionibus progrediendo conficit 1° 31′ 28″. Apsis lunæ est duplovelocior circiter. " As there was a necessity for reconciling thisstubborn fact with the theory, his followers have made up the deficiencyby resorting to the tangential force, or, as Clairant proposed, bycontinuing the approximations to terms of a higher order, or to thesquare of the disturbing force. 

Now, in a circular orbit, this tangential force will alternatelyincrease and diminish the velocity of the disturbed body, withoutproducing any permanent derangement, the same result would obtain in anelliptical orbit, if the position of the major axis were stationary. Inthe case of the moon, the apogee is caused to advance by the disturbingpower of the radial force, and, consequently, an exact compensation isnot effected: there remains a small excess of velocity which geometershave considered equivalent to a doubling of the radial force, and havethus obviated the difficulty. To those not imbued with the profoundpenetration of the modern analyst, there must ever appear a littleinconsistency in this result. The major axis of a planet's orbit dependssolely on the velocity of the planet at a given distance from the sun, and the tangential portion of the disturbance due to the sun, andimpressed upon the moon, must necessarily increase and diminishalternately the velocity of the moon, and interfere with the equabledescription of the areas. If, then, there be left outstanding a smallexcess of velocity over and above the elliptical velocity of the moon, at the end of each synodical revolution, in consequence of the motionimpressed on the moon's apogee by the radial force, the _legitimate_effect would be a small enlargement of the lunar orbit every revolutionin a rapidly-increasing ratio, until the moon would at last be takenentirely away. In the great inequality of Jupiter and Saturn, thistangential force is not compensated at each revolution, in consequenceof continual changes in the configuration of the two planets at theirheliocentric conjunctions, with respect to the perihelion of theirorbits, and the near commensurability of their periods; and the effectof the tangential force is, in this case, legitimately impressed on themajor axes of the orbits. But why (we may ask) should not this also beexpended on the motion of the aphelion as well as in the case of themoon? Astronomy can make no distinctions between the orbit of a planetand the orbit of a satellite. And, we might also ask, why the tangentialresistance to the comet of Encke should not also produce a retrogrademotion in the apsides of the orbit, instead of diminishing its period?To the honor of Newton, be it remembered, that he never resorted to anexplanation of this phenomenon, which would vitiate that fundamentalproposition of his theory, in which the major axis of the orbit is shownto depend on the velocity at any given distance from the focus. 

Some cause, however, exists to double the motion of the apogee, andthat there is an outstanding excess of orbital velocity due to thetangential force, is also true. This excess may tell in the wayproposed, provided some other arrangement exists to _prevent_ apermanent dilation of the lunar orbit; and this provision may be foundin the increasing density of the ether, which prevents the moonoverstepping the bounds prescribed by her own density, and the force ofthe radial stream of the terral vortex. In the case of Jupiter andSaturn, their mutual action is much less interfered with by change ofdensity in the ether in the enlarged or contracted orbit, and, consequently, the effect is natural. Thus, we have in the law of densityof the ethereal medium a better safeguard to the stability of thedynamical balance of the system, than in the profound and beautifulTheorems of La Grange. It will, of course, occur to every one, that weare not to look for the same law in every vortex, and it will, therefore, appear as if the satellites of Jupiter, whose theory is sowell known, should render apparent any deviation between their periodictimes and the periodic times of the contiguous parts of the vortex, which would obtain, if the density of the ether in the Jovian vortexwere not as the square roots of the distances directly. But, we haveshown how there can be a balance preserved, if the tangential resistanceof the vortex shall be equal and contrary at the different distances atwhich the satellites are placed; that is, if these two forces shallfollow the same law. These are matters, however, for futureinvestigation. 

LIGHT AND HEAT. 

But will not the admission of a vorticose motion of the ethereal medium, affect the aberration of light? It is well known that the question hasbeen mooted, whether the velocity of reflected light is the same as thatof direct light. The value of aberration having been considered 20″. 25, from the eclipses of Jupiter's satellites, while later determinations, from observations on Polaris, give 20″. 45. It cannot be doubted thatlight, in traversing the central parts of the solar vortex, that is, having to cross the whole orbit of the earth, should pass this distancein a portion of time somewhat different to a similar distance outsidethe earth's orbit, where the density is greater, and consequently inducean error in the aberration, determined by the eclipses of Jupiter'ssatellites. In the case of Polaris, the circumstances are more equal;still, a difference ought to be detected between the deduced aberrationin summer and in winter, as, in the first case, the light passes nearthe axis of the solar vortex, where (according to the theory) a changeof density occurs. This is an important practical question, and thesuggestion is worthy attention. Now, the question occurs, will lightpass through the rarefied space with greater velocity than through thedenser ether beyond? From recent experiments, first instituted by Arago, it is determined that light passes with less velocity through water thanthrough air; and one result of these experiments is the confirmationthey give to the theory of Fresnel, that the medium which conveys theaction of light partly partakes of the motion of the refracting body. This of itself is a strong confirmation of this theory of an etherealmedium. It may also be remarked, that every test applied to thephenomenon of light, adds additional strength to the undulatory theory, at the expense of the Newtonian theory of emission. As light occupiestime in traversing space, it must follow from the theory that it doesnot come from the radiant point exactly in straight lines, inasmuch asthe ether itself is in motion tangentially, --the velocity being in thesub-duplicate ratio of the distances from the sun inversely. 

May not that singular phenomenon, --the projection of a star on themoon's disc, at the time of an occultation, --be due to this curvature ofthe path of a ray of light, by considering that the rays from the moonhave less intensity, but more mechanical momentum, and consequentlymore power to keep a straight direction? Let us explain: we have urgedthat light, as well as heat, is a mechanical effect of atomic motion, propagated through an elastic medium; that, _ceteris paribus_, theproduct of matter by its motion is ever a constant quantity for equalspaces throughout the universe, --in a word, that it is, and mustnecessarily be, a fundamental law of nature. All departures from thislaw are consequences of accidental arrangements, which can only beconsidered of temporary duration. Our knowledge of planetary matterrequires the admission of differences in the density, form, and size ofultimate atoms, and, according to the above law, when the atoms are ofuniform temperature or motion, the product of the matter of each by itsmotion, when reduced to the same space, will be constant. The momentumof two different atoms, therefore, we will consider equal, for the sakeof illustration; yet this momentum is made up of two differentelements, --matter and motion. Let us exaggerate the difference, andassign a ratio of 1000 to 1. Suppose a ball of iron of 1000 lbs. , resting upon a horizontal plane, should be struck by another ball of 1lb. , having a motion of 1000 feet in a second, and, in a second case, should be struck by a ball of 1000 lbs. , having a velocity of 1 foot persecond, the momentum of each ball is similar; but experience proves thatthe motion impressed on the ball at rest is not similar; the ponderousweight and slow motion is far more effective in displacing this ball, for the reason that time is essential to the distribution of the motion. If the body to be struck be small as, for instance, a nail, a greatermotion and less matter is more effective than much matter and littlemotion. Hence, we have a _distinction_ applicable to the difference ofmomentum of luminous and calorific rays. The velocity of a wave of soundthrough the atmosphere, is the same for the deep-toned thunder and theshrillest whistle, --being dependent on the density of the medium, andnot on the source from which it emanates. So it is in the etherealmedium. 

This view is in accordance with the experiments of M. Delaroche andMelloni, on the transmission of light and heat through diaphanousbodies--the more calorific rays feeling more and more the influence ofthickness, showing that more motion was imparted to the particles of thediaphanous substance by the rays possessing more material momentum, andstill more when the temperature of the radiating body was low, evidentlyanalogous to the illustration we have cited. Light may therefore beregarded as the effect of the vibration of atoms having little mass, andas this mass increases, the rays become more calorific, and finally thecalorific effect is the only evidence of their existence; as towards theextreme red end of the spectrum they cease to be visible, owing to theirinability to impart their vibrations to the optic nerve. This may alsoinfluence the law of gravitation. In this we have also an explanation ofthe dispersion of light. The rays proceeding from atoms of small masshaving less material momentum, are the most refrangible, and thosepossessing greater material momentum, are the least refrangible; so thatinstead of presenting a difficulty in the undulatory theory of light, this dispersion is a necessary consequence of its first principles. 

It is inferred from the experiments cited, and the facts ascertained bythem, viz. : that the velocity of light in water is less than itsvelocity in air; that the density of the ether is greater in the firstcase; but this by no means follows. We have advocated the idea, that theethereal medium is less dense within a refracting body than without. Weregard it as a fundamental principle. Taking the free ether of heaven;the vibrations in the denser ether will no doubt be slowest; but withina refracting body we must consider there is motion lost, or _lightabsorbed_, and the time of the transmission is thus increased. 

There has been a phenomenon observed in transits of Mercury and Venusacross the sun, of which no explanation has been rendered byastronomers. When these planets are visible on the solar disc, they areseen surrounded by rings, as if the light was intercepted and increasedalternately. This is no doubt due to a small effect of interference, caused by change of velocity in passing through the rarefied nucleus ofthese planetary vortices, near the body of the planet, and through thedenser ether beyond, acting first as a concave, and secondly as a convexrefracting body; always considering that the ray will deviate _towards_the side of least insistence, and thus interfere. 

That heat is simply atomic motion, and altogether mechanical, is adoctrine which ought never to have been questioned. The interest excitedby the bold experiments of Ericson, has caused the scientific to_suspect_, that heat can be converted into motion, and motion intoheat--a fact which the author has considered too palpable to deny forthe last twenty years. He has ever regarded matter and motion as the twogreat principles of nature, ever inseparable, yet variously combined;and that without these two elements, we could have no conception ofanything existing. 

It may be thought by some, who are afraid to follow truth up the ruggedprecipices of the hill of knowledge, that this theory of aninterplanetary plenum leads to materialism; forgetting, that He who madethe world, formed it of matter, and pronounced it "very good. " We mayconsider ethereal matter, in one sense, _purer_ than planetary matter, because unaffected by chemical laws. Whether still purer matter exists, it is not for us to aver or deny. The Scriptures teach us that "there isa natural body and there is a spiritual body. " Beyond this we knownothing. We, however, believe that the _invisible_ world of matter, canonly be comprehended by the indications of that which is visible; yetwhile humbly endeavoring to connect by one common tie, the variousphenomena of matter and motion, we protest against those doctrines whichteach the eternal duration of the present order of things, as beingincompatible with the analogies of the past, as well as with therevelations of the future. 

FOOTNOTES:

[35] Silliman's Journal, vol xxxv. , page 283. 

[36] The real diameter of the earth in that latitude, whose sine isone-third, is a little greater than this; but the true mean is morefavorable for the Newtonian law. 

[37] This is, perhaps, the nearest ratio of the densities and distances. 

[38] This is an important consideration, as bearing on the geology ofthe earth. 

[39] It is not as likely that the condensation of the sun was so suddenas that of the planets, and therefore in this case this distance is onlyapproximate. 

[40] Mechanique Celeste. Theory of the Moon. 

[41] Mechanique Celeste. Masses of the planets. 

SECTION FIFTH. 

COMETARY PHENOMENA. 

The planetary arrangements of the solar system are all _à priori_indications of the theory of vortices, not only by the uniform directionof the motions, the circular orbits in which these motions areperformed, the near coincidence of the planes of these orbits, and theuniform direction of the rotation of the planets themselves; but, also, by the law of densities and distances, which we have already attemptedto explain. In the motions of comets we find no such agreement. Thesebodies move in planes at all possible inclinations in orbits extremelyeccentrical and without any general direction--as many moving contraryto the direction of the planets as in the opposite direction; and whenwe consider their great volume, and their want of mass, it appears, atfirst sight, that comets do present a serious objection to the theory. We shall point out, however, a number of _facts_ which tend toinvalidate this objection, and which will ultimately give thepreponderance to the opposite argument. 

Every fact indicative of the nature of comets proves that the nuclei aremasses of material gases, similar, perhaps (at least in the case of theshort-period comets), to the elementary gases of our own planet, and, consequently, these masses must be but small. In the nascent state ofthe system, the radial stream of the vortex would operate as a fan, purging the planetary materials of the least ponderable atoms, and, asit were, separating the wheat from the chaff. It is thus we conceivethat the average atomic density of each planet has been first determinedby the radial stream, and, subsequently, that the solidification of thenebulous planets has, by their atomic density, assigned to each itsposition in the system, from the consequent relation which itestablished between the density of the ether within the planet, and thedensity of the ether external to it, so that, according to this view, asingle isolated atom of the same density as the mean atomic density ofthe earth could (_ceteris paribus_) revolve in an orbit at the distanceof the earth, and in the same periodic time. This, however, is onlyadvanced by way of illustration. 

The expulsive force of the radial stream would thus drive off thiscometary dust to distances in some inverse ratio of the density of theatoms; but, a limit would ultimately be reached, when gravitation wouldbe relatively the strongest--the last force diminishing only as thesquares of the distances, and the first diminishing in the compoundratio of the squares and the square roots of the distances. At theextreme verge of the system, this cometary matter would accumulate, and, by accumulation, would still further gather up the scattered atoms--thesweepings of the inner space--and, in this condensed form, would againvisit the sun in an extremely elongated ellipse. It does not, however, follow, that all comets are composed of such unsubstantial materials. There may be comets moving in parabolas, or even in hyperbolas--bodieswhich may have been accumulating for ages in the unknown regions ofspace, far removed from the sun and stars, drifting on the mightycurrents of the great ethereal ocean, and thus brought within the sphereof the sun's attraction; and these bodies may have no analogy to theperiodical comets of our system, which last are those with which we aremore immediately concerned. 

The periodical comets known are clearly arranged into two distinctclasses--one having a mean distance between Saturn and Uranus, with aperiod of about seventy-five years, and another class, whose meandistance assigns their position between the smaller planets and Jupiter, having periods of about six years. These last may be considered thesiftings of the smaller planets, and the first the refuse of theSaturnian system. In this light we may look for comets having a meandistance corresponding to the intervals of the planets, rather than tothe distances of the planets themselves. One remarkable fact, however, to be observed in these bodies is, that all their motions are in thesame direction as the planets, and, with one exception, there is noperiodical comet positively known whose motion is retrograde. 

The exception we have mentioned is the celebrated comet of Halley, whoseperiod is also about seventy-five years. In reasoning on the resistanceof the ether, we must consider that the case can have very littleanalogy with the theory of projectiles in air; nor can we estimate theinertia of an infinitely divisible fluid, from its resisting influenceon atomic matter, by a comparison of the resistance of an atomic fluidon an atomic solid. Analogy will only justify comparisons of like withlike. The tangent of a comet's orbit, also, can only be tangential tothe circular motion of the ether at and near perihelion, which is a verysmall portion of its period of revolution. As far as the tangentialresistance is concerned, therefore, it matters little whether its motionbe direct or retrograde. If a retrograde comet, of short period andsmall eccentricity, were discovered moving also near the central planeof the vortex, it would present a very serious objection, as beingindicative of contrary motions in the nascent state of the system. Thereis no such case known. So, also, with the inclinations of the orbits; ifthese be great, it matters little whether the comet moves in one way orthe other, as far as the tangential current of the vortex is concerned. Yet, when we consider the average inclination of the orbit, and not ofits plane, we find that the major axes of nearly all known cometaryorbits are very little inclined to the plane of the ecliptic. 

In the following table of all the periodical comets known, theinclination of the major axis of the orbit is calculated to the nearestdegree; but all cometary orbits with very few exceptions, will be foundto respect the ecliptic, and never to deviate far from that plane:

 +--------------------------------------------------------------------+ | Designations | Periodic | Inclination | Motion | Planetary | | of the Comets. | times. | of | in Orbit. | Intervals. | | | | Major Axes | | | |--------------------------------------------------------------------| |Encke | 1818 | 3 years. | 1° | Direct |Mars & Ceres. | |--------------------------------------------------------------------| |De Vico | 1814 | | 2 | Direct | | |Fayo | 1843 | | 4 | Direct | Ceres | |De Avrest| 1851 | From | 1 | Direct | | |Brorsen | 1846 | five | 7 | Direct | and | |Messier | 1766 | to | 0 | Direct | | |Clausen | 1743 | six | 0 | Direct | Jupiter. | |Pigott | 1783 | or | 4 | Direct | | |Pous | 1819 | seven | 3 | Direct | | |Biela | 1826 | years. | 9 | Direct | | |Blaupain | 1819 | | 2 | Direct | | |Lexell | 1770 | | 1 | Direct | | |--------------------------------------------------------------------| |Pous | 1812 | | 17 | Direct | | |Olbers | 1816 | about | 40 | Direct | Saturn | |De Vico | 1846 | 75 | 13 | Direct | and | |Brorsen | 1847 | years. | 12 | Direct | Uranus. | |Westphal | 1852 | | 21 | Direct | | |Halley | 1682 | | 16 | Retrograde| | +--------------------------------------------------------------------+

From which it appears, that the objection arising from the greatinclination of the _planes_ of these orbits is much less important thanat first it appears to be. 

Regarding then, that a comet's mean distance depends on its mean atomicdensity, as in the case of the planets, the undue enlargement of theirorbits by planetary perturbations is inadmissible. In 1770 Messierdiscovered a comet which approached nearer the earth than any cometknown, and it was found to move in a small ellipse with a period of fiveand a half years; but although repeatedly sought for, it was theopinion of many, that it has never been since seen. The cause of thisseeming anomaly is found by astronomers in the disturbing power ofJupiter, --near which planet the comet must have passed in 1779, but thecomet was not seen in 1776 before it passed near Jupiter, although avery close search was kept up about this time. Now there are twosuppositions in reference to this body: the comet either moved in alarger orbit previous to 1767, and was then caused by Jupiter todiminish its velocity sufficiently to give it a period of five and ahalf years, and that after perihelion it recovered a portion of itsvelocity in endeavoring to get back into its natural orbit; or if movingin the natural orbit in 1770, and by passing near Jupiter in 1779 thisorbit was deranged, the comet will ultimately return to that meandistance although not necessarily having elements even approximatingthose of 1770. In 1844, September 15th, the author discovered a comet inthe constellation Cetus, (the same previously discovered by De Vico atHome, ) and from positions _estimated with the naked eye_ approximatelydetermined the form of its orbit and its periodic time to be verysimilar to the lost comet of 1770. These conclusions were published in awestern paper in October 1844, on which occasion he expressed theconviction, that this was no other than the comet of 1770. As thequestion bore strongly on his theory he paid the greater attention toit, and had, previously to this time, often searched in hopes of findingthat very comet. Since then, M. Le Verrier has examined the question ofidentity and given his decision against it; but the author is stillsanguine that the comet of 1844 is the same as that of 1770, once moresettled at its natural distance from the sun. This comet returns to itsperihelion on the 6th of August, 1855, according to Dr.  Brünnow, when, it is hoped, the question of identity will be reconsidered withreference to the author's principles; and, that when astronomers becomesatisfied of this, they will do him the justice of acknowledging thathe was the first who gave publicity to the fact, that the "Lost Comet"was found. 

That comets do experience a resistance, is undeniable; but not in theway astronomers suppose, if these views be correct. The investigationsof Professor Encke, of Berlin, on the comet which bears his name, hasdetermined the necessity of a correction, which has been applied forseveral returns with apparent success. But there is this peculiarityabout it, which adds strength to our theory: "The Constant ofResistance" requires a change after perihelion. The necessity for thischange shows the action of the radial stream. From the law of thisforce, (reckoning on the central plane of the vortex, ) there is anoutstanding portion, acting as a disturbing power, in the sub-duplicateratio of the distances inversely. If we only consider the mean oraverage effect in orbits nearly circular, this force may be consideredas an ablatitious force at all distances below the mean, counterbalancedby an opposite effect at all distances above the mean. But when theorbits become very eccentrical, we must consider this force asmomentarily affecting a comet's velocity, diminishing it as itapproaches the perihelion, and increasing it when leaving theperihelion. A resolution of this force is also requisite for the comet'sdistance above the central plane of the vortex, and a correction, likewise, for the intensity of the force estimated in that plane. Thereis also a correction necessary for the perihelion distance, and anotherfor the tangential current; but we are only considering here the generaleffect. By diminishing the comet's proper velocity in its orbit, if weconsider the attraction of the sun to remain the same, the generaleffect _may_ be (for this depends on the tangential portion of theresolved force preponderating) that the absolute velocity will beincreased, and the periodic time shortened; but after passing theperihelion, with the velocity of a smaller orbit, there is alsosuperadded to this already undue velocity, the expulsive power of theradial stream, adding additional velocity to the comet; the orbit istherefore enlarged, and the periodic time increased. Hence the necessityof changing the "Constant of Resistance" after perihelion, and this willgenerally be found necessary in all cometary orbits, if this theory betrue. But this question is one which may be emphatically called the mostdifficult of dynamical problems, and it may be long before it is fullyunderstood. 

According to the calculations of Professor Encke, the comet's period isaccelerated about 2 hours, 30 minutes, at each return, which heconsiders due to a resisting medium. May it not rather be owing to _thechange of inclination of the major axis of the orbit, to the centralplane of the vortex_? Suppose the inclination of the _plane_ of theorbit to remain unchanged, and the eccentricity of the orbit also, ifthe longitude of the perihelion coincides with that of either node, themajor axis of the orbit lies in the ecliptic, and the comet thenexperiences the greatest mean effect from the radial stream; its meandistance is then, _ceteris paribus_, the greatest. When the anglebetween the perihelion and the nearest node increases, the mean force ofthe radial stream is diminished, and the mean distance is diminishedalso. When the angle is 90°, the effect is least, and the mean distanceleast. This is supposing the ecliptic the central plane of the vortex. When Encke's formula was applied to Biela's comet, it was inadequate toaccount for a tenth part of the acceleration; and although Biela movesin a much denser medium, and is of less dense materials, even this takeninto account will not satisfy the observations, --making no other changein Encke's formula. We must therefore attribute it to changes in theelements of the orbits of these comets. Now, the effect of resistanceshould also have been noticed, as an acceleration of Halley's comet in1835, yet the period was prolonged. To show, that our theory of the_cause_ of these anomalies corresponds with facts, we subjoin theelements in the following tables, taken from Mr.  Hind's catalogue:

THE ELEMENTS OF ENCKE'S COMET. 

 Date of Longitude of Longitude of Difference of Perihelion. Perihelion. Nearest Node Longitude. 1822 157° 11′ 44″ 154° 25′ 9″ 2° 46′ 35″ 1825 157 14 31 154 27 30 2 47 1 1829 157 17 53 154 29 32 2 48 21 1832[42] 157 21 1 154 32 9 2 41 52 1835 157 23 29 154 34 59 2 48 30 1838 157 27 4 154 36 41 2 50 23 1842 157 29 27 154 39 10 2 50 17 1845 157 44 21 154 19 33 3 24 48 1848 157 47 8 154 22 12 3 24 56 1852 157 51 2 154 23 21 3 27 41

In this we see a regular increase of the angle, which ought to beattended with a small acceleration of the comet; but the change ofinclination of the orbit ought also to be taken into consideration, toget the mean distance of the comet above the plane of the vortex, and, by this, the mean force of the radial stream. 

In the following table, the same comparison is made for Biela's comet:--

ELEMENTS OF BIELA'S COMET. 

 Date of Longitude of Longitude of Difference of Perihelion. Perihelion. Nearest Node. Longitude. 1772 110° 14′ 54″ 74° 0′ 1″ 36° 14′ 53″ 1806 109 32 23 71 15 15 38 17 8 1826 109 45 50 71 28 12 38 17 38[43] 1832 110 55 55 68 15 36 41 45 19 1846 109 2 20 65 54 39 43 7 41

Between 1832 and 1846, the increase of the angle is twice as great forBiela as for Encke, and the angle itself throws the major axis of Biela10° above the ecliptic, whereas the angle made by Encke's major axis, isonly about 1°; the cosine of the first angle, diminishes much fastertherefore, and consequently the same difference of longitude between theperihelion and node, will cause a greater acceleration of Biela; andaccording to Prof. Encke's theory, Biela would require a resistingmedium twenty-five times greater than the comet of Encke to reconcileobservation with the theory. Halley's comet can scarcely be consideredto have had an orbit with perfect elements before 1835. If they wereknown accurately for 1759, we should no doubt find, that the anglebetween the node and perihelion _diminished_ in the interval between1750 and 1835, as according to the calculations of M. Rosenberg, thecomet was six days behind its time--a fact fatal to the common ideas ofa resisting medium; but this amount of error must be received as onlyapproximate. 

No comet that has revisited the sun, has given astronomers more troublethan the great comet of 1843. Various orbits have been tried, elliptical, parabolic and hyperbolic; yet none will accord with all theobservations. The day before this comet was seen in Europe and theUnited States, it was seen close to the body of the sun at Conception, in South America; yet this observation, combined with those following, would give an orbital velocity due to a very moderate mean distance. Subsequent observations best accorded with a hyperbolic orbit; and itwas in view of this anomaly, that the late Sears C. Walker consideredthat the comet came into collision with the sun in an elliptical orbit, and its _debris_ passed off again in a hyperbola. That a concussionwould not add to its velocity is certain, and the departure in ahyperbolic orbit would be contrary to the law of gravitation. Thisprinciple is thus stated by Newton:--"In parabola velocitas ubiquoequalis est velocitati corporis revolventis in circulo ad dimidiamdistantiam; in ellipsi minor est in hyperbola major. " (Vid. Prin. Lib. 1. Prop. 6 Cor. 7. )

But as regards the _fact_, it is probable that Mr.  Walker's views arecorrect, so far as the change from an ellipse to an hyperbola isconsidered. The Conception observation cannot be summarily set aside, and Professor Peirce acknowledges, that "If it was made with anything ofthe accuracy which might be expected from Captain Ray, it exhibits adecided anomaly in the nature of the forces to which the comet wassubjected during its perihelion passage. " The comet came up to the sunalmost in a straight line against the full force of the radial stream;its velocity must therefore necessarily have been diminished. After itsperihelion, its path was directly _from_ the sun, and an undue velocitywould be kept up by the auxiliary force impressed upon it by the sameradial stream; and hence, the later observations give orbits much largerthan the early ones, and there can be no chance of identifying thiscomet with any of its former appearances, even should its orbit beelliptical. This unexpected confirmation of the theory by theobservation of Capt.  Ray, cannot easily be surmounted. 

We must now endeavor to explain the physical peculiarities of comets, inaccordance with the principles laid down. The most prominent phenomenonof this class is the change of diameter of the visible nebulosity. It isa most singular circumstance, but well established as a fact, that acomet contracts in its dimensions on approaching the sun, and expands onleaving it. In 1829, accurate measures were taken on different days, ofthe diameter of Encke's comet, and again in 1838. The comet of 1618 wasalso observed by Kepler with this very object, and also the comet of1807; but without multiplying instances, it may be asserted that it isone of those facts in cometary phenomena, to which there are noexceptions. According to all analogy, the very reverse of this ought toobtain. If a comet is chiefly vaporous, (as this change of volume wouldseem to indicate, ) its approach to the sun ought to be attended by acorresponding expansion by increase of temperature. When the contrary isobserved, and invariably so, it ought to be regarded as an index of theexistence of other forces besides gravitation, increasing rapidly in theneighborhood of the sun; for the disturbing power of the sun'sattraction would be to enlarge the diameter of a comet in proportion toits proximity. Now, the force of the radial stream, as we have shown, isas the 2. 5th power of the distances inversely. If this alternatecontraction and expansion be due to the action of this force, thereought to be an approximate correspondence of the law of the effect withthe law of the cause. Arago, in speaking of the comet of 1829, states, "that between the 28th of October and the 24th of December, the volumeof the comet was reduced as 16000 to 1, the change of distance in themeantime only varying about 3 to 1. " To account for this, a memoir waspublished on the subject by M. Valz, in which he supposes an atmospherearound the sun, whose condensation increases rapidly from superincumbentpressure; so that the deeper the comet penetrates into this atmospherethe greater will be the pressure, and the less the volume. In this it isevident, that the ponderous nature of a resisting medium is not yetbanished from the schools. In commenting on this memoir, Arago justlyobserves, that "there would be no difficulty in this if it could beadmitted that the exterior envelope of the nebulosity were not permeableto the ether; but this difficulty seems insurmountable, and merits oursincere regret; for M. Valz's ingenious hypothesis has laid down the lawof variation of the bulk of the nebulosity, as well for the short-periodcomet as for that of 1618, with a truly wonderful exactness. " Now, if wemake the calculation, we shall find that the diameter of the nebulosityof a comet is inversely as the force of the radial stream. This force isinversely as the 2. 5 power of the distances from the axis, and not fromthe sun: it will, therefore, be in the inverse ratio of the cosine ofthe comet's heliocentric latitude to radius, and to this ratio thecomet's distance ought to be reduced. But, this will only be correct forthe same plane or for equal distances above the ecliptic plane, considering this last as approximately the central plane of the vortex. From the principles already advanced, the radial stream is far morepowerful on the central plane than in more remote planes; therefore, ifa comet, by increase of latitude, approaches near the axis, thusreceiving a larger amount of force from the radial stream in that planethan pertains to its actual distance from the sun, it will also receivea less amount of force in that plane than it would in the central planeat the same distance from the axis. Now, we do not know the differenceof force at different elevations above the central plane of the vortex;but as the two differences due to elevation are contrary in theireffects and tend to neutralize each other, we shall make the calculationas if the distances were truly reckoned from the centre of the sun. 

The following table is extracted from Arago's tract on Comets, andrepresents the variations of the diameter of Encke's comet at differentdistances from the sun, --the radius of the orbis magnus being taken asunity. 

 Times of observation, Distances of the Real diameters 1828. Comet from the sun. In radii of the earth. Oct. 28 1. 4617 79. 4 Nov. 7 1. 3217 64. 8 Nov. 30 0. 9668 29. 8 Dec. 7 0. 8473 19. 9 Dec. 14 0. 7285 11. 3 Dec. 24 0. 6419 3. 1

In order the better to compare the diameters with the force, we willreduce them by making the first numbers equal. 

 Distances. Diameters. The 2. 5th power Reduced of the Distances. Diameters. 1. 4617 79. 4 2. 58 2. 58 1. 3217 64. 8 2. 10 2. 10 0. 9668 29. 8 0. 92 0. 97 0. 8473 19. 9 0. 66 0. 65 0. 7285 11. 3 0. 45 0. 37 0. 5419 3. 1 0. 21 0. 10

This is a very close approximation, when we consider the difficulty ofmicrometric measurement, and the fact, that as the comet gets nearer tothe sun, as at the last date of the table, the diameter is more thanproportionally diminished by the fainter nebulosity becoming invisible. But, there may be a reality in the discrepancy apparent at the lastdate, as the comet was then very near the plane of the ecliptic, andwas, consequently, exposed to the more violent action of the radialstream. 

To attempt to explain the _modus agendi_ is, perhaps, premature. Ourprincipal aim is to pioneer the way into the labyrinth, and it issufficient to connect this seeming anomaly with the same general law wehave deduced from other phenomena. Still, an explanation may be given instrict accordance with the general principles of the theory. 

Admitting the _nucleus_ of a comet to be gaseous, there is no difficultyabout the solution. According to Sir John Herschel, "stars of thesmallest magnitude remain distinctly visible, though covered by whatappears the densest portion of their substances; and since it is anobserved fact, that the large comets which have presented the appearanceof a nucleus, have yet exhibited no phases, though we cannot doubt thatthey shine by the reflected solar light, it follows that even these canonly be regarded as great masses of thin vapor. " That comets shinesolely by reflected solar light, is a position that we shall presentlyquestion; but that they are masses of vapor is too evident to dispute. According to the same authority quoted above, "If the earth were reducedto the one thousandth part of its actual mass, its coercive power overthe atmosphere would be diminished in the same proportion, and inconsequence the latter would expand to a thousand times its actual_bulk_. " If this were so, and comets composed of the elementary gases, some of them would have very respectable masses, as the nuclei arefrequently not more than 5, 000 miles in diameter, and consequently itbecomes important to examine the principle. From all experiments thedensity of an elastic fluid is directly as the compressing force; and ifa cylinder reached to the top of our atmosphere, compressed by thegravitation of the earth, considered equal at each end of the cylinder, it would represent the actual compressing force to which it owes itsdensity. If the gravitation of the earth were diminished one thousandtimes this atmospheric column would expand one thousand times, [44](taking no account of the decrease of gravitation by increase ofdistance;) so that the diameter of the aërial globe would be increasedto 108, 000 miles, taking the atmosphere at 50 miles. But the mereincreasing the _bulk_ of the atmosphere 1000 times would increase thediameter to little more than double. Even giving the correct expansion, a comet's mass must be much greater than is generally supposed, or thediameters of the nuclei would be greater if composed of any gas lighterthan atmospheric air. 

It is very improbable that a comet is composed of only one elementarygas, and if of many, their specific gravities will vary; the lighter, ofcourse, occupying the exterior layers. With such a small mass, therefore, the upper portion of its atmosphere must be very attenuated. Now let us remember that the density of the ether at a comet's aphelion, is greater than at the perihelion, in the direct ratio of the squareroots of the distances from the sun nearly. At the aphelion the cometlingers through half his period, giving ample time for the nucleus to bepermeated by ether proportionally dense with the surrounding ether ofthe vortex at that distance. Thus situated, the comet descends to itsperihelion, getting faster and faster into a medium far less dense, andthere must consequently be an escape from the nucleus, or in commonparlance, the comet is positively electric. This escaping ether, inpassing through the attenuated layers composing the surface of thenucleus, impels the lighter atoms of cometic dust further from thecentre, and as for as this _doubly_ attenuated atmosphere of isolatedparticles extends, so far will the escaping ether be rendered luminous. It may be objected here, that a contrary effect ought to be producedwhen the comet is forsaking, its perihelion; but the objection ispremature, as the heat received from the sun will have the same effectin increasing the elasticity, as change of density, and the comet willprobably part with its internal ether as long as it is visible to theearth; and not fully regain it perhaps, until after it arrives at itsaphelion. Suppose that we admit that a comet continues to expand in thesame ratio for all distances, as is laid down for the comet of Enckewhen near its perihelion; it would follow, that the comet of 1811, wouldhave a diameter at its aphelion of fifty millions of millions of miles, that is, its outside would extend one thousand times further from thesun, at the opposite side to that occupied by the centre of the comet, than the distance of the comet's centre from the sun, at its enormousaphelion distance. Such an absurdity shows us that there is a limit ofexpansion due to natural causes, and that if there were no radial streamthe volume of a comet would be greatest when nearest the sun. 

But while the comet is shortening its distance and hastening to the sunin the form of a huge globular mass of diffuse light, it is continuallyencountering another force, increasing in a far more rapid ratio thanthe law of gravitation. At great distances from the sun, the force ofthe radial stream was insufficient to detach any portion of the comet'satmosphere; presently, however, the globular form is changed to anellipsoid, the radial stream begins to strip the comet of that doublyattenuated atmosphere of which we have spoken, and the diameter of thecomet is diminished, merely because the luminosity of the escaping etheris terminated at the limit of that atmosphere. Meanwhile the mass of thecomet has suffered only an infinitely small diminution; but if theperihelion distance be small, the force may become powerful enough todetach the heavier particles of the nucleus, and thus a comet may sufferin mass by this denudating process. We regard, therefore, the nucleus ofa comet to represent the mass of the comet and the coma, as auroral rayspassing through a very attenuated envelope of detached particles. Theindividual gravitating force of these particles to the comet's centre, may be therefore considered as inversely as the squares of thedistances, and directly as the density of the particles; and thisdensity will, according to analogical reasoning, be as the distances orsquare roots of the distances;--grant the last ratio, and thegravitating force of the particles composing the exterior envelope of acomet, becomes inversely as the 2. 5th power of the distances from thecomet's centre. [45] This being the law of the radial stream, it follows, of course, that a comet's diameter is inversely as the force of theradial stream. It must, however, be borne in mind, that we are speakingof the atomic density, and not of density by compression; for thiscometary dust, which renders luminous the escaping ether of the nucleus, must be far too much diffused to merit the name of an elastic fluid. Maynot the concentric rings, which were so conspicuous in the comet of1811, be owing to differences in the gravitating forces of suchparticles, sifted, as it were, and thus arranged, according to someratio of the distances, by the centripulsive force of the electric coma, leaving vacant intervals, through which the ether passed withoutbecoming luminous? This at least is the explanation given by our theory. We may, indeed, consider it possible that the escaping ether, when veryintense, might be rendered luminous by passing into the surroundingether, and, as it became more diffused by radiation, at last becomeinvisible. In this case, as the law of radiation is as the squares ofthe distances from the centre inversely, the rays would be more and morebent at right angles, or apparently shortened, as the power of theradial stream increased, and the apparent diameters of the coma wouldbe diminished faster than the ratio of the 2. 5th power of the distances. But whichever view we adopt, the diameter would again increase in thesame ratio on leaving the sun, if we make allowance for increase oftemperature, as well as for diminution of density, for the ordinarydistance of a comet's visibility. We, however, regard the change ofdiameter, as due to both these nodes of action, as best agreeing withthe indications afforded by their tails. 

From the preceding remarks, it results that the density of the particlesproducing the nebulous envelope of a comet, renders the variations ofdiameter only approximate to the law of the radial stream; a comet's ownelectric energy, or the intensity of the escaping ether, may also modifythis expression, and many other causes may be suggested. That the radialstream is the cause, in the way we have pointed out, is proved by thepositions of the major axis of the short-period comet, making frequentlynearly a right angle with the radius vector of the orbit in 1828. A soapbubble gently blown aside, without detaching it from the pipe, willafford a good illustration of the mode, and a confirmation of the cause. The angles measured by Struve, reckoned from the radius vector, prolonged towards the sun, are subjoined:

 November 7 99°. 7 | December 7 154°. 0 November 30 145 . 3 | December 14 149 . 4

At this last date, the comet was getting pretty close to the sun. Whenthe angle was greater, as on November 7th, the comet appeared to makealmost a right angle with the radius vector; and in this position of theearth and comet, the longer axis of the elliptical comet was directed tothe axis of the vortex, as may be verified by experiment. At the laterdates, the comet was more rapidly descending, and, at the same time, theaxis of the comet was getting more directed towards the earth; so thatthe angle increased between this axis and the radius vector, andconsequently became more coincident with it. We have now to consider theluminous appendage of a comet, commonly called a tail. 

The various theories hitherto proposed to account for this appendage areliable to grave objections. That it is not refracted light needs not aword of comment. Newton supposes the tail to partake of the nature ofvapor, rising from the sun by its extreme levity, as smoke in a chimney, and rendered visible by the reflected light of the sun. But, how vaporshould rise towards opposition in a vacuum, is utterly inexplicable. Inspeaking of the greater number of comets near the sun than on theopposite side, he observes: "Hinc etiam manifestum est quod cœliresistentiâ destituuntur. "[46] And again, in another place, speaking ofthe tail moving with the same velocity of the comet, he says: "Et hincrursus colligitur spatia cœlestia vi resistendi destitui; utpote inquibus non solum solida planetarum et cometarum corpora, sed etiamrarissimi candarum vapores motus suos velocissimos liberrimè peragunt acdiutissimè conservant. " On what _principle_, therefore, Newton relied tocause the vapors to ascend, does not appear. Hydrogen rises in ouratmosphere because specifically lighter. If there were no atmosphere, hydrogen would not rise, but merely expand on all sides. But, a comet'stail shoots off into space in a straight line of one hundred millions ofmiles, and frequently as much as ten millions of miles in a single day, as in the case of the comet of 1843. Sir John Herschel observes, that"no rational or even plausible account has yet been rendered of thoseimmensely luminous appendages which they bear about with them, and whichare known as their tails. " Yet, he believes, and astronomers generallybelieve, that a comet shines by reflected light. This theory ofreflexion is the incubus which clogs the question with such formidabledifficulties; for, it follows, that the reflecting matter must comefrom the comet. But, what wonderful elements must a comet be made of, toproject themselves into space with such immense velocity, and in suchenormous quantities as to exceed in volume the body from which theyemanate many millions of times. This theory may be, therefore, safelyrejected. 

From what we have already advanced concerning the coma or nebulosity ofthe comet, we pass by an easy path to an explanation of the tail. In theshort-period comets, the density of the elementary atoms is too great tobe detached in the gross from the nucleus, or, rather, the density ofthe atoms composing the nucleus is too great to permit the radiatingstream of the comet carrying them to a sufficient distance to bedetached by the radial stream of the sun. Hence, these comets exhibitbut very little tails. We may also conceive, that the continual siftingswhich the nucleus undergoes at each successive perihelion passage, haveleft but little of those lighter elements in comets whose mean distancesare so small. Yet, again, if by any chance the eccentricity isincreased, there are two causes--the density of the ether, and the heatof the sun--which may make a comet assume quite an imposing appearancewhen apparently reduced to the comparatively passive state abovementioned. 

According to our theory, then, the coma of a comet is due to theelasticity of the ethereal medium within the nucleus, caused both by thediminished pressure of the external ether near the sun, and also by theincreased temperature acting on the nucleus, and thus on the involvedether. The tail, on the contrary, is caused by the lighter particles ofthe comet's attenuated atmosphere being blown off by the electric blastof the radial stream of the solar vortex, in sufficient quantities torender its passage visible. It is not, therefore, reflected light, butan ethereal stream rendered luminous by this detached matter still heldin check by the gravitating force of the sun, whose centre eachparticle still respects, and endeavors to describe such an orbit asresults from its own atomic density, and the resultant action of boththe acting forces. From the law of density of the ether, the coma oughtto be brightest and the radiating stream of the comet's nucleusstrongest on the side of least pressure: from this cause, and the factthat the body of the comet affords a certain protection to the particlesimmediately behind it, there will be an interval between the comet andthe tail less luminous, as is almost invariably observed. We thus havean explanation of the fact noticed by Sir John Herschel, "that thestructure of a comet, as seen in section in the direction of its length, must be that of a hollow envelope of a parabolic form, enclosing nearits vertex the nucleus or head. " We have, also, a satisfactoryexplanation of the rapid formation of the tail; of its being wider andfainter at its extremity; of its occasional curvature; and of itsgreater length after perihelion than before. But, more especially may wepoint to the explanation which this theory gives of the fact, that, _ceteris paribus_, the long-period comets, when their periheliondistances are small, have tails of such exaggerated dimensions. 

A comet, whose mean distance is considerable, is supposed by the theoryto be composed of elements less dense, and, during its long sojourn atits aphelion, it may be also supposed that it there receives continualaccessions to its volume from the diffused siftings of the system, andfrom the scattered debris of other comets. On approaching theperihelion, the rapidity of the change in the density of the ether in agiven time, depends on the eccentricity of the orbit, and so does thechange of temperature; so that, from both causes, both the length of thetail and the brilliancy of the comet measurably depends on the magnitudeof the period and of the eccentricity. 

If the nuclei of comets be gaseous as we suppose, and that the smalleststars are visible through them, it is an outrage on common sense, torefer that light, which renders a comet visible at noon-day, within sixminutes of space of the sun itself, to the reflected light of the sun. When a small star has been seen through the nucleus of a comet, withoutany perceptible diminution of light, it indicates perfect transparency;but there can be no reflection from a perfectly transparent body, andtherefore, a comet does not shine by reflected light. It is true thatArago discovered traces of polarized light in the comet of 1819, andalso in more recent comets, but they are mere traces, and Arago himselfadmits, that they do not permit "the conclusion decidedly that thesestars shine only with a borrowed light. " But it still does not followthat a comet (even if independent of reflected light) is in anincandescent state. The auroral light is not polarized, nor any otherelectric light, neither is it owing to a state of incandescence, yet itis luminous. The intense light of a comet at perihelion is analogous tothe charcoal points of a galvanic battery, caused by a rapid current ofether from the nucleus, and assisted by the radial stream of the vortex. This will account for the phenomenon in all its shades of intensity, aswell as for the absence of any perceptible phase. It will also accountfor the non-combustion of such comets as those of the years 1680 and1843. We shall also be at no loss to understand, why there is norefraction when a ray of light from a star passes through the nebulosityof a comet; and if, as we may reasonably suppose, the gaseous mattercomposing the nucleus be very attenuated, instruments are yet tooimperfect to determine whether these also have any refracting power. Onthis point, however, it is safest to suspend our judgment, as there maybe comets not belonging to our system, with even liquid or solid nuclei, or of matter widely different to those elements composing the members ofthe solar system. 

In addition to what has been already advanced on this subject of acomet's light, we may appeal to the well-known fact that the visibilityof a comet is not reciprocally as the squares of the distances from theearth and sun as it ought to be, if shining by reflected light. InMr.  Hind's late work on comets, the fact is stated that "Dr. Olbersfound that the comet of 1780 attained its greatest brightness on the 8thof November, thirteen days subsequent to its discovery, whereasaccording to the law of reflected light, it should have become graduallyfainter from the day of its discovery; and supposing the cometself-luminous, the intensity of light should have increased each dayuntil November 26th; yet in the interval between the 8th and 26th ofthat month, it grew rapidly less. " Now this theory teaches, that a cometis neither self-luminous nor dependent on the sun, but on its distancefrom the axis of the vortex, and a certain amount of elapsed time fromthe perihelion, varying somewhat in each particular case. This fact istherefore a very strong argument in favor of our theory. 

Amidst the many anomalous peculiarities of comets, it has been noticedthat a short tail is sometimes seen at right angles to the principaltail, and in a few cases pointing directly towards the sun. Much of thismay be owing to perspective, but granting the reality of the fact, it isstill explicable on the same general principles. 

In speaking of the modifying causes which influence the weather, wementioned the effect due to the position of the sun with respect to theaxis of the vortex. This will be found to have a sensible effect on theaction of the radial stream. The natural direction of a comet's electricstream is _towards_ the axis of the vortex, and in the central plane ofthe vortex it will be also towards the sun. But this stream is met bythe stronger radial stream from the axis, and as Mr.  Hind describes it, "is driven _backward_ in two streams passing on either side of the head, and ultimately blending into one to form the tail. " Now, if the body ofthe sun be situated between the comet and the axis of the vortex, itwill shield the comet from the action of the radial stream, and thus atail may really point towards the sun. 

In 1744 a brilliant comet exhibited six distinct tails spread out like afan, some seven days after its perihelion passage; its distance fromthe sun at the time not being more than a third of the earth's distance. The comet was then rapidly approaching the plane of the ecliptic, and ifwe make the calculation for the position of the sun, we shall find thatthe body of the sun was on the same side of the axis of the vortex asthe comet, and that the comet was then situated at the boundaries of theconical space, enclosed by the radial stream in its deflected passageround the body of the sun. In this position there are numerous crosscurrents of the stream, and hence the phenomenon in question. As thisfact rests on the testimony of one individual, and is an occurrencenever recorded before or since, many are disposed to doubt the fact, yetour theory explains even this peculiarity, and shows that there is nonecessity for impugning the statement of Cheseaux. 

Another unexplained phenomenon is the corruscation of the tail. It hasbeen attempted to explode this fact also, by referring it to conditionsof our own atmosphere; and it is generally considered the argument ofOlbers, founded on the great length of the tail and the velocity oflight, is sufficient to prove that these corruscations are not actuallyin the tail. Now, it is undoubtedly true, that as light travels lessthan two hundred thousand miles in a second, and a comet's tail isfrequently one hundred millions long, it is impossible to see aninstantaneous motion along the whole line of the tail; but granting thatthere are such flickerings in the tail as are described by so many, itmust necessarily be, that these flickerings will be _visible_. It wouldbe wonderful indeed, if a series of waves passing from the comet to theextremity of the tail, should have their phases so exactly harmonizingwith their respective distances as to produce a uniform steady lightfrom a light in rapid motion. The argument, therefore, proves too much, and as it is in the very nature of electric light thus to corruscate, aswe see frequently in the northern lights, we must be permitted still tobelieve that not only the tails, but also the heads of comets do reallycorruscate as described. 

With respect to the direction of the tail, astronomers have been forcedto abandon the antiquated notion, that the tail always pointed directlyfrom the sun; yet they still pertinaciously cling to the idea, thatalthough this is not always the case, the tail only deviates from thisdirection _in the plane of the orbit_. As this is a most importantquestion, it is necessary formally to protest against such a conclusion. If the earth should happen to be in the plane of the comet's orbit andthe tail appears in that plane, it must of course be in that plane_really_; but if the earth is not in the plane of the comet's orbit, thetail is not _necessarily_ in the same plane, whatever its apparentdirection may indicate. It is true there is a tendency of every particleof the tail, moving under the restraining influence of the sun'sattraction, to continue in the plane of the orbit; and in certainpositions there is no oblique action arising from the force of theradial stream to cause it to deviate from that plane; yet in otherpositions of the comet, the action of the radial stream may be oblique, forcing it out of that plane, and still such a direction might beassigned to it as to make it conform. In the comet of 1843, P. Smytheobserved a forked tail 25° long on March 3d, and from the end of theforked tail, and from its _north_ side, a streamer diverged at an angleof 6° or 7° to the _north_. As this was contrary to the _direction_ ofthe curvature, if the tail had been curved, it could only arise from aportion being driven off by the radial stream, or bent towards the planeof the ecliptic. The curvature observed by others at a later date, wasconcave to the south. Towards the middle and close of March, the tailbecame straight, and with the above exception, might be considered tomove in the plane of the orbit. 

The celebrated comet of Halley, as observed by Dr. Bessel in 1835, showed that a more or less well-defined tuft of rays emanated from thatpart of the nucleus which was turned towards the sun; and the rays being_bent backward_ formed a part of the tail. The nucleus, with itsemanations, presented the appearance of a burning rocket, the end ofwhich was turned sideways by the force of the wind. And, Besselconcludes: "That the cone of light issuing from the comet deviatedconsiderably both to the right and left of the true direction of thesun, but that it always returned to that direction, and passed over tothe opposite side; so that the cone of light, and the body of the cometfrom whence it emanated, experienced a rotatory, or, rather, a vibratingmotion _in the plane of the orbit_. " It is impossible that Bessel shouldhere mean that this motion was certainly in the plane of the orbit; forthe orbit was then viewed sideways, and he had no means of ascertainingthe fact. His meaning must be that it was apparently in the plane of theorbit. If a plane be made to pass through the earth, the comet, and thesun, the tail might be placed in any position in that plane, and yetappear to be at the intersection of the two; that is, in the plane ofthe comet's orbit. The vibration of the tail, in this case, is anotherstrong proof of the correctness of our theory. To make it moreintelligible, we shall resort to a diagram. 

In the following diagram, the comet's orbit, represented by the dottedline, is drawn on the plane of the ecliptic; it is, therefore, necessaryto bear in mind, that it is tilted up from the line of nodes SN, at anangle of 17° 45′. The position of the comet, October 9th, is at C, approaching its perihelion; that of the earth at the same time at T;while S represents the sun, and SQ the line of equinoxes. Now, from acause already explained, the tail always tends to lay behind the comet, in the direction indicated by the lower tail in the diagram at 1, and, if produced, would pass to the left of the sun, as seen from the earth:the force of the radial stream, however, will not allow this lagging ofthe tail, and it is straightened out by this force; but, being directedto the axis of the vortex, and not to the sun, it is not really in theplane of the orbit, but is seen in the direction of the upper taildepicted in the diagram at 3, and, if produced, would pass to the rightof the sun, as seen from T. Now, there is an intermediate position ofthe tail, in which it will appear in the prolongation of the radiusvector SC; this position is represented by the middle or central tail ofthe comet at 2, yet this is not in the plane of the orbit, it onlyappears to be, as may be readily understood by remembering that theearth at this time is under this plane, and the comet is seen at aconsiderable elevation above the plane of the ecliptic. When the comet'stail becomes directed to the axis of the vortex, or in the _apparent_position of No.  3, the comet, rapidly careering on its way to the sun, again leaves the tail behind, and again it is strengthened out by theradial stream oscillating about the mean position at 2, as observed byBessel. From this, it appears, that there is no necessity to makeconfusion worse confounded, by resorting to polar forces, which areabout as intelligible as the foundations of the pillars of Atlas. 

[Illustration: Fig. 25]

It may be objected that the continued action of the radial stream withthat velocity we have contended for, ought to keep the tail invariablydirected from the axis of the vortex; but, where there are two forces ortendencies, as in this case, analogy would teach us that a certaindegree of oscillation is a necessary result. There may, also, be slightand transient changes in the direction of the radial stream. In thehurricane there are short and fitful blasts inclined to the generaldirection of the wind, which must arise from the inertia of the movingmass of atmosphere, causing temporary condensations and rarefactions. Bethis as it may, we have assigned a cause which satisfies the phenomenon, without coming into collision with a single principle of celestialmechanics. 

Prof. Struve compared the tail of this comet to a flame, or "ray of fireshot out from the nucleus, as from some engine of artillery, and drivenon one side by the wind. " At the same time, he saw a second emanationnearly in the opposite direction. This last might arise from a momentaryfluctuation in the relative intensities of the electric radiation of thecomet, and of the radial stream, owing to the probable irregularitiesjust alluded to. Such and kindred phenomena are utterly inexplicable, without we adopt the theory we are advocating. One other feature, and wewill leave the subject. 

From our explanation of the solar spots, we inferred the existence ofanother large planet in the system. Might not the same effect beproduced by a comet? Or may there not be so many comets, whose greatelongation, combined with even a moderate mass, may render it impossibleto calculate the position of the sun with respect to the central axis ofthe vortex, --always considering this last as the axis of equilibrium? Ina general way, we might say that the very number of comets in alldirections and all distances, would tend to neutralize each other'seffects; but we are not under this necessity. A comet, moving in aparabola, does not belong to the system or to the rotating vortex; andthe periodic comets, if of gaseous elements, (as seems so probable, )must, from the size of their nuclei, which the theory considers the onlypart constituting their mass, have far less mass than the very smallestof the asteroids, and consequently could have very little effect on themechanical balance of the vortex, even if elongated as far as the orbitof Neptune. Did we know the influence of cold in limiting theexpansibility of the elementary gases, we might approximately determinethe mass of a comet, from the size of its nucleus; but this is a problemthat has never yet been solved; and astronomers ought to availthemselves of every indication which promises to realize this greatdesideratum. The grand comet of 1556 is now probably approaching, and, from recent investigations, it appears that it will arrive at itsperihelion in 1858, --subject to an error either way of about two years. An opportunity may thus be presented of determining the mass of one ofthe largest comets on record, which may not again occur. This arisesfrom the possible appulse of the comet to the planet Pallas, whose mass, being so small, would more sensibly be disturbed by such an appulse thanthe earth. As the inclinations and ascending nodes of the two orbitsapproximately coincide, and as Pallas will be near the comet's path, onthe approach of the latter to the sun, at the beginning of the year1857, should the comet become visible about that time, a very closeappulse is possible. It is not unlikely, also, that if the elements ofPallas were so far perfected as to afford reliable indications, that thenear approach of the comet might thus be heralded in advance, and leadto an earlier detection of its presence. Would it not be a worthycontribution to science, for some one possessing the necessary leisure, to give an ephemeris of the planet for that epoch; as a very slightchange in Mr.  Hind's elements of the comet, would cause an actualintersection of the two orbits in about heliocentric longitude 153°? Thesubsequent nodal passage of Pallas will take place near opposition, andbe very favorably situated for determining the instant of its passage;and, of all the elements, this would be more likely to be affected thanany other. [47]

THE ZODIAL LIGHT. 

A phenomenon, akin to that which we have just been considering, ispresented by that great cone of diffused light which accompanies thesun, and which in tropical climes displays a brilliancy seldom witnessedin high latitudes, on account of its greater deviation from theperpendicular. Sir John Herschel conjectures that it may be "no otherthan the denser part of that medium, which, as we have reason tobelieve, resists the motion, of comets, --loaded, perhaps, with theactual materials of the tails of millions of those bodies, of which theyhave been stripped in their successive perihelion passages, and whichmay be slowly subsiding into the sun. " If these materials have beenstripped, it is due to some force; and the same force would scarcelypermit them to subside into the sun. Once stripped, these portions mustbe borne outwards, by the radial stream, to the outer verge of thesystem. Still, there are, no doubt, denser particles of matter, of theaverage atomic density of Mercury and Venus, which can maintain theirground against the radial stream, and continue to circulate near thecentral plane of the vortex, in all that space between the earth and thesun. But if the zodial light be the denser part of that medium, whichastronomers now generally recognize as a resisting medium, how happensit that it should be confined to the plane of the ecliptic? Why shouldit not be a globular atmosphere? Here, again, our theory steps in with atriumphant explanation; for while it permits the accumulation of suchparticles around the equatorial plane of the sun, it allows noresting-place very far removed from this plane. The zodial light, therefore, is not the resisting medium, but the passage of the radialstream through a diffuse nebula of atoms, brought down the poles of thevortex by the polar current, and held in check along the central planeby gravitation. 

If these atoms partook of the velocity of the ether, they would not beluminous; but being held back by gravitation, they are opposed to theradial stream, and hence the light. 

Many stars are also nebulous. In some cases we see the nebulosityedgewise, or along the equatorial planes of the stellar vortices; inothers we look down the poles, and the nebulosities are circular, andthere is an endless variety in the shape and intensity of this light. But the universe seems full of motion, and we are not justified insupposing, because a star shows no such light, that it is withoutrotation. The parallax of the nearest star is only one second, the wholelenticular mass of light which surrounds our sun would therefore onlysubtend an angle of a single second at the nearest fixed star. Seeingits extreme faintness, therefore, the effulgence of the star wouldrender it totally invisible, provided that it _could_ traverse the vastimmensity of intervening space, without feeling the influence of thatextinction, which Struve has proved does actually diminish the number ofvisible stars. 

Corruscations and flickerings have also been noticed in the zodiallight, and as usual, the learned have suggested atmospheric conditionsas the cause, instead of trusting to the evidence of their own senses. How prone is philosophy to cling to that which is enveloped in the mistof uncertainty, rather than embrace the _too simple_ indications ofnature. As if God had only intended her glories to be revealed to afavored few, and not to mankind at large. Blessed will be the day when_all_ will appreciate their own powers and privileges, and no longerregard the oracles which emanate from a professional priesthood, whosedicta have so often tended to darken the simple counsels of truth! Toset the question of pulsations in the zodial light, as well as in thetails of comets, at rest, only requires previously concertedobservations, in places not very widely apart; for it is scarcelypossible, that atmospheric conditions should produce simultaneouspulsations in two distant places. If the pulsations are found to besimultaneous, they are real; if not simultaneous, they may depend onsuch conditions; but from the nature of the cause, we should look forthem as much in the zodial light, as in the aurora borealis, regardingthe different intensities. 

There is also reason to suspect that the northern side is always thebrightest, both in spring and autumn. On the morning of October 4th, 1853, the light was very vivid and well defined, its northern margingrazing Regulus and terminating at Mars, which was also to the north ofit. Now, although the _northern side_ was the brightest, the great massof light was to the south of the ecliptic, as far down as the cone shapewas preserved; but at 10° from the horizon, a still brighter massprotruded from the cone towards the north, which was all _north_ of theecliptic, and of an irregular form, extending along the horizon. Thetime was 4 A. M. , and consequently was not due to any crepuscular light. An explanation of the general fact of the brightest light being _always_on the north side, is given in the present section, in connection withanother phenomenon. If, as some suppose, the light does not reach to thesun, the annulus must at least fill all the space between Venus and theearth, but it is far more in accordance with facts as well as with ourtheory, to suppose it increases in density to the body of the sun. 

Observations made at the observatory of the British Association, detected, in 1850, sudden brightenings of the light, altogetherdifferent from pulsations. The theory would refer these to that fitfulirregularity in the momentary intensity of the radial stream, whichgives the flickering and tremulous motion to comets' tails. But, thesteady variations in the intensity of this light must be due to othercauses. The longitude of the sun will here come in as a modifying cause;for the obstruction caused by the body of the sun, when displaced fromthe axis of the vortex, must necessarily exercise an influence on theforce and direction of the radial stream. A sudden influx of cometarymatter down the poles of the vortex, in more than usual quantities, willalso tend to brighten and enlarge the zodial light; and, in this lastcause, we have an explanation not only of ancient obscurations of thesolar light, but, also, of those phosphorescent mists, such as occurredin 1743 and 1831, rendering moonless nights so light that the smallestprint could be read at midnight. 

In total eclipses of the sun, the denser portion of the zodial light isvisible as a brilliant corona; but, on such occasions, the brighteststars only are to be seen, and, consequently, the fainter portions ofthe light must be invisible. Hind mentions as many as ten stars visiblein the total eclipse of 1842. According to the same authority, the colorof the corona was like tarnished silver, and rays of light diverged inevery direction, and appeared shining through the light of the corona inthe total eclipse of 1851. In this year on the day of the eclipse (July28th), the longitude of the sun was about 340°, and, therefore, the bodyof the sun obstructed the radial stream as seen from the earth on theright side; but, in 1842, the longitude of the sun was, according to ourtable, about 116°, the sun's centre then being 700, 000 miles from theaxis of the vortex, and on the opposite side with respect to the earth;the position was, therefore, not so favorable for the appearance ofthese rays which, in many cases, have given the appearance of a whirlingmotion to the corona. 

At this date, July 7th, 1842, the corona, according to Prof. Airy, "possibly had a somewhat radial appearance, but not sufficiently markedto interfere with the general annular structure. " Mr.  Baily, on thecontrary, says, the corona had the appearance of brilliant rays; and, atMilan, long jets of light were particularly noticed. There can be nodoubt but that the passage of the radial stream past the outer margin ofthe moon must also give rise to the same phenomena as when passing thesun, and in this we have an explanation of the fact, that, previous tothe moment of first contact, an appearance resembling afaintly-illuminated limb of the moon, has been perceived near the bodyof the sun; as well as of those flashes of light which have beenobserved in the lunar disc as the eclipse advances. One important fact, worthy of note, is, that these luminous streaks are more nearly parallelthan is due to a radiation from the centre. These streaks have, also, been seen bent at right angles at the middle of their height, as a flameis by means of a blowpipe, precisely analogous to cometary rays beingdriven backwards to form the tail, as already described, thus indicatinga common origin. If the moon had an atmosphere, we should, no doubt, seea greater display; but, having no rotating vortex to protect her fromthe radial stream, her atmosphere must have been long since strippedoff, leaving her exposed to the withering winter blast of the greatstream of the solar vortex. In this connection, we may also allude tothe appearance of the moon when totally eclipsed. Instead ofdisappearing at these times, she sometimes shines bright enough toreveal her smallest spots. This has been generally referred to therefraction of the earth's atmosphere bending inwards the solar rays. Mayit not be owing to the brilliancy of the solar corona, which, in 1842, was described as so intense that the eye was scarcely able to supportit? This is a far more palpable cause for the production of thisphenomenon, but of which astronomers cannot avail themselves, as long asthey are uncertain of the origin of this corona. 

SHOOTING STARS. 

The continual influx of cosmical matter into the heart of the vortex inever-varying quantities, and speedily dispersed along the central plane, according to its density, must necessarily give rise to anotherphenomenon to which we have not yet alluded. Scarcely a night passeswithout exhibiting this phenomena in some degree, and it is generallysupposed that the hourly average of shooting stars is from five to ten, taking the whole year round. The matter composing these meteors weregard as identical with that mass of diffused atoms which forms astratum conforming to the central plane of the vortex, and whose partialresistance to the radial stream occasions that luminosity which we callthe zodial light. These atoms may coalesce into spherical aggregations, either as elastic gas, or as planetary dust, and, passing outward on theradial stream, will occasionally become involved in the vortex of ourown globe; and being drawn inwards by the polar current, and acted on bythe earth's gravity, be impelled with great velocity through therarefied air of the upper atmosphere. That meteors are more abundantabout the time of meridian passage of a vortex (or, perhaps, morecorrectly speaking, from six to twelve hours afterwards, when thecurrent of restoration penetrates the atmosphere), well accords with theauthor's observations. It is about this time that high winds may belooked for, according to the theory; and it has ever been a popularopinion, that these meteors are a sign of windy weather. Even inVirgil's time, the same belief prevailed, as a passage in his Georgicswould seem to indicate. 

 "Sape etiam stellas, vento impendente, videbis Præcipites cœlo labi; noctisque per umbram Flammarum longos à tergo albescere tractus;"

Virgil was a close observer of nature, and commences a storm with thewind at south, "Quo signo caderent Austri;" just as we have representedthe usual course when these vortices pass near the observer's latitude. It is also a well-known fact, that after a display of meteors, (and weare now speaking of ordinary displays, and not of the great showers, )the temperature falls considerably. It is not uncommon also, thatmeteors are more abundant during an auroral display, as they ought to beby the theory. We must, however, exempt from this influence those solidmeteors which sometimes come into collision with the earth, andafterwards grace the cabinets of the curious. These bodies may beconsidered microscopic planets, moving in stated orbits with planetaryvelocity, and bear strongly on the explosive theory of Olbers, as fullydetailed by Sir David Brewster. 

It is a very remarkable fact, first noticed by Olbers, that no fossilmeteoric stones have yet been discovered. If this fact be coupled withthe hypothesis advanced by Olbers, in reference to the origin of theasteroidal group, we should have to date that tremendous catastrophesince the deposition of our tertiary formations, and therefore it mightpossibly be subsequent to the introduction of the present race into theworld. May not some of the legendary myths of the ancient world asmystified by the Greeks, have for a foundation the disappearance of aformer great planet from the system? The idea of the existence of sevenplanets is one of the oldest records of antiquity; but the earth ofcourse would not be counted one, and therefore in after times, the sunwas included to make up the number; just as the signs of the Zodiac havebeen explained in accordance with the seasons of far later times than wecan possibly assign for the invention of this division of the heavens. Let those who have the leisure, try how far the contraction and dilationof the asteroidal orbits, to some average mean distance, will restorethem to a common intersection or node, as the point of divergence of thedifferent fragments. The question is interesting in many of its aspects, and may yet be satisfactorily answered. 

The composition of aërolites may also be taken as indications of thecommon origin and elementary texture of the planets, whether they areindependently formed or have originally pertained to a former planet;for no hypothesis of telluric or selenic origin yet advanced, can standagainst the weight of evidence against it. Their fragmentary characterrather favors the views of Sir David Brewster, and when we consider thatthey have been revolving for thousands of years with planetary velocity, and in very eccentric orbits, through the ether of space, continuallyscathed by the electric blast of the radial stream, their roundedangles, and black glossy crust of an apparently fused envelope, may beaccounted for, without difficulty, from the non-vitrified appearance ofthe interior. The composition of aërolites as far as known, embracenearly one-third of all known simple substances according to Humboldt, and are as follows: iron, nickel, cobalt, manganese, chromium, copper, arsenic, zinc, potash, soda, sulphur, phosphorus, and carbon. 

The theory we have thus given of the common occurrence of shootingstars, will render a satisfactory general account of their sporadicappearance; but there are other phenomena of greater interest, viz. : theoccasional recurrence of swarms of such meteors, which defy allnumerical estimates, being more like a fiery rain than anything they canbe compared to. The most interesting feature of this phenomena, is the_apparent_ periodicity of their return. In the following table we haveset down the most remarkable epochs mentioned by Humboldt, (and no manhas devoted more attention to the subject, ) as worthy of notice:

 About April 22 to 25 " July 17 to 26 " August 9 to 11 " November 12 to 14 " November 27 to 29 " December 6 to 12

Besides these, he mentions two showers, from Arabian authority, inOctober; one in October, observed in Bohemia; one observed by himself, in the Pacific, on March 15; one February 4, just preceding the terribleearthquake of Riobamba, in 1797. The Chinese annals also contain manyshowers of stars, before the present era commenced. Some were in March, more in July, and others in different months. How, then, in view ofthese numerous dates, can we attach so much importance to theperiodicity of these showers? The great shower of 1833, in the UnitedStates, on the 12th and 13th of November, brought to mind the greatshower at Cumana, observed by Humboldt and Bonpland just thirty-threeyears before, to a day; and it must be confessed that more than ordinarydisplays have been seen on this date. Yet, on the strength of this, every meteoric shower is supposed to be periodical, and has resulted ina theory which becomes more complicated as the phenomenon is moreobserved, and can never lead to any useful and practical results. Tocite the numerous instances of discrepant results, would only encumberthis brief notice with facts neither interesting to the general reader, nor convincing to those who hold a contrary opinion. The author of thesepages has watched for many years, and, in view of all the facts, hasconcluded that the doctrine of periodicity (as held by presentmeteorologists) is not tenable. The celebrated August shower failed, also, this year, at least in this place, as for four hours each night, on the 9th, 10th, and 11th, there were fewer bright meteors than at theclose of July. 

Professor Olmsted, who has paid considerable attention to the subject, has indeed attempted to connect the great November shower with thezodial light, which last he considers a nebulous body, of an elongatedform, whose external portions, at this time of the year, lie across theearth's path. (See Silliman's Journal for 1837, vol.  xxxiii. No.  2, p.  392. ) He even gives its periods, (about six months, ) the aphelion ofthe orbit being near the earth's orbit, and the perihelion withinMercury's. In this way he attempts to explain both phenomena; but as thezodial light is seen unchanged all the year round in tropical latitudes, it is not the kind of body supposed by Olmsted, and the theory addsnothing to our knowledge. Others have imagined rings of nebulous matter, in which all the separate parts are moving in the same orbit around thesun, with a retrograde motion, and this, with some modifications, is thecurrent theory of the day. The principal arguments rested on, for thesupport of this view, are derived from the great shower of 1833, inwhich a common radiant point was observed, and confirmed subsequently bythe radiant of other years, in the same month of November. As this pointis almost tangential to the earth's orbit at this season, the earthmeets the nebulous ring moving in the contrary direction, and thusconfers on these meteors the necessary velocity that is thought to bedemanded by observation. 

Now, our theory gives a totally different explanation of the phenomenon. We contend that a retrograde motion of such a nebulous mass, issubversive of our whole theory; and we must be permitted to examinecertain points, hitherto disregarded by those entertaining antagonistviews. It is supposed that the meteors in 1833 fell for eight or ninehours. The orbital velocity of the earth is more than 1, 000 miles perminute, and the orbital velocity of the nebulous zone must have had asimilar velocity. During the nine hours of meteoric display, therefore, the earth traversed 500, 000 miles of her orbit, which would give1, 000, 000 miles for the depth of the nebulous stratum. But if of suchvast extent, how happened it that the only part of the earth in whichthese were visible in great density, was the United States, or a spaceembraced between the latitudes of 50° and 20° north, and the longitudes60° and 100° west, (and these are the widest limits, ) comprising only1/40 of the surface of the globe? To a calm inquirer, this difficultyseems insurmountable. The author was then in the Mediterranean, on deckthe greatest part of the night, --the weather fine, and nothing unusualvisible in the heavens; from other sources he has also derived similarinformation. Yet, were the earth then passing through a stratum ofmeteors 1, 000, 000 miles in extent, it is utterly inconceivable thatother portions of the earth escaped. Much stress is also laid on thefact that these meteors in 1833, passed from east to west generally, asthey ought to do, if tangential to the earth in her orbit; but on thesame phenomenon occurring in 1799, when the earth was in precisely thesame part of her orbit, Humboldt says distinctly, "the direction (of themeteors) was very regular from north to south. " How could this possiblyhappen, and at the same time be moving tangentially to the orbit?

There is also another fact of importance not duly weighed in formingsuch a theory. In 1833 the meteors evidently differed in velocity; oneclass, consisting of luminous points, passed like a shower of fire withgreat velocity to the westward, another class were like large fire-ballswith luminous trains moving with less rapidity, while a third classconsisted of nebulous patches which remained stationary for a long time, and frequently emitting large streams of light. These last, at least, donot deport themselves as planetary bodies moving 2, 000 miles per minute. But the fact still remains, that unusual displays have occurred aboutthe 12th and 14th of November; and also as a general thing when thereare no unusual displays, the meteors are more abundant about this time. Let us try if we can reconcile these facts with the theory of vortices. 

We will first confine our remarks to the increased number of meteorsabout November 12th and 14th. The cosmical matter composing the zodiallight, or at least the lighter parts of it, is continually drivenoutwards by the radial stream, just as the matter of a comet's tail isstripped from the nucleus. This matter becomes involved in the terralvortex by descending the poles, and is again passed out along theequatorial plane. The form of the zodial light, as seen edgewise, givesa lenticular form for the stratum of planetary particles composing it, and its central plane has been considered as coinciding with the planeof the sun's equator. At the orbit of the earth, this lenticular spaceis narrowed to a very thin stratum, but undoubtedly reaches beyond theearth's orbit with a rapidly diminishing density. As the axis of the sunis inclined about 7° to the ecliptic, and the ascending node is in the20th degree of Gemini, the earth can only pass through the plane of thesun's equator about the 12th of December and the 12th of June. If, therefore, the central plane of the vortex coincides with the plane ofthe sun's equator, meteors ought to be more numerous about the datesabove mentioned. But the observed times are on November 12th and 13th. Now, from actual measurements, a computation has been made by M. Houzeau, that the elements of the zodial light are materially differentfrom those of the sun's equator. He fixes the node of the light(according to Mr.  Hind) in 2° heliocentric longitude, subject to anuncertainty of 12° or 13°, and its inclination to the plane of theecliptic, 3° 35′, subject to an uncertainty of about 2°. The truth is, astronomers have argued the coincidence of the two planes fromconsiderations connecting the zodial light with the sun's equator, as ifit were a solar atmosphere; but such an atmosphere is impossible, and itis high time such measures should be taken as will lead to some certainconclusion. If in the present state of the question, we were to take themean, we should find the node in about longitude 40°, which is theposition of the earth on November 2d. But in the absence ofmeasurements, we will assume, for the sake of argument, that theascending node of the central plane of the vortex was, in 1833, in 50°heliocentric longitude, and consequently the earth was passing throughthe meteoric stratum or central plane of the zodial light, on the nightof November 12th. The opposite period of the year is May 12th--a date, it is true, on which no great shower of stars is recorded, but sporadicmeteors are very plentiful at that time, and what is more important toobserve is, that the 11th, 12th, and 13th of May, are the three noted_cold days_ which we have before mentioned. Thus truly indicating thatthe earth is then in or near the central plane of the vortex along whichthe radial stream is at its maximum of power at any given distance fromthe axis. 

But the question occurs, does the node of this plane remain stationary, and is there no variation of the inclination of the axis of the solarvortex? We have found from observation, that the axis of the terralvortex is continually oscillating about a mean position by the action ofthe moon; and reasoning from this analogy, and the constant tendency ofa material vortex to preserve a dynamical balance, the same tendencymust obtain in the solar vortex under the action of the great planets, whose orbits do not coincide with the central plane of the vortex. Theascending node of Jupiter's orbit is in longitude 98°, Saturn's 112°, Uranus' 72°, Neptune's 131°; so that this plane does not correspond withthe plane of greatest inertia discovered by La Place, and from thenon-coincidence of these planes with the central plane of the vortex, must produce the same oscillation in the axis of the solar vortex, asthe moon does in the terral vortex, but to what amount, observation canalone determine. Jupiter and Saturn will of course exert the greatestinfluence, and when these two planets are in conjunction, the ascendingnode of the central plane of the vortex will vary in longitude perhapssufficiently to bring the meteoric maximum at the ascending node intoOctober on the one hand, and to the close of November on the other, andat the descending node to April 25th on the one hand, and the close ofMay on the other. 

The great showers of stars which have been recorded, must be thereforeconsidered as an accidental exaggeration of a perennial phenomenon, attaining its maximum when the earth passes through the central plane ofthe vortex, whose ascending node in 1833 we will suppose was inlongitude 50°. This theory will therefore account for those greatshowers which have occurred about the 24th of April, as well as thoseoccurring in October and November; for it is far more consonant to allanalogy, to suppose the influx of planetary atoms into the solar vortexto be in irregular, than in regular quantities. Yet, whether in the onecase or in the other, the matter will pass along the central plane ofthe vortex, either diffusely scattered or in denser clouds, and will beencountered by the earth when near the nodes _more frequently than atother times_. The phenomenon of 1833, may then be attributed to theearth encountering an unformed comet on the 12th of November; but wemust reflect, that the medium of the vortex is also in motion, and thecometary matter drifting along with it; and that this motion correspondswith the earth's motion. By becoming involved in the terral vortex, itwill in a measure be carried along with the earth in her orbit as atemporary occupant of the terral vortex. But we are here met with theobjection that the radiant being nearly stationary amongst the stars, demonstrated conclusively, that the source of these meteors did notpartake of the earth's motion. There is no difficulty in this. Wesuppose as a general thing, that the meteors descended to the surface ofour atmosphere down the axis of the vortex (at least in the greatestnumbers), and the geocentric longitude of this axis was nearly the sameduring the whole time of the display. We say nearly, for the motion ofthe moon in her orbit in nine hours, would change the longitude of theaxis three or four degrees, and this is about the change in theposition of the radiant noted at the time. This objection, therefore, falls to the ground; for the axis of the vortex, although carried alongwith the earth in her orbit, was unaffected by the earth's rotation, andwould therefore appear nearly as stationary in the heavens as GammaLeonis. But it is again urged, that the moon was near conjunction withthe sun, and consequently the central vortex was on the opposite side ofthe globe. This is true; but the outer vortex must have been near themeridian about three hours after midnight, or about the time when theradiant was vertical and the display the greatest. When the axis was tothe eastward, the stars would shoot westward, when on the meridian, theywould pass in all directions, but principally to the south, on accountof the inclination of the axis of the vortex; but this would only betrue for places situated to the southward of the central latitude. During the great shower of stars seen by Humboldt, in Cumana, thedirection was to the south uniformly. Now, the latitude of Cumana isabove 10° north, yet still too low for the general limits of thevortices; but from the same inclination of the axis (from 30° to 36° tothe surface), the meteors would pass far south of the limit, and mighteven reach to the equator. The latitude of the _outer vortex ascending_on November 12th, must have been near the line of greatest display, fromthe position of the moon at the time. We thus see why the phenomenon waslimited to so small a fraction of the earth's surface; why these meteorsshould be intermingled with nebulous patches stationary in the heavensfor an hour together, and why, notwithstanding these facts, they wereindependent of the earth's rotation. 

We have yet another objection to answer, viz. : the planetary velocity ofsome of these bodies. Let us be understood. The velocity of a solidaërolite is due to gravitation, and is planetary, on the other hand, voluminous collections of cometary dust united by accident, andremaining so by mere inertia, are borne passively on the etherealcurrents with _electric_ velocity, and probably never penetrate far, even into the attenuated atmosphere, which may be supposed (from thefacts connected with the aurora) to extend far above the denser stratumwhich refracts and reflects light, and from which the assigned limits ofour atmosphere have been derived. 

It is generally considered that sporadic meteors are more numerous inthe summer and autumn than in the winter and spring, and we have, likewise, in the tenth of August, a date which corresponds to many greatdisplays and meteoric showers, both in recent and remote times. Thiswould seem to vitiate our theory; for we cannot suppose that there aretwo _central_ planes in the vortex intersecting the ecliptic inlongitude 320° and 50°. We must remember, however, that as these greatdisplays are accidental, and as the stratum composing the zodial lightis manifestly of sufficient thickness to envelope the whole orbit of theearth, that it does not necessarily follow that the dense portions towhich meteoric showers are due, should be always confined to the centralplane of the vortex. And, besides, we have similar displays recorded inother months, which invalidates the theory of a regularly-recurringphenomenon. We shall, therefore, only aim at explaining why meteors aregenerally more abundant in summer and autumn than in the oppositeseasons. 

The axis of the solar vortex, considered as cylindrical, must beadmitted to run out to a great depth on either side from the sun, andreach far into that unoccupied space intervening between our system andthe nearest fixed stars, and from these opposite points the solar vortexis supplied with that stream of ether which passes down either pole torestore a partial equilibrium in the density of the ether of the vortex, rarefied by centrifugal force. As certain portions of the heavens arecrowded with stars, and other parts comparatively vacant, we may expecta similar inequality in the distribution of that cometic dust, whichcauses a certain amount of extinction in the light of the stars, and, therefore, seeing that the two extremities of the axis of the solarvortex are so widely separated, it would not be wonderful if differentquantities of such matter were brought down into the vortex from theseextremities. 

From recent observations made by H.  R. Birt, at the observatory of theBritish Association, it would appear that the brightest portion of thezodial light is always north of the ecliptic. Others have also remarkedthe same, and if we couple this fact with the suggestion just made, weare justified in suspecting that a greater quantity of cometic dustcomes down the northern pole of the vortex than down the southern. Thismatter, in passing outward, does not, of course, immediately attain tothe central plane of the vortex, but is more thickly distributed along aplane parallel to this plane. And the same will be observed by thatmatter coming down the southern pole; it will be, in a certain degree, retained in a plane south of the central plane, but still parallel withit. This would account for the greater brightness of the northern sideof the zodial light. It would, also, account for the greater frequencyof meteors in summer and autumn than in the opposite seasons. From May toNovember the earth is above the central plane of the vortex, and, consequently, on the northern side; but after passing the node inNovember, she is on the under or southern side, and the meteors are lessfrequent. With this general explanation we shall close. If what we haveadvanced be an approximation to the truth, the theory itself affordsample indications of what observations are requisite to prove ordisprove it; and, on this account, a theory is of great benefit, assuggestive of many questions and combinations of facts which otherwisemight never be thought of. 

We have thus taken a cursory glance at the prominent physical phenomenaof the world, and attempted to link them together in the bonds of oneall-pervading principle. We have fearlessly taken a new path, and claimoriginality for the whole, disclaiming all intention of retailingsecond-hand wares, or of compiling an ingenious theory fromheterogeneous scraps. If it be true, or if it be partially true, letthose professionally engaged in such pursuits enter the wide field ofinvestigation we have discovered for them; for if the whole theory betrue, it only shows in a clearer light that the great work which hasbeen fancied so near completion is scarcely yet begun; while theprospect of an ultimate and final completion of the temple which so manyzealous votaries are erecting, is rendered mournfully hopeless by thecontemplation of what yet remains to be performed. 

FOOTNOTES:

[42] The orbit this year was determined under very unfavorablecircumstances. 

[43] According to other tables, this angle would be much greater than isgiven in Mr.  Hind's catalogue. 

[44] Prin. Prop.  xx Lib. Sec. 

[45] With reference to the resisting power of the atoms. 

[46] Prin. Lib. Tor. Prop, xxxix. , also Prop, xli. 

[47] In making this suggestion, the author is well aware thatEphemerides of the four chief asteroids have been given annually in theGreenwich Nautical Almanac; but for the object proposed they are utterlyuseless. Will any astronomer contend that these Ephemerides are true toten seconds of arc? If not, they are useless for the purpose suggestedabove, and the theory wants revision. And it is evident that anyobjection against its practicability, founded on the uncertainty of thenumber of the asteroids themselves, as has already been urged in answerto this suggestion, is an evidence that the objector weighed the subjectin the scales of his imagination only. 

SECTION SIXTH. 

THE POLAR ICE. 

We shall conclude these pages by again referring to our theory of theweather, in connection with an event which every friend of humanity andevery lover of natural science is bound deeply to deplore. 

From the present position of the lunar nodes and apogee, the vortices ofour earth do not ascend into very high latitudes. Now, according to theprinciples laid down, the frequency of storms tends to lower thetemperature in the warm regions of the earth, and to elevate it in thepolar regions. Let us suppose the northern limit of the vortices to bein latitude 70°. There will be, in this case, a greater prevalence ofnortherly winds _within_ this circle of latitude, to supply the drain tothe southward, and the back currents by passing above will descend atthe pole, partaking of the temperature due to that elevation. Thecharacter of the arctic seasons may therefore be considered as partlydependent on the average direction of the wind. Suppose again, theextreme limits of the vortices to be about latitude 80°, the relativeareas of the two circles are as 4 to 1; so that in this last case theexclusive range of the northerly winds is limited to one-fourth of thefirst area. South of 80° the wind will frequently come from the south, and by mixing with the local atmosphere of that latitude, will tend toameliorate the small area to the northward. And the greater atmosphericcommotion when confined to such a small circle of latitude, must assistmaterially to break up the polar ice; which would tend still more toequalize the temperature. 

By referring to our table, we see that the mean conjunction of the poleof the lunar orbit and the moon's apogee, was in longitude 128° on April10, 1846, and let it be remembered that when the conjunction takes placedue south or in longitude 270°, the vortices attain their greatestlatitude north. When, on the contrary, the conjunction takes place duenorth or in longitude 90°, [48] the northern limits of the vortices arethen in the lowest latitude possible. 

Sir John Franklin sailed in May 1845, and was certainly at the entranceof Wellington sound, near latitude 75°, April 3d, 1846, as the dates onthe graves testify. That season, according to the theory, was a coldone; for the vortices could not reach so far to the northward in thatyear, and consequently there were no storms, properly speaking. It wouldprobably be late in the summer of 1846, before the expedition wasliberated, and as the prevailing winds would be from the northward, hewould have little choice, but to stand to the westward if the state ofthe ice permitted. In his instructions he was to use every effort topenetrate to the southward and westward of Cape Walker, and he probablyconformed to them under the circumstances, and passed the winter in theice, in that neighborhood. And in 1847 we do not anticipate, from thetheory, that he would make much progress westward. 

In 1848, Sir James Ross was sent out with the first relief-ship; but wasnot able to reach the entrance of Wellington channel because of compactice from there to Leopold Island. This was about the beginning ofSeptember--a time when the northern channels are usually the most open. On the 11th, they ran the ships into Port Leopold, and the next day theice shut them in for the winter. From the character of the season, wemay infer that if Franklin did not enter Wellington channel in 1847, asis most probable, neither did he in 1848. Perhaps he was not able to gethis ships far to the westward, as we infer from the theory. Still, asthe time was not very protracted, he would wait patiently another seasonand husband his resources. 

In 1849, Sir James Ross cut his ships clear of the ice August 28th, andcrossed over to Wellington channel, where he found the land-ice stillfast, showing that this season was also a bad one in accordance with thetheory. On the 1st of September he met the first gale of wind, at whichtime the _Inner Vortex_ was at its extreme north latitude, and rapidlyextending its limits by the motion of the perigee. 

This vortex describes a smaller orbit than either the central or theouter vortex, and consequently reaches into higher latitudes. But thetime was badly chosen, as the whole series of years since Franklin lefthas been unfavorable for the early rupture of the ice. Sir James Rosshaving been drifted out of Lancaster sound by the gale, finally bore upfor England towards the close of September 1849. 

The same year, the North Star with additional supplies was working upBaffin's bay; but on account of the unusual quantities of ice, and thefrosts "which glued the floes together, " she was unable to force apassage through the middle ice, and wintered on the east side ofBaffin's bay, in latitude 76° 33′--her thermometer marking 64° belowzero, as the coldest of the winter. In 1850, the perigee of the moonattained its northern limit, but the position of the node was bad; stillthis year and 1851, were the best of the series. The North Starsucceeded in getting out of the ice on the 1st of August--a very earlydate for that high latitude--and on the 8th had crossed over toPossession bay; but being prevented by the land-ice, she bore up forPond bay and there landed the provisions. The same year (1850) severalvessels entered Lancaster sound. Sir John Ross also reached MelvilleIsland; from which it is evident that this season was far better thanany preceding. According to Captain Penny, this year a floe of ice atleast two years old, filled Wellington strait; but was diminished inbreadth at a subsequent visit. He also saw a boundless open sea from the_western_ entrance of Wellington strait; but of course the ships couldnot reach it, for the floe before mentioned. Following the indicationsof the theory, we consider it almost certain that Franklin went to thewestward and not through Wellington channel; that he made but slowprogress until 1850, when finding the sea more open to the northward, and attributing it more to local influences than to any change in theseason, he considered it a better course to extricate the expedition, bypushing on towards Behring's straits than to attempt the frozen channelshe had already passed through. But the seasons again getting worse after1850, he was again arrested in the polar basin by the ice and islandsoff the northern coast of America. 

Regarding the old and new continents as in reality a connected body ofland, with a polar depression, we may expect that the great range ofAmerican mountains is continued in a straight line, from the mouth ofthe McKenzie river, obliquely across the Polar sea, and connects withthe Ural; and that along the axis of the chain, protuberant masses willemerge above the sea level, constituting an archipelago of islands, fromNova Zembla to the McKenzie; and that these islands, causing anaccumulation of ice, and arresting its general tendency to thesouthward, is the barrier which Sir John Franklin was finally stoppedby, in a situation where he could neither advance nor return. With themap before us, and the data afforded by former voyages, and guided bythese theoretical views, respecting the prevailing direction of thewinds and the character of the seasons, we should locate Sir JohnFranklin near latitude 80°, and longitude 145°, in 1851; and as theseasons would afterwards become more severe, we may consider that hehas not been since able to change his locality, and dare not desert hisships. 

No mere stranger can feel a deeper interest than the author, in view ofthe hard fortunes of these hardy explorers, and he would not lightlyadvance such opinions, did he not suppose they were in some degreereliable. In 1832, he himself crossed the Atlantic, for the purpose ofoffering himself to the Geographical Society of London, intending to belanded as far northward as possible, with a single companion, [49] fromwhich point he purposed to follow the coast line on foot, with cautiousdiscretion as to seasons, confident that, with arms and ammunition, hecould support himself for many years. It has always been a grave errorin all these northern land expeditions, that they have been toounwieldy, too much encumbered with the comforts and luxuries ofcivilization at the outset, and too much loaded with a philosophicalparaphernalia, for a pioneering survey, --and cherishing too fondly theidea that the wide shores of the Arctic sea could be explored in asingle season. Had the British government established a few posts in theArctic regions in the beginning, --one, for instance, in Lancaster sound, another in Behring's Straits, and a third near the mouth of theCoppermine, volunteers of sufficient scientific attainments might havebeen procured, to banish themselves to these inhospitable regions for aterm of years, if assured of triennial supplies; and in this way, bysummer boat-parties and winter expeditions, over land or ice, theexplorations could have been gradually extended, and a greater knowledgeof the polar regions might have been acquired, with an immense savingboth of life and money. In 1832 the author's plan was deranged, byfinding that Captain Back was about setting out in quest of Ross, whohad then been some four years absent. This officer had all his partyengaged when the author waited upon him in Liverpool, and no notice wastaken of a modified plan which he forwarded to the Society at hissuggestion. It was therefore abandoned. 

The above fact is alluded to, in order to show the author's sincerity inexpressing his belief that, with a previous preparation of mind and bodyfor a sojourn in those frigid climes, a sufficient subsistence may bederived from the country itself. Advantage must, of course, be taken ofthe times of abundance, and due preparation made for the season ofscarcity. Averaging the extremes, there is little doubt but that bothland, and air, and water, afford an abundance of food for man in theArctic zone, and that, when spurred by necessity, it is within his powerto obtain it. We ought not therefore to despond, or give up efforts torescue those who have well earned the sympathy of the world, by whatthey must have already suffered. _These northern seas will yet beexplored. _ The very difficulty of accomplishing it, will itself give ita charm, which in this restless age will operate with increasing power. And should efforts now be relaxed, and in some future time the evidencebe brought to light that some of the party yet existed, long after allefforts to rescue them had been abandoned, the fact would be a dark spoton the escutcheon of England, which time could not erase. 

Since these pages were written, accounts have been received from CaptainMcClure, of H.  M. Ship Investigator, which fully confirm the precedingremarks on the character of the seasons in the Arctic circle; and, morerecently, despatches have been received from the discovery-ship, Amphytrite, in relation to the past season in Behring's straits, whichalso confirms the theory. 

The Investigator (now supposed to be frozen up in lat.  74° 5′ N. , andlong 117° 54′ W. , --the last despatch being dated April 10, 1853) passedround the northern shores of America into the channels communicatingwith Lancaster sound, in 1850, but was unable to extricate herself in1852, and, probably, yet remains in the harbor she made in the winter of1851, in the position above named. No trace of Sir John Franklin'sexpedition was, however, found, and, indeed, according to our theory, the Investigator was not on the most promising ground. We contend thatFranklin has penetrated the pack of apparently perennial ice, which iscontinually pressing to the southward, and blocking up the passagesbetween the northern islands, or skirting the coast line of thecontinent; which pack has since increased, and effectually stopped allegress from the open central portions of the polar sea. If Sir JohnFranklin is ever heard from, this pack _must be penetrated_, and apowerful steamer ought to be sent immediately by the British government, to be ready in Behring's straits early enough to take advantage of thefirst openings, and make a bold push _due north_, so as to get asspeedily as possible into the open waters to the north of the pack. 

If the author could make himself heard at Washington, he would also urgethe government to lose no time in following our own expedition under Dr. Kane, who, if he finds a clear entrance from Smith's sound into theArctic sea, may be induced to push on, and endeavor to make his waythrough the pack towards Behring's straits, and thus fall into the samesnare as Franklin. According to the theory, the higher the passage intothe Arctic sea, the less will it be incumbered with ice, and, consequently, Smith's sound is the best both to enter and return by; andhad the author not already smarted enough by having his professionsderided, he would have submitted these views to the patrons of thatexpedition before it sailed. 

The scientific world is, in reality, chargeable with the disastrousresults of Franklin's expedition. The polar basin is hemmed in by thecoast line of Europe, Asia, and America, in about latitude 70° north, for the greatest part of the entire circumference. And this coast line, and the islands adjacent, will cause the polar ice to accumulate andform a frozen belt along these shores, in consequence of the constanttendency of the earth's rotation to press the ice to the southward. Thefact that an open passage exists between this belt and the shore insummer time, is no objection, as the tides, river currents, and warmland breezes, may very well explain this. The learned have insisted, anddo yet insist, that the earth's rotation can produce no motions in theArctic sea, and, under this delusion, Franklin has passed into thecomparatively open waters inside the pack, perhaps has lost his ships;yet it is very possible that the party may have escaped, and derived asubsistence from the more genial waters of the central portion of thatocean unto this day. 

We have already alluded to the difference of level between the Atlanticand Pacific waters. It is well known that the currents in theSpitzbergen and Greenland seas is to the southward, and that Parry, inhis attempt to reach the pole, was foiled by this very current, frequently setting him back in twenty-four hours more than his partycould travel in the same time over the ice. Through Baffin's andHudson's bay the northern waters are also continually bearing theirfrozen freight southward. We are, therefore, entitled to ask, whatsupplies this immense drain? Behring's straits are only about sixtymiles wide, and twenty-five fathoms deep; the supply, therefore, throughthis channel is totally inadequate, yet there is no other channel intothe Arctic sea where the current is inward. We have already explainedthe reason why the current through Behring's straits is an exception tothe general rule, yet still confirming the principle by referring it tothe configuration of the land enclosing the Pacific ocean. The wholesouth Pacific lies open to the pole, and the inertia of the immense massof mobile waters pressing northward, and continually contracted by theform of the American and Asiatic coasts, is not balanced by a contraryimpulse of the waters of the north Pacific, inasmuch as this oceanbecomes narrower as it extends northward, and the only passage to thefrozen ocean is through the narrow straits of Behring. The axifugalforce of rotation due to the northern waters is, therefore, overborneby the vast preponderance due to the southern waters, and, hence, thenorthern Pacific may be considered as relatively at a higher level, andthere will be a current northward through Behring's straits, as we findit. The same cause accumulates the waters under the equator, thus givinga higher level to the Pacific than to the Atlantic at the isthmus ofPanama, where the difference of level is found by actual measurement tobe five or six feet. This fact has never before been explained; but thecause is too obvious to admit of question. 

That the sea is deeper than was formerly admitted, is now fullyconfirmed. We have before alluded to the results obtained by CaptainDenham, of H.  M. Ship Herald, who found bottom at 7, 706 fathoms, orabout nine English miles. Now, whether that spherical shell, which wehave contended to be the true form of the solid earth, be continuous andentire; or, whether it may not be wanting in localities of limitedextent where the ocean would be absolutely unfathomable, we know not;but if such be the internal constitution of our globe, there will be, nodoubt, many channels of communication between the internal and externalocean, and, as a consequence of the earth's rotation, the axifugalcurrent of the Arctic sea may be supplied by an upward current from theinterior of the globe; and this current may have a higher temperaturethan the surface waters of that sea, and thus the middle portions may, in truth, remain open the whole year round, and be teeming with animallife. According to Captain Penny's observations in 1850, whales andother northern animals existed to the westward, where he saw the opensea stretch out without a bound before him. 

It has been a question mooted by some, that Franklin's ships might beovertaken, at an early stage of the voyage, by a storm, and founderedamidst the ice. The theory would give a negative answer to thisquestion. Stiff gales may prevail far to the north when the vortices donot reach so high; but no storm, properly speaking, will be found farbeyond their northern limit. After the coming winter (1853), thevortices will gradually penetrate farther and farther to the northward, and the years 1857, 1858, and 1859, will be highly favorable fornorthern discovery, accompanied, however, with the necessary draw-backof tempestuous weather. 

FOOTNOTES:

[48] The reader will of course understand these as celestial longitudes, and the latitudes as terrestrial. 

[49] Mr.  William McDonald, of Canada. 

CONCLUSION. 

Our theory has thus extended itself beyond those limits which we atfirst had drawn, and our apology must consist in the necessity existingfor reconciling the most remarkable phenomena of meteorology to itsprinciples. Yet, after all, what has been said is but an outline of whatremains, but this outline is a part of our theory of the weather, and itcould not well do without its aid. In some points we may not havecorrectly interpreted facts; but the facts remain. The numericalelements of the theory may also be in error--we know not; but we thinkthat they are as perfect as the many contingencies on which they dependwill permit. What is _certain_ however, is of ample value to compensatefor trivial errors. We have hitherto experienced but little courtesyfrom those intrusted with the keys of knowledge, and cannot consequentlyanticipate a very lenient verdict. But we now tell them before theworld, that they have a duty to perform, and an examination to make, anda decision to come to, "whether these things are so. " Our theory may becalled an ingenious speculation, but WE CHALLENGE THE SCIENTIFIC TOPROVE IT--NOTHING ELSE. The theory furnishes them with tests of dailyoccurrence, to prove or to disprove it. By such a trial we are willingto be judged; but let it be conducted in the spirit recommended in theopening address before the American Association for the Advancement ofScience, to expose all false developments, and to do it generously andwithout prejudice; and to remember, "that the temple of science belongsto no country or clime. It is the world's temple, and all men are freeof its communion. Let its beauty not be marred by writing names upon itswalls. "[50] The _great_ objection, of friction and resistance of anall-pervading medium, which will be urged against it, we regard asrather the offspring of a bewildered imagination, than of scientificinduction. We can discover no such consequences as final ruin to oursystem through its agency; but even if such were discovered, we mayanswer, that nature nowhere tells us that her arrangements are eternal;but rather, that decay is stamped with the seal of the Almighty on everycreated thing. Change may be one of the great laws of matter and motion, and yet matter and motion be indestructible. The earth was called intoexistence for a specific object, and when that object is accomplished, we are assured that another change awaits her. But when earth, and sun, and planets, are again redissolved into their primitive state, theiratoms will still float on the ever-rolling billows of the great etherealocean, to be again cast up, on the shore of time, whenever it pleasethHim to say, "Let there be light. "

FOOTNOTES:

[50] Prof. Pierce's Address, 1853. 

APPENDIX. 

Since the author's arrival in New York for the purpose of publishing hisoutlines, the third and fourth volume of the Cosmos has been placed inhis hands, containing the latest uranological discoveries andspeculations. It is now more than twenty years since he began toinvestigate the subject he has treated of, and fifteen since he firstannounced to the world, that he had satisfactory evidence of his theorybeing true. Luckily, perhaps, he has been cut off from the great streamsof knowledge; and he may confess that it was with pardonable feelings ofgratification that he discovered in 1853, by the acquisition of the twofirst volumes of the Cosmos, that the philosophic mind of Humboldt hadalso pondered deeply on the planetary peculiarities of size, density, distance, inclination of axes and eccentricities of orbits, withouteliciting any satisfactory relations. 

From the tenor of the third and fourth volume of this learned summary ofscientific knowledge, it is evident that the question of a mediumfilling space is more and more occupying the learned world; but theauthor is unable to discover any consistent theory respecting it. Theincreasing interest attaching to it, however, is evidently preparing theworld for some radical change in preconceived views. The explanationgiven by this present theory to many prominent phenomena, is so totallycontrary to that of the learned world, as to leave it untouched byanything yet advanced. What the fifth volume of the Cosmos willcontain, is not yet known in this country, neither has the author beenfavored with any glimpse of the progress of science as developed beforethe British Association; he supposes, however, that he yet stands alonein the position he has defined. 

As a question of practical importance, the reader will find in the workcited, the various opinions of the temperature of space. Both Fourierand Poisson regard this as the result of radiated heat from the sun andall the stars, minus the quantity lost by absorption in traversing theregions of space filled with ether. [51] But why should we regard thestars as the source of all motions? Why cannot physicists admit the ideaof an infinite space filled (if we may use the expression) with aninfinite medium, possessing an unchangeable mean temperature long beforethe formation of a single star. A star equal to our sun at the distanceof Sirius, would give about one million of million times less heat thanour present sun, which is only able to give an average temperature tothe whole globe--about twenty degrees above freezing--then let usremember that there are only about fifty stars of the first and secondmagnitude, which give more light (and by analogy heat also) than all therest of the stars visible. Such labored theories as this of Poisson's isa lamentable instance of the aberrations of human wisdom. 

We would also call the reader's attention to a late conclusion ofProfessor Dove, viz. : That differences of temperature in differentlongitudes frequently exist on the same parallel of latitude, or, inother words, are laterally disposed. This may be thought adverse to thetheory, but it should be borne in mind that the annual mean temperatureof the whole parallel of latitude should be taken when comparing thetemperatures of different years. 

Another fact cited in the Cosmos apparently adverse to the theory, isthe idea entertained by Sir John Herschel, that the full-moondissipates the clouds. This question has been fully examined byProfessor Loomis before the American Association, and he concludes thatthere is not the slightest foundation for the assertion--taking as datathe Greenwich observations themselves. 

FOOTNOTES:

[51] See _Cosmos_, p.  41, vol.  III.