[Illustration]

SCIENTIFIC AMERICAN SUPPLEMENT NO. 417

NEW YORK, DECEMBER 29, 1883

Scientific American Supplement. Vol. XVI, No. 417. 

Scientific American established 1845

Scientific American Supplement, $5 a year. 

Scientific American and Supplement, $7 a year. 

 * * * * *

TABLE OF CONTENTS

I. ENGINEERING AND MECHANICS. --Machine for Making Electric Light Carbons. --2 figures

 The Earliest Gas Engine

 The Moving of Large Masses. --With engravings of the removal of a belfry at Cresentino in 1776, and of the winged bulls from Nineveh to Mosul in 1854

 Science and Engineering. --The relation they bear to one another. By WALTER R. BROWNE

 Hydraulic Plate Press. --With engraving

 Fast Printing Press for Engravings. --With engraving

 French Cannon

 Apparatus for Heating by Gas. --5 figures

 Improved Gas Burner for Singeing Machines. --1 figure

II. TECHNOLOGY. --China Grass, or Rhea. --Different processes and apparatus used in preparing the fiber for commerce

III. ARCHITECTURE. --Woodlands, Stoke Pogis, Bucks. --With engraving. 

IV. ELECTRICITY, LIGHT, ETC. --Volta Electric Induction as Demonstrated by Experiment. --Paper read by WILLOUGHBY SMITH before the Society of Telegraph Engineers and Electricians. --Numerous figures

 On Telpherage. --The Transmission of vehicles by electricity to a distance. --By Prof. FLEEMING JENKIN

 New Electric Battery Lights

 The Siemens Electric Railway at Zankeroda Mines. --3 figures

 Silas' Chronophore. --3 figures

V. NATURAL HISTORY. --A New Enemy of the Bee

 Crystallization of Honey

 An Extensive Sheep Range

VI. HORTICULTURE, ETC. --The Zelkowas. --With full description of the tree, manner of identification, etc. , and several engravings showing the tree as a whole, and the leaves, fruit, and flowers in detail

VII. MEDICINE, HYGIENE, ETC. -The Disinfection of the Atmosphere. --Extract from a lecture by Dr. R. J. LEE, delivered at the Parkes Museum of Hygiene. London

 A New Method of Staining Bacillus Tuberculosis

 Cure for Hemorrhoids

 * * * * *

VOLTA-ELECTRIC INDUCTION. 

[Footnote: A paper read at the Society of Telegraph Engineers andElectricians on the 8th November, 1883]

By WILLOUGHBY SMITH. 

In my presidential address, which I had the pleasure of reading beforethis society at our first meeting this year, I called attention, somewhat hurriedly, to the results of a few of my experiments oninduction, and at the same time expressed a hope that at a future date Imight be able to bring them more prominently before you. That date hasnow arrived, and my endeavor this evening will be to demonstrate to youby actual experiment some of what I consider the most important resultsobtained. My desire is that all present should see these results, andwith that view I will try when practicable to use a mirror reflectinggalvanometer instead of a telephone. All who have been accustomed to theuse of reflecting galvanometers will readily understand the difficulty, on account of its delicacy, of doing so where no special arrangementsare provided for its use; but perhaps with a little indulgence on yourpart and patience on mine the experiments may be brought to a successfulissue. 

[Illustration: VOLTA-ELECTRIC INDUCTION. ]

Reliable records extending over hundreds of years show clearly with whatenergy and perseverance scientific men in every civilized part of theworld have endeavored to wrest from nature the secret of what is termedher "phenomena of magnetism, " and, as is invariably the case undersimilar circumstances, the results of the experiments and reasoning ofsome have far surpassed those of others in advancing our knowledge. Forinstance, the experimental philosophers in many branches of science weregroping as it were in darkness until the brilliant light of Newton'sgenius illumined their path. Although, perhaps, I should not bejustified in comparing Oersted with Newton, yet he also discovered whatare termed "new" laws of nature, in a manner at once precise, profound, and amazing, and which opened a new field of research to many of themost distinguished philosophers of that time, who were soon engaged inexperimenting in the same direction, and from whose investigations arosea new science, which was called "electro-dynamics. " Oersted demonstratedfrom inductive reasoning that every conductor of electricity possessedall the known properties of a magnet while a current of electricity waspassing through it. If you earnestly contemplate the important adjunctsto applied science which have sprung from that apparently simple fact, you will not fail to see the importance of the discovery; for it waswhile working in this new field of electro-magnetism that Sturgeon madethe first electro-magnet, and Faraday many of his discoveries relatingto induction. 

Soon after the discovery by Oersted just referred to, Faraday, with thecare and ability manifest in all his experiments, showed that when anintermittent current of electricity is passing along a wire it inducesa current in any wire forming a complete circuit and placed parallelto it, and that if the two wires were made into two helices and placedparallel to each other the effect was more marked. This Faradaydesignated "Volta-electric induction, " and it is with this kind ofinduction I wish to engage your attention this evening; for it is aphenomenon which presents some of the most interesting and importantfacts in electrical science. 

Here are two flat spirals of silk-covered copper wire suspendedseparately, spider-web fashion, in wooden frames marked respectively Aand B. The one marked A is so connected that reversals at any desiredspeed per minute from a battery of one or more cells can be passedthrough it. The one marked B is so connected to the galvanometer and areverser as to show the deflection caused by the induced currents, whichare momentary in duration, and in the galvanometer circuit all on thesame side of zero, for as the battery current on making contact producesan induced current in the reverse direction to itself, but in the samedirection on breaking the contact, of course the one would neutralizethe other, and the galvanometer would not be affected; the galvanometerconnections are therefore reversed with each reversal of the batterycurrent, and by that means the induced currents are, as you perceive, all in the same direction and produce a steady deflection. Theconnections are as shown on the sheet before you marked 1, which I thinkrequires no further explanation. 

Before proceeding, please to bear in mind the fact that the inductiveeffects vary inversely as the square of the distance between the twospirals, when parallel to each other; and that the induced current inB is proportional to the number of reversals of the battery currentpassing through spiral A, and also to the strength of the current sopassing. Faraday's fertile imagination would naturally suggest thequestion, "Is this lateral action, which we call magnetism, extended toa distance by the action of intermediate particles?" If so, then it isreasonable to expect that all substances would not be affected in thesame way, and therefore different results would be obtained if differentmedia were interposed between the inductor and what I will merely call, for distinction, the inductometer. 

With a view to proving this experimentally, Faraday constructed threeflat helices and placed them parallel to each other a convenientdistance apart. The middle helix was so arranged that a voltaic currentcould be sent through it at pleasure. A differential galvanometer wasconnected with the other helices in such a manner that when a voltaiccurrent was sent through the middle helix its inductive action onthe lateral helices should cause currents in them, having contrarydirections in the coils of the galvanometer. This was a very prettilyarranged electric balance, and by placing plates of different substancesbetween the inductor and one of the inductometers Faraday expected tosee the balance destroyed to an extent which would be indicated by thedeflection of the needle of the galvanometer. To his surprise he foundthat it made not the least difference whether the intervening space wasoccupied by such insulating bodies as air, sulphur, and shellac, or suchconducting bodies as copper and the other non-magnetic metals. Theseresults, however, did not satisfy him, as he was convinced that theinterposition of the non-magnetic metals, especially of copper, didhave an effect, but that his apparatus was not suitable for making itvisible. It is to be regretted that so sound a reasoner and so carefulan experimenter had not the great advantage of the assistance ofsuch suitable instruments for this class of research as themirror-galvanometer and the telephone. But, although he could notpractically demonstrate the effects which by him could be so clearlyseen, it redounds to his credit that, as the improvement in instrumentsfor this kind of research has advanced, the results he sought for havebeen found in the direction in which he predicted. 

A and B will now be placed a definite distance apart, and comparativelyslow reversals from ten Leclanché cells sent through spiral A; you willobserve the amount of the induced current in B, as shown on the scale ofthe galvanometer in circuit with that spiral. Now midway between the twospirals will be placed a plate of iron, as shown in Plate 2, and at onceyou observe the deflection of the galvanometer is reduced by less thanone half, showing clearly that the presence of the iron plate is in someway influencing the previous effects. The iron will now be removed, butthe spirals left in the same position as before, and by increasing thespeed of the reversals you see a higher deflection is given on thegalvanometer. Now, on again interposing the iron plate the deflectionfalls to a little less than one-half, as before. I wish this fact to becarefully noted. 

The experiment will be repeated with a plate of copper of precisely thesame dimensions as the iron plate, and you observe that, although theconditions are exactly alike in both cases, the interposition of thecopper plate has apparently no effect at the present speed of thereversals, although the interposition of the iron plate under the sameconditions reduced the deflection about fifty per cent. We will nowremove the copper plate, as we did the iron one, and increase the speedof the reversals to the same as in the experiment with the iron, and youobserve the deflection on the galvanometer is about the same as it wason that occasion. Now, by replacing the copper plate to its formerposition you will note how rapidly the deflection falls. We will nowrepeat the experiment with a plate of lead; you will see that, like thecopper, it is unaffected at the low speed, but there the resemblanceceases; for at the high speed it has but very slight effect. Thus thesemetals, iron, copper, and lead, appear to differ as widely in theirelectrical as they do in their mechanical properties. Of course it wouldbe impossible to obtain accurate measurements on an occasion like thepresent, but careful and reliable measurements have been made, theresults of which are shown on the sheet before you, marked 3. 

It will be seen by reference to these results that the percentage ofinductive energy intercepted does not increase for different speeds ofthe reverser in the same rate with different metals, the increase withiron being very slight, while with tin it is comparatively enormous. Itwas observed that time was an important element to be taken into accountwhile testing the above metals, that is to say, the lines of force tookan appreciable time to polarize the particles of the metal placed intheir path, but having accomplished this, they passed more freelythrough it. 

Now let us go more minutely into the subject by the aid of Plate IV. , Figs. 1 and 2. In Fig. 1 let A and B represent two flat spirals, spiralA being connected to a battery with a key in circuit and spiral Bconnected to a galvanometer; then, on closing the battery circuit, aninstantaneous current is induced in spiral B. If a non-magnetic metalplate half an inch thick be placed midway between the spirals, and theexperiment repeated, it will be found that the induced current receivedby B is the same in amount as in the first case. This does not prove, as would at first appear, that the metal plate fails to intercept theinductive radiant energy; and it can scarcely be so, for if the plate isreplaced by a coil of wire, it is found that induced currents are setup therein, and therefore inductive radiant energy must have beenintercepted. This apparent contradiction may be explained as follows:

In Fig. 2 let D represent a source of heat (a vessel of boiling waterfor instance) and E a sensitive thermometer receiving and measuring theradiant heat. Now, if for instance a plate of vulcanite is interposed, it cuts off and absorbs a part of the radiant heat emitted by D, andthus a fall is produced in the thermometer reading. But the vulcanite, soon becoming heated by the radiant heat cut off and absorbed by itself, radiates that heat and causes the thermometer reading to return to aboutits original amount. The false impression is thus produced that theoriginal radiated heat was unaffected by the vulcanite plate; instead ofwhich, as a matter of fact, the vulcanite plate had cut off the radiantheat, becoming heated itself by so doing, and was consequently then theradiating body affecting the thermometer. 

The effect is similar in the case of induction between the two spirals. Spiral A induces and spiral B receives the induced effect. The metalplate being then interposed, cuts off and absorbs either all or part ofthe inductive radiant energy emitted by A. The inductive radiant energythus cut off, however, is not lost, but is converted into electricalenergy in the metal plate, thereby causing it to become, as in the caseof the vulcanite in the heat experiment, a source of radiation whichcompensates as far as spiral B is concerned for the original inductiveradiant energy cut off. The only material difference noticeable inthe two experiments is that in the case of heat the time that elapsesbetween the momentary fall in the thermometer reading (due to theinterception by the vulcanite plate of the radiant beat) and thesubsequent rise (due to the interposing plate, itself radiating thatheat) is long enough to render the effect clearly manifest; whereas inthe case of induction the time that elapses is so exceedingly shortthat, unless special precautions are taken, the radiant energy emittedby the metal plate is liable to be mistaken for the primary energyemitted by the inducing spiral. 

The current induced in the receiving spiral by the inducing one ispractically instantaneous; but on the interposition of a metal platethe induced current which, as before described, is set up by the plateitself has a perceptible duration depending upon the nature and mass ofmetal thus interposed. Copper and zinc produce in this manner an inducedcurrent of greater length than metals of lower conductivity, with theexception of iron, which gives an induced current of extremely shortduration. It will therefore be seen that in endeavoring to ascertainwhat I term the specific inductive resistance of different metals bythe means described, notice must be taken of and allowance made fortwo points. First, that the metal plate not only cuts off, but itselfradiates; and secondly, that the duration of the induced currentsradiated by the plates varies with each different metal underexperiment. 

This explains the fact before pointed out that the apparent percentageof inductive radiant energy intercepted by metal plates varies with thespeed of the reversals; for in the case of copper the induced currentset up by such a plate has so long a duration that if the speed of thereverser is at all rapid the induced current has not time to exhaustitself before the galvanometer is reversed, and thus the current beingon the opposite side of the galvanometer tends to produce a lowerdeflection. If the speed of the reverser be further increased, thegreater part of the induced current is received on the opposite terminalof the galvanometer, so that a negative result is obtained. 

We know that it was the strong analogies which exist between electricityand magnetism that led experimentalists to seek for proofs that wouldidentify them as one and the same thing, and it was the result ofProfessor Oersted's experiment to which I have already referred thatfirst identified them. 

Probably the time is not far distant when it will be possible todemonstrate clearly that heat and electricity are as closely allied;then, knowing the great analogies existing between heat and light, maywe not find that heat, light, and electricity are modifications ofthe same force or property, susceptible under varying conditions ofproducing the phenomena now designated by those terms? For instance, friction will first produce electricity, then heat, and lastly light. 

As is well known, heat and light are reflected by metals; I wastherefore anxious to learn whether electricity could be reflected inthe same way. In order to ascertain this, spiral B was placed in thisposition, which you will observe is parallel to the lines of forceemitted by spiral A. In this position no induced current is set uptherein, so the galvanometer is not affected; but when this plate ofmetal is placed at this angle it intercepts the lines of force, whichcause it to radiate, and the secondary lines of force are interceptedand converted into induced currents by spiral B to the power indicatedby the galvanometer. Thus the phenomenon of reflection appears to beproduced in a somewhat similar manner to reflection of heat and light. The whole arrangement of this experiment is as shown on the sheet beforeyou numbered 5, which I need not, I think, more fully explain to youthan by saying that the secondary lines of force are represented by thedotted lines. 

Supported in this wooden frame marked C is a spiral similar inconstruction to the one marked B, but in this case the copper wire is0. 044 inch in diameter, silk-covered, and consists of 365 turns, witha total length of 605 yards; its resistance is 10. 2 ohms, the whole isinclosed between two thick sheets of card paper. The two ends of thespiral are attached to two terminals placed one on either side of theframe, a wire from one of the terminals is connected to one pole of abattery of 25 Leclanche cells, the other pole being connected with oneterminal of a reverser, the second terminal of which is connected to theother terminal of the spiral. 

Now, if this very small spiral which is in circuit with the galvanometerand a reverser be placed parallel to the center of spiral C, a verylarge deflection will be seen on the galvanometer scale; this willgradually diminish as the smaller spiral is passed slowly over the faceof the larger, until on nearing the edge of the latter the smallerspiral will cease to be affected by the inductive lines of force fromspiral C, and consequently the galvanometer indicates no deflection. Butif this smaller spiral be placed at a different angle to the largerone, it is, as you observe by the deflection of the galvanometer, againaffected. This experiment is analogous to the one illustrated by diagram6, which represents the result of an experiment made to ascertain therelative strength of capability or producing inductive effects ofdifferent parts of a straight electro-magnet. 

A, Fig. 1, represents the iron core, PP the primary coil, connectedat pleasure to one Grove cell, B, by means of the key, K; S, a smallsecondary coil free to move along the primary coil while in circuit withthe galvanometer, G. The relative strength of any particular spot can beobtained by moving the coil, S, exactly over the required position. Thesmall secondary coil is only cut at right angles when it is placed inthe center of the magnet, and as it is moved toward either pole so thelines of force cut it more and more obliquely. From this it would appearthat the results obtained are not purely dependent upon the strength ofthe portion of the magnet over which the secondary coil is placed, butprincipally upon the angle at which the lines of force cut the coil soplaced. It does not follow, therefore, that the center of the magnet isits strongest part, as the results of the experiments at first sightappear to show. 

It was while engaged on those experiments that I discovered that atelephone was affected when not in any way connected with the spiral, but simply placed so that the lines of force proceeding from the spiralimpinged upon the iron diaphragm of the telephone. Please to bear inmind that the direction of the lines of force emitted from the spiralis such that, starting from any point on one of its faces, a circleis described extending to a similar point on the opposite side. Thediameter of the circles described decreases from infinity as the pointsfrom which they start recede from the center toward the circumference. From points near the circumference these circles or curves are verysmall. To illustrate this to you, the reverser now in circuit withspiral C will be replaced by a simple make and break arrangement, consisting on a small electro-magnet fixed between the prongs of atuning-fork, and so connected that electro-magnet influences the arms ofthe fork, causing them to vibrate to a certain pitch. The apparatus isplaced in a distant room to prevent the sound being heard here, as Iwish to make it inductively audible to you. For that purpose I have herea light spiral which is in circuit with this telephone. Now, by placingthe spiral in front of spiral C, the telephone reproduces the soundgiven out by the tuning-fork so loudly that I have no doubt all of youcan hear it. Here is another spiral similar in every respect to spiralC. This is in circuit with a battery and an ordinary mechanical make andbreak arrangement, the sound given off by which I will now make audibleto you in the same way that I did the sound of the tuning-fork. Now youhear it. I will change from the one spiral to the other several times, as I want to make you acquainted with the sounds of both, so that youwill have no difficulty in distinguishing them, the one from the other. 

There are suspended in this room self-luminous bodies which enable us bytheir rays or lines of force to see the non-luminous bodies with whichwe are surrounded. There are also radiating in all directions from mewhile speaking lines of force or sound waves which affect more orless each one of you. But there are also in addition to, and quiteindependent of, the lines of force just mentioned, magnetic linesof force which are too subtle to be recognized by human beings, consequently, figuratively, we are both blind and deaf to them. However, they can be made manifest either by their notion on a suspended magnetor on a conducting body moving across them; the former showing itsresults by attraction and repulsion, the latter by the production of anelectric current. For instance, by connecting the small flat spiral ofcopper wire in direct circuit with the galvanometer, you will perceivethat the slightest movement of the spiral generates a current ofsufficient strength to very sensibly affect the galvanometer; and asyou observe, the amplitude of the deflection depends upon the speedand direction in which the spiral is moved. We know that by moving aconductor of electricity in a magnetic field we are able to produce anelectric current of sufficient intensity to produce light resemblingin all its phases that of solar light; but to produce these strongcurrents, very powerful artificial magnetic fields have to be generated, and the conductor has to be moved therein at a great expenditure of heatenergy. May not the time arrive when we shall no longer require theseartificial and costly means, but have learned how to adopt those forcesof nature which we now so much neglect? One ampere of current passingthrough an ordinary incandescent lamp will produce a light equal to tencandles, and I have shown that by simply moving this small flat spiral acurrent is induced in it from the earth's magnetic field equal to 0. 0007ampere. With these facts before us, surely it would not be boldness topredict that a time may arrive when the energy of the wind or tide willbe employed to produce from the magnetic lines of force given out by theearth's magnetism electrical currents far surpassing anything we haveyet seen or of which we have heard. Therefore let us not despise thesmallness of the force, but rather consider it an element of power fromwhich might arise conditions far higher in degree, and which we mightnot recognize as the same as this developed in its incipient stage. 

If the galvanometer be replaced by a telephone, no matter how the spiralbe moved, no sound will be heard, simply because the induced currentsproduced consist of comparatively slow undulations, and not of sharpvariations suitable for a telephone. But by placing in circuit thismechanical make and break arrangement the interruptions of the currentare at once audible, and by regulating the movement of the spiral I cansend signals, which, if they had been prearranged, might have enabledus to communicate intelligence to each other by means of the earth'smagnetism. I show this experiment more with a view to illustrate thefact that for experiments on induction both instruments are necessary, as each makes manifest those currents adapted to itself. 

The lines of force of light, heat, and sound can be artificiallyproduced and intensified, and the more intense--they are the more weperceive their effects on our eyes, ears, or bodies. But it is not sowith the lines of magnetic force, for it matters not how much theirpower is increased--they appear in no way to affect us. Their presencecan, however, be made manifest to our eyes or ears by mechanicalappliances. I have already shown you how this can be done by means ofeither a galvanometer or a telephone in circuit with a spiral wire. 

I have already stated that while engaged in these experiments I foundthat as far as the telephone was concerned it was immaterial whether itwas in circuit with a spiral or not, as in either case it accuratelyreproduced the same sounds; therefore, much in the same way as lensesassist the sight or tubes the hearing, so does the telephone makemanifest the lines of intermittent inductive energy. This was quite anew phenomenon to me, and on further investigation of the subject Ifound that it was not necessary to have even a telephone, for by simplyholding a piece of iron to my ear and placing it close to the centerof the spiral I could distinctly hear the same sounds as with thetelephone, although not so loud. The intensity of the sound was greatlyincreased when the iron was placed in a magnetic field. Here is a smalldisk of iron similar to those used in telephones, firmly secured in thisbrass frame; this is a small permanent bar magnet, the marked end ofwhich is fixed very closely to, but not touching, the center of the irondisk. Now, by applying the disk to my ear I can hear the same soundsthat were audible to all of you when the telephone in circuit with asmall spiral was placed in front of and close to the large spiral. To methe sound is quite as loud as when you heard it; but now you are one andall totally deaf to it. My original object in constructing two largespirals was to ascertain whether the inductive lines of force given outfrom one source would in any way interfere with those proceeding fromanother source. By the aid of this simple iron disk and magnet it can beascertained that they do in no way interfere with each other; therefore, the direction of the lines proceeding from each spiral can be distinctlytraced. For when the two spirals are placed parallel to each other ata distance of 3 ft. Apart, and connected to independent batteries andtransmitters, as shown in Plate 7, each transmitter having a soundperfectly distinct from that of the other, when the circuits arecompleted the separate sounds given out by the two transmitters can bedistinctly heard at the same time by the aid of a telephone; but, byplacing the telephone in a position neutral to one of the spirals, thenonly the sound proceeding from the other can be heard. These resultsoccur in whatever position the spirals are placed relatively to eachother, thus proving that there is no interference with or blending ofthe separate lines of force. The whole arrangement will be left inworking order at the close of the meeting for any gentlemen present toverify my statements or to make what experiments they please. 

In conclusion, I would ask, what can we as practical men gather fromthese experiments? A great deal has been written and said as to the bestmeans to secure conductors carrying currents of very low tension, such as telephone circuits, from being influenced by induction fromconductors in their immediate vicinity employed in carrying currents ofcomparatively very high tension, such as the ordinary telegraph wires. Covering the insulated wires with one or other of the various metals hasnot only been suggested but said to have been actually employed withmarked success. Now, it will found that a thin sheet of any known metalwill in no appreciable way interrupt the inductive lines of forcepassing between two flat spirals; that being so, it is difficult tounderstand how inductive effects are influenced by a metal covering asdescribed. 

Telegraph engineers and electricians have done much toward accomplishingthe successful working of our present railway system, but still thereis much scope for improvements in the signaling arrangements. In foggyweather the system now adopted is comparatively useless, and resourcehas to be had at such times to the dangerous and somewhat clumsy methodof signaling by means of detonating charges placed upon the rails. Now, it has occurred to me that volta induction might be employed withadvantage in various ways for signaling purposes. For example, one ormore wire spirals could be fixed between the rails at any convenientdistance from the signaling station, so that when necessary intermittentcurrents could be sent through the spirals; and another spiral could befixed beneath the engine or guard's van, and connected to one or moretelephones placed near those in charge of the train. Then as the trainpassed over the fixed spiral the sound given out by the transmitterwould be loudly reproduced by the telephone and indicate by itscharacter the signal intended. 

One of my experiments in this direction will perhaps better illustratemy meaning. The large spiral was connected in circuit with twelveLeclanche cells and the two make and break transmitters beforedescribed. They were so connected that either transmitter could beswitched into circuit when required, and this I considered the signalingstation. This small spiral was so arranged that it passed in front ofthe large one at the distance of 8 in. And at a speed of twenty-eightmiles per hour. The terminals of the small spiral were connected toa telephone fixed in a distant room, the result being that the soundreproduced from either transmitter could be clearly heard and recognizedevery time the spirals passed each other. With a knowledge of this factI think it will be readily understood now a cheap and efficient adjunctto the present system of railway signaling could be obtained by suchmeans as I have ventured to bring to your notice this evening. 

Thus have I given you some of the thoughts and experiments which haveoccupied my attention during my leisure. I have been long under theimpression that there is a feeling in the minds of many that we arealready in a position to give an answer to almost every questionrelating to electricity or magnetism. All I can say is, that the moreI endeavor to advance in a knowledge of these subjects, the more am Iconvinced of the fallacy of such a position. There is much yet to belearnt, and if there be present either member, associate, or student towhom I have imparted the smallest instruction, I shall feel that I havenot unprofitably occupied my time this evening. 

 * * * * *

ON TELPHERAGE. 

[Footnote: Introductory address delivered to the Class of Engineering, University of Edinburgh, October 30, 1883. ]

By Professor FLEEMING JENKIN, LL. D. , F. R. S. 

"The transmission of vehicles by electricity to a distance, independently of any control exercised from the vehicle, I will callTelpherage. " These words are quoted from my first patent relating tothis subject. The word should, by the ordinary rules of derivation, betelphorage; but as this word sounds badly to my ear, I ventured to adoptsuch a modified form as constant usage in England for a few centuriesmight have produced, and I was the more ready to trust to my ear in thematter because the word telpher relieves us from the confusion whichmight arise between telephore and telephone, when written. 

I have been encouraged to choose Telpherage as the subject of my addressby the fact that a public exhibition of a telpher line, with trainsrunning on it, will be made this afternoon for the first time. 

You are, of course, all aware that electrical railways have been run, and are running with success in several places. Their introduction hasbeen chiefly due to the energy and invention of Messrs. Siemens. I donot doubt of their success and great extension in the future--but whenconsidering the earliest examples of these railways in the spring oflast year, it occurred to me that in simply adapting electric motors tothe old form of railway and rolling stock, inventors had not gone farenough back. George Stephenson said that the railway and locomotive weretwo parts of one machine, and the inference seemed to follow that whenelectric motors were to be employed a new form of road and a new type oftrain would be desirable. 

When using steam, we can produce the power most economically in largeengines, and we can control the power most effectually and most cheaplywhen so produced. A separate steam engine to each carriage, with its ownstoker and driver, could not compete with the large locomotive and heavytrain; but these imply a strong and costly road and permanent way. Nomechanical method of distributing power, so as to pull trains along at adistance from a stationary engine, has been successful on our railways;but now that electricity has given us new and unrivaled means for thedistribution of power, the problem requires reconsideration. 

With the help of an electric current as the transmitter of power, wecan draw off, as it were, one, two, or three horse-power from a hundreddifferent points of a conductor many miles long, with as much ease as wecan obtain 100 or 200 horse-power at any one point. We can cut off thepower from any single motor by the mere break of contact between twopieces of metal; we can restore the power by merely letting the twopieces of metal touch; we can make these changes by electro magnets withthe rapidity of thought, and we can deal as we please with each ofone hundred motors without sensibly affecting the others. Theseconsiderations led me to conclude, in the first place, that when usingelectricity we might with advantage subdivide the weight to be carried, distributing the load among many light vehicles following each other inan almost continuous stream, instead of concentrating the load in heavytrains widely spaced, as in our actual railways. The change in thedistribution of the load would allow us to adopt a cheap, light formof load. The wide distribution of weight, entails many small trains insubstitution for a single heavy train; these small trains could not beeconomically run if a separate driver were required for each. But, asI have already pointed out, electricity not only facilitates thedistribution of power, but gives a ready means of controlling thatpower. Our light, continuous stream of trains can, therefore, beworked automatically, or managed independently of any guard or driveraccompanying the train--in other words, I could arrange a self-actingblock for preventing collisions. Next came the question, what would bethe best form of substructure for the new mode of conveyance? Suspendedrods or ropes, at a considerable height, appeared to me to have greatadvantages over any road on the level of the ground; the suspended rodsalso seemed superior to any stiff form of rail or girder supported at aheight. The insulation of ropes with few supports would be easy; theycould cross the country with no bridges or earth-works; they wouldremove the electrical conductor to a safe distance from men and cattle;cheap small rods employed as so many light suspension bridges wouldsupport in the aggregate a large weight. Moreover, I consider that asingle rod or rail would present great advantages over any double railsystem, provided any suitable means could be devised for driving a trainalong a single track. (Up to that time two conductors had invariablybeen used. ) It also seemed desirable that the metal rod bearing thetrain should also convey the current driving it. Lines such as Icontemplated would not impede cultivation nor interfere with fencing. Ground need not be purchased for their erection. Mere wayleaves wouldbe sufficient, as in the case of telegraphs. My ideas had reached thispoint in the spring of 1882, and I had devised some means for carryingthem into effect when I read the account of the electrical railwayexhibited by Professors Ayrton and Perry. In connection with thisrailway they had contrived means rendering the control of the vehiclesindependent of the action of the guard or driver; and this absoluteblock, as they called their system, seemed to me all that was requiredto enable me at once to carry out my idea of a continuous stream oflight, evenly spaced trains, with no drivers or guards. I saw, moreover, that the development of the system I had in view would be a severe taxon my time and energy; also that in Edinburgh I was not well placed forpushing such a scheme, and I had formed a high opinion of the value ofthe assistance which Professors Ayrton and Perry could give in designsand inventions. 

Moved by these considerations, I wrote asking Professor Ayrton toco-operate in the development of my scheme, and suggesting that heshould join with me in taking out my first Telpher patent. It has beenfound more convenient to keep our several patents distinct, but myletter ultimately led to the formation of the Telpherage Company(limited), in which Professor Ayrton, Professor Perry, and I have equalinterests. This company owns all our inventions in respect of electriclocomotion, and the line shown in action to-day has been erected by thiscompany on the estate of the chairman--Mr. Marlborough R. Pryor, ofWeston. Since the summer of last year, and more especially since theformation of the company this spring, much time and thought has beenspent in elaborating details. We are still far from the end of our work, and it is highly probable what has been done will change rapidly by anatural process of evolution. Nevertheless, the actual line now workingdoes in all its main features accurately reproduce my first conception, and the general principles I have just laid down will, I think, remaintrue, however great the change in details may be. 

The line at Weston consist of a series of posts, 60 ft. Apart, with twolines of rods or ropes, supported by crossheads on the posts. Each ofthese lines carries a train; one in fact is the up line, and the otherthe down line. Square steel rods, round steel rods, and steel wire ropesare all in course of trial. The round steel rod is my favorite road atpresent. The line is divided into sections of 120 ft. Or two spans, andeach section is insulated from its neighbor. The rod or rope is at thepost supported by cast-iron saddles, curved in a vertical plane, so asto facilitate the passage of the wheels over the point of support. Each alternate section is insulated from the ground; all the insulatedsections are in electrical connection with one another--so are all theuninsulated sections. The train is 120 ft. Long--the same length as thatof a section. It consists of a series of seven buckets and a locomotive, evenly spaced with ash distance pieces--each bucket will convey, as auseful load, about 2½ cwt. , and the bucket or skep, as it has come to becalled, weighs, with its load, about 3 cwt. The locomotive also weighsabout 3 cwt. The skeps hang below the line from one or from two Vwheels, supported by arms which project out sideways so as to clear thesupports at the posts; the motor or dynamo on the locomotive is alsobelow the line. It is supported on two broad flat wheels, and is drivenby two horizontal gripping wheels; the connection of these with themotor is made by a new kind of frictional gear which I have called nestgear, but which I cannot describe to-day. The motor on the locomotiveas a maximum 1½ horse-power when so much is needed. A wire connects onepole of the motor with the leading wheel of the train, and a second wireconnects the other pole with the trailing wheel; the other wheels areinsulated from each other. Thus the train, wherever it stands, bridges agap separating the insulated from the uninsulated section. The insulatedsections are supplied with electricity from a dynamo driven by astationary engine, and the current passing from the insulated sectionto the uninsulated section through the motor drives the locomotive. Theactual line is quite short, and can only show two trains, one on the upand one on the down line; but with sufficient power at the station anynumber of trains could be driven in a continuous stream on each line. The appearance is that of a line of buckets running along a singletelegraph wire of large size. A block system is devised and partly made, but is not yet erected. It differs from the earlier proposals in havingno working parts on the line. This system of propulsion is called by usthe Cross Over Parallel Arc. Other systems of supplying the currents, devised both by Professors Ayrton and Perry and myself, will be tried onlines now being erected; but that just described gives good results. Themotors employed in the locomotives were invented by Messrs. Ayrton andPerry. They are believed to have the special advantage of giving alarger power for a given weight than any others. One weighing 99 lb. Gave 1½ horse-power in some tests lately made. One weighing 36 lb. Gave0. 41 horse-power. 

No scientific experiments have yet been made on the working of the line, and matters are not yet ripe for this--but we know that we can erect acheap and simple permanent way, which will convey a useful load of say15 cwt. On every alternate span of 130 feet. This corresponds to 16½tons per mile, which, running at five miles per hour, would convey 92½tons of goods per hour. Thus if we work for 20 hours, the line willconvey 1850 tons of goods each way per diem, which seems a very fairperformance for an inch rope. The arrangement of the line with only onerod instead of two rails diminishes friction very greatly. The carriagesrun as light as bicycles. The same peculiarity allows very sharp curvesto be taken, but I am without experimental tests as yet of the limitin this respect. Further, we now know that we can insulate the linesatisfactorily, even if very high potentials come to be employed. Thegrip of the locomotive is admirable and almost frictionless, the gear issilent and runs very easily. It is suited for the highest speeds, andthis is very necessary, as the motors may with advantage, run at 2, 000revolutions per minute. 

 * * * * *

MACHINE FOR MAKING ELECTRIC LIGHT CARBONS. 

One of the hinderances to the production of a regular and steady lightin electric illumination is the absence of perfect uniformity in thecarbons. This defect has more than once been pointed out by us, and weare glad to notice any attempt to remedy an admitted evil. To this endwe illustrate above a machine for manufacturing carbons, invented byWilliam Cunliffe. The object the inventor has in view is not only thebetter but the more rapid manufacture of carbons, candles, or electrodesfor electric lighting or for the manufacture of rods or blocks of carbonor other compressible substances for other purposes, and his inventionconsists in automatic machinery whereby a regular and uniform pressureand compression of the carbon is obtained, and the rods or blocks aredelivered through the formers, in a state of greater density and betterquality then hitherto. The machine consists of two cylinders, A A', placed longitudinally, as shown at Fig. 1, and in reversed position inrelation to each other. In each cylinder works a piston or plunger, a, with a connecting rod or rods, b; in the latter case the ends of therods have right and left handed threads upon which a sleeve, c, withcorresponding threads, works. This sleeve, c, is provided with a handwheel, so that by the turning it the stroke of the plungers, a a, andthe size of the chambers, A A', is regulated so that the quantity ofmaterial to be passed through the dies or formers is thereby determinedand may be indicated. In front of the chambers, A A', are fixed the diesor formers, d d, which may have any number of perforations of the sizeor shape of the carbon it is intended to mould. The dies are held inposition by clamp pieces, e e, secured to the end of the chambers AA', by screws, and on each side of these clamp pieces are guides, withgrooves, in which moves a bar with a crosshead, termed the guillotine, and which moves across the openings of the dies, and opening or closingthem. Near the front end of the cylinders are placed small pistons orvalves, f f, kept down in position by the weighted levers, g g (see Fig. 2, which is drawn to an enlarged scale), which, when the pressure inthe chamber exceeds that of the weighted levers connected to the safetyvalve, f, the latter is raised and the guillotine bar, h, moved acrossthe openings of the dies by the connecting rods, h', thereby allowingthe carbon to be forced through the dies. In the backward movementof the piston, a, a fresh supply of material is drawn by atmosphericpressure through the hoppers, B B', alternately. At the end of thestroke the arms of the rocking levers (which are connected by tensionrods with the tappet levers) are struck by the disk wheel or regulator, the guillotine is moved back and replaced over the openings of thedies, ready for the next charge, as shown. The plungers are operated byhydraulic, steam, compressed air, or other power, the inlet and outletof such a pressure being regulated by a valve, an example of which isshown at Fig. 1, and provided with the tappet levers, i i, hinged to thevalve chest, C, as shown, and attached to spindles, i' i', operating theslide valves, and struck alternately at the end of each stroke, thusoperating the valves and the guillotine connections, i² and i³. Thefront ends of the cylinders may be placed at an angle for the moreconvenient delivery of the moulded articles. --_Iron_. 

[Illustration: MACHINE FOR MAKING ELECTRIC LIGHT CARBONS]

 * * * * *

NEW ELECTRIC BATTERY LIGHTS. 

There has lately been held, at No. 31 Lombard Street, London, a privateexhibition of the Holmes and Burke primary galvanic battery. The chiefobject of the display was to demonstrate its suitability for thelighting of railway trains, but at the same time means were providedto show it in connection with ordinary domestic illumination, as it isevident that a battery will serve equally as well for the latter as forthe former purpose. Already the great Northern express leaving London at5:30 P. M. Is lighted by this means, and satisfactory experiments havebeen made upon the South-western line, while the inventors give a longlist of other companies to which experimental plant is to be supplied. The battery shown, in Lombard Street consisted of fifteen cells arrangedin three boxes of five cells each. Each box measured about 18 in. By12 in. By 10 in. , and weighed from 75 lb. To 100 lb. The electromotiveforce of each cell was 1. 8 volts and its internal resistance from 1/40to 1/50 of an ohm, consequently the battery exhibited had, under themust favorable circumstances, a difference of potential of 27 volts atits poles, and a resistance of 0. 3 ohm. 

When connected to a group of ten Swan lamps of five candle power, requiring a difference of potential of 20 volts, it raised them to vividincandescence, considerably above their nominal capacity, but it failedto supply eighteen lamps of the same kind satisfactorily, showing thatits working capacity lay somewhere between the two. A more powerful lampis used in the railway carriages, but as there was only one erected itwas impossible to judge of the number that a battery of the size shownwould feed. _Engineering_ says the trial, however, demonstrated thatgreat quantities of current were being continuously evolved, and if, as we understood, the production can be maintained constant for abouttwenty-four hours without attention, the new battery marks a distinctstep in this kind of electric lighting. Of the construction of thebattery we unfortunately can say but little, as the patents are not yetcompleted, but we may state that the solid elements are zinc andcarbon, and that the novelty lies in the liquid, and in the ingeniousarrangement for supplying and withdrawing it. 

Ordinarily one charge of liquid will serve for twenty-four hoursworking, but this, of course, is entirely determined by the spaceprovided for it. It is sold at sevenpence a gallon, and each gallon issufficient, we are informed, to drive a cell while it generates 800ampere hours of current, or, taking the electromotive force at 1. 8volts, it represents (800 x 1. 8) / 746 = 1. 93 horse-power hours. Thecost of the zinc is stated to be 35 per cent. Of that of the fluid, although it is difficult to see how this can be, for one horse-powerrequires the consumption of 895. 2 grammes of zinc per hour, or 1. 96 lb. , and this at 18_l_. Per ton, would cost 1. 93 pence per pound, or 3. 8pence per horse-power hour. This added to 3. 6 pence for the fluid, wouldgive a total of 7. 4 pence per horse-power per hour, and assuming twentylamps of ten candle power to be fed per horse-power, the cost would beabout one-third of a penny per hour per lamp. 

Mr Holmes admits his statement of the consumption of zinc does not agreewith what might be theoretically expected but he bases it upon theresult of his experiments in the Pullman train, which place the cost atone farthing per hour per light. At the same time he does not professthat the battery can compete in the matter of cost with mechanicallygenerated currents on a large scale, but he offers it as a convenientmeans of obtaining the electric light in places where a steam engine ora gas engine is inadmissible, as in a private house, and where the costof driving a dynamo machine is raised abnormally high by reason of aspecial attendant having to be paid to look after it. 

But he has another scheme for the reduction of the cost, to which wehave not yet alluded, and of which we can say but little, as the detailsare not at present available for publication. The battery gives offfumes which can be condensed into a nitrogenous substance, valuable, itis stated, as a manure, while the zinc salts in the spent liquid can berecovered and returned to useful purposes. How far this is practicableit is at present impossible to say, but at any rate the idea representsa step in the right direction, and if the electricians can follow theexample of the gas manufacturers and obtain a revenue from the residualsof galvanic batteries, they will greatly improve their commercialposition. There is nothing impossible in the idea, and neither is italtogether novel, although the way of carrying it out may be. In 1848, Staite, one of the early enthusiasts in electric lighting, patented aseries of batteries from which he proposed to recover sulphate, nitrate, and chloride of zinc, but we never heard that he obtained any success. 

 * * * * *

NEW ELECTRIC RAILWAY. 

The original electric railway laid down by Messrs. Siemens and Halskeat Berlin seems likely to be the parent of many others. One of the mostrecent is the underground electric line laid down by the firm in themines of Zankerodain Saxony. An account of this railway has appeared in_Glaser's Annalen_, together with drawings of the engine, which we areable to reproduce. They are derived from a paper by Herr Fischer, readon the 19th December, 1882, before the Electro-Technical Union ofGermany. The line in question is 700 meters long--770 yards--and has twolines of way. It lies 270 meters--300 yards--below the surface of theground. It is worked by an electric locomotive, hauling ten wagons at aspeed of 12 kilometers, or 7½ miles per hour. The total weight drawn iseight tons. The gauge is a narrow one, so that the locomotive can bemade of small dimensions. Its total length between the buffer heads is2. 43 meters; its height 1. 04 meters; breadth 0. 8 meter; diameter ofwheels, 0. 34 meter. From the rail head to the center of the buffers is aheight of 0. 675 meter; and the total weight is only 1550 kilogrammes, orsay 3, 400 lb. We give a longitudinal section through the locomotive. Itwill be seen that there is a seat at each end for the driver, so that hecan always look forwards, whichever way the engine may be running. Thearrangements for connection with the electric current are very simple. The current is generated by a dynamo machine fixed outside the mine, andrun by a small rotary steam engine, shown in section and elevation, at aspeed of 900 revolutions per minute. The current passes through a cabledown the shaft to a T-iron fixed to the side of the heading. On thisT-iron slide contact pieces which are connected with the electric engineby leading wires. The driver by turning a handle can move his enginebackward or forward at will. The whole arrangement has worked extremelywell, and it is stated that the locomotive, if so arranged, could easilydo double its present work; in other words, could haul 15 to 16 tons oftrain load at a speed of seven miles an hour. The arrangements for thedynamo machine on the engine, and its connection with the wheels, aremuch the same as those used in Sir William Siemens' electric railway nowworking near the Giant's Causeway. --_The Engineer_. 

[Illustration: THE SIEMENS ELECTRIC RAILWAY AT ZANKERODA MINES. ]

 * * * * *

THE EARLIEST GAS-ENGINE. 

Lebon, in the certificate dated 1801, in addition to his first patent, described and illustrated a three-cylinder gas-engine in which anexplosive mixture of gas and air was to have been ignited by an electricspark. This is a curious anticipation of the Lenior system, not broughtout until more than fifty years later; but there is no evidence thatLebon ever constructed an engine after the design referred to. It is aninstructive lesson to would-be patentees, who frequently expect to reapimmediate fame and fortune from their property in some crude ideas whichthey fondly deem to be an "invention, " to observe the very wide intervalthat separates Lebon from Otto. The idea is the same in both cases; butit has required long years of patient work, and many failures, to embodythe idea in a suitable form. It is almost surprising, to any one who hasnot specially studied the matter, to discover the number of devicesthat have been tried with the object of making an explosion engine, asdistinguished from one deriving its motive power from the expansion ofgaseous fluids. A narrative of some of these attempts has been presentedto the Societe des Ingenieurs Civils; mostly taken in the first placefrom Stuart's work upon the origin of the steam engine, published in1820, and now somewhat scarce. It appears from this statement that solong ago as 1794, Robert Street described and patented an engine inwinch the piston was to be driven by the explosion of a gaseous mixturewhereof the combustible element was furnished by the vaporization of_terebenthine_ (turpentine) thrown upon red hot iron. In 1807 De Rivazapplied the same idea in a different manner. He employed a cylinder12 centimeters in diameter fitted with a piston. At the bottom of thecylinder there was another smaller one, also provided with a piston. This was the aspirating cylinder, which drew hydrogen from an inflatedbag, and mixed it with twice its bulk of air by means of a two-way cock. The ignition of the detonating mixture was effected by an electricspark. It is said that the inventor applied his apparatus to a smalllocomotive. 

In 1820 Mr. Cecil, of Cambridge, proposed the employment of a mixture ofair and hydrogen as a source of motive power; he gave a detailed accountof his invention in the _Transactions_ of the Cambridge PhilosophicalSociety, together with some interesting theoretical considerations. The author observes here that an explosion may be safely opposed byan elastic resistance--that of compressed air, for example--if suchresistance possesses little or no inertia to be brought into play;contrariwise, the smallest inertia opposed to the explosion of a mixturesubjected to instantaneous combustion is equivalent to an insurmountableobstacle. Thus a small quantity of gunpowder, or a detonating mixture ofair and hydrogen, may without danger be ignited in a large closed vesselfull of air, because the pressure against the sides of the vesselexerted by the explosion is not more than the pressure of the aircompressed by the explosion. If a piece of card board, or even of paper, is placed in the middle of the bore of a cannon charged with powder, thecannon will almost certainly burst, because the powder in detonatingacts upon a body in repose which can only be put in motion in a periodof time infinitely little by the intervention of a force infinitelygreat. The piece of paper is therefore equivalent to an insurmountableobstacle. Of all detonating mixtures, or explosive materials, the mostdangerous for equal expansions, and the least fitted for use as motivepower, are those which inflame the most rapidly. Thus, a mixtureof oxygen and hydrogen, in which the inflammation is producedinstantaneously, is less convenient for this particular usage than amixture of air and hydrogen, which inflames more slowly. From this pointof view, ordinary gunpowder would make a good source of motivepower, because, notwithstanding its great power of dilatation, it iscomparatively slow of ignition; only it would be necessary to takeparticular precautions to place the moving body in close contact withthe powder. Cecil pointed out that while a small steam engine could notbe started in work in less than half an hour, or probably more, a gasengine such as he proposed would have the advantage of being alwaysready for immediate use. Cecil's engine was the first in which theexplosive mixture was ignited by a simple flame of gas drawn into thecylinder at the right moment. In the first model, which was that ofa vertical beam engine with a long cylinder of comparatively smalldiameter, the motive power was simply derived from the descent of thepiston by atmospheric pressure; but Mr. Cecil is careful to state thatpower may also be obtained directly from the force of the explosion. Theengine was worked with a cylinder pressure of about 12 atmospheres, andthe inventor seems to have recognized that the noise of the explosionsmight be an objection to the machine, for he suggests putting the end ofthe cylinder down in a well, or inclosing it in a tight vessel for thepurpose of deadening the shock. 

It is interesting to rescue for a moment the account of Mr. Cecil'sinvention from the obscurity into which it has fallen--obscurity whichthe ingenuity of the ideas embodied in this machine does not merit. Itis probable that in addition to the imperfections of his machinery, Mr. Cecil suffered from the difficulty of obtaining hydrogen at asufficiently low price for use in large quantities. It does nottranspire that the inventor ever seriously turned his attention to theadvantages of coal gas, which even at that time, although very dear, must have been much cheaper than hydrogen. Knowing what we do atpresent, however, of the consumption of gas by a good engine of thelatest pattern, it may be assumed that a great deal of the trouble ofthe gas engine builders of 60 years ago arose from the simple fact oftheir being altogether before their age. Of course, the steam engine of1820 was a much more wasteful machine, as well as more costly to buildthan the steam engine of to-day; but the difference cannot have been sogreat as to create an advantage in favor of an appliance which requiredeven greater nicety of construction. The best gas-engine at present madewould have been an expensive thing to supply with gas at the pricescurrent in 1820, even if the resources of mechanical science at thatdate had been equal to its construction; which we know was not the case. Still, this consideration was not known, or was little valued, by Mr. Cecil and his contemporaries. It was not long, however, before Mr. Cecilhad to give way before a formidable rival; for in 1823 Samuel Brownbrought out his engine, which was in many respects an improvement uponthe one already described. It will probably be right, however, to regardthe Rev. Mr. Cecil, of Cambridge, as the first to make a practicablemodel of a gas-engine in the United Kingdom. --_Journal of Gas Lighting_. 

 * * * * *

Alabama has 2, 118 factories, working 8, 248 hands, with a capitalinvested of $5, 714, 032, paying annually in wages $2, 227, 968, andyielding annually in products $13, 040, 644. 

 * * * * *

THE MOVING OF LARGE MASSES. 

[Footnote: For previous article see SUPPLEMENT 367. ]

The moving of a belfry was effected in 1776 by a mason who knew neitherhow to read nor write. This structure was, and still is, at Crescentino, upon the left bank of the Po, between Turin and Cazal. The following isthe official report on the operation:

"In the year 1776, on the second day of September, the ordinary councilwas convoked, ... As it is well known that, on the 26th of May last, there was effected the removal of a belfry, 7 trabucs (22. 5 m. ) ormore in height, from the church called _Madonna del Palazzo_, with theconcurrence and in the presence and amid the applause of numerous peopleof this city and of strangers who had come in order to be witnesses ofthe removal of the said tower with its base and entire form, by means ofthe processes of our fellow-citizen Serra, a master mason who took itupon himself to move the said belfry to a distance of 3 meters, and toannex it to a church in course of construction. In order to effect thisremoval, the four faces of the brick walls were first cut and opened atthe base of the tower and on a level with the earth. Into the aperturesfrom north to south, that is to say in the direction that the edificewas to take, there were introduced two large beams, and with these thereran parallel, external to the belfry and alongside of it, two other rowsof beams of sufficient length and extent to form for the structure a bedover which it might be moved and placed in position in the new spot, where foundations of brick and lime had previously been prepared. 

[Illustration: FIG. 1. --REMOVAL OF A BELFRY AT CRESCENTINO IN 1776]

"Upon this plane there were afterward placed rollers 3½ inches indiameter, and, upon these latter, there was placed a second row of beamsof the same length as the others. Into the eastern and western aperturesthere were inserted, in cross-form, two beams of less length. 

"In order to prevent the oscillation of the tower, the latter wassupported by eight joists, two of these being placed on each side andjoined at their bases, each with one of the four beams, and, at theirapices, with the walls of the tower at about two-thirds of its height. 

"The plane over which the edifice was to be rolled had an inclination ofone inch. The belfry was hauled by three cables that wound aroundthree capstans, each of which was actuated by ten men. The removal waseffected in less than an hour. 

"It should be remarked that during the operation the son of the masonSerra, standing in the belfry, continued to ring peals, the bells nothaving been taken out. 

"Done at Crescentino, in the year and on the day mentioned. "

A note communicated to the Academie des Sciences at its session of May9, 1831, added that the base of the belfry was 3. 3 m. Square. Thispermits us to estimate its weight at about 150 tons. 

[Illustration: FIG. 2. --MOVING THE WINGED BULLS FROM NINEVEH TO MOSUL IN1854]

Fig. 1 shows the general aspect of the belfry with its stays. This istaken from an engraving published in 1844 by Mr. De Gregori, who, duringhis childhood, was a witness of the operation, and who endeavored torender the information given by the official account completer withoutbeing able to make the process much clearer. 

In 1854 Mr. Victor Place moved overland, from Nineveh to Mosul, thewinged bulls that at present are in the Assyrian museum of the Louvre, and each of which weighs 32 tons. After carefully packing these in boxesin order to preserve them from shocks, Place laid them upon their side, having turned them over, by means of levers, against a sloping bank ofearth That he afterward dug away in such a manner that the operation wasperformed without accident. He had had constructed an enormous car withaxles 0. 25 m. In diameter, and solid wheels 0. 8 m. In thickness (Fig. 2). Beneath the center of the box containing the bull a trench was dugthat ran up to the natural lever of the soil by an incline. This trenchhad a depth and width such that the car could run under the box whilethe latter was supported at two of its extremities by the banks. Theselatter were afterward gradually cut away until the box rested upon thecar without shock. Six hundred men then manned the ropes and hauled thecar with its load up to the level of the plain. These six hundred menwere necessary throughout nearly the entire route over a plain thatwas but slightly broken and in which the ground presented but littleconsistency. 

The route from Khorsabad to Mosul was about 18 kilometers, taking intoaccount all the detours that had to be made in order to have a somewhatfirm roadway. It took four days to transport the first bull thisdistance, but it required only a day and a half to move the other one, since the ground had acquired more compactness as a consequence ofmoving the first one over it, and since the leaders had become moreexpert. The six hundred men at Mr. Place's disposal had, moreover, beenemployed for three months back in preparing the route, in strengtheningit with piles in certain spots and in paving others with flagstonesbrought from the ruins of Nineveh. In a succeeding article I shalldescribe how I, a few years ago, moved an ammunition stone house, weighing 50 tons, to a distance of 35 meters without any other machinethan a capstan actuated by two men. --_A. De Rochas, in La Nature_. 

 * * * * *

[NATURE. ]

SCIENCE AND ENGINEERING. 

In the address delivered by Mr. Westmacott, President of the Institutionof Mechanical Engineers to the English and Belgian engineers assembledat Liege last August, there occurred the following passage: "Engineeringbrings all other sciences into play; chemical or physical discoveries, such as those of Faraday, would be of little practical use if engineerswere not ready with mechanical appliances to carry them out, and makethem commercially successful in the way best suited to each. "

We have no objection to make to these words, spoken at such a time andbefore such an assembly. It would of course be easy to take the converseview, and observe that engineering would have made little progress inmodern times, but for the splendid resources which the discoveries ofpure science have placed at her disposal, and which she has only had toadopt and utilize for her own purposes. But there is no need to quarrelover two opposite modes of stating the same fact. There _is_ need onthe other hand that the fact itself should be fairly recognized andaccepted, namely, that science may be looked upon as at once thehandmaid and the guide of art, art as at once the pupil and thesupporter of science. In the present article we propose to give a fewillustrations which will bring out and emphasize this truth. 

We could scarcely find a better instance than is furnished to our handin the sentence we have chosen for a text. No man ever worked with amore single hearted devotion to pure science--with a more absolutedisregard of money or fame, as compared with knowledge--than MichaelFaraday. Yet future ages will perhaps judge that no stronger impulse wasever given to the progress of industrial art, or to the advancement ofthe material interests of mankind, than the impulse which sprang fromhis discoveries in electricity and magnetism. Of these discoverieswe are only now beginning to reap the benefit. But we have merely toconsider the position which the dynamo-electric machine already occupiesin the industrial world, and the far higher position, which, as almostall admit, it is destined to occupy in the future, in order to seehow much we owe to Faraday's establishment of the connection betweenmagnetism and electricity. That is one side of the question--the debtwhich art owes to science. But let us look at the other side also. Doesscience owe nothing to art? Will any one say that we should know as muchas we do concerning the theory of the dynamo-electric motor, and thelaws of electro-magnetic action generally, if that motor had neverrisen (or fallen, as you choose to put it) to be something besides theinstrument of a laboratory, or the toy of a lecture room? Only a shorttime since the illustrious French physicist, M. Tresca, was enumeratingthe various sources of loss in the transmission of power by electricityalong a fixed wire, as elucidated in the careful and elaborateexperiments inaugurated by M. Marcel Deprez, and subsequently continuedby himself. These losses--the electrical no less than the mechanicallosses--are being thoroughly and minutely examined in the hope ofreducing them to the lowest limit; and this examination cannot fail tothrow much light on the exact distribution of the energy imparted to adynamo machine and the laws by which this distribution is governed. But would this examination ever have taken place--would the costlyexperiments which render it feasible ever have been performed--if thedynamo machine was still under the undisputed control of pure science, and had not become subject to the sway of the capitalist and theengineer?

Of course the electric telegraph affords an earlier and perhaps as goodan illustration of the same fact. The discovery that electricity wouldpass along a wire and actuate a needle at the other end was at first apurely scientific one; and it was only gradually that its importance, from an industrial point of view, came to be recognized. Here again artowes to pure science the creation of a complete and important branch ofengineering, whose works are spread like a net over the whole faceof the globe. On the other hand our knowledge of electricity, andespecially of the electrochemical processes which go on in the workingof batteries, has been enormously improved in consequence of the use ofsuch batteries for the purposes of telegraphy. 

Let us turn to another example in a different branch of science. Whichever of our modern discoveries we may consider to be the moststartling and important, there can I think be no doubt that the mostbeautiful is that of the spectroscope. It has enabled us to do thatwhich but a few years before its introduction was taken for the verytype of the impossible, viz. , to study the chemical composition of thestars; and it is giving us clearer and clearer insight every day intothe condition of the great luminary which forms the center of oursystem. Still, however beautiful and interesting such results may be, it might well be thought that they could never have any practicalapplication, and that the spectroscope at least would remain aninstrument of science, but of science alone. This, however, is not thecase. Some thirty years since, Mr. Bessemer conceived the idea thatthe injurious constituents of raw iron--such as silicon, sulphur, etc. --might be got rid of by simple oxidation. The mass of crude metalwas heated to a very high temperature; atmospheric air was forcedthrough it at a considerable pressure; and the oxygen uniting with thesemetalloids carried them off in the form of acid gases. The very actof union generated a vast quantity of heat, which itself assisted thecontinuance of the process; and the gas therefore passed off in a highlyluminous condition. But the important point was to know where tostop; to seize the exact moment when all or practically all hurtfulingredients had been removed, and before the oxygen had turned from themto attack the iron itself. How was this point to be ascertained? It wassoon suggested that each of these gases in its incandescent state wouldshow its own peculiar spectrum; and that if the flame rushing out of thethroat of the converter were viewed through a spectroscope, the momentwhen any substance such as sulphur, had disappeared would be knownby the disappearance of the corresponding lines in the spectrum. Theanticipation, it is needless to say, was verified, and the spectroscope, though now superseded, had for a time its place among the regularappliances necessary for the carrying on of the Bessemer process. 

This process itself, with all the momentous consequences, mechanical, commercial, and economical, which it has entailed, might be broughtforward as a witness on our side; for it was almost completely workedout in the laboratory before being submitted to actual practice. In thisrespect it stands in marked contrast to the earlier processes for themaking of iron and steel, which were developed, it is difficult to sayhow, in the forge or furnace itself, and amid the smoke and din ofpractical work. At the same time the experiments of Bessemer werefor the most part carried out with a distinct eye to their futureapplication in practice, and their value for our present purpose istherefore not so great. The same we believe may be said with regardto the great rival of the Bessemer converter, viz. , the Siemens openhearth; although this forms in itself a beautiful application of thescientific doctrine that steel stands midway, as regards proportion ofcarbon, between wrought iron and pig iron, and ought therefore to beobtainable by a judicious mixture of the two. The basic process isthe latest development, in this direction, of science as applied tometallurgy. Here, by simply giving a different chemical constitutionto the clay lining of the converter, it is found possible to eliminatephosphorus--an element which has successfully withstood the attack ofthe Bessemer system. Now, to quote the words of a German eulogizer ofthe new method, phosphorus has been turned from an enemy into a friend;and the richer a given ore is in that substance, the more readily andcheaply does it seem likely to be converted into steel. 

These latter examples have been taken from the art of metallurgy; and itmay of course be said that, considering the intimate relations betweenthat art and the science of chemistry, there can be no wonder if theformer is largely dependent for its progress on the latter. I willtherefore turn to what may appear the most concrete, practical, andunscientific of all arts--that, namely, of the mechanical engineer; andwe shall find that even here examples will not fail us of the boonswhich pure science has conferred upon the art of construction, nor evenperhaps of the reciprocal advantages which she has derived from theconnection. 

The address of Mr. Westmacott, from which I have already taken my text, supplies in itself more than one instance of the kind we seek--instancesemphasized by papers read at the meeting where the address was spoken. Let us take, first, the manufacture of sugar from beetroot. Thismanufacture was forced into prominence in the early years of thiscentury, when the Continental blockade maintained by England againstNapoleon prevented all importation of sugar from America; and it has nowattained very large dimensions, as all frequenters of the Continent mustbe aware. The process, as exhaustively described by a Belgian engineer, M. Melin, offers several instances of the application of chemical andphysical science to practical purposes. Thus, the first operation inmaking sugar from beetroot is to separate the juice from the flesh, theformer being as much as 95 per cent. Of the whole weight. Formerly thiswas accomplished by rasping the roots into a pulp, and then pressing thepulp in powerful hydraulic presses; in other words, by purely mechanicalmeans. This process is now to a large extent superseded by what iscalled the diffusion process, depending on the well known physicalphenomena of _endosmosis_ and _exosmosis_. The beetroot is cut up intosmall slices called "cossettes, " and these are placed in vessels filledwith water. The result is that a current of endosmosis takes place fromthe water toward the juice in the cells, and a current of exosmosisfrom the juice toward the water. These currents go on cell by cell, andcontinue until a state of equilibrium is attained. The richer the waterand the poorer the juice, the sooner does this equilibrium take place. Consequently the vessels are arranged in a series, forming what iscalled a diffusion battery; the pure water is admitted to the firstvessel, in which the slices have already been nearly exhausted, andsubtracts from them what juice there is left. It then passes as a thinjuice to the next vessel, in which the slices are richer, and theprocess begins again. In the last vessel the water which has alreadydone its work in all the previous vessels comes into contact with freshslices, and begins the operation upon them. The same process has beenapplied at the other end of the manufacture of sugar. After the juicehas been purified and all the crystallizable sugar has been separatedfrom it by boiling, there is left a mass of molasses, containing so muchof the salts of potassium and sodium that no further crystallization ofthe yet remaining sugar is possible. The object of the process calledosmosis is to carry off these salts. The apparatus used, or osmogene, consists of a series of trays filled alternately with molasses andwater, the bottoms being formed of parchment paper. A current passesthrough this paper in each direction, part of the water entering themolasses, and part of the salts, together with a certain quantity ofsugar, entering the water. The result, of thus freeing the molassesfrom the salts is that a large part of the remaining sugar can now beextracted by crystallization. 

Another instance in point comes from a paper dealing with the questionof the construction of long tunnels. In England this has been chieflydiscussed of late in connection with the Channel Tunnel, where, however, the conditions are comparatively simple. It is of still greaterimportance abroad. Two tunnels have already been pierced through theAlps; a third is nearly completed; and a fourth, the Simplon Tunnel, which will be the longest of any, is at this moment the subject ofa most active study on the part of French engineers. In America, especially in connection with the deep mines of the Western States, the problem is also of the highest importance. But the driving of suchtunnels would be financially if not physically impossible, but forthe resources which science has placed in our hands, first, by thepreparation of new explosives, and, secondly, by methods of dealing withthe very high temperatures which have to be encountered. As regards thefirst, the history of explosives is scarcely anything else than a recordof the application of chemical principles to practical purposes--arecord which in great part has yet to be written, and on which we cannothere dwell. It is certain, however, that but for the invention ofnitroglycerine, a purely chemical compound, and its development invarious forms, more or less safe and convenient, these long tunnelswould never have been constructed. As regards the second point, thequestion of temperature is really the most formidable with which thetunnel engineer has to contend. In the St. Gothard Tunnel, just beforethe meeting of the two headings in February, 1880, the temperaturerose as high as 93° Fahr. This, combined with the foulness of the air, produced an immense diminution in the work done per person and per horseemployed, while several men were actually killed by the dynamite gases, and others suffered from a disease which was traced to a hithertounknown species of internal worm. If the Simplon Tunnel should beconstructed, yet higher temperatures may probably have to be dealt with. Although science can hardly be said to have completely mastered thesedifficulties, much has been done in that direction. A great deal ofmechanical work has of course to be carried on at the face or far end ofsuch a heading, and there are various means by which it might be done. But by far the most satisfactory solution, in most cases at least, isobtained by taking advantage of the properties of compressed air. Aircan be compressed at the end of the tunnel either by steam-engines, or, still better, by turbines where water power is available. Thiscompressed air may easily be led in pipes to the face of the heading, and used there to drive the small engines which work the rock-drillingmachines, etc. The efficiency of such machines is doubtless low, chieflyowing to the physical fact that the air is heated by compression, andthat much of this heat is lost while it traverses the long line of pipesleading to the scene of action. But here we have a great advantage fromthe point of view of ventilation; for as the air gained heat while beingcompressed, so it loses heat while expanding; and the result is that acurrent of cold and fresh air is continually issuing from themachines at the face of the heading, just where it is most wanted. Inconsequence, in the St. Gothard, as just alluded to, the hottest partswere always some little distance behind the face of the heading. Although in this case as much as 120, 000 cubic meters of air (takenat atmospheric pressure) were daily poured into the heading, yet theventilation was very insufficient. Moreover, the high pressure which isused for working the machines is not the best adapted for ventilation;and in the Arlberg tunnel separate ventilating pipes are employed, containing air compressed to about one atmosphere, which is deliveredin much larger quantities although not at so low a temperature. In connection with this question of ventilation a long series ofobservations have been taken at the St. Gothard, both during and sincethe construction; these have revealed the important physical fact(itself of high practical importance) that the barometer never stands atthe same level on the two sides of a great mountain chain; and so havemade valuable contributions to the science of meteorology. 

Another most important use of the same scientific fact, namely, theproperties of compressed air, is found in the sinking of foundationsbelow water. When the piers of a bridge, or other structure, had to beplaced in a deep stream, the old method was to drive a double row ofpiles round the place and fill them in with clay, forming what iscalled a cofferdam. The water was pumped out from the interior, and thefoundation laid in the open. This is always a very expensive process, and in rapid streams is scarcely practicable. In recent times largebottomless cases, called caissons, have been used, with tubes attachedto the roof, by which air can be forced into or out of the interior. These caissons are brought to the site of the proposed pier, and arethere sunk. Where the bottom is loose sandy earth, the vacuum process, as it is termed, is often employed; that is, the air is pumped out fromthe interior, and the superincumbent pressure then causes the caissonto sink and the earth to rise within it. But it is more usual to employwhat is called the plenum process, in which air under high pressureis pumped into the caisson and expels the water, as in a diving bell. Workmen then descend, entering through an air lock, and excavate theground at the bottom of the caisson, which sinks gradually as theexcavation continues. Under this system a length of some two miles ofquay wall is being constructed at Antwerp, far out in the channel of theriver Scheldt. Here the caissons are laid end to end with each other, along the whole curve of the wall, and the masonry is built on the topof them within a floating cofferdam of very ingenious construction. 

There are few mechanical principles more widely known than that ofso-called centrifugal force; an action which, though still a puzzleto students, has long been thoroughly understood. It is, however, comparatively recently that it has been applied in practice. One of theearliest examples was perhaps the ordinary governor, due to the geniusof Watt. Every boy knows that if he takes a weight hanging from a stringand twirls it round, the weight will rise higher and revolve in a largercircle as he increases the speed. Watt saw that if he attached such anapparatus to his steam engine, the balls or weights would tend to risehigher whenever the engine begun to run faster, that this action mightbe made partly to draw over the valve which admitted the steam, and thatin this way the supply of steam would be lessened, and the speed wouldfall. Few ideas in science have received so wide and so successful anapplication as this. But of late years another property of centrifugalforce has been brought into play. The effect of this so-called force isthat any body revolving in a circle has a continual tendency to fly offat a tangent; the amount of this tendency depending jointly on the massof the body and on the velocity of the rotation. It is the former ofthese conditions which is now taken advantage of. For if we have anumber of particles all revolving with the same velocity, but ofdifferent specific gravities, and if we allow them to follow theirtendency of moving off at a tangent, it is evident that the heaviestparticles, having the greatest mass, will move with the greatest energy. The result is that, if we take a mass of such particles and confine themwithin a circular casing, we shall find that, having rotated this casingwith a high velocity and for a sufficient time, the heaviest particleswill have settled at the outside and the lightest at the inside, whilebetween the two there will be a gradation from the one to the other. Here, then, we have the means of separating two substances, solidor liquid, which are intimately mixed up together, but which are ofdifferent specific gravities. This physical principle has been takenadvantage of in a somewhat homely but very important process, viz. , theseparation of cream from milk. In this arrangement the milk is chargedinto a vessel something of the shape and size of a Gloucester cheese, which stands on a vertical spindle and is made to rotate with a velocityas high as 7, 000 revolutions per minute. At this enormous speed themilk, which is the heavier, flies to the outside, while the creamremains behind and stands up as a thin layer on the inside of therotating cylinder of fluid. So completely does this immense speedproduce in the liquid the characteristics of a solid, that if therotating shell of cream be touched by a knife it emits a harsh, gratingsound, and gives the sensation experienced in attempting to cut a stone. The separation is almost immediately complete, but the difficult pointwas to draw off the two liquids separately and continuously withoutstopping the machine. This has been simply accomplished by takingadvantage of another principle of hydromechanics. A small pipe openingjust inside the shell of the cylinder is brought back to near thecenter, where it rises through a sort of neck and opens into an exteriorcasing. The pressure due to the velocity causes the skim milk to rise inthis pipe and flow continuously out at the inner end. The cream is atthe same time drawn off by a similar orifice made in the same neck andleading into a different chamber. 

Centrifugal action is not the only way in which particles of differentspecific gravity can he separated from each other by motion only. Ifa rapid "jigging" or up-and-down motion be given to a mixture of suchparticles, the tendency of the lighter to fly further under the actionof the impulse causes them gradually to rise to the upper surface; thissurface being free in the present case, and the result being thereforethe reverse of what happens in the rotating chamber. If such a mixturebe examined after this up-and down motion has gone on for a considerableperiod, it will be found that the particles are arranged prettyaccurately in layers, the lightest being at the top and the heaviestat the bottom. This principle has long been taken advantage of in suchcases as the separation of lead ores from the matrix in which they areembedded. The rock in these cases is crushed into small fragments, andplaced on a frame having a rapid up-and-down-motion, when the heavy leadore gradually collects at the bottom and the lighter stone on the top. To separate the two the machine must be stopped and cleared by hand. Inthe case of coal-washing, where the object is to separate fine coal fromthe particles of stone mixed with it, this process would be very costly, and indeed impossible, because a current of water is sweeping throughthe whole mass. In the case of the Coppee coal-washer, the desiredend is achieved in a different and very simple manner. The well knownmineral felspar has a specific gravity intermediate between that of thecoal and the shale, or stone, with which it is found intermixed. If, then, a quantity of felspar in small fragments is thrown into themixture, and the whole then submitted to the jigging process, the resultwill be that the stone will collect on the top, and the coal at thebottom, with a layer of felspar separating the two. A current of watersweeps through the whole, and is drawn off partly at the top, carryingwith it the stone, and partly at the bottom, carrying with it the finecoal. 

The above are instances where science has come to the aid ofengineering. Here is one in which the obligation is reversed. The rapidstopping of railroad trains, when necessary, by means of brakes, is aproblem which has long occupied the attention of many engineers; and themechanical solutions offered have been correspondingly numerous. Someof these depend on the action of steam, some of a vacuum, some ofcompressed air, some of pressure-water; others again ingeniously utilizethe momentum of the wheels themselves. But for a long time no effortwas made by any of these inventors thoroughly to master the theoreticalconditions of the problem before them. At last, one of the mostingenious and successful among them, Mr. George Westinghouse, resolvedto make experiments on the subject, and was fortunate enough toassociate with himself Capt. Douglas Galton. Their experiments, carriedon with rare energy and perseverance, and at great expense, not onlybrought into the clearest light the physical conditions of the question(conditions which were shown to be in strict accordance with theory), but also disclosed the interesting scientific fact that the frictionbetween solid bodies at high velocities is not constant, as theexperiments of Morin had been supposed to imply, but diminishes rapidlyas the speed increases--a fact which other observations serve toconfirm. 

The old scientific principle known as the hydrostatic paradox, accordingto which a pressure applied at any point of an inclosed mass of liquidis transmitted unaltered to every other point, has been singularlyfruitful in practical applications. Mr. Bramah was perhaps the firstto recognize its value and importance. He applied it to the well knownBramah press, and in various other directions, some of which were lesssuccessful. One of these was a hydraulic lift, which Mr. Bramah proposedto construct by means of several cylinders sliding within each otherafter the manner of the tubes of a telescope. His specification ofthis invention sufficiently expresses his opinion of its value, for itconcludes as follows: "This patent does not only differ in its natureand in its boundless extent of claims to novelty, but also in its claimsto merit and superior utility compared with any other patent everbrought before or sanctioned by the legislative authority of anynation. " The telescope lift has not come into practical use; but liftsworked on the hydraulic principle are becoming more and more commonevery day. The same principle has been applied by the genius of SirWilliam Armstrong and others to the working of cranes and other machinesfor the lifting of weights, etc. ; and under the form of the accumulator, with its distributing pipes and hydraulic engines, it provides a storeof power always ready for application at any required point in a largesystem, yet costing practically nothing when not actually at work. Thissystem of high pressure mains worked from a central accumulator hasbeen for some years in existence at Hull, as a means of supplying powercommercially for all the purposes needed in a large town, and it isat this moment being carried out on a wider scale in the East End ofLondon. 

Taking advantage of this system, and combining with it anotherscientific principle of wide applicability, Mr. J. H. Greathead hasbrought out an instrument called the "injector hydrant, " which seemslikely to play an important part in the extinguishing of fires. Thissecond principle is that of the lateral induction of fluids, and may bethus expressed in the words of the late William Froude: "Any surfacewhich in passing through a fluid experiences resistance must in so doingimpress on the particles which resist it a force in the line of motionequal to the resistance. " If then these particles are themselves partof a fluid, it will result that they will follow the direction of themoving fluid and be partly carried along with it. As applied in theinjector hydrant, a small quantity of water derived from the highpressure mains is made to pass from one pipe into another, coming incontact at the same time with a reservoir of water at ordinary pressure. The result is that the water from the reservoir is drawn into the secondpipe through a trumpet-shaped nozzle, and may be made to issue asa stream to a considerable height. Thus the small quantity ofpressure-water, which, if used by itself, would perhaps rise to a heightof 500 feet, is made to carry with it a much larger quantity to a muchsmaller height, say that of an ordinary house. 

The above are only a few of the many instances which might be given toprove the general truth of the fact with which we started, namely, theclose and reciprocal connection between physical science and mechanicalengineering, taking both in their widest sense. It may possibly be worthwhile to return again to the subject, as other illustrations arise. Two such have appeared even at the moment of writing, and though theirpractical success is not yet assured, it may be worth while to citethem. The first is an application of the old principle of the siphon tothe purifying of sewage. Into a tank containing the sewage dips a siphonpipe some thirty feet high, of which the shorter leg is many timeslarger than the longer. When this is started, the water rises slowly andsteadily in the shorter column, and before it reaches the top has leftbehind it all or almost all of the solid particles which it previouslyheld in suspension. These fall slowly back through the column andcollect at the bottom of the tank, to be cleared out when needful. Theeffluent water is not of course chemically pure, but sufficiently soto be turned into any ordinary stream. The second invention rests ona curious fact in chemistry, namely, that caustic soda or potash willabsorb steam, forming a compound which has a much higher temperaturethan the steam absorbed. If, therefore, exhaust-steam be dischargedinto the bottom of a vessel containing caustic alkali, not only will itbecome condensed, but this condensation will raise the temperature ofthe mass so high that it may be employed in the generation of freshsteam. It is needless to observe how important will be the bearing ofthis invention upon the working of steam engines for many purposes, if only it can be established as a practical success. And if it is soestablished there can be no doubt that the experience thus acquired willreveal new and valuable facts with regard to the conditions of chemicalcombination and absorption, in the elements thus brought together. 

WALTER R. BROWNE. 

 * * * * *

HYDRAULIC PLATE PRESS. 

One of the most remarkable and interesting mechanical arrangements atthe Imperial Navy Yard at Kiel, Germany, is the iron clad plate bendingmachine, by means of which the heavy iron clad plates are bent for theuse of arming iron clad vessels. 

Through the mechanism of this remarkable machine it is possible to bendthe strongest and heaviest iron clad plates--in cold condition--so thatthey can be fitted close on to the ship's hull, as it was done with theman-of-war ships Saxonia, Bavaria, Wurtemberg, and Baden, each of whichhaving an iron strength of about 250 meters. 

[Illustration: IMPROVED HYDRAULIC PLATE PRESS. ]

One may make himself a proximate idea of the enormous power of pressureof such a machine, if he can imagine what a strength is needed to bendan iron plate of 250 meters thickness, in cold condition; being also 1. 5meters in width, and 5. 00 meters in length, and weighing about 14, 555kilogrammes, or 14, 555 tons. 

The bending of the plates is done as follows: As it is shown in theillustration, connected herewith, there are standing, well secured intothe foundation, four perpendicular pillars, made of heavy iron, allof which are holding a heavy iron block, which by means of female nutscrews is lifted and lowered in a perpendicular direction. Beneath theiron block, between the pillars, is lying a large hollow cylinder inwhich the press piston moves up and down in a perpendicular direction. These movements are caused by a small machine, or, better, presspump--not noticeable in the illustration--which presses water froma reservoir through a narrow pipe into the large hollow cylinder, preventing at the same time the escape or return of the water so forcedin. The hollow cylinder up to the press piston is now filled with water, so remains no other way for the piston as to move on to the top. Theiron clad plate ready to undergo the bending process is lying betweenpress piston and iron block; under the latter preparations are alreadymade for the purpose of giving the iron clad plate such a form as itwill receive through the bending process. After this the press pistonwill, with the greatest force, steadily but slowly move upward, untilthe iron clad plate has received its intended bending. 

Lately the hydraulic presses are often used as winding machines, thatis, they are used as an arrangement to lift heavy loads up on elevatedpoints. 

The essential contrivance of a hydraulic press is as follows:

One thinks of a powerful piston, which, through, human, steam, or waterpower, is set in a moving up-and-down motion. Through the ascent of thepiston, is by means of a drawing pipe, ending into a sieve, the waterabsorbed out of a reservoir, and by the lowering of the piston water isdriven out of a cylinder by means of a narrow pipe (communication pipe)into a second cylinder, which raises a larger piston, the so-calledpress piston. (See illustration. )

One on top opening drawing valve, on the top end of the drawing pipeprevents the return of the water by the going down of the piston; and abarring valve, which is lifted by the lowering of the piston, obstructsthe return of the water by the ascent of the piston, while the drawingvalve is lifted by means of water absorbed by the small drawingpipe. --_Illustrirte Zeitung_. 

 * * * * *

FAST PRINTING PRESS FOR ENGRAVINGS. 

_Uber Land und Meer_, which is one of the finest illustrated newspaperspublished in Germany, gives the following: We recently gave our readersan insight into the establishment of _Uber Land und Meer_, and to-day weshow them the machine which each week starts our paper on its journeyaround the world--a machine which embodies the latest and greatestprogress in the art of printing. The following illustration representsone of the three fast presses which the house of Hallberger employs inthe printing of its illustrated journals. 

With the invention of the cylinder press by Frederick König was verifiedthe saying that the art of printing had lent wings to words. Everywherethe primitive hand-press had to make way for the steam printing machine;but even this machine, since its advent in London in 1810, has itselfundergone so many changes that little else remains of König's inventionthan the principle of the cylinder. The demands of recent times forstill more rapid machines have resulted in the production of pressesprinting from a continuous roll or "web" of paper, from cylindersrevolving in one given direction. The first of this class of presses(the "Bullock" press) was built in America. Then England followed, and there the first newspaper to make use of one was the _Times_. TheAugsburg Machine Works were the first to supply Germany with them, andit was this establishment which first undertook to apply the principleof the web perfecting press (first intended for newspaper work only, where speed rather than fine work is the object sought) to bookprinting, in which far greater accuracy and excellence is required, andthe result has been the construction of a rotary press for the highestgrade of illustrated periodical publications, which meets all therequirements with the most complete success. 

[Illustration: IMPROVED FAST PRINTING PRESS FOR ENGRAVERS]

The building of rotary presses for printing illustrated papers wasattempted as early as 1874 or 1875 in London, by the _Times_, butapparently without success, as no public mention has ever been made ofany favorable result. The proprietor of the _London Illustrated News_obtained better results. In 1877 an illustrated penny paper, anoutgrowth of his great journal, was printed upon a rotary press whichwas, according to his statement, constructed by a machinist namedMiddleton. The first one, however, did not at all meet the higherdemands of illustrated periodical printing, and, while another machineconstructed on the same principle was shown in the Paris Exposition of1878, its work was neither in quality nor quantity adequate to the needsof a largely circulated illustrated paper. A second machine, also onexhibition at the same time, designed and built by the celebrated Frenchmachinist, P. Alauzet, could not be said to have attained the object. Its construction was undertaken long after the opening of theExposition, and too late to solve the weighty question. But thehalf-successful attempt gave promise that the time was at hand when apress could be built which could print our illustrated periodicals morerapidly, and a conference with the proprietors of the Augsburg MachineWorks resulted in the production by them of the three presses from which_Uber Land und Meer_ and _Die Illustrirte Welt_ are to-day issued. Asa whole and in detail, as well as in its productions, the press is themarvel of mechanic and layman. 

As seen in the illustration, the web of paper leaves the roll at itsright, rising to a point at the top where it passes between two hollowcylinders covered with felt and filled with steam, which serve to dampenthe paper as may be necessary, the small hand-wheel seen above thesecylinders regulating the supply of steam. After leaving these cylindersthe paper descends sloping toward the right, and passes through twohighly polished cylinders for the purpose of recalendering. After thisit passes under the lowest of the three large cylinders of the press, winds itself in the shape of an S toward the outside and over the middlecylinder, and leaves the press in an almost horizontal line, afterhaving been printed on both sides, and is then cut into sheets. Theprinting is done while the paper is passing around the two whitecylinders. The cylinder carrying the first form is placed inside andtoward the center of the press, only a part of its cog-wheel and itsjournal being shown in the engraving. The second form is placed upon theuppermost cylinder, and is the outside or cut form. Each one of the formcylinders requires a separate inking apparatus. That of the upper one isplaced to the right at the top, and the bottom one is also at the right, but inside. Each one has a fountain the whole breadth of the press, in which the ink is kept, and connected with which, by appropriatemechanism, is a system of rollers for the thorough distribution of theink and depositing it upon the forms. 

The rapidity with which the impressions follow each other does not allowany time for the printing on the first side to dry, and as a consequencethe freshly printed sheet coming in contact with the "packing" of thesecond cylinder would so soil it as to render clean printing absolutelyimpossible. To avoid this, a second roll of paper is introduced into themachine, and is drawn around the middle cylinder beneath the paper whichhas already been printed upon one side, and receives upon its surfaceall "offset, " thus protecting and keeping perfectly clean both theprinted paper and the impression cylinder. This "offset" web, as itleaves the press, is wound upon a second roller, which when full isexchanged for the new empty roller--a very simple operation. 

The machines print from 3, 500 to 4, 000 sheets per hour _upon bothsides_, a rate of production from twenty-eight to thirty-two times asgreat as was possible upon the old-fashioned hand-press, which wascapable of printing not more than 250 copies upon _one side_ in the sametime. 

The device above described for preventing "offset" is, we believe, theinvention of Mr. H. J. Hewitt, a well known New York printer, 27 RoseStreet. 

 * * * * *

FRENCH CANNON. 

Five new cannons, the largest yet manufactured in France, have beensuccessfully cast in the foundry of Ruelle near Angouleme. They are madeof steel, and are breech loading. The weight of each is 97 tons, withoutthe carriage. The projectile weighs 1, 716 pounds, and the charge orpowder is 616 pounds. To remove them a special wagon with sixteen wheelshas had to be constructed, and the bridges upon the road from Ruelle toAngouleme not being solid enough to bear the weight of so heavy aload, a special roadway will be constructed for the transport of theseweapons, which are destined for coast defences and ironclads. 

 * * * * *

WOODLANDS, STOKE POGIS, BUCKS. 

The illustration represents a house recently reconstructed. Thedining-room wing was alone left in the demolition of the old premises, and this part has been decorated with tile facings, and otherwisealtered to be in accordance with the new portion. The house ispleasantly situated about a mile from Stoke Church of historic fame, in about 15 acres of garden, shrubbery, and meadow land. The hall andstaircase have been treated in wainscot oak, and the whole of the workhas been satisfactorily carried out by Mr. G. Almond, builder, ofBurnham, under the superintendence of Messrs. Thurlow & Cross, architects. --_The Architect_. 

[Illustration: WOODLANDS, STOKE POGES, BUCKS]

 * * * * *

CHINA GRASS. 

The following article appeared in a recent number of the _London Times_:

The subject of the cultivation and commercial utilization of the Chinagrass plant, or rhea, has for many years occupied attention, thequestion being one of national importance, particularly as affectingIndia. Rhea which is also known under the name of ramie, is a textileplant which was indigenous to China and India. It is perennial, easy ofcultivation, and produces a remarkably strong fiber. The problem of itscultivation has long being solved, for within certain limits rhea canbe grown in any climate. India and the British colonies offer unusualfacilities, and present vast and appropriate fields for that enterprise, while it can be, and is, grown in most European countries. All this haslong been demonstrated; not so, however, the commercial utilization ofthe fiber, which up to the present time would appear to be a problemonly partially solved, although many earnest workers have been engagedin the attempted solution. 

There have been difficulties in the way of decorticating the stems ofthis plant, and the Indian Government, in 1869, offered a reward of£5, 000 for the best machine for separating the fiber from the stems andbark of rhea in its green or freshly cut state. The Indian Governmentwas led to this step by the strong conviction, based upon ampleevidence, that the only obstacle to the development of an extensivetrade in this product was the want of suitable means for decorticatingthe plant. This was the third time within the present century that rheahad become the subject of official action on the part of the Government, the first effort for utilizing the plant dating from 1803, when Dr. Roxburg started the question, and the second from 1840, when attentionwas again directed to it by Colonel Jenkins. 

The offer of £5, 000, in 1869, led to only one machine being submittedfor trial, although several competitors had entered their names. Thismachine was that of Mr. Greig, of Edinburgh, but after careful trialby General (then Lieutenant Colonel) Hyde it was found that it did notfulfill the conditions laid down by the Government, and therefore thefull prize of £5, 000 was not awarded. In consideration, however, of theinventor having made a _bona fide_ and meritorious attempt to solvethe question, he was awarded a donation of £1, 500. Other unsuccessfulattempts were subsequently made, and eventually the offer of £5, 000 waswithdrawn by the Government. 

But although the prize was withdrawn, invention did not cease, and theGovernment, in 1881, reoffered the prize of £5, 500. Another competitiontook place, at which several machines were tried, but the trials, asbefore, proved barren of any practical results, and up to the presenttime no machine has been found capable of dealing successfully with thisplant in the green state. The question of the preparation of the fiber, however, continued to be pursued in many directions. Nor is this to bewondered at when it is remembered that the strength of some rhea fiberfrom Assam experimented with in 1852 by Dr. Forbes Royle, as comparedwith St. Petersburg hemp, was in the ratio of 280 to 160, while the wildrhea from Assam was as high as 343. But, above and beyond this, rhea hasthe widest range of possible applications of any fiber, as shown by anexhaustive report on the preparation and use of rhea fiber by Dr. ForbesWatson, published in 1875, at which date Dr. Watson was the reporter onthe products of India to the Secretary of State, at the India Office. Last year, however, witnessed the solution of the question ofdecortication in the green state in a satisfactory manner by M. A. Favier's process, as reported by us at the time. 

This process consists in subjecting the plant to the action of steam fora period varying from 10 to 25 minutes, according to the length of timethe plant had been cut. After steaming, the fiber and its adjunctswere easily stripped from the wood. The importance and value of thisinvention will be realized, when it is remembered that the plant iscultivated at long distances from the localities where the fiberis prepared for the market. The consequence is, that for everyhundredweight of fiber about a ton of woody material has to betransported. Nor is this the only evil, for the gummy matter in whichthe fiber is embedded becomes dried up during transport, and theseparation of the fiber is thus rendered difficult, and even impossible, inasmuch as some of the fiber is left adhering to the wood. 

M. Favier's process greatly simplifies the commercial production of thefiber up to a certain point, for, at a very small cost, it gives themanufacturer the whole of the fiber in the plant treated. But it stillstops short of what is required, in that it delivers the fiber inribbons, with its cementitious matter and outer skin attached. To removethis, various methods have been tried, but, as far as we are aware, without general success--that is to say, the fiber cannot alwaysbe obtained of such a uniformly good quality as to constitute acommercially reliable article. Such was the position of the questionwhen, about a year ago, the whole case was submitted to thedistinguished French chemist, Professor Fremy, member of the Instituteof France, who is well-known for his researches into the nature offibrous plants, and the question of their preparation for the market. Professor Fremy thoroughly investigated the matter from a chemical pointof view, and at length brought it to a successful and, apparently, apractical issue. 

One great bar to previous success would appear to have been the absenceof exact knowledge as to the nature of the constituents of that portionof the plant which contains the fiber, or, in other words, the casing orbark surrounding the woody stem of the rhea. As determined by ProfessorFremy, this consists of the cutose, or outer skin, within which is thevasculose containing the fiber and other conjoined matter, known ascellulose, between which and the woody stem is the pectose, or gum, which causes the skin or bark, as a whole, fiber included, to adhere tothe wood. The Professor, therefore, proceeded to carefully investigatethe nature of these various substances, and in the result he foundthat the vasculose and pectose were soluble in an alkali under certainconditions, and that the cellulose was insoluble. He therefore dissolvesout the cutose, vasculose, and pectose by a very simple process, obtaining the fiber clean, and free from all extraneous adherent matter, ready for the spinner. 

In order, however, to insure as a result a perfectly uniform andmarketable article, the Professor uses various chemicals at the severalstages of the process. These, however, are not administered haphazard, or by rule of thumb, as has been the case in some processes bearing inthe same direction, and which have consequently failed, in the sensethat they have not yet taken their places as commercial successes. TheProfessor, therefore, carefully examines the article which he has totreat, and, according to its nature and the character of its components, he determines the proportions of the various chemicals which heintroduces at the several stages. All chance of failure thus appears tobe eliminated, and the production of a fiber of uniform and reliablequality removed from the region of doubt into that of certainty. The twoprocesses of M. Favier and M. Fremy have, therefore, been combined, andmachinery has been put up in France on a scale sufficiently largeto fairly approximate to practical working, and to demonstrate thepracticability of the combined inventions. 

The experimental works are situated in the Route d'Orleans, GrandMontrouge, just outside Paris, and a few days ago a series ofdemonstrations were given there by Messrs. G. W. H. Brogden and Co. , ofGresham-house, London. The trials were carried out by M. Albert Alroy, under the supervision of M. Urbain, who is Professor Fremy's chiefassistant and copatentee, and were attended by Dr. Forbes Watson, Mr. M. Collyer, Mr. C. J. Taylor, late member of the General Assembly, NewZealand, M. Barbe, M. Favier, Mr. G. Brogden, Mr. Caspar, and a numberof other gentlemen representing those interested in the question atissue. The process, as carried out, consists in first treating the rheaaccording to M. Favier's invention. The apparatus employed for thispurpose is very simple and inexpensive, consisting merely of a stoutdeal trough or box, about 8 ft. Long, 2 ft. Wide, and 1 ft. 8 in. Deep. The box has a hinged lid and a false open bottom, under which steam isadmitted by a perforated pipe, there being an outlet for the condensedwater at one end of the box. Into this box the bundles of rhea wereplaced, the lid closed, steam turned on, and in about twenty minutes itwas invariably found that the bark had been sufficiently softened toallow of its being readily and rapidly stripped off by hand, togetherwith the whole of the fiber, in what may be called ribbons. Thus theprocess of decortication is effectively accomplished in a few minutes, instead of requiring, as it sometimes does in the retting process, days, and even weeks, and being at the best attended with uncertainty asto results, as is also the case when decortication is effected bymachinery. 

Moreover, the retting process, which is simply steeping the cut plantsin water, is a delicate operation, requiring constant watching, to saynothing of its serious inconvenience from a sanitary point of view, onaccount of the pestilential emanations from the retteries. Decorticationby steam having been effected, the work of M. Favier ceases, andthe process is carried forward by M. Fremy. The ribbons having beenproduced, the fiber in them has to be freed from the mucilaginoussecretions. To this end, after examination in the laboratory, they arelaid on metal trays, which are placed one above the other in a verticalperforated metal cylinder. When charged, this cylinder is placed withina strong iron cylinder, containing a known quantity of water, to whichan alkali is added in certain proportions. Within the cylinder is asteam coil for heating the water, and, steam having been turned on, thetemperature is raised to a certain point, when the cylinder is closedand made steam-tight. The process of boiling is continued under pressureuntil the temperature--and consequently the steam pressure--within thecylinder has attained a high degree. 

On the completion of this part of the process, which occupies aboutfour hours, and upon which the success of the whole mainly depends, the cementitious matter surrounding the fiber is found to have beentransformed into a substance easily dissolved. The fibrous mass is thenremoved to a centrifugal machine, in which it is quickly deprived of itssurplus alkaline moisture, and it is then placed in a weak solution ofhydrochloric acid for a short time. It is then transferred to a bathof pure cold water, in which it remains for about an hour, and it issubsequently placed for a short time in a weak acid bath, after which itis again washed in cold water, and dried for the market. Such are theprocesses by which China grass may become a source of profit alike tothe cultivator and the spinner. A factory situate at Louviers has beenacquired, where there is machinery already erected for preparing thefiber according to the processes we have described, at the rate of oneton per day. There is also machinery for spinning the fiber into yarns. These works were also visited by those gentlemen who were at theexperimental works at Montrouge, and who also visited the Governmentlaboratory in Paris, of which Professor Fremy is chief and M. Urbain_sous-chef_, and where those gentlemen explained the details of theirprocess and made their visitors familiar with the progressive steps oftheir investigations. 

With regard to the rhea treated at Montrouge, we may observe that it wasgrown at La Reolle, near Bordeaux. Some special experiments were alsocarried out by Dr. Forbes Watson with some rhea grown by the Duke ofWellington at Stratfield-saye, his Grace having taken an active interestin the question for some years past. In all cases the rhea was usedgreen and comparatively freshly cut. One of the objects of Dr. Watson'sexperiments was, by treating rhea cut at certain stages of growth, to ascertain at which stage the plant yields the best fiber, andconsequently how many crops can be raised in the year with the bestadvantage. 

This question has often presented itself as one of the points to bedetermined, and advantage has been taken of the present opportunity witha view to the solution of the question. Mr. C. J. Taylor also took withhim a sample of New Zealand flax, which was successfully treated bythe process. On the whole, the conclusion is that the results ofthe combined processes, so far as they have gone, are eminentlysatisfactory, and justify the expectation that a large enterprise in thecultivation and utilization of China grass is on the eve of being openedup, not only in India and our colonies, but possibly also much nearerhome. 

 * * * * *

APPARATUS FOR HEATING BY GAS. 

This new heating apparatus consists of a cast iron box, E, provided withan inclined cover, F, into which are fixed 100 copper tubes that arearranged in several lines, and form a semi-cylindrical heating surface. The box, E, is divided into two compartments (Fig. 5), so that the airand gas may enter simultaneously either one or both of the compartments, according to the quantity of heat it is desired to have. Regulation iseffected by means of the keys, G and G', which open the gas conduitsof the solid and movable disk, H, which serves as a regulator fordistributing air through the two compartments. This disk revolves byhand and may be closed or opened by means of a screw to which it isfixed. 

Beneath the tubes that serve to burn the mixture of air and gas, thereis placed a metallic gauze, I, the object of which is to prevent theflames from entering the fire place box. These tubes traverse a sheetiron piece, J, which forms the surface of the fire place, and arecovered with a layer of asbestos filaments that serve to increase thecalorific power of the apparatus. 

[Illustration: GOMEZ'S APPARATUS FOR HEATING BY GAS. 

FIG. 1. --Front View. Scale of 0. 25 to 1. FIG. 2. --Section through AB. FIG. 3. --Plan View. FIG. 4. --Section through CD. FIG. 5. --TransverseSection through the Fireplace. Scale of 0. 50 to 1. ]

The cast iron box, E, is inclosed within a base of refractory clay, L, which is surmounted by a reflector, M, of the same material, that isdesigned to concentrate the heat and increase its radiation. Thisreflector terminates above in a dome, in whose center is placed arefractory clay box. This latter, which is round, is provided in thecenter with a cylinder that is closed above. The box contains a largenumber of apertures, which give passage to the products of combustioncarried along by the hot air. The carbonic acid which such productscontain is absorbed by a layer of quick-lime that has previously beenintroduced into the box, N. 

This heating apparatus, which is inclosed within a cast iron casingsimilar to that of an ordinary gas stove, is employed without a chimney, thus permitting of its being placed against the wall or at any otherpoint whatever in the room to be heated. --_Annales Industrielles_. 

 * * * * *

IMPROVED GAS BURNER FOR SINGEING MACHINES. 

Since the introduction of the process of gas-singeing in finishingtextiles, many improvements have been made in the construction of themachines for this purpose as well as in that of the burners, for theobject of the latter must be to effect the singeing not only evenly andthoroughly, but at the same time with a complete combustion of the gasand avoidance of sooty deposits upon the cloth. The latter object isattained by what are called atmospheric or Bunsen burners, and in whichthe coal gas before burning is mixed with the necessary amount ofatmospheric air. The arrangement under consideration, patented abroad, has this object specially in view. The main gas pipe of the machine isshown at A, being a copper pipe closed at one end and having a tap atthe other. On this pipe the vertical pipes, C, are screwed at statedintervals, each being in its turn provided with a tap near its base. Onthe top of each vertical table the burner, IJ, is placed, whose upperend spreads in the shape of a fan, and allows the gas to escape througha slit or a number of minute holes. Over the tube, C, a mantle, E, isslipped, which contains two holes, HG, on opposite sides, and madenearly at the height of the outlet of the gas. When the gas passes outof this and upward into the burner, it induces a current of air upthrough the holes, HG, and carries it along with it. By covering theseholes with a loose adjustable collar, the amount of admissible air canbe regulated so that the flame is perfectly non-luminous, and thereforecontaining no free particles of carbon or soot. The distance of thevertical tubes, C; and of the fan-shaped burners is calculated so thatthe latter touch each other, and thus a continuous flame is formed, which is found to be the most effective for singeing cloth. Should it bedeemed advisable to singe only part of the cloth, or a narrow piece, the arrangement admits of the taps, D, being turned off asdesired. --_Textile Manufacturer_. 

[Illustration]

 * * * * *

SILAS' CHRONOPHORE. 

In many industries there are operations that have to be repeatedat regular intervals, and, for this reason, the construction of anapparatus for giving a signal, not only at the hour fixed, but also atequal intervals, is a matter of interest. The question of doing this hasbeen solved in a very elegant way by Mr. Silas in the invention of theapparatus which we represent in Fig. 1. It consists of a clock whosedial is provided with a series of small pins. The hands are insulatedfrom the case and communicate with one of the poles of a pile containedin the box. The case is connected with the other pole. A small vibratingbell is interposed in the circuit. If it be desired to obtain a signalat a certain hour, the corresponding pin is inserted, and the handupon touching this closes the circuit, and the bell rings. The bell islikewise inclosed within the box. There are two rows of pins--one ofthem for hours, and the other for minutes. They are spaced according torequirements. In the model exhibited by the house Breguet, at the ViennaExhibition, there were 24 pins for minutes and 12 for hours. Fig. 2gives a section of the dial. It will be seen that the hands are providedat the extremity with a small spring, r, which is itself provided witha small platinum contact, p. The pins also carry a small platinum orsilver point, a. In front of the box there will be observed a smallcommutator, M, (Fig. 1). The use of this is indicated in the diagram(Fig. 3). It will be seen that, according as the plug, B, is introducedinto the aperture to the left or right, the bell. S, will operate as anordinary vibrator, or give but a single stroke. 

[Illustration: FIG. 1. --SILAS' CHRONOPHORE. ]

P is the pile; C is the dial; and A is the commutator. 

It is evident that this apparatus will likewise be able to renderservices in scientific researches and laboratory operations, by sparingthe operator the trouble of continually consulting his watch. --_LaLumiere Electrique_. 

[Illustration: FIG. 2. ]

[Illustration: FIG. 3. ]

 * * * * *

[THE GARDEN. ]

THE ZELKOWAS. 

Two of the three species which form the subject of this article are notonly highly ornamental, but also valuable timber trees. Until recentlythey were considered to belong to the genus Planera, which, however, consists of but a single New World species; now, they properlyconstitute a distinct genus, viz. , Zelkova, which differs materiallyfrom the true Planer tree in the structure of the fruit, etc. Z. Crenata, from the Caucasus, and Z. Acuminata, from Japan, are quickgrowing, handsome trees, with smooth bark not unlike that of beech orhornbeam; it is only when the trees are old that the bark is cast off inrather large sized plates, as is the case with the planes. The habit ofboth is somewhat peculiar; in Z. Crenata especially there is a decidedtendency for all the main branches to be given off from one point;these, too, do not spread, as for instance do those of the elm or beech, but each forms an acute angle with the center of the tree. The trunksare more columnar than those of almost all other hardy trees. Theirdistinct and graceful habit renders them wonderfully well adapted forplanting for effect, either singly or in groups. The flowers, like thoseof the elm, are produced before the leaves are developed; in color theyare greenish brown, and smell like those of the elder. It does notappear that fruits have yet been ripened in England. All the Zelkowasare easily propagated by layers or by grafting on the common elm. 

[Illustration: YOUNG ZELKOWA TREE (21 FEET HIGH)]

_Zelkcova crenata_--The Caucasian Zelkowa is a native of the countrylying between the Black and the Caspian Sea between latitudes 35° and47° of the north of Persia and Georgia. According to Loudon, it wasintroduced to this country in 1760, and it appears to have been plantedboth at Kew and Syon at about that date. A very full account of thehistory, etc. , of the Zelkowa, from which Loudon largely quotes, waspresented to the French Academy of Science by Michaux the younger, whospeaks highly of the value of the tree. In this he is fully corroboratedby Mirbel and Desfontaine, on whom devolved the duty of reporting onthis memoir. They say that it attains a size equal to that of thelargest trees of French forests, and recommend its being largelyplanted. They particularly mention its suitability for roadside avenues, and affirm that its leaves are never devoured by caterpillars, and thatthe stems are not subject, to the canker which frequently ruins the elm. The name Orme de Siberie, which is or was commonly applied to Zelkovacrenata in French books and gardens, is doubly wrong, for the tree isneither an elm nor is it native of Siberia. In 1782 Michaux, the fatherof the author of the paper above mentioned, undertook, under theauspices, of a Monsieur (afterward Louis XVIII. ), a journey into Persia, in order to make botanical researches. 

[Illustration: FOLIAGE OF A YOUNG ZELKOWA TREE, WITH FLOWERS AND FRUIT. ]

"Having left Ispahan, in order to explore the province of Ghilan, hefound this tree in the forests which he traversed before arrivingat Recht, a town situated on the Caspian Sea. In this town he hadopportunities of remarking the use made of the wood, and of judging howhighly it was appreciated by the inhabitants. " The first tree introducedinto Europe appears to have been planted by M. Lemonnier, Professor ofBotany in the Jardin des Plautes, etc. , in his garden near Versailles. This garden was destroyed in 1820, and the dimensions of the treewhen it was cut down were as follows: Height 70 feet, trunk 7 feet incircumference at 5 feet from the ground. The bole of the trunk was 20feet in length and of nearly uniform thickness; and the proportion ofheart-wood to sap-wood was about three quarters of its diameter. Thistree was about fifty years old, but was still in a growing state and invigorous health. The oldest tree existing in France at the time of thepublication of Loudon's great work, was one in the Jardin des Plantes, which in 1831 was about 60 feet high. It was planted in 1786 (when asucker of four years old), about the same time as the limes which formthe grand avenue called the Allee de Buffon. "There is, however, a muchlarger Zelkowa on an estate of M. Le Comte de Dijon, an enthusiasticplanter of exotic trees, at Podenas, near Nerac, in the department ofthe Lot et Garonne. This fine tree was planted in 1789, and on the 20thof January, 1831. It measured nearly 80 feet high, and the trunk wasnearly 3 feet in diameter at 3 feet from the ground. " A drawing of thistree, made by the count in the autumn of that year, was lent to Loudonby Michaux, and the engraving prepared from that sketch (on a scale of 1inch to 12 feet) is herewith reproduced. At Kew the largest tree is onenear the herbarium (a larger one had to be cut down when the herbariumwas enlarged some years ago, and a section of the trunk is exhibitedin Museum No. 3). Its present dimensions are: height, 62 feet;circumference of stem at 1 foot from the ground, 9 feet 8 inches; dittoat ground level, 10 feet; Height of stem from ground to branches, 7feet; diameter of head, 46 feet. The general habit of the tree is quitethat as represented in the engraving of the specimen at Podenas. Themeasurements of the large tree at Syon House were, in 1834, according toLoudon: Height, 54 feet; circumference of of stem, 6 feet 9 inches;and diameter of head, 34 feet; the present dimensions, for which I amindebted to Mr. Woodbridge, are: Height, 76 feet; girth of trunk at 2½feet from ground, 10 feet; spread of branches, 36 feet. 

[Illustration: FLOWERS AND FRUIT OF ZELKOVA CRENATA (_PlaneraRichardi_). ]

IDENTIFICATION. --Zelkova crenata, Spach in Ann. Des Sc. Nat. 2d ser. 15, p. 358. D. C. Prodromus, xvii. , 165 Rhamnus ulmoides, Güldenst. It. , p. 313. R carpinifolius, Pall. Fl Rossica, 2 p. 24, tab. 10. Ulmuspolygama, L C. Richard in Mem. Acad. Des Sciences de Paris, ann. 1781. Planera Richardi, Michx. Fl. Bor. Amer. 2, p. 248; C. A. Meyer, Enumer. Causas. Casp. , n. 354; Dunal in Bulletin Soc. Cent d'Agricult. Del'Herault. Ann. 1841, 299, 303, et ann. 1843, 225, 236. Loudon, Arbor, et Frut. Brit. , vol. 3, p. 1409. Planera crenata, Desf. Cat. Hort. Pariset hortul, fere omnium. Michaux fil. Mem. Sur le Zelkowa, 1831. Planeracarpinifolia, Watson, Dend. Brit. , t. 106. Koch Dendrologie, zweittheil, sweit. Abtheil. P. 425. 

[Illustration: ZELKOWA TREE AT PODENAS

Showing peculiar habit of branching. In old trees the effect is veryremarkable in winter as at Oxford, Versailles (_Petit Trianon_) andSyon. ]

_Var pendula_ (the weeping Zelkowa). --This is a form of which I do notknow the origin or history. It is simply a weeping variety of the commonZelkowa. I first saw it in the Isleworth Nurseries of Messrs. C. Lee &Son, and a specimen presented by them to Kew for the aboretum is nowgrowing freely. I suspect that the Zelkova crenata var. Repens of M. Lavallee's "Aboretum Segrezianum" and the Planera repens of foreigncatalogues generally are identical with the variety now mentioned underthe name it bears in the establishment of Messrs. Lee & Son. 

[Illustration: FOLIAGE OF A FULL-GROWN ZELKOWA TREE. ]

_Z. Acuminata_ is one of the most useful and valuable of Japanese timbertrees. It was found near Yeddo by the late Mr. John Gould Veitch, andwas sent out by the firm of Messrs. J. Veitch & Sons. Maximowicz alsofound the tree in Japan, and introduced it to the Imperial BotanicGardens of St. Petersburg, from whence both seeds and plants wereliberally distributed. In the _Gardeners' Chronicle_ for 1862 Dr. Lindley writes as follows: "A noble deciduous tree, discovered nearYeddo by Mr. J. G. Veitch, 90 feet to 100 feet in height, with aremarkably straight stem. In aspect it resembles an elm. We understandthat a plank in the Exotic Nursery, where it has been raised, measures 3feet 3 inches across. Mr. Veitch informs us that it is one of the mostuseful timber trees in Japan. Its long, taper-pointed leaves, withcoarse, very sharp serratures, appear to distinguish it satisfactorilyfrom the P. Richardi of the northwest of Asia. " There seems to be nodoubt as to the perfect hardiness of the Japanese Zelkowa in Britain, and it is decidedly well worth growing as an ornamental tree apartfrom its probable value as a timber producer. A correspondent in theperiodical just mentioned writes, in 1873, p. 1142, under the signatureof "C. P. ": "At Stewkley Grange it does fairly well; better than mostother trees. In a very exposed situation it grew 3 feet 5 inches lastyear, and was 14 feet 5 inches high when I measured it in November;girth at ground, 8¾ inches; at 3 feet, 5 inches. " The leaves vary insize a good deal on the short twiggy branches, being from 3 inches to3½ inches in length and 1¼ inches to 1½ inches in width, while those onvigorous shoots attain a length of 5 inches, with a width of about halfthe length. They are slightly hairy on both surfaces. The long acuminatepoints, the sharper serratures, the more numerous nerves (nine tofourteen in number), and the more papery texture distinguish Z. Acuminata easily from its Caucasian relative, Z. Crenata. The foliage, too, seems to be retained on the trees in autumn longer than that of thespecies just named; in color it is a dull green above and a brighterglossy green beneath. The timber is very valuable, being exceedinglyhard and capable of a very fine polish. In Japan it is used in theconstruction of houses, ships, and in high class cabinet work. In case99, Museum No. 1 at Kew, there is a selection of small useful andornamental articles made in Japan of Keyaki wood. Those manufacturedfrom ornamental Keyaki (which is simply gnarled stems or roots, orpieces cut tangentially), and coated with the transparent lacquer forwhich the Japanese an so famous, are particularly handsome. In themuseum library is also a book, the Japanese title of which is givenbelow--"Handbook of Useful Woods, " by E. Kinch. Professor at theImperial College of Agriculture, at Tokio, Japan. This work containstransverse and longitudinal sections of one hundred Japanese woods, andnumbers 45 and 46 represent Z. Acuminata. It would be worth the while ofthose who are interested in the introduction and cultivation of timbertrees in temperate climates to procure Kinch's handbook. 

IDENTIFICATION. --Zelkova acuminata, D. C. Prodr. , xvii. , 166; Z. Keaki, Maxim. Mel. Biol. Vol. Ix, p. 21. Planera acuminata, Lindl. In Gard. Chron. 1862, 428; Regel, "Gartenflora" 1863, p. 56. P Japonica, Miq. Ann. Mus. Ludg Bat iii. , 66; Kinch. Yuyo Mokuzai Shoran, 45, 46. P. Keaki, Koch Dendrol. Zweit. Theil zweit Abtheil, 427. P. Dentatajaponica, Hort. P. Kaki, Hort. 

[Illustration: FLOWERING TWIG OF PLANERA GMELINI. ]

_Z. Cretica_ is a pretty, small foliaged tree, from 15 to 20 feet inheight. The ovate crenate leaves, which measure from an inch or evenless, to one inch and a half in length by about half the length inbreadth, are leathery, dark green above, grayish above. They are hairyon both surfaces, the underside being most densely clothed, and thetwigs, too, are thickly covered with short grayish hairs. This species, which is a native of Crete, is not at present in the Kew collection; itsname, however, if given in M. Lavallee's catalogue, "Enumeration desArbres et Arbris Cultives à Segrez" (Seine-et-Oise). 

[Illustration: OLD SPECIMEN OF ZELKOWA TREE IN SUMMER FOLIAGE, CONCEALING FORM OF BRANCHING. ]

IDENTIFICATION. --Zelkova cretica. Spach in Suit à Buff, ii, p. 121. Ulmus Abelicea, Sibth & Sm. Prod. Fl. , Graeca, i. , p. 172. PlaneraAbelicea Roem. & Schltz. Syst. , vi. P. 304; Planch, in Ann. Des Sc. Nat. 1848, p. 282. Abelicea cretica, Smith in Trans. Linn. Sov. , ix. , 126. 

I have seen no specimens of the Zelkova stipulacea of Franchet andSavatier's "Enumeratio Plantarum Japonicarum, " vol. Ii. , p. 489, and asthat seems to have been described from somewhat insufficient material, and, moreover, does not appear to be in cultivation, I passed it over asa doubtful plant. 

GEORGE NICHOLSON. 

Royal Gardens, Kew. 

 * * * * *

A NEW ENEMY OF THE BEE. 

Prof. A. J. Cook, the eminent apiarist, calls attention to a new pestwhich has made its appearance in many apiaries. After referring to thefact that poultry and all other domestic animals of ten suffer seriousinjury from the attacks of parasitic mites, and that even such householdstores as sugar, flour, and cheese are not from their ravages, he tellsof the discovery of a parasitic pest among bees. He says:

"During the last spring a lady bee-keeper of Connecticut discoveredthese mites in her hives while investigating to learn the cause of theirrapid depletion. She had noticed that the colonies were greatly reducedin number of bees, and upon close observation found that the diseased orfailing colonies were covered with the mites. So small are these peststhat a score of them can take possession of a single bee and not becrowded for room either. The lady states that the bees roll and scratchin their vain attempts to rid themselves of these annoying stick-tights, and finally, worried out, fall to the bottom of the hive, or go forthto die on the outside. Mites are not true insects, but are the mostdegraded of spiders. The sub-class _Arachnida_ are at once recognized bytheir eight legs. The order of mites (_Accorina_), which includes thewood-tick, cattle-tick, etc. , and mites, are quickly told from thehigher orders--true spiders and scorpions--by their rounded bodies, which appear like mere sacks, with little appearance of segmentation, and their small, obscure heads. The mites alone, of all the_Arachinida_, pass through a marked metamorphosis. Thus the young mitehas only six legs, while the mature form has eight. The bee mite isvery small, not more than one-fiftieth of an inch long. The female isslightly longer than the male, and somewhat transparent. The color isblack, though the legs and more transparent areas of the female appearyellowish. All the legs are fine jointed, slightly hairy, and eachtipped with two hooks or claws. "

As to remedies, the Professor says that as what would kill the miteswould doubtless kill the bees, makes the question a difficult one. Hesuggests, however, the frequent changing of the bees from one hive toanother, after which the emptied hives should be thoroughly scalded. Hethinks this course of treatment, persisted in, would effectually cleanthem out. 

 * * * * *

CRYSTALLIZATION OF HONEY. 

_To the Editor of the Scientific American_:

Seeing in your issue of October 13, 1883, an article on "Crystallizationin Extracted Honey, " I beg leave to differ a little with the gentleman. I have handled honey as an apiarist and dealer for ten years, and findby actual experience that it has no tendency to crystallize in warmweather; but on the contrary it will crystallize in cold weather, and the colder the weather the harder the honey will get. I have hadcolonies of bees starve when there was plenty of honey in the hives; itwas in extreme cold weather, there was not enough animal heat in thebees to keep the honey from solidifying, hence the starvation of thecolonies. 

To-day I removed with a thin paddle sixty pounds of honey from a largestone jar where it had remained over one year. Last winter it was sosolid from crystallization, it could not be cut with a knife; in fact, Ibroke a large, heavy knife in attempting to remove a small quantity. 

As to honey becoming worthless from candying is a new idea to me, as Ihave, whenever I wanted our crystallized honey in liquid form, treatedit to water bath, thereby bringing it to its natural state, in whichcondition it would remain for an indefinite time, especially ifhermetically sealed. I never had any recrystallize after once havingbeen treated to the water bath; and the flavor of the honey was in noway injured. I think the adding of glycerine to be entirely superfluous. 

W. R. MILLER. 

Polo, October 15. 

 * * * * *

AN EXTENSIVE SHEEP RANGE. 

The little schooner Santa Rosa arrived in port from Santa Barbara a fewdays ago. She comes up to this city twice a year to secure provisions, clothing, lumber, etc. , for use on Santa Rosa Island, being owned by thegreat sheep raiser A. P. Moore, who owns the island and the 80, 000 sheepthat exist upon it. The island is about 30 miles south of Santa Barbara, and is 24 miles in length and 16 in breadth, and contains about 74, 000acres of land, which are admirably adapted to sheep raising. Last June, Moore clipped 1, 014 sacks of wool from these sheep, each sack containingan average of 410 pounds of wool, making a total of 415, 740 pounds, which he sold at 27 cents a pound, bringing him in $112, 349. 80, or aclear profit of over $80, 000. This is said to be a low yield, so it isevident that sheep raising there, when taking into consideration thatshearing takes place twice a year, and that a profit is made off thesale of mutton, etc. , is very profitable. The island is divided intofour quarters by fences running clear across at right angles, and thesheep do not have to be herded like those ranging about the foothills. 

Four men are employed regularly the year round to keep the ranch inorder, and to look after the sheep, and during the shearing time fiftyor more shearers are employed. These men secure forty or fifty days'work, and the average number of sheep sheared in a day is about ninety, for which five cents a clip is paid, thus $4. 50 a day being made by eachman, or something over $200 for the season, or over $400 for ninety daysout of the year. Although the shearing of ninety sheep in a day is theaverage, a great many will go as high as 110, and one man has been knownto shear 125. 

Of course, every man tries to shear as many as he can, and, owing tohaste, frequently the animals are severely cut by the sharp shears. Ifthe wound is serious, the sheep immediately has its throat cut and isturned into mutton and disposed of to the butchers, and the shearer, ifin the habit of frequently inflicting such wounds, is discharged. In theshearing of these 80, 000 sheep, a hundred or more are injured to such anextent as to necessitate their being killed, but the wool and meat areof course turned into profit. 

Although no herding is necessary, about 200 or more trained goats arekept on the island continually, which to all intents and purposes takethe place of the shepherd dogs so necessary in mountainous districtswhere sheep are raised. Whenever the animals are removed from onequarter to another, the man in charge takes out with him several of thegoats, exclaims in Spanish, "Cheva" (meaning sheep). The goat, throughits training, understands what is wanted, and immediately runs to theband, and the sheep accept it as their leader, following wherever itgoes. The goat, in turn, follows the man to whatever point he wishes totake the band. 

To prevent the sheep from contracting disease, it is necessary to givethem a washing twice a year. Moore, having so many on hand, found itnecessary to invent some way to accomplish this whereby not so muchexpense would be incurred and time wasted. After experimenting for sometime, he had a ditch dug 8 feet in depth, a little over 1 foot in width, and 100 feet long. In this he put 600 gallons of water, 200 pounds ofsulphur, 100 pounds of lime, and 6 pounds of soda, all of which isheated to 138°. The goats lead the sheep into a corral or trap at oneend, and the animals are compelled to swim through to the further end, thus securing a bath and taking their medicine at one and the same time. 

The owner of the island and sheep, A. P. Moore, a few years ago purchasedthe property from the widow of his deceased brother Henry, for $600, 000. Owing to ill health, he has rented it to his brother Lawrence for$140, 000 a year, and soon starts for Boston, where he will settle downfor the rest of his life. He still retains an interest in the Santa CruzIsland ranch, which is about 25 miles southeast of Santa Barbara. Thisisland contains about 64, 000 acres, and on it are 25, 000 sheep. OnCatalina Island, 60 miles east of Santa Barbara, are 15, 000 sheep, andon Clementa Island, 80 miles east of that city, are 10, 000 sheep. Fortymiles west of the same city is San Miguel, on which are 2, 000 sheep. Each one of these ranches has a sailing vessel to carry freight, etc. , to and fro between the islands and the mainland, and they are kept busythe greater part of the time. --_San Francisco Call_. 

 * * * * *

THE DISINFECTION OF THE ATMOSPHERE. 

At the Parkes Museum of Hygiene, London, Dr. Robert J. Lee recentlydelivered a lecture on the above subject, illustrated by experiments. 

The author remarked that he could not better open up his theme thanby explaining what was meant by disinfection. He would do so by anillustration from Greek literature. When Achilles had slain Hector, the body still lay on the plain of Troy for twelve days after; thegod Hermes found it there and went and told of it--"This, the twelfthevening since he rested, untouched by worms, untainted by the air. "The Greek word for taint in this sense was _sepsis_, which meantputrefaction, and from this we had the term "antiseptic, " or that whichwas opposed to or prevented putrefaction. The lecturer continued:

I have here in a test tube some water in which a small piece of meat wasplaced a few days ago. The test tube has been in rather a warm room, andthe meat has begun to decompose. What has here taken place is the firststep in this inquiry. This has been the question at which scientificmen have been working, and from the study of which has come a valuableaddition to surgical knowledge associated with the name of ProfessorLister, and known as antiseptic. What happens to this meat, and what isgoing on in the water which surrounds it? How long will it be before allthe smell of putrefaction has gone and the water is clear again? Forit does in time become clear, and instead of the meat we find a finepowdery substance at the bottom of the test tube. It may take weeksbefore this process is completed, depending on the rate at which itgoes on. Now, if we take a drop of this water and examine it with themicroscope, we find that it contains vast numbers of very small livingcreatures or "organisms. " They belong to the lowest forms of life, andare of very simple shape, either very delicate narrow threads or rods orglobular bodies. The former are called bacteria, or staff-like bodies;the latter, micrococci. They live upon the meat, and only disappear whenthe meat is consumed. Then, as they die and fall to the bottom of thetest tube, the water clears again. 

Supposing now, when the meat is first put into water, the water is madeto boil, and while boiling a piece of cotton wool is put into themouth of the tube. The tube may be kept in the same room, at the sametemperature as the unboiled one, but no signs of decomposition will befound, however long we keep it. The cotton wool prevents it; for we mayboil the water with the meat in it, but it would not be long beforebacteria and micrococci are present if the wool is not put in the mouthof the test tube. The conclusion you would naturally draw from thissimple but very important experiment is that the wool must have someeffect upon the air, for we know well that if we keep the air out wecan preserve meat from decomposing. That is the principle upon whichpreserved meats and fruits are prepared. We should at once conclude thatthe bacteria and micrococci must exist in the air, perhaps not in thestate in which we find them in the water, but that their germs or eggsare floating in the atmosphere. How full the air may be of these germswas first shown by Professor Tyndall, when he sent a ray of electriclight through a dark chamber, and as if by a magician's wand revealedthe multitudinous atomic beings which people the air. It is a beautifulthing to contemplate how one branch of scientific knowledge may assistanother; and we would hardly have imagined that the beam of the electriclight could thus have been brought in to illumine the path of thesurgeon, for it is on the exclusion of these bacteria that it is foundthe success of some great operation may depend. It is thus easy tounderstand how great an importance is to be attached to the purity ofair in which we live. This is the practical use of the researches towhich the art of surgery is so much indebted; and not surgery alone, but all mankind in greater or less degree. Professor Tyndall has gonefurther than this, and has shown us that on the tops of lofty mountainsthe air is so pure, so free from organisms, that decomposition isimpossible. 

Now, supposing we make another experiment with the test tube, andinstead of boiling we add to its contents a few drops of carbolic acid;we find that decomposition is prevented almost as effectually as by theuse of the cotton wool. There are many other substances which act likecarbolic acid, and they are known by the common name of antiseptics orantiseptic agents. They all act in the same way; and in such cases asthe dressing of wounds it is more easy to use this method of excludingbacteria than by the exclusion of the air or by the use of cotton wool. We have here another object for inquiry--viz. , the particular propertyof these different antiseptics, the property which they possess ofpreventing decomposition. This knowledge is _very_ ancient indeed. Wehave the best evidence in the skill of the Egyptians in embalming thedead. These substances are obtained from wood or coal, which once waswood. Those woods which do not contain some antiseptic substance, suchas a gum or a resin, will rot and decay. I am not sure that we cangive a satisfactory reason for this, but it is certain that all thesesubstances act as antiseptics by destroying the living organisms whichare the cause of putrefaction. Some are fragrant oils, as, for example, clove, santal, and thyme; others are fragrant gums, such as gum bezoinand myrrh. A large class are the various kinds of turpentine obtainedfrom pine trees. We obtain carbolic acid from the coal tar largelyproduced in the manufacture of gas. Both wood tar, well known under thename of creosote, and coal tar are powerful antiseptics. It is easy tounderstand by what means meat and fish are preserved from decompositionwhen they have been kept in the smoke of a wood fire. The smoke containscreosote in the form of vapor, and the same effect is produced on themeat or fish by the smoke as if they had been dipped in a solution oftar--with this difference, that they are dried by the smoke, whereasmoisture favors decomposition very greatly. 

I can show why a fire from which there is much smoke is better than onewhich burns with a clear flame, by a simple experiment. Here is a pieceof gum benzoin, the substance from which Friar's balsam is made. Thiswill burn, if we light it, just as tar burns, and without much smoke orsmell. If, instead of burning it, we put some on a spoon and heat itgently, much more smoke is produced, and a fragrant scent is given off. In the same way we can burn spirit of lavender or eau de Cologne, but weget no scent from them in this way, for the burning destroys the scent. This is a very important fact in the disinfection of the air. The lessthe flame and the larger the quantity of smoke, the greater the effectproduced, so far as disinfection is concerned. As air is a vapor, wemust use our disinfectants in the form of vapor, so that the one may mixwith the other, just as when we are dealing with fluids we must use afluid disinfectant. 

The question that presents itself is this: Can we so diffuse the vaporof an antiseptic like carbolic acid through the air as to destroy thegerms which are floating in it, and thus purify it, making it like airwhich has been filtered through wool, or like that on the top of a loftymountain? If the smoke of a wood fire seems to act as an antiseptic, and putrefaction is prevented, it seems reasonable to conclude that aircould be purified and made antiseptic by some proper and convenientarrangement. Let us endeavor to test this by a few experiments. 

Here is a large tube 6 inches across and 2 feet long, fixed just above asmall tin vessel in which we can boil water and keep it boiling as longas we please. If we fill the vessel with carbolic acid and water andboil it very gently, the steam which rises will ascend and fill the tubewith a vapor which is strong or weak in carbolic acid, according as weput more or less acid in the water. That is to say, we have practicallya chimney containing an antiseptic vapor, very much the same thing asthe smoke of a wood fire. We must be able to keep the water boiling, forthe experiment may have to be continued during several days, and duringthis time must be neither stronger nor weaker in carbolic acid, neitherwarmer nor colder than a certain temperature. This chimney must bealways at the same heat, and the fire must therefore be kept constantlyburning. This is easily accomplished by means of a jet of gas, andby refilling the vessel every 24 hours with the same proportions ofcarbolic acid and water. 

The question arises, how strong must this vapor be in carbolic acid toact as an antiseptic? It is found that 1 part acid to 50 of water isquite sufficient to prevent putrefaction. If we keep this just belowboiling point there will be a gentle and constant rising of steam intothe cylinder, and we can examine this vapor to see if it is antiseptic. We will take two test tubes half filled with water and put a small pieceof beef into each of them and boil each for half a minute. One testtube we will hang up inside the cylinder, so that it is surrounded bycarbolic acid vapor. The other we stand up in the air. If the latter ishung in a warm room, decomposition will soon take place in it; will thesame thing happen to the other cylinder? For convenience sake we hadbest put six tubes inside the cylinder, so that we can take one outevery day for a week and examine the contents on the field of amicroscope. It will be necessary to be very particular as to thetemperature to which the tubes are exposed, and the rates of evaporationbeneath the cylinder. I may mention that on some of the hottest days oflast summer I made some experiments, when the temperature both ofthe laboratory and inside the cylinder was 75°F. I used test tubescontaining boiled potatoes instead of meat, and found that the tube inthe air, after 48 hours, abounded not simply with bacteria and othersmall bodies present in decomposition, but with the large and variedforms of protozoa, while the tube inside the cylinder contained no signsof decomposition whatever. When the room was cold the experiments werenot so satisfactory, because in the former case there was very little ifany current of air in the cylinder. This leads us to the question, whyshould we not make the solution of carbolic acid and water, and heat it, letting the steam escape by a small hole, so as to produce a jet? It isa singular fact that for all practical purposes such a steam jet willcontain the same proportion of acid to water as did the originalsolution. The solution can of course be made stronger or weaker till weascertain the exact proportion which will prevent decomposition. 

From this arises naturally the question, what quantity of vapor must beproduced in a room in order to kill the bacteria in its atmosphere? Ifwe know the size of the room, shall we be able tell? These questionshave not yet been answered, but the experiments which will settle themwill be soon made, I have no doubt, and I have indicated the lines uponwhich they will be made. I have here a boiler of copper into which wecan put a mixture, and can get from it a small jet of steam for somehours. A simple experiment will show that no bacteria will exist in thatvapor. If I take a test tube containing meat, and boil it while holdingthe mouth of it in this vapor, after it has cooled we close the mouthwith cotton wool, and set it aside in a warm place; after some days weshall find no trace of decomposition, but if the experiment is repeatedwith water, decomposition will soon show itself. Of course, any strengthof carbolic acid can be used at will, and will afford a series of tests. 

There are other methods of disinfecting the atmosphere which we cannotconsider this evening, such as the very potent one of burning sulphur. 

In conclusion, the lecturer remarked that his lecture had been cast intoa suggestive form, so as to set his audience thinking over the causeswhich make the air impure, and how these impurities are to be preventedfrom becoming deleterious to health. 

 * * * * *

A NEW METHOD OF STAINING BACILLUS TUBERCULOSIS. 

By T. J. BURRILL, M. D. , Champaign, Ill. 

Having had considerable experience in the use of the alcoholic solutionsof aniline dyes for staining bacteria, and having for some months usedsolutions in glycerine instead, I have come to much prefer the latter. Evaporation of the solvent is avoided, and in consequence a freedomfrom vexatious precipitations is secured, and more uniform and reliableresults are obtained. There is, moreover, with the alcoholic mixtures atendency to "creep, " or "run, " by which one is liable to have stainedmore than he wishes--fingers, instruments, table, etc. 

From these things the glycerine mixtures are practically free, and thereare no compensating drawbacks. For staining _Bacillus tuberculosis_ thefollowing is confidently commended as preferable to the materials andmethods heretofore in use. Take glycerine, 20 parts; fuchsin, 3 parts;aniline oil, 2 parts; carbolic acid, 2 parts. 

The solution is readily and speedily effected, with no danger ofprecipitation, and can be kept in stock without risk of deterioration. When wanted for use, put about two drops into a watch glass (a smallpomatum pot is better) full of water and gently shake or stir. Justhere there is some danger of precipitating the coloring matter, but thedifficulty is easily avoided by gentle instead of vigorous stirring. After the stain is once dissolved in the water no further troubleoccurs; if any evaporation takes place by being left too long, it is thewater that goes, not the main solvent. The color should now be a light, translucent red, much too diffuse for writing ink. Put in the smearedcover glass, after passing it a few times through a flame, and leave it, at the ordinary temperature of a comfortable room, half an hour. If, however, quicker results are desired, boil a little water in a test tubeand put in about double the above indicated amount of the glycerinemixture, letting it run down the side of the tube, gently shake untilabsorbed, and pour out the hot liquid into a convenient dish, and atonce put in the cover with sputum. Without further attention to thetemperature the stain will be effected within two minutes; but theresult is not quite so good, especially for permanent mounts, as by theslower process. 

After staining put the cover into nitric (or hydrochloric) acid andwater, one part to four, until decolorized, say one minute; wash inwater and examine, or dry and mount in balsam. 

If it is desired to color the ground material, which is not necessary, put on the decolorized and washed glass a drop of aniline blue inglycerine; after one minute wash again in water and proceed as before. 

Almost any objective, from one-fourth inch up will show the bacilli ifsufficient attention is paid to the illumination. --_Med. Record_. 

 * * * * *

CURE FOR HEMORRHOIDS. 

"The carbolic acid treatment of hemorrhoids is now receivingconsiderable attention. Hence the reprint from the _Pittsburgh MedicalJournal_, November, 1883, of an article on the subject by Dr. George B. Fundenberg is both timely and interesting. After relating six cases, theauthor says: "It would serve no useful purpose to increase this list ofcases. The large number I have on record all prove that this treatmentis safe and effectual. I believe that the great majority of cases can becured in this manner. Whoever doubts this should give the method a fairtrial, for it is only those who have done so, that are entitled to speakupon the question. "

 * * * * *

A catalogue, containing brief notices of many important scientificpapers heretofore published in the SUPPLEMENT, may be had gratis at thisoffice. 

 * * * * *

THE SCIENTIFIC AMERICAN SUPPLEMENT. 

PUBLISHED WEEKLY. 

TERMS OF SUBSCRIPTION, $5 A YEAR. 

Sent by mail, postage prepaid, to subscribers in any part of the UnitedStates or Canada. Six dollars a year, sent, prepaid, to any foreigncountry. 

All the back numbers of THE SUPPLEMENT, from the commencement, January1, 1876, can be had. Price, 10 cents each. 

All the back volumes of THE SUPPLEMENT can likewise be supplied. Twovolumes are issued yearly. Price of each volume, $2. 50, stitched inpaper, or $3. 50, bound in stiff covers. 

COMBINED RATES--One copy of SCIENTIFIC AMERICAN and one copy ofSCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7. 00. 

A liberal discount to booksellers, news agents, and canvassers. 

MUNN & CO. , PUBLISHERS, 261 BROADWAY, NEW YORK, N. Y. 

 * * * * *

PATENTS. 

In connection with the SCIENTIFIC AMERICAN, Messrs. MUNN & Co. AreSolicitors of American and Foreign Patents, have had 38 years'experience, and now have the largest establishment in the world. Patentsare obtained on the best terms. 

A special notice is made in the SCIENTIFIC AMERICAN of all Inventionspatented through this Agency, with the name and residence of thePatentee. By the immense circulation thus given, public attention isdirected to the merits of the new patent, and sales or introductionoften easily effected. 

Any person who has made a new discovery or invention can ascertain, freeof charge, whether a patent can probably be obtained, by writing to MUNN& Co. 

We also send free our Hand Book about the Patent Laws, Patents, Caveats. Trade Marks, their costs, and how procured, with hints for procuringadvances on inventions. Address

MUNN & CO. , 261 BROADWAY, NEW YORK. 

Branch Office, cor. F and 7th Sts. , Washington, D. C.