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SCIENTIFIC AMERICAN SUPPLEMENT NO. 344

NEW YORK, August 5, 1882

Scientific American Supplement. Vol. XIV, No. 344. 

Scientific American established 1845

Scientific American Supplement, $5 a year. 

Scientific American and Supplement, $7 a year. 

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TABLE OF CONTENTS. 

I. ENGINEERING AND MECHANICS. --The Panama Canal. By MANUEL EISSLER. I. --Historical notes. --Spanish Discoveries in Central America. --Early explorations. --Nicaragua projects. --Panama railway, etc. 

 Improved Averaging Machine. 

 Compound Beam Engine. 4 figures. --Borsig's improved compound beam engine. 

 Power Hammers with Movable Fulcrum. --By DANIEL LONGWORTH. 5 figures. 

 The Bicheroux System of Furnaces Applied to the Puddling of Iron. 2 figures. 

 Gessner's Continuous Cloth Pressing Machine. 3 figures. 

 Novelties in Ring Spindles. 4 figures. 

 Improvements in Woolen Carding Engines. 

II. NATURAL HISTORY. --Metamorphosis of the Deer's Antlers. --Annual changes. 9 figures. 

 Monkeys. By A. R. WALLACE. --Comparison of skeletons of man, orang outang, and chimpanzee. --Other anatomical resemblances and diversities. --The different kinds of monkeys and the countries they inhabit. --American monkeys. --Lemurs. --Distribution, affinities, and zoological rank of monkeys. 

 Silk Producing Bombyces and other Lepidoptera reared in 1881. By ALFRED WAILLY, Member Lauriat de la Societe d'Acclimatation de France. --An extended and important European, Asiatic, and American silk worms, and other silk producers. 

III. MINERALOGY, METALLURGY, ETC. --The Mineralogical Localities In and Around New York City and the Minerals Occurring Therein. --By NELSON H. DARTON. --Chances for collecting within one hour's ride of New York. --Methods of collecting and testing. --Localities on Bergen Hill. --The Weehawken Tunnel. --Minerals and modes of occurrence. --Calcite. --Natrolite. --Pectolite. --Datholite. --Apopholite. --Phrenite. --Iron and copper pyrites. --Stilbite. --Laumonite. --Heulandite. 

 Antiseptics. 

 Crystallization and its Effects Upon Iron. By N. B. WOOD. -- Beauty of Crystals. --Nature of cohesion. --Cleavage. --Growth of crystals. --Some large crystals. --Cast iron. --Influence of phosphorus and sulphur. --Nature of steel. --Burnt steel. --Effect of annealing. 

IV. ARCHITECTURE, ART, ETC. --The Cathedral of Burgos, Spain. --Full page illustration from photograph. 

 Description of Burgos Cathedral. 

 Photo-Engraving on Zinc and Copper. By LEON VIDAL. 

 Meridian Line. --A surveyor's method of finding the true meridian. --By R. W. MCFARLAND. 

V. ELECTRICITY, ETC. --Electro Mania. By W. MATTIEU WILLIAMS. --Example of electrical exaggeration and delusion. --Early scientific attempts at electro-motors, electric lamps, etc. 

 Action of Magnets Upon the Voltaic Arc. By TH. DU MONCEL. 2 figures. 

 Volckmar's Secondary Batteries. 

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METAMORPHOSIS OF THE DEER'S ANTLERS. 

Every year in March the deer loses its antlers, and fresh onesimmediately begin to grow, which exceed in size those that have justbeen lost. Few persons probably have been able to watch and observe thehabits of the animal after it has lost its antlers. It will, therefore, be of interest to examine the accompanying drawings, by Mr. L. Beckmann, one of them showing a deer while shedding its antlers, and the otheras the animal appears after losing them. In the first illustration theanimal has just lost one of its antlers, and fright and pain cause itto throw its head upward and become disturbed and uneasy. The remainingantler draws down one side of the head and is very inconvenient for theanimal. The remaining antler becomes soon detached from its base, and the deer turns--as if ashamed of having lost its ornament andweapon--lowers its head, and sorrowfully moves to the adjoining thicket, where it hides. A friend once observed a deer losing its antlers, butthe circumstances were somewhat different. The animal was jumping over aditch, and as soon as it touched the further bank it jumped high in theair, arched its back, bent its head to one side in the manner of ananimal that has been wounded, and then sadly approached the nearestthicket, in the same manner as the artist has represented in theaccompanying picture. Both antlers dropped off and fell into the ditch. 

[Illustration: METAMORPHOSIS OF DEER'S ANTLERS. --FIRST STAGE. ]

Strong antlers are generally found together, but weak ones are lost atintervals of two or three days. A few days after this loss the stumpsupon which the antlers rested are covered with a skin, which growsupward very rapidly, and under which the fresh antlers are formed, sothat by the end of July the bucks have new and strong antlers, fromwhich they remove the fine hairy covering by rubbing them against youngtrees. It is peculiar that the huntsman, who knows everything in regardto deer, and has seventy-two signs by which he can tell whether a maleor female deer passes through the woods, does not know at what age thedeer gets its first antlers and how the antlers indicate the age of theanimal. Prof. Altum, in Eberswalde, has given some valuable informationin regard to the relation between the age of the deer and the forms oftheir antlers, but in some respects he has not expressed himself veryclearly, and I think that my observations given in addition to his maybe of importance. When the animal is a year old--that is, in June--theburrs of the antlers begin to form, and in July the animal has twoprotuberances of the size of walnuts, from which the first branches ofthe antlers rise; these branches having the length of a finger only, orbeing even shorter, as shown at 1, in diagram, on p. 5481. After thesecond year more branches are formed, which are considerably longer andmuch rougher at the lower ends than the first. The third pair of antlersis different from its predecessors, inasmuch as it has "roses, " that is, annular ridges around the bases of the horn, which latter are now bentin the shape of a crescent. Either the antler has a single branch (Fig. 3, _a_), or besides the point it has another short end, which is a mostrare shape, and is known as a "fork" (Fig. 3, _b_), or it has two forks(Fig. 3, _c_). In the following year the antlers take the form shownin Fig. 4, and then follows the antler shown in Fig. 5, _a_, whichgenerally has "forks" in place of points, and is known as forked antlerin contradistinction to the point antler shown in Fig. 5, _b_, whichretains the shape of the antler, Fig. 4, but has additional orintermediate prongs or branches. The huntsmen designate the antlers bythe number of ends or points on the two antlers. For instance, Fig. 4 isa six-ender; Fig. 5 shows an eight-ender, etc. ; and antlers have beenknown to have as many as twenty-two ends. If the two antlers do nothave the same number of ends the number of ends on the larger antleris multiplied by two and the word "odd" is placed before the worddesignating the number of ends. For instance, if one antler hasthree ends and the other four, the antler would be termed an "odd"eight-ender. The sixth antler shown in Fig. 6 is a ten-ender, andappears in two different forms, either with a fork at the upper end, asshown in Fig. 6, _a_, or with a crown, as shown in Fig. 6, _b_. In Fig. 7 an antler is shown which the animal carries from its seventh yearuntil the month of March of its eighth year. From that time on thecrowns only increase and change. The increase in the number of points isnot always as regular as I have described it, for in years when foodis scarce and poor the antlers are weak and small, and when food isplentiful and rich the antlers grow exceedingly large, and sometimesskip an entire year's growth. --_Karl Brandt, in Leipziger lllustrirteZeitung_. 

[Illustration: METAMORPHOSIS OF DEER'S ANTLERS. --SECOND STAGE. ]

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MONKEYS. 

By ALFRED R. WALLACE. 

If the skeleton of an orang-outang and a chimpanzee be compared withthat of a man, there will be found to be the most wonderful resemblance, together with a very marked diversity. Bone for bone, throughout thewhole structure, will be found to agree in general form, position, andfunction, the only absolute differences being that the orang has ninewrist bones, whereas man and the chimpanzee have but eight; and thechimpanzee has thirteen pairs of ribs, whereas the orang, like man, hasbut twelve. With these two exceptions, the differences are those ofshape, proportion, and direction only, though the resulting differencesin the external form and motions are very considerable. The greatest ofthese are, that the feet of the anthropoid or man-like apes, as well asthose of all monkeys, are formed like hands, with large opposable thumbsfitted to grasp the branches of trees, but unsuitable for erect walking, while the hands have weak, small thumbs, but very long and powerfulfingers, forming a hook, rather than a hand, adapted for climbing uptrees and suspending the whole weight from horizontal branches. Thealmost complete identity of the skeleton, however, and the closesimilarity of the muscles and of all the internal organs, have producedthat striking and ludicrous resemblance to man, which every onerecognizes in these higher apes, and, in a less degree, in the wholemonkey tribe; the face and features, the motions, attitudes, andgestures being often a strange caricature of humanity. Let us, then, examine a little more closely in what the resemblance consists, and howfar, and to what extent, these animals really differ from us. 

Besides the face, which is often wonderfully human--although the absenceof any protuberant nose gives it often a curiously infantile aspect, monkeys, and especially apes, resemble us most closely in the hand andarm. The hand has well-formed fingers, with nails, and the skin of thepalm is lined and furrowed like our own. The thumb is, however, smallerand weaker than ours, and is not so much used in taking hold ofanything. The monkey's hand is, therefore, not so well adapted as thatof man for a variety of purposes, and cannot be applied with suchprecision in holding small objects, while it is unsuitable forperforming delicate operations, such as tying a knot or writing with apen. A monkey does not take hold of a nut with its forefinger and thumb, as we do, but grasps it between the fingers and the palm in a clumsyway, just as a baby does before it has acquired the proper use ofits hand. Two groups of monkeys--one in Africa and one in SouthAmerica--have no thumbs on their hands, and yet they do not seem to bein any respect inferior to other kinds which possess it. In most of theAmerican monkeys the thumb bends in the same direction as the fingers, and in none is it so perfectly opposed to the fingers as our thumbs are;and all these circumstances show that the hand of the monkey is, bothstructurally and functionally, a very different and very inferior organto that of man, since it is not applied to similar purposes, nor is itcapable of being so applied. 

When we look at the feet of monkeys we find a still greater difference, for these have much larger and more opposable thumbs, and are thereforemore like our hands; and this is the case with all monkeys, so that eventhose which have no thumbs on their hands, or have them small and weakand parallel to the fingers, have always large and well-formed thumbs ontheir feet. It was on account of this peculiarity that the great Frenchnaturalist Cuvier named the whole group of monkeys Quadrumana, orfour-handed animals, because, besides the two hands on their fore-limbs, they have also two hands in place of feet on their hind-limbs. Modernnaturalists have given up the use of this term, because they say thatthe hind extremities of all monkeys are really feet, only these feetare shaped like hands; but this is a point of anatomy, or rather ofnomenclature, which we need not here discuss. 

Let us, however, before going further, inquire into the purpose anduse of this peculiarity, and we shall then see that it is simply anadaptation to the mode of life of the animals which possess it. Monkeys, as a rule, live in trees, and are especially abundant in the greattropical forests. They feed chiefly upon fruits, and occasionally eatinsects and birds'-eggs, as well as young birds, all of which they findin the trees; and, as they have no occasion to come down to the ground, they travel from tree to tree by jumping or swinging, and thus pass thegreater part of their lives entirely among the leafy branches of loftytrees. For such a mode of existence, they require to be able to movewith perfect ease upon large or small branches, and to climb up rapidlyfrom one bough to another. As they use their hands for gathering fruitand catching insects or birds, they require some means of holding onwith their feet, otherwise they would be liable to continual falls, andthey are able to do this by means of their long finger-like toes andlarge opposable thumbs, which grasp a branch almost as securely as abird grasps its perch. The true hands, on the contrary, are used chieflyto climb with, and to swing the whole weight of the body from one branchor one tree to another, and for this purpose the fingers are very longand strong, and in many species they are further strengthened by beingpartially joined together, as if the skin of our fingers grew togetheras far as the knuckles. This shows that the separate action of thefingers, which is so important to us, is little required by monkeys, whose hand is really an organ for climbing and seizing food, while theirfoot is required to support them firmly in any position on the branchesof trees, and for this purpose it has become modified into a large andpowerful grasping hand. 

Another striking difference between monkeys and men is that the formernever walk with ease in an erect posture, but always use their arms inclimbing or in walking on all-fours like most quadrupeds. The monkeysthat we see in the streets dressed up and walking erect, only do soafter much drilling and teaching, just as dogs may be taught to walk inthe same way; and the posture is almost as unnatural to the one animalas it is to the other. The largest and most man-like of the apes--thegorilla, chimpanzee, and orang-outang--also walk usually on all-fours;but in these the arms are so long and the legs so short that the bodyappears half erect when walking; and they have the habit of resting onthe knuckles of the hands, not on the palms like the smaller monkeys, whose arms and legs are more nearly of an equal length, which tendsstill further to give them a semi-erect position. Still they are neverknown to walk of their own accord on their hind legs only, though theycan do so for short distances, and the story of their using a stick andwalking erect by its help in the wild state is not true. Monkeys, then, are both four-handed and four-footed beasts; they possess four handsformed very much like our hands, and capable of picking up or holdingany small object in the same manner; but they are also four-footed, because they use all four limbs for the purpose of walking, running, orclimbing; and, being adapted to this double purpose, the hands want thedelicacy of touch and the freedom as well as the precision of movementwhich ours possess. Man alone is so constructed that he walks erect withperfect ease, and has his hands free for any use to which he wishesto apply them; and this is the great and essential bodily distinctionbetween monkeys and men. 

We will now give some account of the different kinds of monkeys and thecountries they inhabit. 

THE DIFFERENT KINDS OF MONKEYS AND THE COUNTRIES THEY INHABIT. 

Monkeys are usually divided into three kinds--apes, monkeys, andbaboons; but these do not include the American monkeys, which are reallymore different from all those of the Old World than any of thelatter are from each other. Naturalists, therefore, divide the wholemonkey-tribe into two great families, inhabiting the Old and the NewWorld respectively; and, if we learn to remember the kind of differencesby which these several groups are distinguished, we shall be ableto understand something of the classification of animals, and thedifference between important and unimportant characters. 

Taking first the Old World groups, they may be thus defined: apes haveno tails; monkeys have tails, which are usually long; while baboons haveshort tails, and their faces, instead of being round and with a man-likeexpression as in apes and monkeys, are long and more dog-like. Thesedifferences are, however, by no means constant, and it is oftendifficult to tell whether an animal should be classed as an ape, amonkey, or a baboon. The Gibraltar ape, for example, though it has notail, is really a monkey, because it has callosities, or hard pads ofbare skin on which it sits, and cheek pouches in which it can stow awayfood; the latter character being always absent in the true apes, whileboth are present in most monkeys and baboons. All these animals, however, from the largest ape to the smallest monkey, have the samenumber of teeth as we have, and they are arranged in a similar manner, although the tusks or canine teeth of the males are often large, likethose of a dog. 

The American monkeys, on the other hand, with the exception of themarmosets, have four additional grinding teeth (one in each jaw oneither side), and none of them have callosities, or cheek pouches. Theynever have prominent snouts like the baboons; their nostrils are placedwide apart and open sideways on the face; the tail, though sometimesshort, is never quite absent; and the thumb bends the same way as thefingers, is generally very short and weak, and is often quite wanting. We thus see that these American monkeys differ in a great number ofcharacters from those of the Eastern hemisphere; and they have thisfurther peculiarity, that many of them have prehensile or graspingtails, which are never found in the monkeys of any other country. This curious organ serves the purpose of a fifth hand. It has so muchmuscular power that the animal can hang by it easily with the tip curledround a branch, while it can also be used to pick up small objects withalmost as much ease and exactness as an elephant's trunk. In thosespecies which have it most perfectly formed it is very long andpowerful, and the end has the underside covered with bare skin, exactlyresembling that of the finger or palm of the hand and apparently equallysensitive. One of the common kinds of monkeys that accompany streetorgan-players has a prehensile tail, but not of the most perfect kind;since in this species the tail is entirely clad with hair to the tip, and seems to be used chiefly to steady the animal when sitting on abranch by being twisted round another branch near it. The statement isoften erroneously made that all American monkeys have prehensile tails;but the fact is that rather less than half the known kinds have themso, the remainder having this organ either short and bushy, or longand slender, but entirely without any power of grasping. Allprehensile-tailed monkeys are American, but all American monkeys are notprehensile-tailed. 

By remembering these characters it is easy, with a little observation, to tell whether any strange monkey comes from America or from the OldWorld. If it has bare seat-pads, or if when eating it fills its mouthtill its cheeks swell out like little bags, we may be sure it comes fromsome part of Africa or Asia; while if it can curl up the end of its tailso as to take hold of anything, it is certainly American. As all thetailed monkeys of the Old World have seat-pads (or ischial callositiesas they are called in scientific language), and as all the Americanmonkeys have tails, but no seat-pads, this is the most constant externalcharacter by which to distinguish them; and having done so we can lookfor the other peculiarities of the American monkeys, especially thedistance apart of the nostrils and their lateral position. 

The whole monkey-tribe is especially tropical, only a few kinds beingfound in the warmer parts of the temperate zone. One inhabits the Rockof Gibraltar, and there is one very like it in Japan, and these are thetwo monkeys which live furthest from the equator. In the tropics theybecome very abundant and increase in numbers and variety as we approachthe equator, where the climate is hot, moist, and equable, and whereflowers, fruits, and insects are to be found throughout the year. Africahas about 55 different kinds, Asia and its islands about 60, whileAmerica has 114, or almost exactly the same as Asia and Africa together. Australia and its islands have no monkeys, nor has the great andluxuriant island of New Guinea, whose magnificent forests seem so welladapted for them. We will now give a short account of the differentkinds of monkeys inhabiting each of the tropical continents. 

Africa possesses two of the great man-like apes--the gorilla and thechimpanzee, the former being the largest ape known, and the one which, on the whole, perhaps most resembles man, though its countenance is lesshuman than that of the chimpanzee. Both are found in West Africa, nearthe equator, but they also inhabit the interior wherever there are greatforests; and Dr. Schweinfurth states that the chimpanzee inhabits thecountry about the sources of the Shari River in 28° E. Long. And 4° N. Lat. 

The long-tailed monkeys of Africa are very numerous and varied. Onegroup has no cheek pouches and no thumb on the hand, and many of thesehave long soft fur of varied colors. The most numerous group are theGuenons, rather small long-tailed monkeys, very active and lively, and often having their faces curiously marked with white or black, orornamented with whiskers or other tufts of hair; and they all have largecheek pouches and good sized thumbs. Many of them are called greenmonkeys, from the greenish yellow tint of their fur, and most of themare well formed, pleasing animals. They are found only in tropicalAfrica. 

The baboons are larger but less numerous. They resemble dogs in thegeneral form and the length of the face or snout, but they have handswith well-developed thumbs on both the fore and hind limbs; and this, with something in the expression of the face and their habit of sittingup and using their hands in a very human fashion, at once shows thatthey belong to the monkey tribe. Many of them are very ugly, and intheir wild state they are the fiercest and most dangerous of monkeys. Some have the tail very long, others of medium length, while it issometimes reduced to a mere stump, and all have large cheek pouches andbare seat pads. They are found all over Africa, from Egypt to the Capeof Good Hope; while one species, called the hamadryas, extends fromAbyssinia across the Red Sea into Arabia, and is the only baboon foundout of Africa. This species was known to the ancients, and it is oftenrepresented in Egyptian sculptures, while mummies of it have been foundin the catacombs. The largest and most remarkable of all the baboonsis the mandrill of West Africa, whose swollen and hog-like face isornamented with stripes of vivid blue and scarlet. This animal has atail scarcely two inches long, while in size and strength it is not muchinferior to the gorilla. The large baboons go in bands, and are said tobe a match for any other animals in the African forests, and even toattack and drive away the elephants from the districts they inhabit. 

Turning now to Asia, we have first one of the best known of the largeman-like apes--the orang-outang, found only in the two large islands, Borneo and Sumatra. The name is Malay, signifying "man of the woods, "and it should be pronounced órang-óotan, the accent being on the firstsyllable of both words. It is a very curious circumstance that, whereasthe gorilla and chimpanzee are both black, like the negroes of the samecountry, the orang-outang is red or reddish brown, closely resemblingthe color of the Malays and Dyaks who live in the Bornean forests. Though very large and powerful, it is a harmless creature, feeding onfruit, and never attacking any other animal except in self-defense. Afull-grown male orang-outang is rather more than four feet high, butwith a body as large as that of a stout man, and with enormously longand powerful arms. 

Another group of true apes inhabit Asia and the larger Asiatic islands, and are in some respects the most remarkable of the whole family. Theseare the Gibbons, or long-armed apes, which are generally of small sizeand of a gentle disposition, but possessing the most wonderful agility. In these creatures the arms are as long as the body and legs together, and are so powerful that a gibbon will hang for hours suspended froma branch, or swing to and fro and then throw itself a great distancethrough the air. The arms, in fact, completely take the place of thelegs for traveling. Instead of jumping from bough to bough and runningon the branches, like other apes and monkeys, the gibbons move alongwhile hanging suspended in the air, stretching their arms from bough tobough, and thus going hand over hand as a very active sailor will climbalong a rope. The strength of their arms is, however, so prodigious, and their hold so sure, that they often loose one hand before they havecaught a bough with the other, thus seeming almost to fly through theair by a series of swinging leaps; and they travel among the network ofinterlacing boughs a hundred feet above the earth with as much ease andcertainty as we walk or run upon level ground, and with even greaterspeed. These little animals scarcely ever come down to the ground oftheir own accord; but when obliged to do so they run along almost erect, with their long arms swinging round and round, as if trying to find sometree or other object to climb upon. They are the only apes who naturallywalk without using their hands as well as their feet; but this does notmake them more like men, for it is evident that the attitude is not aneasy one, and is only adopted because the arms are habitually used toswing by, and are therefore naturally held upward, instead of downward, as they must be when walking on them. 

The tailed monkeys of Asia consist of two groups, the first of whichhave no cheek pouches, but always have very long tails, They aretrue forest monkeys, very active and of a shy disposition. The mostremarkable of these is the long-nosed monkey of Borneo, which is verylarge, of a pale brown color, and distinguished by possessing a long, pointed, fleshy nose, totally unlike that of all other monkeys. Anotherinteresting species is the black and white entellus monkey of India, called the "Hanuman, " by the Hindoos, and considered sacred by them. These animals are petted and fed, and at some of the temples numbersof them come every day for the food which the priests, as well as thepeople, provide for them. 

The next group of Eastern monkeys are the Macaques, which are more likebaboons, and often run upon the ground. They are more bold and viciousthan the others. All have cheek pouches, and though some have longtails, in others the tail is short, or reduced to a mere stump. In somefew this stump is so very short that there appears to be no tail, as inthe magot of North Africa and Gibraltar, and in an allied species thatinhabits Japan. 

AMERICAN MONKEYS. 

The monkeys which inhabit America form three very distinct groups:1st, the Sapajous, which have prehensile or grasping tails; 2nd, theSagouins, which have ordinary tails, either long or short; and, 3rd, theMarmosets, very small creatures, with sharp claws, long tails which arenot prehensile, and a smaller number of teeth than all other Americanmonkeys. Each of these three groups contain several sub-groups, or_genera_, which often differ remarkably from each other, and from allthe monkeys of the Old World. 

We will begin with the howling monkeys, which are the largest found inAmerica, and are celebrated for the loud voice of the males. Often inthe great forests of the Amazon or Oronooko a tremendous noise is heardin the night or early morning, as if a great assemblage of wild beastswere all roaring and screaming together. The noise may be heard formiles, and it is louder and more piercing than that of any otheranimals, yet it is all produced by a single male howler, sitting on thebranches of some lofty tree. They are enabled to make this extraordinarynoise by means of an organ that is possessed by no other animal. Thelower jaw is unusually deep, and this makes room for a hollow bonyvessel about the size of a large walnut, situated under the root of thetongue, and having an opening into the windpipe by which the animalcan force air into it. This increases the power of its voice, actingsomething like the hollow case of a violin, and producing thosemarvelous rolling and reverberating sounds which caused the celebratedtraveler Waterton to declare that they were such as might have had theirorigin in the infernal regions. The howlers are large and stout bodiedmonkeys, with bearded faces, and very strong and powerfully graspingtails. They inhabit the wildest forests; they are very shy, and areseldom taken captive, though they are less active than many otherAmerican monkeys. 

Next come the spider monkeys, so called from their slender bodies andenormously long limbs and tail. In these monkeys the tail is so long, strong, and perfect, that it completely takes the place of a fifth hand. By twisting the end of it round a branch the animal can swing freely inthe air with complete safety; and this gives them a wonderful power ofclimbing end passing from tree to tree, because the distance they canstretch is that of the tail, body, and arm added together, and these areall unusually long. They can also swing themselves through the air forgreat distances, and are thus able to pass rapidly from tree to treewithout ever descending to the ground, just like the gibbons in theMalayan forests. Although capable of feats of wonderful agility, thespider monkeys are usually slow and deliberate in their motions, andhave a timid, melancholy expression, very different from that of mostmonkeys. Their hands are very long, but have only four fingers, beingadapted for hanging on to branches rather than for getting hold of smallobjects. It is said that when they have to cross a river the trees onthe opposite banks of which do not approach near enough for a leap, several of them form a chain, one hanging by its tail from a loftyoverhanging branch and seizing hold of the tail of the one below it, then gradually swinging themselves backward and forward till the lowerone is able to seize hold of a branch on the opposite side. He thenclimbs up the tree, and, when sufficiently high, the first one lets go, and the swing either carries him across to a bough on the opposite sideor he climbs up over his companions. 

Closely allied to the last are the woolly monkeys, which have an equallywell developed prehensile tail, but better proportioned limbs, and athick woolly fur of a uniform gray or brownish color. They have wellformed fingers and thumbs, both on the hands and feet, and are ratherdeliberate in their motions, and exceedingly tame and affectionate incaptivity. They are great eaters, and are usually very fat. They arefound only in the far interior of the Amazon valley, and, having adelicate constitution, seldom live long in Europe. These monkeys are notso fond of swinging themselves about by their tails as are the spidermonkeys, and offer more opportunities of observing how completely thisorgan takes the place of a fifth hand. When walking about a house, or onthe deck of a ship, the partially curled tail is carried in a horizontalposition on the ground, and the moment it touches anything it twistsround it and brings it forward, when, if eatable, it is at onceappropriated; and when fastened up the animal will obtain any food thatmay be out of reach of its hands with the greatest facility, picking upsmall bits of biscuit, nuts, etc. , much as an elephant does with the tipof his trunk. 

We now come to a group of monkeys whose prehensile tail is of a lessperfect character, since it is covered with hair to the tip, and is ofno use to pick up objects. It can, however, curl round a branch, andserves to steady the animal while sitting or feeding, but is never usedto hang and swing by in the manner so common with the spider monkeys andtheir allies. These are rather small-sized animals, with round heads andwith moderately long tails. They are very active and intelligent, theirlimbs are not so long as in the preceding group, and though they havefive fingers on each hand and foot, the hands have weak and hardlyopposable thumbs. Some species of these monkeys are often carried aboutby itinerant organ men, and are taught to walk erect and perform manyamusing tricks. They form the genus _Cebus_ of naturalists. 

The remainder of the American monkeys have non-prehensile tails, likethose of the monkeys of the Eastern hemisphere; but they consist ofseveral distinct groups, and differ very much in appearance and habits. First we have the Sakis, which have a bushy tail and usually very longand thick hair, something like that of a bear. Sometimes the tail isvery short, appearing like a rounded tuft of hair; many of the specieshave fine bushy whiskers, which meet under the chin, and appear as ifthey had been dressed and trimmed by a barber, and the head is oftencovered with thick curly hair, looking like a wig. Others, again, havethe face quite red, and one has the head nearly bald, a most remarkablepeculiarity among monkeys. This latter species was met with by Mr. Bateson the Upper Amazon, and he describes the face as being of a vividscarlet, the body clothed from neck to tail with very long, straight, and shining white hair, while the head was nearly bald, owing to thevery short crop of thin gray hairs. As a finish to their strikingphysiognomy these monkeys have bushy whiskers of a sandy color meetingunder the chin, and yellowish gray eyes. The color of the face is sovivid that it looks as if covered with a thick coat of bright scarletpaint. These creatures are very delicate, and have never reached Europealive, although several of the allied forms have lived some time in ourZoological Gardens. 

An allied group consists of the elegant squirrel monkeys, with long, straight, hairy tails, and often adorned with pretty variegated colors. They are usually small animals; some have the face marked with black andwhite, others have curious whiskers, and their nails are rather sharpand claw like. They have large round heads, and their fur is more glossyand smooth than in most other American monkeys, so that they moreresemble some of the smaller monkeys of Africa. These little creaturesare very active, running about the trees like squirrels, and feedinglargely on insects as well as on fruit. 

Closely allied to these are the small group of night monkeys, which havelarge eyes, and a round face surrounded by a kind of ruff of whitishfur, so as to give it an owl like appearance, whence they are sometimescalled owl-faced monkeys. They are covered with soft gray fur, like thatof a rabbit, and sleep all day long concealed in hollow trees. Theface is also marked with white patches and stripes, giving it a rathercarnivorous or cat like aspect, which, perhaps, serves as a protection, by causing the defenseless creature to be taken for an arboreal tigercat or some such beast of prey. 

This finishes the series of such of the American monkeys as have alarger number of teeth than those of the Old World. But there is anothergroup, the Marmosets, which have the same number of teeth as Easternmonkeys, but differently distributed in the jaws, a premolar beingsubstituted for a molar tooth. In other particulars they resemble therest of the American monkeys. They are very small and delicate creaturessome having the body only seven inches long. The thumb of the handsis[1] not opposable, and instead of nails they have sharp compressedclaws. These diminutive monkeys have long, non-prehensile tails, andthey have a silky fur often of varied and beautiful colors. Some arestriped with gray and white, or are of rich brown or golden brown tints, varied by having the head or shoulders white or black, while in manythere are crests, frills, manes, or long ear tufts, adding greatly totheir variety and beauty. These little animals are timid and restless;their motions are more like those of a squirrel than a monkey. Theirsharp claws enable them to run quickly along the branches, but theyseldom leap from bough to bough like the larger monkeys. They live onfruits and insects, but are much afraid of wasps, which they are said torecognize even in a picture. 

[Transcribers note 1: Changed from '... It not opposable', ... ]

This completes our sketch of the American monkeys, and we see that, although they possess no such remarkable forms as the gorilla or thebaboons, yet they exhibit a wonderful diversity of external characters, considering that all seem equally adapted to a purely arboreal life. In the howlers we have a specially developed voice organ, which isaltogether peculiar; in the spider monkeys we find the adaptation toactive motion among the topmost branches of the forest trees carried toan extreme point of development; while the singular nocturnal monkeys, the active squirrel monkeys, and the exquisite little marmosets, showhow distinct are the forms under which the same general type, may beexhibited, and in how many varied ways existence may be sustained underalmost identical conditions. 

LEMURS. 

In the general term, monkeys, considered as equivalent to the orderPrimates, or the Quadrumana of naturalists, we have to include anothersub-type, that of the Lemurs. These animals are of a lower grade thanthe true monkeys, from which they differ in so many points of structurethat they are considered to form a distinct sub-order, or, by somenaturalists, even a separate order. They have usually a much larger headand more pointed muzzle than monkeys; they vary considerably in thenumber, form, and arrangement of the teeth; their thumbs are always welldeveloped, but their fingers vary much in size and length; their tailsare usually long, but several species have no tail whatever, and theyare clothed with a more or less woolly fur, often prettily variegatedwith white and black. They inhabit the deep forests of Africa, Madagascar, and Southern Asia, and are more sluggish in their movementsthan true monkeys, most of them being of nocturnal and crepuscularhabits. They feed largely on insects, eating also fruits and the eggs oryoung of birds. 

The most curious species are--the slow lemurs of South India, smalltailless nocturnal animals, somewhat resembling sloths in appearance, and almost as deliberate in their movements, except when in the act ofseizing their insect prey; the Tarsier, or specter lemur, of the Malayislands, a small, long tailed nocturnal lemur, remarkable for thecurious development of the hind feet, which have two of the toes veryshort, and with sharp claws, while the others have nails, the third toebeing exceedingly long and slender, though the thumb is very large, giving the feet a very irregular and _outré_ appearance; and, lastly, the Aye-aye, of Madagascar, the most remarkable of all. This animal hasvery large ears and a squirrel like tail, with long spreading hair. It has large curved incisor teeth, which add to its squirrel likeappearance, and caused the early naturalists to class it among therodents. But its most remarkable character is found in its fore feetor hands, the fingers of which are all very long and armed with sharpcurved claws, but one of them, the second, is wonderfully slender, being not half the thickness of the others. This curious combination ofcharacters shows that the aye-aye is a very specialized form--that is, one whose organization has been slowly modified to fit it for a peculiarmode of life. From information received from its native country, andfrom a profound study of its organization, Professor Owen believesthat it is adapted for the one purpose of feeding on small wood-boringinsects. Its large feet and sharp claws enable it to cling firmly to thebranches of trees in almost any position; by means of its large delicateears it listens for the sound of the insect gnawing within the branch, and is thus able to fix its exact position; with its powerful curvedgnawing teeth it rapidly cuts away the bark and wood till it exposes theburrow of the insect, most probably the soft larva of some beetle, andthen comes into play the extraordinary long wire-like finger, whichenters the small cylindrical burrow, and with the sharp bent claw hooksout the grub. Here we have a most complex adaptation of different partsand organs, all converging to one special end, that end being the sameas is reached by a group of birds, the woodpeckers, in a different way;and it is a most interesting fact that, although woodpeckers abound inall the great continents, and are especially common in the tropicalforests of Asia, Africa, and America, they are quite absent fromMadagascar. We may, therefore, consider that the aye-aye really occupiesthe same place in nature in the forests of this tropical island, as dothe woodpeckers in other parts of the world. 

DISTRIBUTION, AFFINITIES, AND ZOOLOGICAL RANK OF MONKEYS. 

Having thus sketched an outline of the monkey tribe as regards theirmore prominent external characters and habits, we must say a few wordson their general relations as a distinct order of mammalia. No othergroup so extensive and so varied as this, is so exclusively tropical inits distribution, a circumstance no doubt due to the fact that monkeysdepend so largely on fruit and insects for their subsistence. A veryfew species extend into the warmer parts of the temperate zones, theirextreme limits in the northern hemisphere being Gibraltar, the WesternHimalayas at 11, 000 feet elevation, East Thibet, and Japan. In Americathey are found in Mexico, but do not appear to pass beyond the tropic. In the Southern hemisphere they are limited by the extent of the forestsin South Brazil, which reach about 30° south latitude. In the East, owing to their entire absence from Australia, they do not reach thetropic; but in Africa, some baboons range to the southern extremity ofthe continent. 

But this extreme restriction of the order to almost tropical lands isonly recent. Directly we go back to the Pliocene period of geology, we find the remains of monkeys in France, and even in England. In theearlier Miocene, several kinds, some of large size, lived in France, Germany, and Greece, all more or less closely allied to living forms ofAsia and Africa. About the same period monkeys of the South Americantype inhabited the United States. In the remote Eocene period the sametemperate lands were inhabited by lemurs in the East, and by curiousanimals believed to be intermediate between lemurs and marmosets in theWest. We know from a variety of other evidence that throughout thesevast periods a mild and almost sub-tropical climate extended over allCentral Europe and parts of North America, while one of a temperatecharacter prevailed as far north as the Arctic circle. The monkey tribethen enjoyed a far greater range over the earth, and perhaps filled amore important place in nature than it does now. Its restriction to thecomparatively narrow limits of the tropics is no doubt mainly due to thegreat alteration of climate which occurred at the close of the Tertiaryperiod, but it may have been aided by the continuous development ofvaried forms of mammalian life better fitted for the contrasted seasonsand deciduous vegetation of the north temperate regions. The moreextensive area formerly inhabited by the monkey tribe, would havefavored their development into a number of divergent forms, in distantregions, and adapted to distinct modes of life. As these retreatedsouthward and became concentrated in a more limited area, such as wereable to maintain themselves became mingled together as we now find them, the ancient and lowly marmosets and lemurs subsisting side by side withthe more recent and more highly developed howlers and anthropoid apes. 

Throughout the long ages of the Tertiary period monkeys must have beenvery abundant and very varied, yet it is but rarely that their fossilremains are found. This, however, is not difficult to explain. Thedeposits in which mammalian remains most abound are those formed inlakes or in caverns. In the former the bodies of large numbers ofterrestrial animals were annually deposited, owing to their having beencaught by floods in the tributary streams, swallowed up in marginal bogsor quicksands, or drowned by the giving way of ice. Caverns were thehaunts of hyenas, tigers, bears, and other beasts of prey, which draggedinto them the bodies of their victims, and left many of their bones tobecome embedded in stalagmite or in the muddy deposit left by floods, while herbivorous animals were often carried into them by these floods, or by falling down the swallow-holes which often open into caverns fromabove. But, owing to their arboreal habits, monkeys were to a greatextent freed from all these dangers. Whether devoured by beasts or birdsof prey, or dying a natural death, their bones would usually be left ondry land, where they would slowly decay under atmospheric influences. Only under very exceptional circumstances would they become embeddedin aqueous deposits; and instead of being surprised at their raritywe should rather wonder that so many have been discovered in a fossilstate. 

Monkeys, as a whole, form a very isolated group, having no nearrelations to any other mammalia. This is undoubtedly an indication ofgreat antiquity. The peculiar type which has since reached so high adevelopment must have branched off the great mammalian stock at a veryremote epoch, certainly far back in the Secondary period, since in theEocene we find lemurs and lemurine monkeys already specialized. At thisremoter period they were probably not separable from the insectivora, or (perhaps) from the ancestral marsupials. Even now we have one livingform, the curious Galeopithecus or flying lemur, which has only recentlybeen separated from the lemurs, with which it was formerly united, to beclassed as one of the insectivora; and it is only among the Opossums andsome other marsupials that we again find hand-like feet with opposablethumbs, which are such a curious and constant feature of the monkeytribe. 

This relationship to the lowest of the mammalian tribes seemsinconsistent with the place usually accorded to these animals at thehead of the entire mammalian series, and opens up the question whetherthis is a real superiority or whether it depends merely on the obviousrelationship to ourselves. If we could suppose a being gifted withhigh intelligence, but with a form totally unlike that of man, to havevisited the earth before man existed in order to study the various formsof animal life that were found there, we can hardly think he would haveplaced the monkey tribe so high as we do. He would observe that theirwhole organization was specially adapted to an arboreal life, and thisspecialization would be rather against their claiming the first rankamong terrestrial creatures. Neither in size, nor strength, nor beauty, would they compare with many other forms, while in intelligence theywould not surpass, even if they equaled, the horse or the beaver. Thecarnivora, as a whole, would certainly be held to surpass them in theexquisite perfection of their physical structure, while the flexibletrunk of the elephant, combined with his vast strength and admirablesagacity, would probably gain for him the first rank in the animalcreation. 

But if this would have been a true estimate, the mere fact that the apeis our nearest relation does not necessarily oblige us to come to anyother conclusion. Man is undoubtedly the most perfect of all animals, but he is so solely in respect of characters in which he differs fromall the monkey tribe--the easily erect posture, the perfect freedomof the hands from all part in locomotion, the large size and completeopposability of the thumb, and the well developed brain, which enableshim fully to utilize these combined physical advantages. The monkeyshave none of these; and without them the amount of resemblance they haveto us is no advantage, and confers no rank. We are biased by the tooexclusive consideration of the man-like apes. If these did not existthe remaining monkeys could not be thereby deteriorated as to theirorganization or lowered in their zoological position, but it is doubtfulif we should then class them so high as we now do. We might then dwellmore on their resemblances to lower types--to rodents, to insectivora, and to marsupials, and should hardly rank the hideous baboon above thegraceful leopard or stately stag. The true conclusion appears to be, that the combination of external characters and internal structure whichexists in the monkeys, is that which, when greatly improved, refined, and beautified, was best calculated to become the perfect instrumentof the human intellect and to aid in the development of man's highernature; while, on the other hand, in the rude, inharmonious, andundeveloped state which it has reached in the quadrumana, it is by nomeans worthy of the highest place, or can be held to exhibit the mostperfect development of existing animal life. --_Contemporary Review_. 

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[JOURNAL OF THE SOCIETY OF ARTS. ]

SILK-PRODUCING BOMBYCES AND OTHER LEPIDOPTERA REARED IN 1881. 

By ALFRED WAILLY, Membre Lauréat de la Société d'Acclimatation deFrance. 

By referring to my reports for the years 1879 and 1880, which appearedin the _Journal of the Society of Arts_, February 13 and March 5, 1880, February 25 and March 4, 1881, it will be seen that the bad weatherprevented the successful rearing in the open air of most species ofsilk-producing larvæ. In 1881, the weather was extremely favorable upto the end of July, but the incessant and heavy rains of the month ofAugust and beginning of September, proved fatal to most of the larvæwhen they were in their last stages. However, in spite of my manydifficulties, I had the satisfaction of seeing them to their laststage. Larvæ of all the silk-producing bombyces were preserved in theirdifferent stages, and can be seen in the Bethnal-green Museum. In July, when the weather was magnificent, the little trees in my garden wereliterally covered with larvæ of more species than I ever had before, andtwo or three more weeks of fair weather would have given me a good cropof cocoons, instead of which I only obtained a very small number. Thesparrows, as usual, also destroyed a quantity of worms, in spite of wireor fish-netting placed over some of the trees. 

On the trees were to be seen--_Attacus cynthia_ (the Ailantus silkworm), the rearing of which was, as usual, most successful; _Samia cecropia_and _Samia gloveri_, from America; also hybrids of _Gloveri cecropia_and _Cecropia gloveri_; _Samia promethea_ and _Telea polyphemus_;_Attacus pernyi_, and a new hybrid, which I obtained this last season bythe crossing of Pernyi with Royle. For the first time I reared _Actiasselene_, from India, on a nut-tree in the garden, and _Attacus atlas_, on the ailantus. The _Selene_ larvæ reached their fifth and last stage. The Atlas larvæ only reached the third stage, and were destroyed by theheavy rains; only two remained on the tree till about the 8th or 9th ofSeptember, when they had to be removed. I shall now reproduce the notesI took on some of the various species I reared. 

_Actias Selene_. --With sixty cocoons I only obtained one pairing. Themoths emerged from the beginning of March till the 13th of August, at intervals of some duration, or in batches of males or females. Iobtained a pairing of Selene on the 30toh of June, 1881, and the wormscommenced to hatch on the 13th of July. The larvæ in first stage are ofa fine brown-red, with a broad black band in the middle of the body. Thesecond stage commenced on the 20th of July; larvæ, of a lighter reddishcolor, without the black band; tubercles black. Third stage commenced onthe 28th of July; larvæ green; the first four tubercles yellow, with ablack ring at the base; other tubercles, orange yellow. Fourth stagecommenced on the 6th of August; larvæ green; first four tuberclesgolden-yellow, the others orange-red. Fifth stage commenced on the 19thof August; first four tubercles yellow, with a black ring at the base;other tubercles yellow, slightly tinged with orange-red; lateral bandbrown and greenish yellow; head and forelegs dark-brown. As statedbefore, the larvæ were reared on a nut-tree in the garden, till the laststage. Selene feeds on various trees--walnut, wild cherry, wild pear, etc. In Ceylon (at Kandy), it is found on the wild olive tree. As far asI am informed by correspondents in Ceylon, this species is not found--oris seldom found--on the coasts, but _Attacus atlas_ and Mylitta arecommonly found there. 

_Attacus (antheroea) roylei_ (with sixty cocoons); three pairings onlywere obtained, and this species I found the most difficult to pair incaptivity. Two moths emerged on the 5th of March, a male and a female, and a pairing was obtained; but the weather being then too cold, the ovawere not fertile, the female moth, after laying about two hundred eggs, lived till the 22d of March, which is a very long time; this was owingto the low temperature. The moths emerged afterward from the 8th ofApril till the 25th of June. A pairing took place on the 2d of June, andanother on the 6th of June. 

Roylei (the Himalaya oak silkworm) is very closely allied to Pernyi, theChinese oak silkworm; the Roylei moths are of a lighter color, but thelarvæ of both species can hardly be distinguished from one another. The principal difference between the two species is in the cocoon. TheRoylei cocoon is within a very large and tough envelope, while that ofPernyi has no outer envelope at all. The larvæ of Roylei I reared didnot thrive, and the small number I had only went to the fourth stage, owing to several causes. I bred them under glass, in a green-house. Acertain number of the larvæ were unable to cut the shell of the egg. 

Here are a few notes I find in my book: Ova of Roylei commenced to hatchon the 29th of June; second stage commenced on the 9th of July. Thelarvæ in the first two stages seemed to me similar to those of Pernyi, as far as I could see. In second stage, the tubercles were of abrilliant orange-red; on anal segment, blue dot on each side. Thirdstage, four rows of orange-yellow tubercles, two blue dots on analsegment, brilliant gold metallic spots at the base of the tubercles onthe back, and silver metallic spots at the base of the tubercles on thesides. No further notes taken. 

One of my correspondents in Vienna (Austria) obtained a remarkablesuccess in the rearing of Roylei. From the twenty-five eggs he hadtwenty-three larvæ hatched, which produced twenty-three fine cocoons. The same correspondent, with thirty-five eggs of _Samia gloveri_, obtained twenty cocoons. My other correspondents did not obtain anysuccess in rearing these two species, as far as I know. 

_Hybrid Roylei-Pernyi_. --I have said that it is extremely difficult toobtain the pairing of Roylei moths in captivity. But the male Pernyipaired readily with the female Roylei. I obtained six such pairings, anda large quantity of fertile ova. The pairings of Roylei (female) withPernyi (male) took place as follows: two on the 21st of May, one on the3d of June, two on the 4th of June, and one on the 6th. 

The larvæ of this new hybrid, _Roylei-Pernyi_, contrary to what mighthave been expected, were much easier to rear than those of Roylei, andthe cocoons obtained are far superior to those of Roylei, in size, weight, and richness of silk. The cocoon of my new hybrid has, likeRoylei, an envelope, but there is no space between this envelope and thetrue cocoon inside. Therefore, this time, the crossing of two differentspecies (but, it must be added, two very closely allied species) hasproduced a hybrid very superior, at least to one of the types, that ofRoylei. The cocoons of the hybrid _Roylei-Pernyi_ seem to me larger andheavier than any Pernyi cocoons I have as yet seen. 

The larvæ of this new hybrid have been successfully reared in France, in Germany, in Austria, and in the United States of North America. Thecocoons obtained by Herr L. Huessman, one of my German correspondents, are remarkable for their size and beauty. The silk is silvery white. 

I have seventeen cocoons of this hybrid species, which number may besufficient for its reproduction. But the question arises, "Will themoths obtained from these cocoons be susceptible of reproduction?"

In my report on Lepidoptera for the year 1879, I stated, with respect tohybrids and degeneracy, that hybrids had been obtained by the crossingof _Attacus pernyi_ and _Attacus yama-maï_, but that, although the moths(some of which may be seen in the Bethnal-green Museum) are large andapparently perfect in every respect, yet these hybrids could not bereproduced. It must be stated that these two species differ essentiallyin one particular point. _Yama-maï_ hibernates in the _ovum_ state, while Pernyi hibernates in the _pupa_ state. The hybrids hibernated inthe _pupa_ state. Roylei, as Pernyi, hibernates in the _pupa_ state. 

In the November number, 1881, of "The Entomologist, " Mr. W. F. Kirby, of the British Museum, wrote an article having for its title, "Hermaphrodite-hybrid Sphingidæ, " in which, referring to hybrids of_Smerinthus ocellatus_ and _populi_, he says that hermaphroditism is theusual character of such hybrids. 

I extract the following passage from his article: "I was under theimpression that hermaphroditism was the usual character of thesehybrids; and it has suggested itself to my mind as a possibility, whichI have not, at present, sufficient data either to prove or to disprove, that the sterility of hybrids in general (still a somewhat obscuresubject) may perhaps be partly due to hybridism having a tendency toproduce hermaphroditism. "

Now, will the moths of new hybrid Roylei pernyi (which I expect willemerge in May or June, 1882) have the same tendency to hermaphroditismas has been observed with the hybrids obtained by the crossing of_Smerinthus populi_ with _Sm. Ocellatus_? I do not think that such willbe the case with the moths of the hybrid Roylei-pernyi, on account ofthe close relationship of Roylei with Pernyi, but nothing certain can beknown till the moths have emerged. Here are the few notes taken on thehybrid Roylei-pernyi: Ova commenced to hatch on the 12th of June; thesewere from the pairing which had taken place on the 21st of May. Larvæ, black, with long white hairs. Second stage commenced on the 21st ofJune. Larva, of a beautiful green; tubercles orange-yellow; head darkbrown. Third stage commenced on the 1st of July; fourth stage on the7th. Larva of same color in those stages; tubercles on the back, violet-blue or mauve; tubercles on the sides, blue. Fifth stagecommenced on the 18th of July. Larva, with tubercles on back and sides, blue, or violet-blue. First cocoon commenced on the 10th of August. Wantof time prevented me from taking fuller and more accurate notes. 

_Attacus Atlas_. --For the first time, as stated before, I attempted therearing of a small number of Atlas larvæ in the open air on the ailantustree, but had to remove the last two remaining larvæ in September; theothers had all disappeared in consequence of the heavy and incessantrains. These larvæ were from eggs sent to me by one of my Germancorrespondents. The pairing of the moths had taken place on the 17th ofJuly, and the eggs had commenced to hatch on the 4th of August. 

I had about eighty cocoons of another and larger race of Atlas importedfrom the Province of Kumaon, but only eight moths emerged at intervalsfrom the 31st of July to the 30th of September. Not only did the mothsemerge too late in the season, but there never was a chance of obtaininga pairing. In my report on Indian silkworms, published in the Novembernumber of the "Bulletin de la Societe d'Acclimatation, " for the year1881, compiled from the work of Mr. J. Geoghegan, I reproduce the firstappendix of Captain Thomas Hutton to Mr. Geoghegan's work, in which aregiven the names of all the Indian silkworms known by him up to the year1871. 

Of _Attacus atlas_, Captain Hutton says: "It is common at 5, 500 feet atMussoorie, and in the Dehra Doon; it is also found in some of the deepwarm glens of the outer hills. It is also common at Almorah, where thelarva feeds almost exclusively upon the 'Kilmorah' bush or _Berberisasiatica_; while at Mussoorie it will not touch that plant, but feedsexclusively upon the large milky leaves of _Falconeria insignis_. The worm is, perhaps, more easily reared than any other of the wildbombycidæ. "

I will now quote from letters received from one of my correspondents inCeylon, a gentleman of great experience and knowledge in sericulture. 

In a letter dated 24th August, 1881, my correspondent says: "The Atlasmoth seems to be a near relation of the Cynthia, and would probably feedon the Ailantus. Here it feeds on the cinnamon and a great number ofother trees of widely different species; but the tree on which Ihave kept it most successfully in a domestic state is the _Milnearoxburghiana_, a handsome tree, with dark-green ternate leaves, whichkeep fresh long after being detached from the tree. I do not think thecocoon can ever be reeled, as the thread usually breaks when it comesto the open end. I have tried to reel a great many Atlas cocoons, butalways found the process too tedious and troublesome for practical use. 

"The Mylitta (Tusser) is a more hardy species than the Atlas, and I havehad no difficulty in domesticating it. Here it feeds on the cashew-nuttree, on the so-called almond of this country (_Terminalia catappa_), which is a large tree entirely different from the European almond, andon many other trees. Most of the trees whose leaves turn red when aboutto fall seem to suit it, but it is not confined to these. In the case ofthe Atlas moth, I discovered one thing which may be well worth knowing, and that was, that with cocoons brought to the seaside after the larvæhad been reared in the Central Provinces, in a temperature ten or twelvedegrees colder, the moths emerged in from ten to twenty days after theformation of the cocoon. The duration of the _pupa_ stage in this, andprobably in other species, therefore, depends upon the temperature inwhich the larvæ have lived, as well as the degree of heat in which thecocoons are kept; and in transporting cocoons from India to Europe, Ithink it will be found that the moths are less liable to be prematurelyforced out by the heat of the Red Sea when the larvæ have been reared ina warm climate than when they have been reared in a cold one. 

"I do not agree with the opinion expressed in one of your reports, thatthe short duration of the larva stage, caused by a high temperature, hasthe effect of diminishing the size of the cocoons, because the Atlasand Tusser cocoons produced at the sea-level here are quite as large asthose found in the Central Provinces at elevations of three thousandfeet or more. According to the treatise on the "Silk Manufacture, " in"Lardner's Cyclopedia, " the Chinese are of opinion that one drachmof mulberry silkworms' eggs will produce 25 ounces of silk if thecaterpillars attain maturity within twenty-five days; 20 ounces if thecommencement of the cocoons be delayed until the twenty-eighth day; andonly 10 ounces if it be delayed until between the thirtieth and fortiethday. If this is correct, a short-lived larva stage must, instead ofcausing small cocoons, produce just the contrary effect. "

In another letter, dated November 25, 1881, my correspondent says: "I amsorry that you have not had better success in the rearing of yourlarvæ, but you should not despair. It is possible that the choice of animproper food-plant may have as much to do with failures as the coldnessand dampness of the English climate. I lost many thousands of Atlascaterpillars before I found out the proper tree to keep them on in adomesticated state; and when I did attain partial success, I couldnot keep them for more than one generation, till I found the _Milnearoxburghiana_ to be their proper food plant. I do not know the properfood-plant of the Mylitta (Tusser), but I have succeeded very well withit, as it is a more hardy species than the Atlas. Though a Bombyx bepolyphagous in a state of nature, yet I think most species have a treeproper to themselves, on which they are more at home than on anyother plant. I should like, if you could find out from some yourcorrespondents in India, on what species of tree Mylitta cocoons arefound in the largest numbers, and what is about the greatest numberfound on a single tree. The Mylitta is common enough here, but theredoes not seem to be any kind of tree here on which the cocoons are to befound in greater numbers than twos and threes; and there must be sometree in India on which the cocoons are to be found in much greaterplenty, because they could not otherwise be collected in sufficientquantity for manufacturing purposes. The Atlas is here found on twentyor more different kinds of trees, but a hundred or a hundred and fiftycocoons or larvæ may be found on a single tree of _Milnea roxburghiana_, while they are to be found only singly, or in twos and threes, on anyother tree that I know of. The Atlas and Mylitta seem to be respectivelythe Indian relations of the Cynthia and Pernyi. It is, therefore, probable that the Ailantus would be the most suitable European tree forthe Atlas, and the oak for the Mylitta. "

_Attacus mylitta_ (_Antheræa paphia_). --I did not receive a singlecocoon of this species for the season 1881. My stock consisted of sevencocoons, from the lot received from Calcutta at the end of February, 1880. Five were female, and two male cocoons; one of the latter died, thus reducing the number to six. The moths emerged as follows: Onefemale on the 21st of June, one female on the 26th, one female on the28th, one female on the 1st of July, and one male on the 3d of August;the latter emerging thirty-four days too late to be of any use forrearing purposes. The last female moth emerged, I think, about the endof September. These cocoons had hibernated twice, as has been the casewith other Indian species. I had Indian cocoons which hibernated eventhree times. 

_Attacus cynthia_, from the province of Kumaon. --With the Atlas cocoons, a large quantity of Cynthia cocoons were collected in the provinceof Kumaon. Both species had, no doubt, fed on the same trees; as theCynthia, like the Atlas cocoons, were all inclosed in leaves of the_Berberis vulgaris_, which shows that Cynthia is also a polyphagousspecies. It is already known that it feeds on several species of trees, besides the ailantus, such as the laburnum, lilac, cherry, and, I think, also on the castor-oil plant; the common barberry has, therefore, to beadded to the above food plants. 

These Kumaon Cynthia cocoons were somewhat smaller and much darker incolor than those of the acclimatized Cynthia reared on the ailantus. Themoths of this wild Indian Cynthia were also of a richer color than thoseof the cultivated species in Europe. 

During the summer 1881, I saw cocoons of my own Cynthia race obtainedfrom worms which had been reared on the laburnum tree. These cocoonswere, as far as I can remember, of a yellowish or saffron color; whichI had never seen before. This difference in the color of the cocoon wasvery likely produced by the change of food, although it has been stated, and I think it may be quite correct, that with many species of nativelepidoptera the change of food-plants does not produce any difference ofcolor in the insects obtained. With respect to the Cynthia worms rearedon the laburnum instead of the ailantus, it may be that the moths, whichwill emerge from the yellow cocoons, will be similar to those obtainedfrom cocoons spun by worms bred on the ailantus, and that the onlydifference will be in the color of the cocoons. 

The Kumaon Cynthia cocoons, as I found it to be the case with Indianspecies introduced for the first time into Europe, did not produce mothsat the same time, nor as regularly as the acclimatized species. Themoths emerged as follows: One female on the 22d of July; one female onthe 25th; one male on the 3d August; one female on the 19th; one male onthe 28th of August; one male on the 2d September; one female on the 3d. A pairing was obtained with the latter two. Two males emerged on the 4thof September; one male on the 6th; one male and one female on the 22d;one female on the 23d; and one female on the 25th of September. Fivecocoons, which did not produce any moths, contain pupæ, which are stillin perfect condition; and the moths will no doubt emerge next summer(1882). As seen in my note, a pairing of this wild Indian Cynthia tookplace; this was from the evening of the 4th to the 5th of September. Theeggs laid by the female moth were deposited in a most curious way, insmaller or larger quantities, but all forming perfect triangles. Theseeggs I gave to a florist who has been very successful in the rearingof silk-producing and other larvæ; telling him to rear the Cynthia onlilacs grown in pots and placed in a hot-house, which was done. Theworms, which hatched in a few days, as they were placed in a hot-house, thrived wonderfully well, and I might say they thrived too well, as theygrew so fast and became so voracious that the growth of the lilac treescould not keep pace with the growth of the worms. These, at the fourthstage, became so large that the foliage was entirely devoured, and, ofcourse, the consequence was that all the worms were starved. I onlyheard of the result of that experiment long after the death of thelarvæ; otherwise I should have suggested the use of another plant afterthe destruction of the foliage of the lilacs; the privet (_Ligustrumvulgare_) might have been tried, and success obtained with it. 

Of such species as _Attacus pyri_, of Central Europe, and _Attacuspernyi_, the North Chinese oak silkworm, which I have mentioned in myprevious reports, and bred every season for several years, I shall onlysay that I never could rear Pyri in the open air in London, up to theformation of the cocoon. As to Pernyi, I had, in 1881, an immensequantity of splendid moths, from which I obtained the largest quantityof ova I ever had of this species. I had many thousands of fertile ovaof Pernyi, which I was unable to distribute. Many schoolboys rearedPernyi worms, but with what success I do not yet know. The number offertile ova obtained from Pyri moths was also more considerable than informer years, which was due partly to the good quality of the pupæ, andpartly to the very favorable weather in June, at the time the pairingsof the moths took place. 

Leaving these, I now come to the North American species. 

_Telea polyphemus_. --As I have stated in former years, this is the bestNorth American silkworm, producing a closed cocoon, somewhat smallerthan that of Pernyi, but the silk seems as good as that of Pernyi. 

The cocoons of Polyphemus I had in 1881 were smaller and inferior inquality to those I had before. Those received in 1878 and 1879 wereconsiderably finer and larger than those which were sent in 1880 and1881; besides, they were sent in much larger quantities. The cocoonsreceived this year (1882) are finer than those of 1881, but yet theycannot be compared with those of 1878 and 1879. 

With about sixty cocoons of _Telea polyphemus_ I only obtained threepairings, which I attribute solely to the weakness of the moths, asthe weather was all that could be desired for the pairings. The mothsemerged from the 1st of June to the 20th of July. One male moth emergedon the 7th September. This latter was one from a small number of cocoonsreceived from Alabama; the other cocoons of the same race had emerged atthe same time as the cocoons from the Northern States. In the NorthernStates the species is single-brooded; in the Southern States it isdouble-brooded. 

The larvæ of Polyphemus can be bred in the open air in England, almostas easily as those of Pernyi, and even Cynthia; they will pass throughtheir five stages and spin their cocoons on the trees, unless theweather should be unexceptionally cold and wet, as was the case duringthe month of August, 1881, when the larvæ had reached their full size;they were reared this year on the nut-tree, and some on the oak. Thespecies is extremely polyphagous, and will feed well on oak, birch, chestnut, beech, willow, nut, etc. 

The moth of Polyphemus is very beautiful, and, as in some other species, varies in its shades of color. The larva is of a transparent green, ofextreme beauty; the head is light brown; without any black dots, as inPernyi; the spines are pink, and at the base of each of them there is abrilliant metallic spot. When the sun shines on them the larvæ seem tobe covered with diamonds. These metallic spots at the base of the spinesare also seen on Pernyi, Yama mai, Mylitta, and other species of thegenus Antheræa, all having a closed cocoon, but none of these have somany as Polyphemus. 

The cocoons of the species of the genus Actias are closed, but the larvæhave not the metallic spots of the species of the genus Antheræa. 

_Samia Gloveri_. --Three North American silk-producing bombyces, veryclosely allied, have been mentioned in my previous reports; they are;_Samia ceanothi_, from California; _Samia gloveri_, from Utah andArizona; and _Samia cecropia_, commonly found in most of the NorthernStates--the latter is the best and largest silk producer. Crossings ofthese species took places in 1880, and, as I stated before, the ovaobtained from a long pairing between a Ceanothi female with a Gloverimale, were the only ones which were fertile. The Gloveri cocoonsreceived in 1880 were of a very inferior quality, and produced mothsfrom which no pairings could be obtained, although some crossings tookplace. In 1881, the Gloveri cocoons, on the contrary, produced fine, healthy moths; yet only five pairings could be obtained, with about onehundred cocoons. Besides these five pairings, a quantity of fertileova were obtained by the crossings of _S. Gloveri_ (female) with _S. Cecropia_ (male), and Cecropia (female) with Gloveri (male). No success, so far as I know, was obtained with the rearing of the hybrid larvæ; therearings of the larvæ of pure Gloveri were also, I think, a failure, only one correspondent having been successful; but some correspondentshave not yet made the result of their experiments known to me. The larvæof _Samia cecropia, S. Gloveri_, and _S. Ceanothi_, are very much alike;and hardly any difference can be observed in the first two stages. Inthe third and fourth stages, the larvæ of _S. Cecropia_ and _S. Gloveri_are also nearly alike; the principal difference between these twospecies and _S. Cecropia_ being that the tubercles on the back are of auniform color--orange-red, or yellow--while on Cecropia the first fourdorsal tubercles are red, and the rest yellow. The tubercles on thesides are blue on the three species. 

The larvæ of the hybrids _Gloveri-cecropia_ were, as far as I couldobserve, like those of Cecropia, but I noticed some with six redtubercles on the back instead of four, as on Cecropia. They were rearedon plum, apple, and _Salix caprea_; in the open air. 

The larvæ of _Samia gloveri_ were reared, during the first four stageson a wild plum-tree, then on _Salix, caprea_, and I reproduce the notestaken on this species, which I bred this year (1881) for the first time. 

Gloveri moths emerged from the 15th of May to the end of June; fivepairings took place as follows: 1st, 4th, 9th, 24th, and 26th of June. First stage--larvæ quite black. Second stage--larvæ orange, with blackspines. Third stage--dorsal spines, orange-red; spines on sides blue. Fourth stage--dorsal spines, orange or yellow, spines on the sides blue;body light blue on the back, and greenish yellow on the sides; head, green; legs, yellow. Fifth and sixth stage--larvæ nearly the same;tubercles on the back yellow, the first four having a black ring at thebase; side tubercles ivory-white, with a dark-blue base. 

The above-mentioned American species, like most other silk-producingbombyces, were bred in the open air; but besides these, I reared threeother species of American bombyces in the house, under glass, and withthe greatest success. These are: _Hyperchiria io_, a beautiful speciesmentioned in my report for the year 1879; _Orgyia leucostigma_, from ovareceived on December 29, 1880, from Madison, Wis. , which hatched on the27th of May, 1881. 

The third American species reared under glass is the following veryinteresting bombyx: _Ceratocampa (Eacles) imperialis_. The pupæ ofthis species are rough, and armed with small, sharp points at all thesegments; the last segment having a thick, straight, and bifid tail. Themoths, which measure from four to about six inches in expanse of wings, are bright yellow, with large patches and round spots of reddish-brown, with a purple gloss; besides these patches and round spots, the wingsare covered with small dark dots. The male moth is much more blotchedthan the female, and although of a smaller size, is much more showy thanthe female. 

With twenty-four pupæ of Imperialis I obtained nineteen moths from the21st of June to the 19th of July; five pupæ died. Two pairings tookplace; the first from the evening of the 13th to the morning of the14th; the second from the evening of the 15th to the morning of the 16thof July. 

The ova, which are about the size of those of Yama-mai, Pernyi, orMylitta, are rather flat and concave on one side, of an amber-yellowcolor and transparent, like those of sphingidæ. When the larvæ haveabsorbed the yellow liquid in the egg, and are fully developed; they canbe seen through the shell of the egg, which is white or colorless whenthe larva has come out. 

The larvæ of Imperialis, which have six stages, commenced to hatch onthe 31st of July; the second stage commenced on the 7th of August; thethird, on the 17th; the fourth, on the 29th of August; the fifth, onthe 18th of September; and the sixth, on the 1st of October. The larvæcommenced to pupate on 13th of October. 

The larvæ of this curious species vary considerably in color. Some areof a yellowish color, others are brown and tawny, others are black ornearly black. My correspondent in Georgia, who bred this species thesame season as I did, in 1881, had some of the larvæ that were green. Inall the stages the larvæ have five conspicuous spines or horns; two onthe third segment, two on the fourth, and one on the last segment butone; this is taking the head as the first segment with regard to thefirst four spines These spines are rough and covered with sharp pointsall round, and their extremities are fork-like. In the first threestages they are horny; in the last three stages these spines are fleshy, and much shorter in proportion than they are in the first threestages. The color of the spines in the last three stages is coral-red, yellowish, or black. In the fifth and sixth stages the spine on the lastsegment but one is very short. 

Here are a few and short notes from my book:

1st stage. Larvæ, about one-third of an inch; head, brown, shiny, andglobulous. 

2d stage. Larvæ, dark-brown, almost black; spines, white at the base, and black at the extremities; head shiny and light brown. 

3d stage. Larve, fine black; head black; white hairs on the back;spines, whitish, buff, or yellowish at the base, and black at theextremities; other larvæ of a brown color. 

4th stage. Larvæ, black granulated with white; long white hairs; horns, brown-orange with white tips; on each segment two brown spots. Spiracleswell marked with outer circle, brown, then black; white and black dot inthe center. Anal segment with brown ribs, the intervals black with whitedots; head shining, black with two brown bands on the face, forming atriangle. Other larvæ in fourth stage, velvety black, with coral-redspines; others with black spines. 

5th stage. Larvæ, entirely black, with showy eye-like spiracles, polished black head; other larvæ having the head brown and black. Larvæcovered with long white hair; spines black or red. No difference noticedbetween the fifth and sixth stages. 

One larva on fourth stage was different from all others, and wasdescribed at the British Museum by Mr. W. F. Kirby as follows: "Larvareddish-brown, sparingly clothed with long slender white hairs, withfour reddish stripes on the face, two rows of red spots on the back, spiracles surrounded with yellow, black and red rings; legs red, prolegsblack, spotted with red. On segments three and four are four longcoral-red fleshy-branched spines, two on each segment, below which, oneach side, are two rudimentary ones just behind the head; in front ofsegment two are four similar rudimentary orange spines or tubercles;last segment black, strongly granulated and edges triangularly above andat the sides, with coral-red; several short rudimentary fleshy spinesrising from the red portion; the last segment but one is reddish above, with a short red spine in the middle, and the one before it has a longcoral-red spine in the middle similar to those of segments three andfour, but shorter"

As soon as my Imperialis larvæ had hatched, I gave them various kinds offoliage, plane-tree, oak, pine, sallow, etc. At first they did not touchany kind of foliage, or they did not seem to touch any; and I was afraidI should be unable to rear them; but on the second or third day of theirexistence, they made up their minds and decided upon eating the foliageof some of the European trees I had offered them. They attacked oak, sallow, and pine, but did not touch the plane-tree leaves. In America, the larvæ of Imperialis feed on button-wood, which is the Americanplane-tree (_Platanus occidentalis_), yet they did not take to _Platanusorientalis_. After a little time I reduced the foliage to oak and sallowbranches, and ultimately gave them the sallow (_Salix caprea_) only, onwhich they thrived very well. I was pleased with this success; as I hadpreviously read in a volume of the "Naturalist's Library" a descriptionof _Ceratocampa imperialis_, which ends as follows: "The caterpillarsare not common, and are the most difficult to bring to perfection inconfinement, as they will not eat in that situation; and, even if theychange into a chrysalis, they die afterward. "

Before I finish with _C. Imperialis_, I must mention a peculiar fact. During the first stage, and, I think, also during the second, severallarvæ disappeared without leaving any traces. I also saw two smallerlarvæ held tight by the hind claspers of two larger ones. The larvæ thusheld and pressed were perfectly dead when I observed them, and I removedthem. My impression then was that these larvae were carnivorous, notfrom this last fact alone, as I had previously observed it with larvæof Catocalæ when they are too crowded, but from the fact that some haddisappeared entirely from the glass under which they were confined. Ibegan to reduce their numbers, and put six only under each glass, so asto be able to watch them better. Whether I had made a mistake or notpreviously to this I do not exactly know; but from this moment thelarvae behaved in a most exemplary manner, especially when they becamelarger. They crawled over each other's backs without the least sign ofspite or animosity, even when they were in sleep, in which case larvæare generally very sensitive and irritable, all were of a most pacificnature. It is, therefore, with the greatest pleasure that, for want ofsufficient evidence, I withdraw this serious charge of cannibalism whichI first intended to bring against them. 

From what has been said respecting the rearing of exotic silk-producingbombyces, especially tropical species, it must have been observedthat several difficulties, standing in the way of success, have to beovercome. The moths of North American species emerge regularly enoughduring the months of May, June, or July, but Indian and other tropicalspecies may emerge at any time of the year, if the weather is mild, ashas been the case during this unusually mild winter of 1881-1882. Fromthe end of December to the present time (March 14, 1882) moths of fourspecies of Indian silk-producers, especially _Antheræa roylei_ and_Actias selene_, have constantly emerged, but only one or two at a time. These moths emerged from cocoons received in December and January last. 

It is only when these tropical species shall have been already reared inEurope that the emergence of the moths will be regular; then they willbe single-brooded in Northern or Central Europe, and some will verylikely become double-brooded in Southern Europe. But when just importedthe moths of these tropical species will always be uncertain andirregular in their emergence; hence the importance of having asufficient number of cocoons so as to meet this difficulty, i. E. , theloss of the moths that emerge prematurely or irregularly. 

Before I conclude, I shall repeat what I already stated in a previousreport, that the sending of live cocoons and pupæ from India and otherdistant countries to Europe, can easily be done, so that they willarrive alive and in good condition, if care be taken that the boxescontaining these live cocoons and pupæ should not be left in the sun ornear a fire (which has been the case before), and that they should atonce be put in a cool place or in the ice-room of the steamer. Thecocoons and pupæ should be sent from October to March or April, according to distance, and it is most important to write on the cases, "Living silkworm cocoons or pupæ, the case to be placed in the iceroom. "

By taking this simple precaution, live cocoons and pupæ, when newlyformed, can be safely sent from very distant countries of Europe. 

To continue these interesting and useful studies, I shall always be gladto buy any number of live cocoons, or exchange them for other species, if preferable. 

ALFRED WAILLY. 

110 Clapham Road, London, S. W. 

 * * * * *

MOSQUITO OIL. 

A correspondent from Sheepshead Bay, a place celebrated for the size ofits mosquitoes and the number of its amateur fishermen, recommends thefollowing as a very good mixture for anointing the face and hands whilefishing:

 Oil of tar. 1 ounce. Olive oil. 1 ounce. Oil of pennyroyal. ½ ounce. Spirit of camphor. ½ ounce. Glycerine. ½ ounce. Carbolic acid. 2 drachms. 

Mix. Shake well before using. --_Drug. Circular_. 

 * * * * *

THE CATHEDRAL OF BURGOS. 

This most remarkable structure, in the province of the same name, adornsthe city of Burgos, 130 miles north of Madrid. The corner stone was laidJuly 20, A. D. 1221, by Fernando III. , and his Queen Beatrice, assistedby Archbishop Mauricio. The world is indebted to Mauricio for theselection of the site, and for the general idea and planning of what heintended should be, and in fact now is, the finest temple of worship inthe world. This immense stone structure, embellished with airy columns, pointed arches, statues, inscriptions, delicate crestings, and flankedby two needles or aerial arrows, rises toward the heavens, a sublimeinvocation of Christian genius. 

Illuminated by the morning sun it appears, at a certain distance, as ifthe pyramids were floating in space; further on is seen the marvelousdome of the transept, crowned with eight towers of chiseled lace-work, over the center of the church. 

Pubic worship was held in a portion of the edifice nine years after thework was begun; from that time onward for three hundred years, variousadditional portions were completed. On March 4, 1539, the greattransept, built fifty years previous, fell down; but was soon restored. August 16, 1642, at 6½ o'clock, P. M. , a furious hurricane overthrew theeight little towers that form the exterior corner of the dome; but intwo years they were replaced, namely July 19, 1644: the same night thegreat bells sounded an alarm of fire, the transept having in some waybecome ignited. The activity of the populace, however, prevented theloss of the edifice, which for a time was in great danger. 

The first architect publicly mentioned in the archives of the edificewas the Master Enrique. He also directed the work of the Cathedral ofLeon. He died July 10, 1277. The second architect was Juan Perez, whodied in 1296, and was buried in the cloister, under the cathedral. He isbelieved to have been either the son or brother of the celebrated MasterPedro Perez, who designed the Cathedral of Toledo, and who died in 1299. The third architect of the Cathedral of Burgos was Pedro Sanchez, whodirected the work in 1384; after him followed Juan Sanchez de Molina, Martin Fernandez, the three Colonias, Juan de Vallejo, Diego de Siloe, the elder Nicolas de Vergara, Matienzo, Pieredonda, Gil, Regines, andothers. It is worthy of note that a number of Moorish architects wereemployed on the work during the 14th and 15th centuries, such asMohomad, Yunce, the Master Hali, the Master Mahomet de Aranda, theMaster Yunza de Carrion, the Master Carpenter Brahen. Among the figuresculptors employed were Juan Sanchez de Fromesta, the Masters Gil andCopin, the famous Felipe de Vigardi, Juan de Lancre, Anton de Soto, Juande Villareal, Pedro de Colindres, and many others. Our engraving is froma recent number of _La Ilustracion Espanola y Americana_. 

[Illustration: THE CATHEDRAL OF BURGOS, SPAIN. --PHOTOGRAPH BY DELAURENT. --DRWAWING BY M. HEBERT. ]

 * * * * *

THE PANAMA CANAL. 

By MANUEL EISSLER, M. E. , of San Francisco, Cal. 

I. 

HISTORICAL NOTES. 

When Cortez, in the year 1530, made the observation that the two greatoceans could be seen from the peaks of mountains, he, in those remotedays, preoccupied himself with the question to cut through theCordilleras. 

Therefore, the idea of an interoceanic canal is by no means a modernone, as travelers and navigators observed that there was a greatdepression among the hills of the Isthmus of Panama. As Professor T. E. Nurse, of the U. S. N. , says in his memoirs:

"This problem of interoceanic communication has been justly said topossess not only practical value, but historical grandeur. It clearlylinks itself back to the era of the conquest of Cortez, three and a halfcenturies. " [1] It is a problem which has been left for our modern erato solve, but nevertheless its history is thereby rendered still moreinteresting, having needed so many centuries to bring it to an issue. 

[Footnote 1: From Prof. Nurse's historical essay. See Survey ofNicaragua Canal, by Com. Lull. ]

Spain, which acquired through her Columbus a new empire, lying near, asit was supposed, to the riches of Asia, could not be indifferent, fromthe moment of her discoveries, to the means of crossing these lands toyet richer ones beyond. 

India, from the days of Alexander and of the geographers, Mela, Strabo, and Ptolemy, was the land of promise, the home of the spices, theinexhaustible fountain of wealth. The old routes of commerce thither hadbeen closed one by one to the Christians; the overland trade had falleninto the hands of the Arabs; and at the fall of Constantinople, 1453, the commerce of the Black Sea and of the Bosphorus, the last of the oldroutes to the East, finally failed the Christian world. Yet even beyondthe fame of the East, which tradition had brought down from Greek andRoman, much more had the crusaders kindled for Asia (Cathay) and itsriches an ardor not easily suppressed in men's minds. 

The error of the Spanish Admiral in supposing that the eastern shoresof Asia extended 240 degrees east of Spain, or to the meridian ofthe modern San Diego, in California--this error, insisted on in hisdispatches and adopted and continued by his followers, still furtheranimated the earlier Spanish sovereigns and the men whom they sent intothe New World to reach Asia by a short and easy route. 

Nobody in Europe dreamt that Columbus had discovered a new continent, and when Balbao, in 1513, discovered the South Sea, then it was knownthat Asia lay beyond, and navigators directed their course there. Onhis deathbed, in 1506, Columbus still held to his delusion that he hadreached Zipanga, Japan. In 1501 he was exploring the coast of Veragua, in Central America, still looking for the Ganges, and announcing hisbeing informed on this coast of a sea which would bear ships to themouth of that river, while about the same time the Cabots, under HenryVII. , were taking possession of Newfoundland, believing it to be part ofthe island coast of China. 

Although these were grave blunders in geography and in navigation, thediscoveries really made in the rich tropical zones, the acquirement ofa new world, and the rich products continually reaching Europe from it, for a time aroused Spain from her lethargy. The world opened east andwest. The new routes poured their spices, silks, and drugs through newchannels into all the Teutonic countries. The strong purposes of havingnear access to the East were deepened and perpetuated doubly strong, bythe certainties before men's eyes of what had been attained. 

Balbao, in 1513, gained from a height on the Isthmus of Panama the firstproof of its separation from Asia; and Magellan enters the South Seaat the southern extremity of the country, now first proven to be thusseparate and a continent. Men in those days began to think that creationwas doubled, and that such discovered lands must be separate from India, China, and Japan. And the very successes of the Portuguese under Vascoda Gama, bringing from their eastern course the expectancy of Asia'swealth, intensely excited the Spaniards to renew their western search. 

The Portuguese, led around the Cape of Good Hope, had brought home vasttreasures from the East, while the Spanish discoverers, as yet, had notreached the countries either of Montezuma or of the Inca. Their success"troubled the sleep of the Spaniards. "

Everything, then, of personal ambition and national pride, the thirstfor gold, the zeal of religious proselytism, and the cold calculationsof state policy, now concurred in the disposition to sacrifice whatSpain already had of most value on the American shores in order to seizeupon a greater good, the Indies, still supposed to be near at hand. Andsince it was now certain that the new lands were not themselves Asia, the next aim was to find the secret of the narrow passage acrossthem which must lead thither. The very configuration of the isthmusstrengthened the belief in the existence of such a passage by the numberof its openings, which seemed to invite entrance in the expectancy thatsome one of them must extend across the narrow breadth of land. 

For this the Spanish government, in 1514, gave secret orders toD'Avilla, Governor of Castila del Oro, and to Juan de Solis, thenavigator, to determine whether Castila del Oro were an island, and tosend to Cuba a chart of the coast, if any strait were possible. Forthis, De Solis visited Nicaragua and Honduras; and later, led far to thesouth, perished in the La Plata. For this, Magellan entered the straits, which, strangely enough, he affirmed before setting out, that he "wouldenter, " since he "had seen them marked out on the geographer MartinBehaim's globe. " For this, Cortez sent out his expeditions on bothcoasts, exposing his own life and treasure, and sending home to theemperor, in his second relation, a map of the entire Gulf of Mexico(Dispatch from Cortez to Charles V. , October 15, 1524). For this greatpurpose, and in full expectancy of success in it, the whole coast ofthe New World on each side, from Newfoundland on the northeast, curvingwestward on the south, around the whole sweep of the Gulf of Mexico, thence to Magellan's Straits, and thence through them up the Pacific tothe Straits of Behring, was searched and researched with diligence. "Men could not get accustomed, " says Humboldt, "to the idea that thecontinent extended uninterruptedly both so far north and south. " Henceall these large, numerous, and persevering expeditions by the Europeanpowers. 

Among them, by priority of right and by her energy, was Spain. The greatemperor was urgent on the conqueror of Mexico, and on all in subordinatepositions in New Spain, to solve the secret of the strait. All Spain wasawakened to it. "How majestic and fair was she, " says Chevalier, "in thesixteenth century; what daring, what heroism and perseverance! Never hadthe world seen such energy, activity, or good fortune. Hers was a willthat regarded no obstacles. Neither rivers, deserts, nor mountains farhigher than those in Europe, arrested her people. They built grandcities, they drew their fleets, as in a twinkling of the eye, from thevery forests. A handful of men conquered empires. They seemed a race ofgiants or demi-gods. One would have supposed that all the work necessaryto bind together climates and oceans would have been done at the word ofthe Spaniards as by enchantment, and since nature had not left a passagethrough the center of America, no matter, so much the better forthe glory of the human race; they would make it up by artificialcommunication. What, indeed, was that for men like them? It were doneat a word. Nothing else was left for them to conquer, and the world wasbecoming too small for them. "

Certainly, had Spain remained what she then was, what had been in vainsought from nature would have been supplied by man. A canal or severalcanals would have been built to take the place of the long-desiredstrait. Her men of science urged it. In 1551, Gomara, the author of the"History of the Indies, " proposed the union of the oceans by three ofthe very same lines toward which, to this hour, the eye turns with hope. 

"It is true, " said Gomara, "that mountains obstruct these passes, but ifthere are mountains there are also hands; let but the resolve be made, there will be no want of means; the Indies, to which the passage willbe made, will supply them. To a king of Spain, with the wealth of theIndies at his command, when the object to be obtained is the spicetrade, what is possible is easy. 

But the sacred fire suddenly burned itself out in Spain. The peninsulahad for its ruler a prince who sought his glory in smothering freethought among his own people, and in wasting his immense resources invain efforts to repress it also outside of his own dominions through allEurope. From that hour, Spain became benumbed and estranged from allthe advances of science and art, by means of which other nations, andespecially England, developed their true greatness. 

Even after France had shown, by her canal of the south, that boats couldascend and pass the mountain crests, it does not appear that theSpanish government seriously wished to avail itself of a like means ofestablishing any communication between her sea of the Antilles and theSouth Sea. The mystery enveloping the deliberations of the council ofthe Indies has not always remained so profound that we could not knowwhat was going on in that body. The Spanish government afterward openedup to Humboldt free access to its archives, and in these he foundseveral memoirs on the possibility of a union between the two oceans;but he says that in no one of them did he find the main point, theheight of the elevations on the isthmus, sufficiently cleared up, andhe could not fail to remark that the memoirs were exclusively French orEnglish. Spain herself gave it no thought. Since the glorious age ofBalbao among the people, indeed, the project of a canal was in everyone's thoughts. In the very wayside talks, in the inns of Spain, when atraveler from the New World chanced to pass, after making him tell ofthe wonders of Lima and Mexico, of the death of the Inca, Atahualpa, and the bloody defeat of the Aztecs, and after asking his opinion of ElDorado, the question was always about the two oceans, and what greatthings would happen if they could succeed in joining them. 

During the whole of the seventeenth and eighteenth centuries, Spainhad need of the best mode of conveyance for her treasures across theisthmus. Yet those from Peru came by the miserable route from Panama tothe deadliest of climates. Porto Bello and her European wares forher colonies toiled up the Chagres river, while the roughest ofcommunication farther north connected the Chimalapa and the Guasacoalcosin Mexico, and the trade there was limited sternly to but one port oneach side. As late as Humboldt's visit, in 1802, when remarking upon the"unnatural modes of communication" by which, through painful delays, theimmense treasures of the New World passed from Acapulco, Guayaquil, and Lima, to Spain, he says: "These will soon cease whenever an activegovernment, willing to protect commerce, shall construct a good roadfrom Panama to Porto Bello. The aristocratic nonchalance of Spain, andher fear to open to strangers the way to the countries explored for herown profit, only kept those countries closed. " The court forbade, onpain of death, the use of plans at different times proposed. Theywronged their own colonies by representing the coasts as dangerous andthe rivers impassable. On the presentation of a memoir for improving theroute through Tehuantepec, by citizens of Oaxaca, as late as 1775, an order was issued forbidding the subject to be mentioned. Thememorialists were censured as intermeddlers, and the viceroy fell underthe sovereign's displeasure for having seemed to favor the plans. 

The great isthmus was, however, further explored by the Spanishgovernment for its own purposes; the recesses were traversed, and thelines of communication which we know to-day were then noted. 

In addition to the fact that comparatively little was explored north orsouth of that which early became the main highway, the Panama route, there is confirmation here of the truth that Spain concealed and evenfalsified much of her generally accurately made surveys. No strongerproof of this need be asked than that which Alcedo gives in connectionwith the proposal by Gogueneche, the Biscayan pilot, to opencommunication by the Atrato and the Napipi. "The Atrato, " says thehistorian, "is navigable for many leagues, but the navigation of it isprohibited under pain of death, without the exception of any personwhatever. "

The Isthmus of Nicaragua has always invited serious consideration fora ship canal route by its very marked physical characteristics, amongwhich is chiefly its great depression between two nearly parallel rangesof hills, which depression is the basin of its large lake, a natural andall-sufficient feeder for such a canal. 

In 1524 a squadron of discovery sent out by Cortez on the coast of theSouth Sea, announced the existence of a fresh water sea at onlythree leagues from the coast; a sea which, they said, rose and fellalternately, communicating, it was believed, with the Sea of the North. Various reconnoissances were therefore made, under the idea that herethe easy transit would be established between Spain and the spice landsbeyond. 

It was even laid down on some of the old maps, that this opencommunication by water existed from sea to sea; while later mapsrepresented a river, under the name of Rio Partido, as giving one ofits branches to the Pacific Ocean and the other to Lake Nicaragua. Anexploration by the engineer, Bautista Antonelli, under the orders ofPhilip II. , corrected the false idea of an open strait. 

In the eighteenth century a new cause arose for jealousy of herneighbors and for keeping her northern part of the isthmus from theirview. In the years 1779 and 1780 the serious purposes of the Englishgovernment for the occupancy of Nicaragua, awakened the solicitudes ofthe Spanish government for this section. The English colonels, Hodgsonand Lee, had secretly surveyed the lake and portions of the country, forwarding their plans to London, as the basis of an armed incursion, to renew such as had already been made by the superintendent of theMosquito coast, forty years before, when, crossing the isthmus, he tookpossession of Realejo, on the Pacific, seeking to change its name toPort Edward. In 1780, Captain, afterward Lord Nelson, under orders fromAdmiral Sir Peter Parker, convoyed a force of two thousand men to SanJuan de Nicaragua, for the conquest of the country. 

In his dispatches, Nelson said: "In order to give facility to the greatobject of government, I intend to possess the lake of Nicaragua, which, for the present, may be looked upon as the inland Gibraltar of SpanishAmerica. As it commands the only water pass between the oceans, itssituation must ever render it a principal post to insure passage to theSouthern Ocean, and by our possession of it Spanish America is severedinto two. "

The passage of San Juan was found to be exceedingly difficult; for theseamen, although assisted by the Indians from Bluetown, scarcely forcedtheir boats up the shoals. Nelson bitterly regretted that the expeditionhad not arrived in January, in place of the close of the dry season. Itwas a disastrous failure, costing the English the lives of one thousandfive hundred men, and nearly losing to them their Nelson. 

At this period, Charles III. , of Spain, sent a commission to explore thecountry. These commissioners reported unfavorably as regarded the route;but fearing further intrusion from England, forbade all access to thecoast; even falsifying and suppressing its charts and permanentlyinjuring the navigation of the San Juan and the Colorado by obstructionsin their beds. 

It is, however, a relief here to learn that when Humboldt visited theNew World, he could say: "The time is passed when Spain, through ajealous policy, refused to other nations a thoroughfare across thepossessions of which they kept the whole world so long in ignorance. Accurate maps of the coasts, and even minute plans of militarypositions, are published. " It is also true that the Spanish Cortes, in 1814, decreed the opening of a canal, a decree deferred and neverexecuted. 

It was reserved for our century to see this great project carried intoexecution, and it is but just that as a chronicler of events I shouldconnect with the Canal of Panama the name of a family who have done muchto bring the scheme, so to say, into practical execution. 

As early as the year 1836, Mr. Joly de Sabla turned his views toward thecutting of a canal across the Isthmus of Panama. He resided at the timeon the Island of Guadeloupe, one of the French West India Islands, where he possessed large estates. Of a high social position, therepresentative of one of France's ancient and noble families, with largemeans at his disposal and of an enterprising spirit much in advance ofhis time, he was well calculated to carry out such a grand scheme. 

He soon set about procuring from the Government of New Granada (nowColombia) the necessary grants and concessions, but much time and manyefforts were spent before these could be brought to a satisfactorycondition, and it was not until the year 1841 that he could again visitthe Isthmus, bringing with him this time, on a vessel chartered by himfor the purpose, a corps of engineers and employes, medical staff, etc. , etc. After two years spent in exploring and surveying a country at thattime very imperfectly known, he returned to Guadeloupe to find hisresidence and most of his estates destroyed by the terrible earthquakethat visited the island in February, 1843. 

Undaunted by this unexpected and severe blow, Mr. De Sabla persisted inhis efforts, and in the same year obtained from the French governmentthe establishment of a Consulate at Panama to insure protection to thefuture canal company, and also the sending of two government engineersof high repute (Messrs. Garella and Courtines), to verify the surveysalready made and complete them. 

After receiving the respective reports of Garella and Courtines, Mr. De Sabla decided upon first constructing a railway across the Isthmus, postponing the cutting of the canal until this indispensable auxiliaryshould have rendered it practicable and profitable. He then presentedthe scheme in that shape to his friends in Paris and London, and formeda syndicate of thirteen members, among whom we may recall the names ofthe well known Bankers Caillard of Paris, and Baimbridge of London, of Sir John Campbell, then Vice President of the Oriental SteamshipCompany, of Viscount Chabrol de Chameane, and of Courtines, theexploring engineer. 

A new contract was then entered upon with New Granada in June, 1847, andearly in 1848, the Syndicate was about to forward to the Isthmus theexpedition which was to execute the preliminary works, while the companywas being finally organized in Paris, and its stock placed. 

The success of the undertaking seemed to be assured beyond peradventure, when the unexpected breaking out of the French revolution in February, 1848, dashed all hopes to the ground. Several of the prominentfinanciers engaged in the affair, taken by surprise by the suddenness ofthe revolution, had to suspend their payments and of course to withdrawfrom the Panama Canal and railroad scheme. Others withdrew fromcontagious fear and timidity. Finally the term fixed for carrying outcertain obligations of the contract expired without their fulfillmentby the company, and the concession was forfeited. Another contract wasalmost immediately applied for and granted with unseemly haste by thePresident of New Granada to Messrs. Aspinwall, Stephens and Chauncey, which resulted in the construction of the actual Panama Railroad. 

These gentlemen acted fairly in the matter, and in 1849, calling Mr. De Sabla to New York, offered him to join them in the new scheme. Unfortunately they had decided upon placing the Atlantic terminus of therailroad upon the low and swampy mud Island of Manzanillo, while Mr. De Sabla insisted on having it on the mainland on the dry and healthynorthern shore of the Bay of Limon. They could not come to anunderstanding on this point, and Mr. De Sabla, whose experience andforesight taught him the dangers that would result to the shipping fromthe unprotected situation of the projected part (now Colon--Aspinwall), and who well knew the insalubrity of the malarial swamp constitutingthe Island of Manzanillo, withdrew forever from the undertaking, afterhaving devoted to it without any benefit to himself, the best years ofhis life and a large portion of his private means. 

One of his sons, Mr. Theodore J. De Sabla, after having activelyco-operated with Lieutenant Commander Wyse, in the original schemeof the present canal company, is now one of Count de Lesseps'srepresentatives in the City of New York, and a director of the PanamaRailroad Company. 

 * * * * *

IMPROVED AVERAGING MACHINE. 

At the recent meeting of the American Society of Civil Engineers, inthis city, a paper on an improved form of the averaging machine was readby its inventor, Mr. Wm. S. Auchincloss. 

The ingenious method by which the weight of the platform is eliminatedfrom the result of the work of the machine was exhibited and explained. This is accomplished by counterweights sliding automatically in tubes, so that in any position the unloaded platform is always in equilibrium. Any combination of representative weights can then be placed on thisplatform at the proper points of the scale. By then drawing the platformto its balancing point, the location of the center of gravity will atonce be indicated on the scale by the pointer over the central trunnion. 

The weights may be arranged on a decimal system, with intermediateweights for closer working, or they may be made so as to expressmultiples or factors. 

Each machine is provided with a number of differing scales, dividedsuitably for various purposes. When the problem is one of time, thescale represents months and days; for problems of proportion, the zeroof the scale is at the center of its length; for problems for thelocation of center of gravity of a system from a fixed point, the zerois at the extremity of the scale, etc. 

The machine exhibited has sixty-three transverse grooves, which, byarrangement of weights, can be made to serve the purposes of two hundredand fifty-two grooves. 

The machine is 29 inches in length, 9 inches in width, and weighs about13 pounds. 

With the machine can be found average dates, as, for instance, ofpurchases and of payments extending over irregular periods; also averageprices, as for "futures, " in comman use among cotton brokers. Theproblem of average haul, so often presented to the engineer, can besolved with ease and great celerity. Practical examples of the solutionof these and a number of other problems involving proportions oraverages were given by the author. 

 * * * * *

COMPOUND BEAM ENGINE. 

The engine represented in Figs. 1 to 4 herewith is intended for a mill, and is of 530 to 800 indicated horse-power, the pressure being sevenatmospheres, and the number of revolutions forty-five per minute. Aswill be seen by the drawing each cylinder is placed in a separatefoundation plate, the two connecting rods acting upon cranks keyedat right angles upon the shaft, W, which carries the drum, T. Thehigh-pressure cylinder, C, is 760 mm diameter, the low pressure cylinderbeing 1, 220 mm. Diameter, and the piston speed 2. 28 m. The drum, whichalso fulfills the purpose of a fly wheel, is provided with twenty-eightgrooves for ropes of 50 mm. Diameter. With the exception of thecylinders, pistons, valves, and valve chests, the engines are of thesame size, corresponding to the equal maximum pressures which come intoaction in each cylinder, and in this respect alone the engine differs inprinciple from an ordinary twin machine. 

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 1]

The steam passes from the stop-valve, A, Fig. 4, through the steam pipe, D, to the high pressure cylinder, C, and having done its work, goes intothe receiver, R, where it is heated. From the receiver it is led intothe low-pressure cylinder, C1, and thence into the condenser. Provisionis made for working both engines independently with direct steam whendesired, suitable gear being provided for supplying steam of the properpressure to the condensing engine, so that each engine shall performexactly the same amount of work. The starting gear consists of ahand-wheel, H, which controls the stop valve, A, and of another h, whichopens the valves for the jackets of the cylinders and receiver. Thehand-wheel, h1 and h2, govern the valves, which turn the steam directinto the two cylinders. There are also lever, g, which opens theprincipal injection cock, H1, and the auxiliary injection cock, H2, thefunction of which is to assist in forming a speedy vacuum, when theengine has been standing for some time. 

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 2]

The drum is 6. 08 m. Diameter, the breadth being 2. 04 m. , with a totalweight of 33, 000 kilos. The beams are of cast iron with balance weightscast on. The connecting rods and cross beams are of wrought iron, andthe cranks, crank shaft, piston rods, valve rods, etc. , of steel. Thebed-plate for the main shaft bearings are cast in one piece with thestandards for the beam, which are connected firmly together by thecenter bearing, M M1, which is cast in one piece, and also by thediagonal bracing piece, N N1. The construction of the cylinder and valvechests is shown in Fig. 1. The working cylinder is in the form of aliner to the cylinder, thus forming the steam jacket, with a view tofuture renewal. This lining has a flange at the lower part for boltingit down, being made steam-tight by the intervention of a copper packingring. There is a similar ring at the upper part which is pressed down bythe cylinder cover. The latter is cast hollow and strengthened by ribs. The pistons are provided with cast iron double self-expanding packingrings. For preventing accidents by condensed water, spring safetyvalves, ss and s1 s1, are connected to the valve chests. The valve gear, which is arranged in the same manner for both cylinders, is actuatedby shafts, w and w1, rotated by toothed wheels as shown. Motion iscommunicated from the way-shafts, w and w1, by the eccentrics, and theeccentric rods, e1 e2 e3 e4, and the levers and rods belonging thereto, to the short steam valve rocking shafts levers, f1 f2 f3 f4, and theexhaust valve rocking shafts, k1 k2 k3 k4, the bearings of which arecarried on brackets above the valve chests, which, being furnished withtappet levers, raise and lower the valves. 

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 3]

The valves are conical, double-seated, and of cast iron, and the inletand outlet valves are placed the one above the other, the seats beingalso conically ground and inserted through the cover of the valve chest. Both inlet and outlet valves are actuated from above, and are removableupward, an arrangement which admits of the valves being more easilyexamined than when the two are actuated from different sides of thevalve chest. To carry out this idea the inlet valves are furnished withtwo guides, which, passing upward through the stuffing-box, are attachedto a hard steel cross piece, which receives the action of a bent catchturning on a pin attached to the levers, t1, t2, t3, t4. The exhaustvalves, on the contrary, have only one guide each, which passes upwardthrough the seat of the admission valve, through the valve itself bymeans of a collar, and through the stuffing-box. It is furnished withhard steel armatures, through which the levers, z1 z2, Fig. 3, act uponthe exhaust valves. 

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 4]

The governor effects the acceleration or retardation of the loosening ofthe catch actuating the steam valve by means of hard steel projectionson the shaft, v1, the position of which, by means of levers, isregulated by the governor, which in its highest position does not allowthe lifting of the inlet valve at all. The regulation of the expansionby the governor from 0 to 0. 45 takes place generally only in the case ofthe high-pressure cylinder, while the low-pressure cylinder has a fixedrate of expansion. Only when the low-pressure cylinder is requiredto work with steam direct from the boiler is the governor applied toregulate the expansion in it. An exact action in the valve guides anda regular descent is secured by furnishing them with small dash potpistons working in cylinders. Into them the air is readily admitted bya small India-rubber valve, but the passage out again is controlled atpleasure. --_The Engineer_. 

 * * * * *

TO DETECT ALKALIES IN NITRATE OF SILVER--Stolba recommends the saltto be dissolved in the smallest quantity of water, and to add tothe filtered solution hydrofluosilicic acid, drop by drop. Should aturbidity appear an alkaline salt is present. But should the liquidremain limpid, an equal volume of alcohol is to be added, which willcause a precipitate in case the slightest trace of an alkali be present. 

 * * * * *

POWER HAMMERS WITH MOVABLE FULCRUM. 

[Footnote: Paper read before the Institution of MechanicalEngineers. --_Engineering_. ]

By DANIEL LONGWORTH, of London. 

The movable-fulcrum power hammer was designed by the writer about fiveand a half years ago, to meet a want in the market for a power hammerwhich, while under the complete control of only one workman, couldproduce blows of varying forces without alteration in the rapidity withwhich they were given. It was also necessary that the vibration andshock of the hammer head should not be transmitted to the drivingmechanism, and that the latter should be free from noise and liabilityto derangement. The various uses to which the movable fulcrum hammershave been put, and their success in working[1]--as well as theimportance of the general subject which includes them, namely, thesubstitution of stored power for human effort--form the author's excusefor now occupying the time of the meeting. 

[Footnote 1: The hammers have been for some years used by A. Bamlett, ofThirsk; the American Tool Company, of Antwerp; Messrs. W. &T. Avery, ofBirmingham; Pullar & Sons, of Perth; Salter & Co. , of West Bromwich;Vernon Hope & Co. , of Wednesbury, etc. ; and also for stamps by Messrs. Collins & Co. , of Birmingham, etc. ]

Until these hammers were introduced, no satisfactory method had beendevised for altering the force of the blow. The plan generally adoptedwas to have either a tightening pulley acting on the driving belt, afriction driving clutch, or a simple brake on the driving pulley, put inaction by the hand or foot of the workman. Heavy blows were producedby simply increasing the number of blows per minute (and therefore thevelocity), and light blows by diminishing it--a plan which was quitecontrary to the true requirements of the case. To prevent the shockof the hammer head being communicated to the driving gear, an elasticconnection was usually formed between them, consisting of a steel springor a cushion of compressed air. With the steel spring, the variationwhich could be given in the thickness of the work under the hammer wasvery limited, owing to the risk of breaking the spring; but with thecompressed air or pneumatic connection the work might vary considerablyin thickness, say from 0 to 8 in. With a hammer weighing 400lb. Thepneumatic hammers had a crank, with a connecting rod or a slottedcrossbar on the piston-rod, a piston and a cylinder which formed thehammer-head. The piston-rod was packed with a cup leather, or withordinary packing, the latter required to be adjusted with the greatestnicety, otherwise the piston struck the hammer before lifting it, orelse the force of the blow was considerably diminished. As the pistonmoved with the same velocity during its upward and downward strokes, and, in the latter, had to overtake and outrun the hammer falling underthe action of gravity, the air was not compressed sufficiently to givea sharp blow at ordinary working speeds, and a much heavier hammer wasrequired than if the velocity of the piston had been accelerated to agreater degree. 

As it is impossible in the limits of this paper to describe all theforms in which the movable fulcrum hammers have been arranged, two typesonly will be selected taken from actual work; namely, a small planishinghammer, and a medium-sized forging hammer. [1]

[Footnote 1: To the makers, Messrs. J. Scott Rawlings & Co, ofBirmingham, the author is indebted for the working drawings of thesehammers. ]

The small planishing hammer, Figs. 1 to 3, next page, is used forcopper, tin, electro, and iron plate, for scythes, and other thin work, for which it is sufficient to adjust the force of the blow once for allby hand, according to the thickness and quality of the material beforecommencing to hammer it. The hammer weighs 15 lb. , and has a strokevariable from 2½ in. To 9½ in. , and makes 250 blows per minute. Thedriving shaft, A, is fitted with fast and loose belt pulleys, the beltfork being connected to the pedal, P, which when pressed down by thefoot of the workman, slides the driving belt on to the fast pulley andstarts the hammer; when the foot is taken off the pedal, the weight onthe latter moves the belt quickly on to the loose pulley, and the hammeris stopped. The flywheel on the shaft, A, is weighted on one side, so that it causes the hammer to stop at the top of its stroke afterworking; thus enabling the material to be placed on the anvil beforestarting the hammer. The movable fulcrum, B, consists of a stud, free toslide in a slot, C, in the framing, and held in position by a nut andtoothed washer. On the fulcrum is mounted the socket, D, through whichpasses freely a round bar or rocking lever, E, attached at one end tothe main piston, F, of the hammer, G, and having at the other extremitya long slide, H, mounted upon it. This slide is carried on thecrank-pin, I, fastened to the disk, J, attached to the driving shaft, A. The crank-pin, in revolving, reciprocates the rocking lever, E, andmain piston, F, and through the medium of the pneumatic connection, thehammer, G. The slide, H, in revolving with the crank-pin, also movesbackward and forward along the rocking lever, approaching the fulcrum, B, during the down-stroke of the hammer, and receding from it duringthe up-stroke. By this means the velocity of the hammer is considerablyaccelerated in its downward stroke, causing a sharp blow to be givenwhile it is gently raised during its upward stroke. 

To alter the force of the blow, the hammer, G, is made to rise and fallthrough a greater or less distance, as may be required, from the fixedanvil block, K, after the manner of the smith giving heavy or lightblows on his anvil. It is evident that this special alteration of thestroke could not be obtained by altering the throw of a simple crank andconnecting rod; but by placing the slot, C, parallel with the directionof the rocking lever, E, when the latter is in its lowest position, withthe hammer resting on the anvil, and with the crank at the top of itsstroke, this lowest position of the rocking lever and hammer is madeconstant, no matter what position the fulcrum, B, may have in the slot, C. To obtain a short stroke, and consequently a light blow, the fulcrumis moved in the slot toward the hammer, G; and to produce a long strokeand heavy blow the fulcrum is moved in the opposite direction. 

Fig. 3 gives the details of the pneumatic connection between the mainpiston and the hammer, in which packing and packing glands are dispensedwith. The hammer, G, is of cast steel, bored out to fit the main piston, F, the latter being also bored out to receive an internal piston, L. Apin, M, passing freely through slots in the main piston, F, connectsrigidly the internal piston, L, with the hammer, G. When the main pistonis raised by the rocking lever, the air in the space, X, between themain and internal pistons, is compressed, and forms an elastic mediumfor lifting the hammer; when the main piston is moved down, the air inthe space, Y, is compressed in its turn, and the hammer forced down togive the blow. Two holes drilled in the side of the hammer renew the airautomatically in the spaces, X and Y, at each blow of the hammer. 

Figs. 4 to 6, on the next page, represent the medium size forginghammer, for making forgings in dies, swaging and tilting bars, andplating edged tools, etc. 

The hammer weighs 1 cwt. , has a stroke variable from 4 in. To 14½ in. , and gives 200 blows per minute; the compressed air space between themain piston and the hammer is sufficiently long to admit forgings up to3 in. Thick under the hammer. 

To make forgings economically, it is necessary to bring them into thedesired form by a few heavy blows, while the material is still in ahighly plastic condition, and then to finish them by a succession oflighter blows. The heavy blows should be given at a slower rate than thelighter ones, to allow time for turning the work in the dies or on theanvil, and so to avoid the risk of spoiling it. In forging with thesteam hammer the workman requires an assistant, who, with the leverof the valve motion in hand, obeys his directions as to starting andstopping, heavy or light blows, slow or quick blows, etc; the quickestspeed attainable depending on the speed of the arm of the assistant. In the movable-fulcrum forging hammer the operations of starting andstopping, and the giving of heavy or light blows, are under the completecontrol of one foot of the workman, who requires therefore no assistant;and by properly proportioning the diameter of the driving pulley andsize of belt to the hammer, the heavy blows are given at a slower ratethan the light ones, owing to the greater resistance which they offer tothe driving belt. 

In this hammer the pneumatic connection, the arrangements for thestarting, stopping, and holding up of the hammer, as well as those forcommunicating the motion of the crank-pin to the hammer by means ofa rocking lever and movable fulcrum, are similar to those in theplanishing hammer, differing only in the details, which provide doubleguides and bearings for the principal working parts. 

[Illustration: LONGWORTH'S POWER HAMMER WITH MOVABLE FULCRUM. ]

The movable fulcrum, B, Figs. 4 and 5, consists of two adjustable steelpins, attached to the fulcrum lever, Q, and turned conical where theyfit in the socket, D. The fulcrum lever is pivoted on a pin, R, fixed inthe framing of the machine, and is connected at its lower extremityto the nut, S, in gear with the regulating screw, T. The to-and-fromovement of the fulcrum lever, Q, by which heavy or light blows aregiven by the hammer, is placed under the control of the foot of theworkman, in the following manner: U is a double-ended forked lever, pivoted in the center, and having one end embracing the starting pedal, P, and the other end the small belt which connects the fast pulleyon the driving shaft, A, with the loose pulley, V, or the reversingpulleys, W and X. These are respectivly connected with the bevel wheels, W_{1}, and X_{1}, gearing into and placed at opposite sides of the bevelwheel, Z, on the regulating screw in connection with the fulcrum lever. When the workman places his foot on the pedal, P, to start the hammer, he finds his foot within the fork of the lever, U; and by slightlyturning his foot round on his heel he can readily move the forkedlever to right or left, so shifting the small belt on to either of thereversing pulleys, W or X, and causing the regulating screw, T, torevolve in either direction. The fulcrum lever is thus caused to moveforward or backward, to give light or heavy blows. By moving the forkedlever into mid position, the small belt is shifted into its usual placeon the loose pulley, V, and the fulcrum remains at rest. To fix thelightest and heaviest blow required for each kind of work, adjustablestops are provided, and are mounted on a rod, Y, connected to an arm ofthe forked lever. When the nut of the regulating screw comes in contactwith either of the stops, the forked lever is forced into mid position, in spite of the pressure of the foot of the workman, and thus furthermovement of the fulcrum lever, in the direction which it was taking, is prevented. The movable fulcrum can also be adjusted by hand to anyrequired blow, when the hammer is stopped, by means of a handle inconnection with the regulating screw. 

In conclusion the author wishes to direct attention to the fact, that inmany of our largest manufactories, particularly in the midland counties, foot and hand labor for forging and stamping is still employed to anenormous extent. Hundreds of "Olivers, " with hammers up to 60 lb. Inweight, are laboriously put in motion by the foot of the workman, at aspeed averaging fifty blows per minute; while large numbers of stamps, worked by hand and foot, and weighing up to 120 lb. , are also employed. The low first cost of the foot hammers and stamps, combined with thesystem of piece work, and the desire of manufacturers to keep theirmethods of working secret, have no doubt much to do with the smallamount of progress that has been made; although in a few casescompetition, particularly with the United States of America, has forcedthe manufacturer to throw the Oliver and hand-stamp aside, and to employsteam power hammers and stamps. The writer believes that in connectionwith forging and stamping processes there is still a wide and profitablefield for the ingenuity and capital of engineers, who choose tooccupy themselves with this minor, but not the less useful, branch ofmechanics. 

 * * * * *

THE BICHEROUX SYSTEM OF FURNACES APPLIED TO THE PUDDLING OF IRON. 

Since the year 1872, the large iron works at Ougrée, near Liege, haveapplied the Bicheroux system of furnaces to heating, and, since theyear 1877, to puddling. The results that have been obtained in thislast-named application are so satisfactory that it appears to us to beof interest to speak of the matter in some detail. 

The apparatus, which is shown in the opposite page, consists of threedistinct parts: (1) a gas generator; (2) a mixing chamber into whichthe gases and air are drawn by the natural draught, and wherein thecombustion of the gases begins; and (3) a furnace, or laboratory (notrepresented in the figure), wherein the combustion is nearly finished, and wherein take place the different reactions of puddling. These threeparts are given dimensions that vary according to the composition of thedifferent coals, and they may be made to use any sort of coal, eventhe fine and schistose kinds which would not be suitable for ordinarypuddling. The gases and the air necessary for the combustion of thesebeing brought together at different temperatures, and being drawn intothe mixing chamber through the same chimney, it will be seen that thedimensions of the flues that conduct them should vary with the kind ofcoal used; and the manner in which the gases are brought together is nota matter of indifference. 

[Illustration: THE BICHEROUX SYSTEM OF FURNACE. 

Vertical Section, and Horizontal Section through MNOPQR]

The gas generator consists of a hopper, A, into which drops, throughsmall apertures a, the coal piled up on the platform, D. These aperturesare closed with coal or bricks. The bottom of the generator is formed ofa small standing grate. The coal, on falling upon a mass in a state ofignition, distills and becomes transformed into coke, which graduallyslides down over a grate to produce afterward, through its owncombustion, a distillation of the coal following it. But as these arefeatures found in all generators we will not dwell upon them. 

The gases that are produced flow through a long horizontal flue, B, intoa vertical conduit, E, into which there debouches at the upper part aseries of small orifices, F, that conduct the air that has been heated. The gases are inflamed, and traverse the furnace c (not shown in thecut), from whence they go to the chimney. Before the air is allowed toreach the intervening chamber it is made to pass into the sole of thefurnace and into the walls of the chamber, so that to the advantage ofhaving the air heated there is joined the additional one of having thoseportions of the furnace cooled that cannot be heated with impunity. 

The incompletely burned gases that escape from the furnace are utilizedin heating the boilers of the establishment. The dimensions given thesefurnaces vary greatly according to the charge to be used. All theresults at Ougrée have been obtained with 400 kilogramme charges, and the dimensions of the gas generators have been calculated forSix-Bonniers coal, which does not yield over 20 per cent. Of gas. 

The advantages of this system, which permits of expediting all theoperations of puddling, are as follows:

1. A notable economy in fuel, both as regards quantity and quality. 

2. Economy resulting from diminution in the waste of metal, with aconsequent improvement in the quality of the products obtained. 

3. Diminution in cost of repairs. 

4. Less rapid wear in the grates. 

5. Improvement in the conditions of the work of puddling. 

As regards the first of these advantages, it may be stated that thepuddling of ordinary Ougrée forge iron, which required with otherfurnaces 900 to 1, 000 kilogrammes of coal, is now performed with lessthan 600 kilogrammes per ton of the iron produced. The puddling of finegrained iron which required 1, 300 to 1, 500 kilogrammes of coal is nowdone with 800. So much for quantity; as for quality the system presentsalso a very marked advantage in that it requires no rolling coal--theoperation of the furnace being just as regular with fine coal, even thatsifted through screens of 0. 02 meter. 

The second class of advantages naturally results from the almostcomplete prevention of access of cold air. The saving in wastage amountsto 3 or 4 per cent. , that is to say, 100 kilogrammes of iron produced isaccompanied by a loss of only 9 to 10 kilogrammes, instead of 13 to 15as ordinarily reckoned. 

The diminution in the cost of repairs is due to the fact that thefurnace doors, of which there are two, permit of easy access to allparts of the sole; moreover, the coal never coming in contact with thefire-bridges, the latter last much longer than those in other styles offurnaces, and can be used for several weeks without the necessity ofthe least repair. The reduced wear of the grates results from the lowtemperature that can be used in the furnace, and the quantity of clinkerthat can be left therein without interfering with its operation, thuspermitting of having the grates always black. These latter in no wisechange, and after five months of work the square bars still preservetheir sharpness of edges. 

As for the improvements in the conditions of the work of puddling, itmay be stated that with a uniform price per 100 kilogrammes for all thefurnaces, the laborers working at the gas furnaces can earn 25 to 30 percent. More than those working at ordinary furnaces. 

 * * * * *

GESSNER'S CONTINUOUS CLOTH-PRESSING MACHINE. 

It is well known that there are several serious drawbacks in the usualplan of pressing woolen or worsted cloths and felts with press plates, press papers, and presses. Three objections of great weight may bementioned, and events in Leeds give emphasis to a fourth. The threeobjections are--the labor required in setting or folding the cloth, the expense of the press papers, and the time required. The fourthobjection, about which a dispute has occurred between the press-settersand the master finishers in Leeds, refers to the inapplicability of thecommon system to long lengths. The men object to these on account ofthe great labor involved in shifting the heavy mass of cloth and pressplates to and from the presses. A minor drawback of this system isthat it involves the presence of a fold up the middle of the piece. Onaccount of these drawbacks it has long been understood to be desirableto expedite the process, and also to dispense with the press papers. This is the main purpose of the machine we now illustrate in section, inwhich the pressing is done continuously by what may be termed a speciesof ironing. The machine consists of a central hollow cylinder, C, three-quarters of the circumference of which is covered by the hollowboxes, M, heated by steam through the pipes shown, and which aremounted upon the levers, BB', whose fulcra are at bb. By means of thehand-wheel, T, and worm-wheel, n, which closes or opens the levers, BB', the pressure of the boxes upon the central roller may be adjusted atwill, the spring-bolt, F, allowing a certain amount of yield. The facesof the press-boxes, MM, are covered by a curved sheet of German silverattached to the point, Y. This sheet takes the place of the press papersin the ordinary process. The course of the cloth through the machine isas follows, and is shown by the arrows: It is placed on the bottom boardin front, and in its travel it passes over the rails, O, after which itis operated on by the brush, Z, leaving which it is conveyed over therails, V and I, the rollers, K and P, and thence between the pressingroller, C, and the German silver press plate covering the heated boxes, M. Leaving these the piece passes over the roller, P, and is cuttleddown in the bottom board by the cuttling motion, F, or a rolling-upmotion may be applied. The maker states that arrangements for brushingand steaming may also be attached, so that in one passage through themachine a piece may be pressed, brushed, and steamed. The speed of thecylinder may be adjusted according to the quality or requirements ofthe goods that are under treatment. At the time of our visit, says the_Textile Manufacturer_, printed woolen pieces were being pressed at therate of about four yards a minute, but higher speeds are often obtained. Messrs. Taylor, Wordsworth & Co. , who have erected many of thesemachines in Leeds, Bradford, and Batley, inform us that they find theyare adapted for the pressing of a wide variety of cloths, from Bradfordgoods and thin serges to the heavy pieces of Dewsbury and Batley. Theinventor, Ernst Gessner, of Aue, Saxony, adopts an ingenious expedientfor pressing goods with thick lists. He provides an arrangement formoving the cylinder endwise, according to the different widths ofthe pieces to be treated. One list is left outside at the end of thecylinder, and the other at the opposite end of the pressing boxes. Themachine we saw was 80 in. Wide on the roller, and it was one the designand construction of which undoubtedly do credit to Mr. Gessner. 

[Illustration]

 * * * * *

IMPROVEMENTS IN WOOLEN CARDING ENGINES. 

Mr. Bolette, who has made a name for himself in connection with strapdividers, has experimented in another direction on the carding engine, and as his ideas contain some points of novelty we herewith give thenecessary illustrations, so that our readers can judge for themselves asto the merit of these inventions. 

[Illustration: Fig. 1. ]

Fig. 1 represents the feeding arrangement. Here the wool is delivered bythe feed rollers, A A, in the usual manner. The longer fibers are thentaken off by a comb, B, and brought forward to the stripper, E, whichtransfers them to the roller, H, and thence to the cylinder. The shorterfibers which are not seized by the comb fall down, but as they dropthey meet a blast of air created by a fan, which throws the lighter andcleaner parts in a kind of spray upon the roller, L, whence they pass onto the cylinder, while the dirt and other heavier parts fall downwardsinto a box, and are by this means kept off the cylinder. It is evidentthat in this arrangement it is not intended to keep the long and theshort fibers separate, but to utilize them all in the formation ofthe yarn. The arrangement shown in Fig. 2 refers to the delivery end. Instead of the sliver being wound upon the roller in the usual way, itruns upon a sheet of linen, P¹, as in the case of carding for felt, witha to-and-fro motion in the direction of the axis of the rollers. In thisway one or more layers of the fleece can be placed on the sheet, whichin that case passes backwards and forwards from roller S to R, and _viceversa_. It is, in fact, the bat arrangement used for felt, only withthis difference, that the bat is at once rolled up instead of goingthrough the bat frame. In the manufacture of felt it is of course ofimportance to have many very thin layers of fleece superposed overeach other in order to equalize it, and if the same is applied to themanufacture of cloth it will no doubt give satisfactory results, but maybe rather costly. 

[Illustration: Fig. 2. ]

 * * * * *

NOVELTIES IN RING SPINDLES. 

One of the drawbacks of ring spinning is the uneven pull of thetraveler, which is the more difficult to counteract as it is exertedin jerks at irregular intervals. It is argued that with spindles andbearings as usually made the spindle is supported firmly in its bearing, and cannot give in case of such a lateral pull when exerted through theyarn by the traveler, and the consequence is either a breakage of theyarn or an uneven thread. Impressed with this idea, and in order toremedy this defect, an eminent Swiss firm has hit upon the notion ofdriving the spindle by friction, and to make it more or less loose inthe bearings, so that in case of an extra pull by the traveler thespindle can give way a little, and thus prevent the breakage of theyarn. This idea has been carried out in four different ways, and as thisseems to be an entirely new departure in ring spinning, we give theillustrations of their construction in detail. 

[Illustration: Fig. 1. Fig. 2. Fig. 3. Fig. 4. ]

Fig. 1 represents Bourcart's recent arrangement of attaching the threadguide to the spindle rail and the adjustable spindle. The spindle isheld by the sleeve, g, which latter is screwed into the spindle rail, S, this being moved by the pinion, a; the collar is elongated upwards in acuplike form, c, the better to hold the oil, and keep it from flying;d is the wharf, which has attached to it the sleeve, m, and which issituated loosely in the space between the spindle and the footstep, e. Above the wharf the spindle is hexagonal in shape, and to this part isattached the friction plate, a. Between the latter and the upper surfaceof the wharf a cloth or felt washer is inserted, to act as a brake. Thefootstep, e, is filled with oil, in which run the foot of the spindleand the sleeve m, the latter turning upon a steel ring situated on thebottom of the footstep. As, thus, the foot of the spindle is quite free, the upper part of the spindle can give sideways in the direction of anysudden pull, and the foot of the spindle can follow this motion in theopposite direction, the collar forming the fulcrum for the spindle. Bythis alteration of the vertical position of the spindle into an inclinedone (though ever so trifling), the contact of the friction plate, a, andthe wharf is interrupted, and thus the speed of the spindle reduced. This will cause less yarn to be wound on, and the pull thus to beneutralized; but as the wharf keeps turning at the same speed, itscentrifugal force will act again upon the friction plate, and thus bringthe spindle back to its vertical position as soon as the extra drag hasbeen removed. 

In Fig. 2 the footstep, e, has the foot of the spindle more closelyfitting at the bottom, but the upper part of the step opens outgradually, and forms a conical cavity of a little larger diameter thanthe spindle, so that the latter has a considerable play sideways. Thewharf carries in its lower part the sleeve, g, which runs upon a steelring as above. The upper surface of the wharf is arched, and upon thisis fitted the correspondingly arched friction plate, a, which latteris attached to the spindle by a screw. The position of the spindle ismaintained by the collar, m. This collar is loose in the spindle rail, and only held by the spring, m'. If now, a lateral drag is exerted uponthe upper part of the spindle, the collar car follows the direction ofthis drag, and the spindle thus be brought out of the vertical position, the friction plate slipping at the same time. The force of the springconjointly with the centrifugal force will then bring back the spindleinto its normal position as soon as the drag is again even. 

Fig. 3 shows a spindle with a very long conical oil vessel, B, restingupon a disk, e", in cup, e', with a cover, e"'. The wharf, d, is heresituated high up the spindle, has the same sleeve as in the precedingcase, and runs round the bush, g, upon the ring, z. The friction plateresting upon the wharf is joined to the collar, a, running out into acup shape, which is fixed to the spindle, which here has a hexagonalform. In this case the collar gives with the spindle, which latterhas the necessary play in the long footstep; and as the collar andfriction-plate are one, it is brought back to its normal place bycentrifugal force. 

A peculiar arrangement is shown in Fig. 4. Here the ring and traveler, f, are placed as usual, but the spindle carries at the same time aninverted flier, t. The spindle turns loosely in the footstep, e, theoil chamber being carried up to the middle of its height. The wharfis placed in the same position as in the previous case, having alsoa sleeve running in the oil chamber, c, upon a steel ring, z. Thefriction-plate a, on the top of the wharf carries the flier, and on itsupper surface is in contact with the inverted cup, a, which is attachedto the spindle by a pin or screw. In order to limit at will the lateralmotion of the spindle there is attached to the latter, between thefootstep and the collar, a split ring, i, which can be closed moreor less by a small set screw. The spindle is thus only held in theperpendicular position by its own velocity, which will facilitate ahigh degree of speed, through the entire absence of all friction in thebearings, this vertical position being assisted by the friction motionwhenever the spindle has been drawn on one side. Although the notion ofmounting spindles so that they can yield in order to center themselvesis not new, it is evident that considerable ingenuity has been broughtto bear upon the arrangement of the spindles we have described, but weare not in a position to say to what extent practice has in this casecoincided with theory. --_Textile Manufacturer_. 

 * * * * *

PHOTO-ENGRAVING ON ZINC OR COPPER. 

By LEON VIDAL. 

This process is similar in many respects to the one which was sometime ago communicated to the Photographic Society of France by M. Stronbinsky, of St. Petersburg, but in a much improved and completeform. An account of it was given by M. Gobert, at the meeting of thesame society, on the 2d December, 1882. The following are the details, as demonstrated by me at the meeting of the 9th of May last:

Sheets of zinc or of copper of a convenient size are carefully planishedand polished with powdered pumice stone. The sensitive mixture iscomposed of:

 The whites of four fresh eggs beaten to a froth......................... 100 parts Pure bichromate of ammonia......... 2. 50 " Water.............................. 50 "

After this mixture has been carefully filtered through a paper filter, afew drops of ammonia are added. It will keep good for some time if wellcorked and preserved from exposure to the light. Even two months afterbeing prepared I have found it to be still good; but too large aquantity should not be prepared at a time, as it does not improve withkeeping. 

I find that the dry albumen of commerce will answer as well as thefresh. In that case I employ the following formula:

 Dry albumen from eggs.............. 15 to 20 parts Water.............................. 100 " Ammonia bichromate................. 2. 50 "

Always add some drops of ammonia, and keep this mixture in a well corkedbottle and in a dark place. 

To coat the metal plate, place it on a turning table, to which it ismade fast at the center by a pneumatic holder; to assure the perfectadhesion of this holder, it is as well to wet the circular elastic ringof the holder before applying it to the metallic surface. When this isdone, the table may be made to rotate quickly without fear of detachingthe plate by the rapidity of the movement. The plate is placed in aperfectly horizontal position, where no dust can settle on it; themixture is then poured on it, and distributed by means of a triangularpiece of soft paper, so as to cover equally all the parts of the plate. Care should be taken not to flow too much liquid over the plate, andwhen the latter is everywhere coated, the excess is poured off into adifferent vessel from that which contains the filtered mixture, or elseinto a filter resting on that vessel. The turning table should now beinverted so that the sensitive surface may be downwards, and it is madeto rotate at first slowly, afterwards more rapidly, so as to make thefilm, which should be very thin, quite smooth and even. The wholeoperation should be carried out in a subdued light, as too strong alight would render insoluble the film of bichromated albumen. 

When the film is equalized the plate must be detached from the turningtable and placed on a cast iron or tin plate heated to not more than 40°or 50° C. A gentle heat is quite sufficient to dry the albumen quickly;a greater heat would spoil it, as it would produce coagulation. So soonas the film is dry, which will be seen by the iridescent aspect itassumes, the plate is allowed to cool to the ordinary temperature, and is then at once exposed either beneath a positive, or beneath anoriginal drawing the lines of which have been drawn in opaque ink, so asto completely prevent the luminous rays from passing through them; thelight should only penetrate through the white or transparent ground ofthe drawing. 

I say a _positive_ because I wish to obtain an engraved plate; if Iwanted to have a plate for typographic printing, I should have to take a_negative_. After exposure the plate must be at once developed, which iseffected by dissolving in water those parts of the bichromated gelatinewhich have been protected from the action of light by the dark spacesof the cliché; these parts remain soluble, while the others have beenrendered completely insoluble. If the plate were dipped in clear waterit would be difficult to observe the picture coming out, especially oncopper. To overcome this difficulty the water must be tinged with someaniline color; aniline red or violet, which are soluble in water, answers the purpose very well. Enough of the dye must be dissolved inthe water to give it a tolerably deep color. So soon as the plate isplunged into this liquid the albumen not acted on by light is dissolved, while the insoluble parts are colored by absorbing the dye, so that themetal is exposed in the lines against a red or violet ground, accordingto the color of the dye used. 

When the drawing comes out quite perfect, and a complete copy of theoriginal, the plate with the image on it is allowed to dry either of itsown accord, or by submitting it to a gentle heat. So soon as it is dryit is etched, and this is done by means of a solution of perchlorideof iron in alcohol. Both alcohol and iron perchloride will coagulatealbumen; their action, therefore, on the image will not be injurious, since they will harden the remaining albumen still further. But to getthe full benefit of this, the alcohol and the iron perchloride mustboth be free from water; it is therefore advisable to use the salt incrystals which have been thoroughly dried, and the alcohol of a strengthof 95°. 

The following is the formula:

 Perchloride of iron, well dried 50 gr. Alcohol at 95° 100 "

This solution must be carefully filtered so as to get rid of any depositwhich may form, and must be preserved in a well-corked bottle, when itwill keep for a long time. The plate is first coated with a varnish ofbitumen of Judea on the edges (if those parts are not already coveredwith albumen) and on the back, so that the etching liquid can only acton the lines to be engraved. It is then placed, with the side to beengraved downwards, in a porcelain basin, into which a sufficientquantity of the solution of perchloride of iron is poured, and theliquid is kept stirred so as to renew the portion which touches theplate; but care must be taken not to touch with the brush the partswhere there is albumen remaining. The length of time that the etchingmust be continued depends on the depth required to be given tothe engraving; generally a quarter of an hour will be found to besufficient. Should it be thought desirable to extend the action overhalf an hour, the lines will be found to have been very deeply engraved. When the etching is considered to have been pushed far enough, the platemust be withdrawn from the solution, and washed in plenty of water;it must then be forcibly rubbed with a cloth so as to remove all thealbumen, and after it has been polished with a little pumice, theengraving is complete. 

It will be seen that this process may be used with advantage instead ofthat of photo-engraving with bitumen, in cases where it is not advisableto use acids. One of my friends, Mr. Fisch, suggests the plan--whichseems to deserve a careful investigation--of combining this processwith that where bitumen is employed; it would be done somewhat in thefollowing way. The plate of metal would be first coated evenly withbitumen of Judea on the turning table, and when the bitumen is quitedry, it should be again coated with albumen in the manner as describedabove. In full sunlight the exposure need not exceed a minute in length;then the plate would be laid in colored water, dried, and immersed inspirits of turpentine. The latter will dissolve the bitumen in allthe parts where it has been exposed by the removal of the albumen notrendered insoluble by the action of light. But it remains to be seenwhether the albumen will not be undermined in this method; therefore, before recommending the process, it ought to be thoroughly studied. Themetal is now exposed in all the parts that have to be etched, whileall the other parts are protected by a layer of bitumen coated withcoagulated albumen. Hence we may employ as mordant water acidulated with3, 4, or 5 per cent. Of nitric acid, according as it is required to havethe plate etched with greater or less vigor. 

By following the directions above given, any one wishing to adopt theprocess cannot fail of obtaining good results, One of its greatestadvantages is that it is within the reach of every one engaged inprinting operations. --_Photo News_. 

 * * * * *

MERIDIAN LINE. 

[Footnote: From Proceedings of the Association of County Surveyors ofOhio, Columbus, January, 1882. ]

The following process has been used by the undersigned for many years. The true meridian can thus be found within one minute of arc:

_Directions_. --Nail a slat to the north side of an upper window--thehigher the better. Let it be 25 feet from the ground or more. Let itproject 3 feet. Kear the end suspend a plumb-bob, and have it swing in abucket of water. A lamp set in the window will render the upper part ofthe string visible. Place a small table or stand about 20 feet south ofthe plumb-bob, and on its south edge stick the small blade of a pocketknife; place the eye close to the blade, and move the stand so as tobring the blade, string, and polar star into line. Place the table sothat the star shall be seen very near the slat in the window. Let thisbe done half an hour before the greatest elongation of the star. Withinfour or five minutes after the first alignment the star will have movedto the east or west of the string. Slip the table or the knife a littleto one side, and align carefully as before. After a few alignments thestar will move along the string--down, if the elongation is west; up, ifeast. On the first of June the eastern elongation occurs about half-pasttwo in the morning, and as daylight comes on shortly after theobservation is completed, I prefer that time of year. The time ofmeridian passage or of the elongation can be found in almost any work onsurveying. Of course the observer should choose a calm night. 

In the morning the transit can be ranged with the knife blade andstring, and the proper angle turned off to the left, if the elongationis east; to the right, if west. 

Instead of turning off the angle, as above described, I measure 200 or300 feet northtward, in the direction of the string, and compute theoffset in feet and inches, set a stake in the ground, and drive a tackin the usual way. 

Suppose the distance is 250 feet and the angle 1° 40', then the offsetwill be 7, 271 feet, or 7 feet 3¼ inches. A minute of arc at the distanceof 250 feet is seven-eighths of an inch; and this is the most accurateway, for the vernier will not mark so small a space accurately. 

ANGLE OF ELONGATION. 

This should be computed by the surveyor for each observation. Thedistance between the star and the pole is continually diminishing, andon January 1, 1882, was 1° 18' 48". 

There is a slight annual variation in the distance. July 1, 1882, itwill be 1° 19' 20". If from this latter quantity the observer willsubtract 16" for 1883, and the same quantity for each succeeding yearfor the next four or five years, no error so great as one-quarter of aminute will be made in the position of the meridian as determined in thesummer months. If winter observations are made, the distance in Januaryshould be used. The formula for computing the angle of elongation iseasily made by any one understanding spherical trigonometry, and isthis:

 R x sin. Polar dist. --------------------- = sin. Of angle of elongation. Cos. Lat. 

As an example, suppose the time is July, 1882, and the latitude 40°. Then the computation being made, the angle will be found to be 1° 43'34". A difference of six minutes in the latitude will make less than10" difference in the angle, as one can see by trial. Any good Stateor county map will give the latitude to within one or two miles--orminutes. 

The facts being as here stated, the absurdity of the Ohio law, concerning the establishment of county meridians, becomes apparent. Thelongitude has nothing at all to do With the meridian; and a differenceof _six miles_ in latitude makes no appreciable error in the meridianestablished as here suggested, whereas the statute requires the latitudewithin _one half a second_, which is _fifty feet_. There are some otherthings, besides the ways of Providence, which may be said to be "pastfinding out. " It is not probable that a surveyor would err so much as_three_ miles in his latitude, but should he do so, then the error inhis meridian line, resulting from the mistake, will be _five seconds_, and a line _one mile_ long, run on a course 5" out of the way, will varybut _an inch and a half_ from the true position. Surveyors well knowthat no such accuracy is attainable. R. W. McFARLAND, * * * * *

ELECTRO-MANIA. 

By W. MATTIEU WILLIAMS. 

A history of electricity, in order to be complete, must include twodistinct and very different subjects: the history of electrical science, and a history of electrical exaggerations and delusions. The progress ofthe first has been followed by a crop of the second from the time whenKleist, Muschenbroek, and Cuneus endeavored to bottle the supposedfluid, and in the course of these attempts stumbled upon the "Leydenjar. "

Dr. Lieberkuhn, of Berlin, describes the startling results which heobtained, or imagined, "when a nail or a piece of brass wire is put intoa small apothecary's phial and electrified. " He says that "if, while itis electrifying, I put my finger or a piece of gold which I hold in myhand to the nail, I receive a shock which stuns my arms and shoulders. "At about the same date (the middle of the last century), Muschenbroekstated, in a letter to Réaumur, that, on taking a shock from a thinglass bowl, "he felt himself struck in his arms, shoulders, and breast, so that he lost his breath, and was two days before he recovered fromthe effects of the blow and the terror" and that he "would not take asecond shock for the kingdom of France. " From the description Of theapparatus, it is evident that this dreadful shock was no stronger thanmany of us have taken scores of times for fun, and have given toour school-follows when we became the proud possessors of our firstelectrical machine. 

Conjurers, mountebanks, itinerant quacks, and other adventurers operatedthroughout Europe, and were found at every country fair and _fete_displaying the wonders of the invisible agent by giving shocks andprofessing to cure all imaginable ailments. 

Then came the discoveries of Galvani and Volta, followed by thedemonstrations of Galvani's nephew Aldini, whereby dead animals weremade to display the movements of life, not only by the electricity ofthe Voltaic pile, but, as Aldini especially showed, by a transfer ofthis mysterious agency from one animal to another. 

According to his experiments (that seem to be forgotten by modernelectricians) the galvanometer of the period, a prepared frog, could bemade to kick by connecting its nerve and muscle with muscle and nerve ofa recently killed ox, with, or without metallic intervention. 

Thus arose the dogma which still survives in the advertisements ofelectrical quacks, that "electricity is life, " and the possibility ofreviving the dead was believed by many. Executed criminals were inactive demand; their bodies were expeditiously transferred from thegallows or scaffold to the operating table, and their dead limbs weremade to struggle and plunge, their eyeballs to roll, and their featuresto perpetrate the most horrible contortions by connecting nerves withone pole, and muscles with the opposite pole of a battery. 

The heart was made to beat, and many men of eminence supposed that ifthis could be combined with artificial respiration, and kept up forawhile, the victim of the hangman might be restored, provided the neckwas not broken. Curious tales were loudly whispered concerning gentlehangings and strange doings at Dr. Brookes's, in Leicester Square, andat the Hunterian Museum, in Windmill Street, now flourishing as "TheCafé de l'Etoile. " When a child, I lived about midway between thesecelebrated schools of practical anatomy, and well remember the tales ofhorror that were recounted concerning them. When Bishop and Williams (norelation to the writer) were hanged for burking, i. E. , murdering peoplein order to provide "subjects" for dissection, their bodies were sent toWindmill Street, and the popular notion was that, being old and faithfulservants of the doctors, they were galvanized to life, and again set upin their old business. 

It is amusing to read some of the treatises on medical galvanism thatwere published at about this period, and contrast their positivestatements of cures effected and results anticipated with the positionnow attained by electricity as a curative agent. 

Then came the brilliant discoveries of Faraday, Ampère, etc. , demonstrating the relations between electricity and magnetism, andimmediately following them a multitude of patents for electro-motors, and wild dreams of superseding steam-engines by magneto-electricmachinery. 

The following, which I copy from the _Penny Mechanic_, of June 10, 1837, is curious, and very instructive to those who think of investing in anyof the electric power companies of to-day: "Mr. Thomas Davenport, aVermont blacksmith, has discovered a mode of applying magnetic andelectro-magnetic power, which we have good ground for believing will beof immense importance to the world. " This announcement is followed byreference to Professor Silliman's _American Journal of Science and theArts_, for April, 1837, and extracts from American papers, of which thefollowing is a specimen: "1. We saw a small cylindrical battery, aboutnine inches in length, three or four in diameter, produce a magneticpower of about 300 lb. , and which, therefore, we could not move withour utmost strength. 2. We saw a small wheel, five-and-a-half inches indiameter, performing more than 600 revolutions in a minute, and lift aweight of 24 lb. One foot per minute, from the power of a battery ofstill smaller dimensions. 3. We saw a model of a locomotive enginetraveling on a circular railroad with immense velocity, and rapidlyascending an inclined plane of far greater elevation than any hithertoascended by steam-power. And these and various other experiments whichwe saw, convinced us of the truth of the opinion expressed by ProfessorsSilliman, Renwick, and others, that the power of machinery may beincreased from this source beyond any assignable limit. It is computedby these learned men that a circular galvanic battery about three feetin diameter, with magnets of a proportionable surface, would produce atleast a hundred horse-power; and therefore that two such batteries wouldbe sufficient to propel ships of the largest class across the Atlantic. The only materials required to generate and continue this power forsuch a voyage would be a few thin sheets of copper and zinc, and a fewgallons of mineral water. "

The Faure accumulator is but a very weak affair compared with this, SirWilliam Thomson notwithstanding. To render the date of the above fullyappreciable, I may note that three months later the magazine from whichit is quoted was illustrated with a picture of the London and BirminghamRailway Station displaying a first-class passenger with a box seat onthe roof of the carriage, and followed by an account of the trip toBoxmoor, the first installment of the London and North-Western Railway. It tells us that, "the time of starting having arrived, the doors ofthe carriages are closed, and, by the assistance of the conductors, thetrain is moved on a short distance toward the first bridge, where itis met by an engine, which conducts it up the inclined plane as far asChalk Farm. Between the canal and this spot stands the station-house forthe engines; here, also, are fixed the engines which are to be employedin drawing the carriages up the inclined plane from Euston Square, bya rope upwards of a mile in length, the cost of which was upwards of£400. " After describing the next change of engines, in the same matterof course way as the changing of stage-coach horses, the narrativeproceeds to say that "entering the tunnel from broad daylight to perfectdarkness has an exceedingly novel effect. "

I make these parallel quotations for the benefit of those who imaginethat electricity is making such vastly greater strides than othersources of power. I well remember making this journey to Boxmoor, andfour or five years later traveling on a circular electro-magneticrailway. Comparing that electric railway with those now exhibiting, and comparing the Boxmoor trip with the present work of the London andNorth-Western Railway, I have no hesitation in affirming that the rateof progress in electro-locomotion during the last forty years has beenfar smaller than that of steam. 

The leading fallacy which is urging the electro-maniacs of the presenttime to their ruinous investments is the idea that electro-motorsare novelties, and that electric-lighting is in its infancy; whilegas-lighting is regarded as an old, or mature middle-aged business, and therefore we are to expect a marvelous growth of the infant and nofurther progress of the adult. 

These excited speculators do not appear to be aware of the fact thatelectric-lighting is older than gas-lighting; that Sir Humphry Davyexhibited the electric light in Albemarle Street, while London was stilldimly lighted by oil-lamps, and long before gas-lighting was attemptedanywhere. The lamp used by Sir Humphry Davy at the Royal Institution, atthe beginning of the present century, was an arrangement of twocarbon pencils, between which was formed the "electric arc" by theintensely-vivid incandescence and combustion of the particles of carbonpassing between the solid carbon electrodes. The light exhibited by Davywas incomparably more brilliant than anything that has been lately showneither in London, or Paris, or at Sydenham. His arc was _four inchesin length_, the carbon pencils were four inches apart, and a broad, dazzling arch of light bridged the whole space between. The modern arclights are but pygmies, mere specks, compared with this; a leap of 1/3or 1/4 inch constituting their maximum achievement. 

Comparing the actual progress of gas and electric lighting, the gas hasachieved by far the greater strides; and this is the case even when wecompare very recent progress. 

The improvements connected with gas-making have been steadilyprogressive; scarcely a year has passed from the date of Murdoch'sefforts to the present time, without some or many decided steps havingbeen made. The progress of electric-lighting has been a series ofspasmodic leaps, backward as well as forward. 

As an example of stepping backward, I may refer to what the newspapershave described as the "discoveries" of Mr. Edison, or the use of anincandescent wire, or stick, or sheet of platinum, or platino-iridium;or a thread of carbon, of which the "Swan" and other modern lights arerival modifications. 

As far back as 1846 I was engaged in making apparatus and experimentsfor the purpose of turning to practical account "King's patent electriclight, " the actual inventor of which was a young American, named Starr, who died in 1847, when about 25 years of age, a victim of overworkand disappointment in his efforts to perfect this invention and amagneto-electric machine, intended to supply the power in accordancewith some of the "latest improvements" of 1881 and 1882. 

I had a share in this venture, and was very enthusiastic until after Ihad become practically acquainted with the subject. We had no difficultyin obtaining a splendid and perfectly steady light, better than any thatare shown at the Crystal Palace. 

We used platinum, and alloys of platinum and iridium, abandoned them asEdison did more than thirty years later, and then tried a multitude offorms of carbon, including that which constitutes the last "discovery"of Mr. Edison, viz. , burnt cane. Starr tried this on theoreticalgrounds, because cane being coated with silica, he predicted that bycharring it we should obtain a more compact stick or thread, as thefusion of the silica would hold the carbon particles together. Hefinally abandoned this and all the rest in favor of the hard deposit ofcarbon which lines the inside of gas-retorts, some specimens of which wefound to be so hard that we required a lapidary's wheel to cut them intothe thin sticks. 

Our final wick was a piece of this of square section, and about 1/8 ofan inch across each way. It was mounted between two forceps--one holdingeach end, and thus leaving a clear half-inch between. The forceps weresoldered to platinum wires, one of which passed upward through the topof the barometer tube, expanded into a lamp glass at its upper part. This wire was sealed to the glass as it passed through. The lower wirepassed down the middle of the tube. 

The tube was filled with mercury and inverted over a cup of mercury. Being 30 inches long up to the bottom of the expanded portion, or lampglobe, the mercury fell below this and left a Torricellian vacuum there. One pole of the battery, or dynamo-machine, was connected with themercury in the cup, and the other with the upper wire. The stick ofcarbon glowed brilliantly, and with perfect steadiness. 

I subsequently exhibited this apparatus in the Town-hall of Birmingham, and many times at the Midland Institute. The only scientific difficultyconnected with this arrangement was that due to a slight volatilizationof the carbon, and its deposition as a brown film upon the lamp glass;but this difficulty is not insuperable. --_Knowledge_. 

 * * * * *

ACTION OF MAGNETS UPON THE VOLTAIC ARC. 

The action of magnets upon the voltaic arc has been known for a longtime past. Davy even succeeded in influencing the latter powerfullyenough in this way to divide it, and since his time Messrs. Grove andQuet have studied the effect under different conditions. In 1859, Imyself undertook numerous researches on this subject, and experimentedon the induction spark of the Ruhmkorff coil, the results of theseresearches having been published in the last two editions of my notes onthe Ruhmkorff apparatus. 

[Illustration: FIG. 1]

These researches were summed up in the journal _La Lumière Electrique_for June 15, 1879. Recently, Mr. Pilleux has addressed to us some newexperiments on the same subject, made on the voltaic arc produced by aDe Meritens alternating current machine. Naturally, he has found thesame phenomena that I had made known; but he thinks that these newresearches are worthy of interest by reason of the nature of the arc inwhich he experimented, and which, according to him, is of a differentnature from all those on which, up to the present time, experiments havebeen made. Such a distinction as this, however, merits a discussion. 

With the induction spark, magnets have an action only on the aureolawhich accompanies the line of fire of the static discharge; and thisaureola, being only a sort of sheath of heated air containing manyparticles of metal derived from the rheophores, represents exactly thevoltaic arc. 

[Illustration: FIG. 2]

Moreover, although the induced currents developed in the bobbin arealternately of opposite direction, the galvanometer shows that thecurrents that traverse the break are of the same direction, and thatthese are direct ones. The reversed currents are, then, arrested duringtheir passage; and, in order to collect them, it becomes necessary toconsiderably diminish the gaseous pressure of the aeriform conductorinterposed in the discharge; to increase its conductivity; or to open tothe current a very resistant metallic derivation. By this latter means, I have succeeded in isolating, one from the other, in two differentcircuits, the direct induced currents and the reversed induced ones. As only direct currents can, in air at a normal pressure, traversethe break through which the induction spark passes, the aureola thatsurrounds it may be considered as being exactly in the same conditionsas a voltaic arc, and, consequently, as representing an extensibleconductor traversed by a current flowing in a definite direction. Sucha conductor is consequently susceptible of being influenced by all theexternal reactions that can be exerted upon a current; only, by reasonof its mobility, the conductor may possibly give way to the actionexerted upon the current traversing it, and undergo deformations thatare in relation with the laws of Ampère. It is in this manner that Ihave explained the different forms that the aureola of the inductionspark assumes when it is submitted to the action of a magnet in thedirection of its axial line, or in that of its equatorial line, orperpendicular to these latter, or upon the magnetic poles themselves. 

Experiments of a very definite kind have not yet been made as to thenature of the arc produced by induced currents developed in alternatingcurrent machines; but, from the experiments made with electric candles, we are forced to admit that the current reacts as if it were alternatelyreversed through the arc, since the carbons are used up to an equaldegree; and, moreover, Mr. Pilleux's experiments show that effectsanalogous to those of induction coils are produced by the reaction ofmagnets upon the arc. There is, then, here a doubtful point that itwould be interesting to clear up; and we believe that it is consequentlyproper to introduce in this place Mr. Pilleux's note:

"Having at my disposal, " says he, "a powerful vertical voltaic arc of 12centimeters in length, kept up by alternately reversed currents, and oneof the most powerful permanent magnets that Mr. De Meritens employs formagneto-electric machines, I have been enabled to make the followingexperiments:

"1. When I caused one of the poles of my magnet to slowly approach thevoltaic arc, I ascertained that, at a distance of 10 centimeters, thearc became flattened so as to assume the appearance of those gas jetscalled 'butterfly. ' The plane of the 'butterfly' was parallel with thepole that I presented, or, in other words, with the section of themagnet. At the same time, the arc began to emit a strident noise, whichbecame deafening when the pole of the magnet was brought to within adistance of about 2 millimeters. At this moment, the butterfly formproduced by the arc was _greatly spread out, and reduced to thethickness of a sheet of paper_; and then it burst with violence, andprojected to a distance a great number of particles of incandescentcarbon. 

"2. The magnet employed being a horseshoe one, when I directed itlaterally so as to present successively, now the north and then thesouth pole to the arc, the 'butterfly' pivoted upon itself so as not topresent the same surface to each pole of the magnet. "

By referring to the accompanying figure, which we extract from our noteon the Ruhmkorff apparatus, it will be seen that the aureola whichdeveloped as a circular film from right to left at D, on the north poleof the magnet, N. S. (Fig. 1), projected itself in an opposite directionat C, upon the south pole, S, of the same magnet; but, between the twopoles, these two contrary actions being obliged to unite, they gave risein doing so to a very characteristic helicoid spiral whose directiondepended upon that of the current of discharge through the aureola, or upon the polarity of the magnetic poles. On the contrary, when thedischarge took place in the direction of the equatorial line, as in Fig. 2, the circular film developed itself in the plane of the neutral lineabove or below the line of discharge, according to the direction of thecurrent and the magnetic polarity of the magnet. 

There is, then, between Mr. Pilleux's experiments and my own so great ananalogy that we might draw the deduction therefrom that induced currentsin alternating machines have, like those of the Ruhmkorff coil, adefinite direction, which would be that of currents having the greatesttension, that is to say, that of direct currents. This hypothesis seemsto us the more plausible in that Mr. J. Van Malderem has demonstratedthat the attraction of solenoids with the currents, not straight, of magneto-electric machines is almost as great as that of the samesolenoids with straight currents; and it is very likely that thedifference which may then exist should be so much the less in proportionas the induced currents have more tension. We might, then, perhapsexplain the different effects of the wear of the carbons serving asrheophores, according as the currents are continuous or alternating, bythe different calorific effects produced on these carbons, and by theeffects of electric conveyance which are a consequence of the passage ofthe current through the arc. 

We know that with continuous currents the positive carbon possesses amuch higher temperature than the negative, and that its wear is abouttwice greater than that of the latter. But such greater wear of thepositive carbon is especially due to the fact that combustion is greateron it than on the negative, and also to the fact that the carbonaceousparticles carried along by the current to the positive pole aredeposited in part upon the other pole. Supposing that these polaritiesof the carbons were being constantly alternately reversed, the effectsmight be symmetrical from all quarters, although the only currenttraversing the break were of the same direction; for, admitting that thereverse currents could not traverse the break, they would exist none theless for all that, and they might give rise (as has been demonstratedby Mr. Gaugain with regard to the discharges of the induction sparkintercepted by the insulating plate of a condenser) to return dischargesthrough the generator, which would then have, in the metallic part ofthe circuit, the same direction as the direct currents succeeding, although they had momentarily brought about opposite polarities in theelectrodes. What might make us suppose such an interpretation of thephenomenon to have its _raison d'etre_, is that with the inducedcurrents of the Ruhmkorff coil, it is not the positive pole that isthe hottest, but rather the negative; from whence we might draw thededuction that it is not so much the direction of the current thatdetermines the calorific effect in the electrodes, as the conditions ofsuch current with respect to the generator. I should not besurprised, then, if, in the arc formed by the alternating currents ofmagneto-electric machines, there should pass only one current of thesame direction, and which would be the one formed by the superpositionof direct currents, and if the reverse currents should cause returndischarges in the midst of the generating bobbins at the moment thedirect currents were generated. --_Th. Du Moncel_. 

 * * * * *

VOLCKMAR'S SECONDARY BATTERIES. 

The inventive genius of the country is now directed to these importantaccessories of electric enterprise, and no wonder, for as far as can atpresent be seen, the secret of electric motion lies in these secondarybatteries. Among other contributions of this kind is the following, byErnest Volckmar, electrician, Paris:

The object of this invention is to render unnecessary the use insecondary batteries of a porous pot which creates useless resistanceto the electric current, and to store in an apparatus of comparativelysmall weight and bulk considerable electric force. To this end tworeticulated or perforated plates of lead of similar proportions areprepared, and their interstices are filled with granules or filaments oflead, by preference chemically pure. These plates are then submitted topressure, and placed together, with strips of nonconducting materialinterposed between them, in a suitable vessel containing a bath ofacidulated water. The plates being connected with wires from an electricgenerator are brought for a while under the action of the current, toperoxidize and reduce the whole of the finely divided lead exposed tothe acidulated water. The secondary battery is then complete. It will beunderstood that any number of these pairs of plates may be combined toform a secondary battery, their number being determined by the amountof storage required. The perforated plates of lead may be prepared bydrilling, casting, or in other convenient manner, but the apertures, ofwhatever form, should be placed as closely together as possible, andthe finely divided lead to be peroxidized is pressed into the cells orcavities so as to fill their interiors only. 

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THE MINERALOGICAL LOCALITIES IN AND AROUND NEW YORK CITY, AND THEMINERALS OCCURRING THEREIN. 

By NELSON H. DARTON. 

There will be many persons in the city of New York and its suburbs whowill not have the time or facilities for leaving town during the summer, to spend a part of their time enjoying the country, but would havesufficient time to take occasional recreation for short periods. I havesought by this paper to show a pleasurable, and at the same time veryinstructive use for the time of this latter class, and that is inmineralogy. In the surrounding parts of New York are many mineralogicallocalities, known to no others than a few professional mineralogists, etc. , and from which an excellent assortment of minerals may beobtained, which would well grace a cabinet and afford considerableinstruction and entertainment to their owner and friends, besides actingas an incentive to a further study of this and the other sciences. Theselocalities which I will discuss are all within an hour's ride from NewYork, and the expenses inside of a half dollar, and generally very muchless. I could detail many other places further off, but will reservethat for another paper. 

The course which I will pursue in my explanations I have purposely madevery simple, avoiding--or when using, explaining--all technical terms. The apparatus and tests noticed are of the most rudimentary styleconsistent with that which is necessary to attain the simple purpose ofdistinguishment, and altogether I have prepared this paper for thosehaving at the present time little or no knowledge or practice inmineralogy, while those having it can be led perhaps by the details ofthe localities noticed. Another reason why I have written so in detailof this last subject is, because the experiences of most amateurmineralogists are generally so very discouraging in their endeavors tofind the minerals, and there is everything in giving a good startto properly fix the interest on the subject. The reason of thesediscouragements is simple, and generally because they do not know theportion of the locality, say, for instance, a certain township, in whichthe minerals occur. And if they do succeed in finding this, it is seldomthat the portion in which the mineral occurs, which is generally somesmall inconspicuous vein or fissure, is found; and even in this itis generally difficult to recognize and isolate the mineral from theextraneous matter holding it. As an instance of this I might cite thus:Dana, in his text book on mineralogy, will mention the locality fora certain species, as Bergen Hill--say for this instance, dogtoothcalespar. When we consider that Bergen Hill, in the limited sense of theexpression, is ten miles long and fully one mile wide, and as the rockoutcrops nearly all over it, and it is also covered with quarries, cuttings, etc. , it may be seen that this direction is rather indefinite. To the professional mineralogist it is but an index, however, and hemay consult the authority it is quoted from--the _American Journal ofScience_, etc. --and thus find the part referred to, or by consultingother mineralogists who happen to know. Again, the person having foundby inquiry that the part referred to is the Pennsylvania Railroad, andas this is fully a mile long and interspersed with various prominentlooking, but veins of a mineral of little value, at any rate not the onein question, they are few who could suppose that it occurred in that. Apparently a vein of it would not be noticed at all from the surroundingrock of gravelly earth, but there it is, and in a vein of chlorite. Thisis so throughout the long and more or less complete stated lists ofmineralogical localities. Thus I will, in describing the mineral, afterexplaining the conditions under which it occurs, give almost theexact spot where I have found the same mineral myself, and have leftsufficiently fine specimens to carry away, and thus no time will be lostin going over fruitless ground, and further, this paper is written up tothe date given at its end, insuring a necessary presence of them. 

In order that one not familiar with mineral specimens should not carryoff from the various localities a variety of worthless stones, etc. , which are frequently more or less attractive to an inexperienced eye, the following hints may be salutary. 

There are the varieties of three minerals, which are very commonly metwith in greater or less abundance in mineralogical trips: they are ofcalcite, steatite, and quartz. They occur in so many modifications ofform, color, and condition that one might speedily form a cabinet ofthese, if they were taken when met with, and imagine it to be of greatvalue. The first of these is calcite. It occurs as marble, limestone;calcspar, dogtooth spar, nail head spar, stalactites, and a number ofother forms, which are only valuable when occurring in perfect crystalsor uniquely set upon the rock holding it. The calcspar is extremelyabundant at Bergen Hill, where it might be mistaken for many of theother minerals which I describe as occurring there, and even inpreference to them, to one's great chagrin upon arriving home andtesting it, to find that it is nothing but calcite. In order to avoidthis and distinguish this mineral on the field, it should be tested witha single drop of acid, which on coming in contact with it bubbles up oreffervesces like soda water, seidlitz powder, etc. , while it does not doso with any of the minerals occurring in the same locality. This acidis prepared for use as follows: about twenty drops of muriatic acid areprocured from a druggist in a half-ounce bottle, which is then filled upwith water and kept tightly corked. It is applied by taking a drop outon a wisp of broom or a small minim dropper, which may be obtained atthe druggist's also. I do not say that in every case this mineral shouldbe rejected, because it is frequently very beautiful and worthy of placein a cabinet, but should be kept only under the conditions mentionedfurther on in this paper, under the head of "Calcite in WeehawkenTunnel. "

The next mineral abundant in so many forms is quartz, and is not soreadily distinguished as calcite. It is found of every color, shape, etc. , possible, and that which is found in any of the localities I amabout to describe, with the exception of fine crystals on Staten Island, are of no value and may be rejected, unless answering in detail to thedescription given under Staten Island. The method of distinguishing thequartz is by its hardness, which is generally so great that it cannot bescratched by the point of a knife, or at least with great difficulty, and a fragment of it will scratch glass readily; thus it isdistinguished from the other minerals occurring in the localitiesdiscussed in this paper. 

The other minerals so common are the varieties of steatite. This isespecially so at Bergen Hill and Staten Island. They occur in amorphousmasses generally, and may be distinguished by being so soft as to bereadily cut by the finger nail. I will detail further upon the soapstoneforms in discussing the localities on Staten Island, and the chloriticform under the head of "Weehawken Tunnel. " The surest method of avoidingthese and recognizing the others by their appearance, which is generallythe only guide used by a professional mineralogist, is to copy off thelists of the various minerals I describe, and, by visiting the AmericanMuseum of Natural History on any week day except Mondays and Tuesdays, one may see and become familiar with the minerals they are goingin quest of, besides others in the cases. This method is much moresatisfactory than printed descriptions, and saves the labor of many ofthe distinguishing manipulations I am about to describe, besides savingthe trouble of bringing inferior specimens of the minerals home. 

In going forth on a trip one should be provided with a mineralogicalhammer, or one answering its purpose, and a cold chisel with which todetach or trim the minerals from adhering rocks, the bottle of acidbefore referred to, and a three cornered file for testing hardness, as explained further on. As I noticed before, the better plan ofdistinguishing a mineral is by being familiar with its appearance, butas this is generally impracticable, I will detail the modes used inlieu of this to be applied on bringing the minerals home. Thesedistinguishments depend on difference in specific gravity, hardness, solubility in hot acids, and the action of high heat. I will explain theapplication of each one separately, commencing with--

_The Specific Gravity_. --In ascertaining the specific gravity thefollowing apparatus is necessary: a small pair of hand scales with a setof weights, from one grain to one ounce. These can be procured from theapparatus maker, the scales for about fifty cents, and the weights fornot much over the same amount. The scales are prepared for this work bycutting two small holes in one of the scale pans, near together, witha pointed piece of metal, and tying a piece of silk thread about eightinches long into these. In a loop at the end of this thread the mineralto be examined is suspended. It should be a pure representative of themineral it is taken from, should weigh about from one hundred grains toan ounce, and be quite dry and free from dirt. If the piece of mineralobtained is very large, this sized portion may be often taken from itwithout injury; but it will not do to mar the beauty of a mineral toascertain its specific gravity, and it is generally only applicablewhen a small piece is at hand. With more weights, however, a piece of aquarter pound weight may be taken if necessary. The mineral is tied intothe loop and weighed, the weight being set down in the note book, eitherin grains or decimal parts of an ounce. Call this result A. It is thenweighed in some water held in a vessel containing about a quart, takingcare while weighing it that it is entirely immersed, but at the sametime does not touch either the sides or bottom. Both weighings shouldbe accurate to a grain. This result we call B. The specific gravity isfound by subtracting B from A, and dividing A by the remainder. Forinstance, if the mineral weighed eight hundred grains when weighed inthe air, and in the water six hundred, giving us the equation: 800/ (800 - 600) = sp. Gr. , or 4, which is the specific gravity ofthe mineral. If the mineral whose specific gravity is sought is anincrustation on a rock, or a mixture of a number of minerals, or wouldbreak to pieces in the water, the specific gravity is by this method ofcourse unattainable, and other data must be used. 

_The Comparative Hardness_. --The next characteristic of the mineral tobe ascertained is the comparative hardness. In mineralogy there is ascale fixed for comparison, from 1 to 10, 10 being the hardest, thediamond, and Number 1 the soft soapstone. These and the intermediateminerals fixed upon the scale are generally inaccessible to those whomay use the contents of this paper, and I will give some more familiarmaterials for comparison. 8, 9, and 10 are the topaz, sapphire, anddiamond respectively, and as these and minerals of similar hardness willprobably not be found in any of the localities of which I make mention, we need not become accustomed to them for the present. 7 is ofsufficient hardness to scratch glass, and is also not to be cut with thefile before mentioned, which is used for these determinations. 6 isof the hardness of ordinary French glass. 5 is about the hardness ofhorse-shoe or similar iron; 4 of the brown stone (sandstone) of whichthe fronts of many city buildings, etc. , are built; 3 of marble; 2 ofalabaster; and 1 as French chalk, or so soft as to be readily cut withthe finger nail. The method of using and applying these comparisons isby having the above matters at hand, and compare them by the relativeease with which they can be cut by running the edge of the file overtheir surface. One will soon become familiar with the scale, and itmay of course then be discarded. As it is one of the most importantcharacteristics of some of the minerals, it should be carefullyexecuted, and the result carefully considered. It is of courseinapplicable under those conditions with minerals that are in very smallcrystals or in a fibrous condition. 

_Action of Hot Acids_. --This very important test is never, like theabove, applicable upon the field, but applied when home is reached. From the body of the mineral as pure and clean as possible a portion ischipped, about the size of a small pea; this is wrapped in a piece ofstiff wrapping paper, and after placing it in contact with a solid body, crushed finally by a blow from the hammer. A pinch of the powder soobtained is taken up on the point of a penknife, and transferred intoa test tube. Two or more of these should be provided, about six incheslong. They may be obtained in the apparatus shop for a trifle. Somehydrochloric, or, as it is generally called, muriatic acid, is pouredupon it to the depth of about three quarters of an inch; the tube isthen placed in some boiling water heated over a lamp in a tinned orother vessel, and allowed to boil for from ten to fifteen minutes;the tube is then removed and its contents allowed to cool, and thenexamined. If the powder has all disappeared, we term the mineral"soluble;" if more or less is dissolved, "partly soluble;" if none, "insoluble;" and if the contents of the tube are of a solid transparentmass like jelly, "gelatinous;" while if transparent gelatinous flakesare left, it is so termed. As this method of distinguishment is alwaysapplicable, it is very important, and its detail and result should becarefully noticed. Care should be taken that only a small portion ofthe mineral is used, and also but little acid; the action should beobserved, and is frequently a characteristic, in the case with calcspar, which effervesces while dissolving. The acid used is hydrochloric atfirst, and then, if the mineral cannot he recognized, the same treatmentmay be repeated using nitric acid. Both of these acids should be at handand two ounces are generally sufficient. 

_Action of Heat_. --This is, perhaps, the most important characteristic, and, when taken with the preceding data, will identify any of theminerals found in any one locality, which I will describe, from eachother. The heat is applied to the mineral by means of a candle andblowpipe. A thick wax candle answers well, and an ordinary japanned tinblowpipe, costing twenty cents, will serve the purpose. The substanceto be examined is held on a loop of platinum wire about one inch to theleft and just below the top of the wick, which is bent toward it. Hereit is steadily held, as is shown in Fig. 1, and the flame of the candlebent over upon it, and the heat intensified by blowing a steady andstrong current of air across it by means of the blowpipe held in themouth and supported by the right hand, whose elbow is resting upon thetable. The current of air is difficult to keep up by one unaccustomed tothe blowpipe, the skill of using which is readily obtained; it consistsin breathing through the nostrils, while the air is forced out bypressure on the air held by the inflated cheeks, and not from the lungs. This can be practiced while not using the blow-pipe, and may readilybe accomplished by one's keeping his cheeks distended with air andbreathing at the same time. 

This heat is steadily applied until the splinter of mineral has beenkept at a high red heat for a sufficient length of time to convince oneof what it may do, as fuse or not, or on the edges. The first twoare evident, as when it fuses it runs into a globule; the last, byinspecting it before and after the heating with a magnifying glass;sometimes it froths up when heated, and is then said to "intumesce;" or, if it flies to fragments, "decrepitates. " Upon the first it is furtherheated; but in the latter case, a new splinter of mineral must be brokenoff from the mass and heated upon the wire very cautiously until quitehot, when it may then be readily heated further without fear of loss. For holding the splinter of mineral, which should well represent themass and be quite small, is a three-inch length of platinum wire of thethickness of a cambric-needle; this may be bought for about ten cents atthe apparatus shop. The ends should be looped, as is shown in Fig. 2, and the mineral placed in the loop. 

Sometimes a mineral has to be fused with borax, as I mention furtheron in my tables. This is done by heating the wire-loop to redness, andplunging it into some borax; what adheres is fused upon it by heating. Some more is accumulated in the same manner, until the loop is filledwith a fair-sized globule. A small quantity of the mineral, which hadbeen crushed as for the acid test, is caused to adhere to it while it ismolten, and then the heat of the blast directed upon it for some timeuntil either the small fragments of mineral dissolve, or positivelyrefuse to do so. After cooling, the aspect of the globule is noticed asto color, transparency, etc. Care must be taken that too large an amountof the mineral is not taken, a very minute amount being sufficient. 

I trust by the use of these distinguishing reactions one will be ableto recognize by the tables to be given the name of the mineral in hand, especially as they are from certain parts, where all the mineralsoccurring therein are known to us; and I have worded the characteristicsso that they will serve to isolate from all that possibly could be foundin that locality. 

The first general locality is Bergen Hill, New Jersey. This comprisesthe range of bluffs of trap rock commencing at Bergen Point and runningup behind Jersey City and Hoboken, etc. , to the part opposite aboutThirtieth Street, New York, where it comes close to the river, and fromthere along the river to the north for a long distance, known as thePalisades. It is about a mile wide on an average, and from a few feet toabout two hundred feet in height. The mineralogical localities in andupon it are at the following parts, commencing at the south: FirstPennsylvania Railroad cuts where the mining operations are just aboutcompleted; then the Erie Tunnel, in which the specimens that first madeBergen Hill noted as a mineralogical locality, and whose equals have notsince been procured, were found, but which is now inaccessible to thegeneral public. Further north is the Morris and Essex Tunnel, in whichmany fine specimens were secured, and is also inaccessible; and last, but far from being least, is the Ontario Tunnel at Weehawken; and, asit is the only practicable part besides the Pennsylvania Railroad and anumber of surface outcrops which I will mention, I will commence withthat. 

_The Weehawken Tunnel_--This tunnel is now being cut through thetrap-rock for the New York, Ontario, and Western Railroad, and willbe completed in a few months, but will, probably, be available as amineralogical locality for a year to come. It is located about half amile south of the Weehawken Ferry from Forty-second Street, New Yorkcity, and the place where to climb upon the hill to get to the shaftsleading to it is made prominent by the large body of light-colored rockon the dump, a few rods north of where the east entrance is to be. Thewestern end is in the village of New Durham, on the New Jersey NorthernRailroad, and recognized by the immense earth excavations. A pass isnecessary to gain admittance down the shafts, and this can be procuredfrom the office of the company, between the third and fourth shafts tothe tunnel, in the grocery and provision store just to the north ofthe tramway connecting the shafts on the surface. As it will not benecessary to go down in any of the shafts besides the first and secondin order to fulfill the objects of this paper, no difficulty need beencountered in procuring the pass if this is stated. 

These two shafts are about eight hundred feet apart and one hundred andseventy feet deep. A platform elevator is the mode of access to thetunneled portion below, and a free shower-bath is included in thedescent; consequently, a rubber-coat and water tight boots arenecessary. A pair of overalls should be worn if one is to engage inany active exploration below; candles should also be provided, as theelectric lights, at the face of the headings, give but little light, andremind one very forcibly of a dim flash light with a foliaged tree infront of it. The electric wires for supplying these arrangements runalong the north side of the tunnel for those on the east headings, andon the south side for the west. They are excellent things to keep clearof, as they have sufficient current passing through them to knock onedown; thus their position can be readily ascertained. 

_Modes of Occurrence of the Minerals_. --In general, the greater numberof the specimens which are to be found in the tunnel occur in veinsgenerally perpendicular, and with other minerals of little or no value, as calcite, chlorite, and imperfect crystals of the same mineral. Afew occur in nodules inclosed in the solid body of rock, and in whichcondition they are seldom of value. The greater abundance are in theveins of the dark-green soft chlorite, and some few in horizontal beds. The minerals are found in the first condition by examining all the veinsrunning from floor to ceiling of the tunnel. The ores of calcite firstmentioned are very conspicuous, they being white in the dense blackrock. They may be chipped from, as there are about thirty or forty ofthem exposed in each shaft, and the character of the minerals examinedto see if anything but calcite is in it. This is ascertained by a dropof acid, as explained before, and by the descriptions given further on. The veins of chlorite are not so conspicuous, being of a dark-greencolor; but by probing along the walls with a stick or hammer, they maybe recognized by their softness, or by its dull glistening appearance. They are comparatively few, but from an inch to three feet wide; andminerals are found by digging it out with a stick or a three-foot drill, to be had at the headings. Where the most minerals occur in the chloriteis when plenty of veins of calcite are in its vicinity, and its edgesnear the trap are dry and crumbly. It is here where the minerals arefound in this crumbly chlorite, and generally in geodes--that is, thefaces of the minerals all point inward, formerly a spherical mass--roughand uncouth on the outside, and from half an inch to nearly a foot indiameter. These are valuable finds, and well worth digging for. The bedsof minerals generally are of but one species, and will be mentionedunder the head of the minerals occurring in them. Besides, in the tunnelthere are generally more or less perfect minerals upon the main dumpover the edge of the bluff toward the river. Here many specimens thathave escaped the eyes of the miners may be found among the loose rock, being constantly strewn out by the incline of the bed; in fact, this isthe only place in which quite a number of the incident minerals may befound; but I will not linger longer on this, as I shall refer to itunder the minerals individually. 

The minerals occurring at the tunnel are as follows, with theirdescriptions and locations in the order of their greatest abundance:

_Calcite_. --This mineral occurs in great abundance in and about thetunnel, and from all the shafts. There are two forms occurring there, the most abundant of which is the rhombohedral, after Fig. 3. It cangenerally be obtained, however, in excellent crystals, which, althoughperfect in form, are opaque, but often large and beautiful. It is alwayspacked with a thousand or its multiple of other crystals into veins of afew inches thick; and crystals are obtained by carefully breaking withedge of the cold chisel these masses down to the fundamental form shown. As the masses are never secured by the miners, they can always be pickedfrom the piles of _débris_ around the shafts and the dumps, and affordsome little instruction as to the manner in which a mineral is built upby crystallization, and may be subdivided by cleavage to a crystal ofthe same shape exactly, but infinitesimally small. A crystal to be worthpreserving should be about an inch in diameter, and as transparent as isattainable. 

Another form of calcite which is to be sparingly found is what is calleddogtooth spar, having the form shown in Fig. 4. They occur in clearwine-yellow-colored crystals, from a quarter to half an inch in length;they occur in the chlorite in geodes of variable sizes, but generallytwo and a half inches in diameter, and which, when carefully broken inhalf, showed beautiful grottoes of these crystals. The few of these thatI have found were in the four-foot vein of chlorite down the Shaft No. 1, to the west of the shaft about one hundred and fifty feet, and onthe south wall; it may be readily found by probing for it, and then thegeodes by digging in. There need be no difficulty in finding this veinif these conditions are carefully considered, or if one of the minersbe asked as to the soft vein. Both these forms of calcite may bedistinguished from the other minerals by first effervescing on comingin contact with the acids; second, by glowing with an intense (almostunbearably so) light when heated with the blowpipe, but not fusing. Their specific gravity is 2. 6, or near it, and hardness about 3, orequal to ordinary unpolished white marble. 

_Natrolite_. --The finest specimens of this mineral that have ever beenfound in Bergen Hill were taken from a bed of it in this tunnel, havingin its original form, before it was cut out by the tunnel passingthrough, over one hundred square feet, and from one-half to two and ahalf and even three inches in thickness; it was in all possible shapesand forms--all extremely rare and beautiful. A large part of one endof this bed still remains, and, by careful cutting, fine masses may beobtained. This bed may be readily found; it is nearly horizontal, and inits center about four feet from the floor of the tunnel, and about halfan inch thick. It is down Shaft No. 2, on the north wall, and commencesabout eighty feet from the shaft. It is cut into in some places, butthere is plenty more left, and can be obtained by cutting the rockabove it and easing it out by means of the blade of a knife or similarinstrument. This natrolite is a grouping of very small but perfectcrystals, having the forms shown in Fig. 5; they are from a quarter toan inch long, and, if not perfectly transparent, are of a pure whitecolor; they may be readily recognized by their form, and occurring inthis bed. Its hardness, which is seldom to be ascertained owing to thedelicacy of the crystals, is about 5, and the specific gravity 2. 2. This is readily found, but is no distinction; its reaction before theblowpipe, however, is characteristic, it readily fusing to a transparentglobule, clear and glassy, and by forming a jelly when heated withacids. The bed holding the upright crystals is also natrolite inconfused matted masses. This mineral has also been found in other partsof the shaft, but only in small druses. There is a prospect at presentthat another bed will be uncovered soon, and some more fine specimens tobe easily obtained. 

_Pectolite_, or as it is termed by the miners, "silky spar. "--Thismineral is quite abundant and in fine masses, not of the great beautyand size of those taken from the Erie Tunnel, but still of greatuniqueness. The mineral is recognized by its peculiar appearance, asis shown in Fig. 6, where it may be seen that it is in groups offine delicate fibers about an inch long, diverging from a point intofan-shaped groups. The fibers are very tightly packed together, as arealso the groups; they are very tough individually, and have a hardnessof 4, and a specific gravity of about 2. 5. It gelatinizes on boilingwith acid, and a fragment may be readily fused in the blowpipe flame, yielding a transparent globule. The appearance is the most strikingcharacteristic, and at once distinguishes this mineral from any of theothers occurring in this locality. Considerable quantities of pectolitemay generally be found on the dump, but also in Shaft No. 1, andespecially No. 2. The veins of it are difficult to distinguish from thecalcite, as they are almost identical in color, and many of the calciteveins are partly of pectolite--in fact, every third or fourth vein willcontain more or less of it. There is, however, a very fine vein ofpectolite about twenty-five feet further east from the natrolite bed; itruns from the floor to ceiling, and is about two inches in thickness;some specimens of which I took from these were unusually unique in bothsize and appearance. It makes a very handsome specimen for the cabinet, and should be carefully trimmed to show the characteristics of themineral. 

_Datholite_. --This mineral has been found very frequently in the tunnel, it occurring in pockets in the softer trap near the chlorite, and alsoin the latter, generally at a depth of one hundred and fifty feet fromthe surface, and consequently near the ceiling of the tunnel. All thathas been found of any great beauty has been in the western end of theShaft No. 1 and the eastern of Shaft No. 2, where the trap is quitesoft; here it is found nearly every day in greater or less quantity, andfrom this some may generally be found on the dump, or, in the veinof chlorite which I mentioned as a locality for the dogtooth spar, considerable may be obtained in it and on its western edge near theceiling. A ladder about thirteen feet long is used for attending thelights, and may generally be borrowed, and access to the remainderof this pocket thus gained. Datholite is also very characteristic inappearance, and can only be confounded with some forms of calciteoccurring near it. It occurs in small glassy, nearly globular crystals;they are generally not over three-sixteenths of an inch in diameter, andgenerally pure and perfectly transparent, having a hardness of a littleover 5, and specific gravity of 3; as it generally occurs as a druseupon the trap, or an apopholite, calcite, etc. , this is seldomattainable, however, and we have a very distinctive characteristic inanother test: this is the blowpipe, under which it at first intumescesand then fuses to a transparent globule, and the flame, after playingupon it, is of a deep green color. Nitric acid must be used to boil itup with, and with it it may be readily gelatinized. This last test willseldom be necessary, however, and may be dispensed with if the hardnessand blowpipe reactions may be ascertained. 

_Apopholite_. --This beautiful mineral has been found in fair abundanceat times in Shafts No. 1 and 2 in pockets, and seldom in place, most ofit being taken from the loose stone at the mouth of the shaft, and itmay generally be found on the dump. It is readily mistaken for calciteby the miners and those unskilled in mineralogy, but a drop of acid willquickly show the difference. The sizes of the crystals are very various, from an eighth of an inch long or thick, to, in one case, an inch anda half. The colors have been varied from white to nearly all tints, including pink, purple, blue, and green; the white variety is, however, the most abundant, and makes a handsome cabinet specimen. The crystalsare generally packed together in a mass, but are frequently set apart asheavy druses of crystals having the form shown in Fig. 7. Sometimes, as in the former grouping, the crystals are without the pyramidalterminations, and are then right square prisms. The fracture being atperfect right angles, distinguishes it from calcite. Its hardness isgenerally fully 5, the specific gravity between 2. 4 and 2. 5; it isdifficult to fuse before the blowpipe, but is finally fused into anopaque globule. Upon heating with nitric acid it partly dissolves, andthe remainder becomes flaky and gelatinous. Apopholite, although quiterare, now may be bought from the men, or at least one of the engineersof Shaft No. 2's elevator, and generally at low terms. 

_Phrenite_. --This mineral is quite abundant in Shafts No. 1 and 2, invery small masses, incrustations, and even in small crystals. Itoccurs embedded in or incrusting the trap, and also with calcite andapopholite. The only sure place to find it is at the southwest side ofan opening through the pile of drift rock under the trestle work of thetramway, between shaft No. 1 and the dump, and within a few feet of anumber of wooden vats sunk into the ground seen just before descendingthe hills and near the edge. Here on a number of blocks of trap it maybe found, a greenish white incrustation about as thick as a knife blade;it also may be found on the main dump, and is sometimes found in platesone-eighth of an inch thick, of a darker green color, upon calcite. Itseasiest distinguishment from the other minerals of this locality, withwhich it might be confounded, is its great hardness of from 6 to 7. It is very fragile and brittle, however, and is never perfectlytransparent, but quite opaque; its specific gravity is 2. 9, and it isreadily fused before the blowpipe after intumescing. It partly dissolvesin acid without gelatinizing, leaving a flaky residue; it is a beautifulmineral when in masses or crystals of a dark green color, but the bestplace in the vicinity to secure specimens of this kind is, as I willdetail hereafter, at Paterson, N. J. 

_Iron and Copper Pyrites_. --Both of these common but frequentlybeautiful minerals occur in the tunnel and adjacent rocks in greatabundance. The crystals are generally about one-fourth of an inch indiameter, and groups of these may be frequently obtained on the dump inthe shafts, especially No. 1 and 2, and where the rock is being clearedaway for the eastern entrance to the tunnel. They resemble each othervery much; the iron pyrites, however, is in cubical forms and having thegreat hardness of from 6 to 7, while the copper pyrites, less abundantand in forms having triangles for bases, but having sometimes otherforms and a hardness of but 3 to 4. Both are similar in aspect to apiece of brass, and cannot be mistaken for any other mineral. The formof the copper pyrites is shown in Fig. 8; the iron is, as before noted, in cubes, more or less modified. 

_Stilbite_. --Small quantities of this beautiful mineral have been foundin Shaft No. 2, in a small bed of but a few square feet in area, butquite thick and appearing much like natrolite. This bed was about onehundred feet east from Shaft No. 2, and in the center of the headingwhen it was at that point. It has been encountered since in smallquantities, and it would do well to look out for it in the freshtunneled portion after the date appended to this paper. It generallyoccurs in the form shown in Fig. 9, grouped very similarly to natrolite, and being right upon the rock or a thin bed of itself. The crystals aregenerally half an inch long, but often less. The modifications of theabove form, which are frequent in this species, strike one forcibly ofthe resemblance they bear to a broad stone spear head on a diminutivescale, with a blunted edge; their hardness is about 4, specific gravity2. 2, the color generally a pearly white or grayish. After a longboiling with nitric acid it gelatinizes, but it foams up and fuses to atransparent glass before the blowpipe. A little stilbite may often befound on the dumps. 

_Laumonite_ occurs in very small quantities on calcite or apopholite, and can hardly be expected to be found on the trip; but as it might befound, I will detail some of its characteristics. Hardness 4, specificgravity 2. 3; it generally occurs in small crystals, but more frequentlyin a crumbly, chalky mass, which it becomes upon exposure to the air. The crystals are generally transparent and frequently tinged yellow incolor. It gelatinizes by boiling with acid, and after intumescing beforethe blowpipe, fuses to a frothy mass. To keep this mineral when incrystals from crumbling upon exposure it may be dipped in a thin masticvarnish or in a gum-arabic solution. 

_Heulandite_. --This rare mineral has been found under the sameconditions as laumonite in Shaft No. 2, but it is seldom to be met with, and then in small crystals. It is of a pure white color, sometimestransparent. It intumesces and readily fuses before the blowpipe, anddissolves in acid without gelatinizing. Hardness 4, specific gravity2. 2. 

The few other minerals occurring in the tunnel are so extremly rare asnot to be met with by any other than an expert, and it is impossibleto detail the localities, as they generally occur as minute druses orincrustations upon other minerals with which they may be confounded, andhave been removed as soon as discovered. The minerals referred to areanalcime, chabazite, Thompsonite, and finally, the mineral which I firstfound in this formation, Hayesine, which is extremely rare, and of whichI only obtained sufficient to cover a square inch. The particulars inregard to its locality, etc. , maybe found in the _American Journal ofSciences_ for June, page 458. I will now sum up the characteristics ofthese several minerals of this locality in the table:

------------------------------------------------------------------------------- | | | | | | Name. | H. |Sp. |Action of |Action of |Color. |Appearance. | |Gr. |Blowpipe. |hot acid. | |----------+-----+---+-----------------+-----------------+------+--------------- | | | | | |Calcite | 3 |2. 6|Infusible, |Soluble with |White |Like Fig. | | |but glows |effervescence | |3 and 4. | | | | | |Natrolite | 5 |2. 2|Readily fused |Forms a jelly | do. |Like Fig 5. | | |to clear globule | | | | | | | | |Pectolite | 4 |2. 5| do. | do. Do. | do. |Divergent | | | | | |fibers, Fig. 6. | | | | | |Datholite | 5 |3. 0|Intumesces, fused|Forms a jelly |Color-|Small, nearly | | |to clear globule, | |less |spherical, etc. | | |gives green flame| |white | | | | | | |Apopholite| 5 |2. 5|Difficult, fused |Partly soluble |Tinted|Like Fig. 7. | | |to opaque globule|in nitric acid | | | | | | | |Phrenite | 6 |2. 9|Intomesces, fused|Partly soluble |Green-|In tables and |to 7 | |to clear globule |in nitric acid, |ish |incrustations. | | | |leaving flakes | | | | | | | |Iron | 6 |5. 0|Burns and yields | |Brass |Cubical. Pyrites |to 7 | |a black globule, | | | | | |decrepitates | | | | | | | | |Copper | 3 |4. 2| do. Do. | | do. |Tetrahedronal. Pyrites |to 4 | | | | | | | | | | |Stilbite | 4 |2. 2|Intumesces and |Difficult; jelly |White |Like Fig. 8. | | |fuses readily |on long boiling | | | | | |with nitric acid. | | | | | | | |Laumonite | 4 |2. 3|Intumesces and |Readily | do. |Generally |to 0 | |fuses to frothy |gelatinizes | |chalky. | | |mass | | | | | | | | |Heulandite| 4 |2. 2|Intumesces and |Soluble, no | do. |In right | | |readily fuses |jelly | |rhomboidal | | | | | |prisms. | | | | | |-------------------------------------------------------------------------------

_To Distinguish the Minerals together the one from the other_. --Calciteby effervescing on placing a drop of acid upon it. Natrolite resemblesstilbite, but may be distinguished by gelatinizing readily withhydrochloric acid and by not intumescing when heated before theblowpipe; from the other minerals by the form of the crystals and theirsetting, also the locality in the tunnel in which it was found. 

Pectolite sometimes resembles some of the others, but may be readilydistinguished by its _tough_ long fibers, not brittle like natrolite. Datholite may generally be distinguished by the form of its crystals andtheir glassy appearance, with great hardness, and by tingeing the flamefrom the blowpipe of a true green color. Apopholite is distinguishedfrom calcite, as noticed under that species, and from the others by itsform, difficult fusibility, and part solubility. 

Phrenite is characterized by its hardness, greenish color, occurrence, and action of acid. Iron pyrites is always known by its brassy metallicaspect and great hardness. Copper pyrites, by its aspect from the otherminerals, and from iron pyrites by its inferior hardness and lessgravity. 

Stilbite is characterized by its form, difficult gelatinizing, andintumescence before the blowpipe; from natrolite as mentioned under thatspecies. 

Laumonite is known by its generally chalky appearance and a probablefailure in finding it. 

Heulandite is distinguished from stilbite by its crystals and perfectsolubility; from apopholite by form of crystals. 

In the next part of this paper I will commence with Staten Island. 

July 1, 1882. (_To be continued_. )

 * * * * *

ANTISEPTICS. 

The author has endeavored to ascertain what agents are able to destroythe spores of bacilli, how they behave toward the microphytes mosteasily destroyed, such as the moulds, ferments, and micrococci, and ifthey suffice at least to arrest the development of these organisms inliquids favorable to their multiplication. His results with phenol, thymol, and salicylic acid have been unfavorable. Sulphurous acidand zinc chloride also failed to destroy all the germs of infection. Chlorine, bromine, and mercuric chloride gave the best results;solutions of mercuric chloride, nitrate, or sulphate diluted to 1 partin 1, 000 destroy spores in ten minutes. --_R. Koch_. 

 * * * * *

CRYSTALLIZATION AND ITS EFFECTS UPON IRON. 

By N. B. WOOD, Member of the Civil Engineers' Club, of Cleveland. 

[Footnote: Read January 10th. 1882. ]

The question has been asked, "What is the chemically scientificdefinition of crystallization?" Now as the study of crystallization andits effect upon matter, physically as well as chemically, will be ofinterest, considering the subject matter for discussion, I shall notonly endeavor to answer the question, as I understand it, but try totreat it somewhat technologically. 

Having this object in view, I have prepared or brought about theconditions necessary to the formation of a few crystals of variouschemical substances, which for various reasons, such as lack of time andbad weather, are not as perfect as could be desired, but will perhapssubserve the purpose for which they were designed. I think you willagree with me that they are beautiful, if they are imperfect, and I canassure you that the pleasure of watching their formation fully repaysone for the trouble, if for no other reason than the mere gratificationof the senses. From the earliest times and by all races of men, thecrystal has been admired and imitated, or improved by cutting andpolishing into faces of various substances. I have also procuredspecimens of steel and iron which show the effect of crystallization, which was produced (perhaps) under known conditions, so that theconclusions which we arrive at from their study will have a fair chanceof being logical, at least, and perhaps of some practical value. 

When we examine inanimate nature we find two grand divisions of matter, _fluid_ and _solid_. These two divisions may be subdivided into, theformer gaseous and liquid, the latter amorphous and crystalline; butwhether one or the other of these divisions be considered, theirultimate and common division will be the ATOM. By the atom we understandthat portion of matter which admits of no further division, which, though as inconceivable for minuteness as space is for extent, has stilldefinite weight, form, and volume; which under favorable circumstances, has that power or force called cohesion, the intensity of whichconstitutes strength of material, which every engineer is supposed tounderstand, but which lies far beyond the powers of the human mind forcomprehension or analysis. When we apply a magnet to a mass of ironfilings, we observe the particles arrange themselves in regular order, having considerable strength in one direction, and very little or nonein any other. Now, although we understand very little about the forcewhich holds these particles in position, we do know that it is actualforce applied from without and maintained at the expense of some of theknown sources of force. But the force or power or property of cohesionseems to be a quality stored within the atom itself, in many casessimilar to magnetism, having powerful attraction in some directionsand very little or none in others. A crystal of mica, for instance, orgypsum may be divided to any degree of thinness, but is very difficultto even break. This property of crystals is termed cleavage. Cohesionand crystallization are affected variously by various circumstances, such as heat or its absence, motion or its absence, etc. In fact, almostevery phenomenon of nature within the range of ordinary temperatureshas effects which may be favorable to the crystallization of somesubstances, and at the same time unfavorable to others; so it will beseen that it is impossible to lay down any rule for it except for namedsubstances, like substances requiring like conditions, to bring itsatoms into that state of equilibrium where crystallization can occur. If we examine crystals carefully we find, not only that nature has hereprovided geometric forms of marvelous beauty and exactness, with facesof polish and quoins of acuteness equal to the work of the most skillfullapidist, "but that in whatever manner or under whatever circumstances acrystal may have been formed, whether in the laboratory of the chemistor the workshop of nature, in the bodies of animals or the tissues ofplants, up in the sky or in the depths of the earth, whether so rapidlythat we may literally see its growth, or by the slow aggregation of itsmolecules during perhaps thousands of years, we always find that thearrangement of the faces is subject to fixed and definite laws. " We findalso that a crystal is always finished and has its form as perfectlydeveloped when it is the minutest point discernible by the microscope aswhen it has attained its ultimate growth. I might add parentheticallythat crystals are sometimes of immense size, one at Milan of quartzbeing 3 feet 3 inches long and 5 feet 6 inches in circumference, and isestimated to weigh over 800 pounds; and a gigantic beryl at Grafton, N. H. , is over 4 feet in length and 32 inches in diameter, and weighs notless than 5, 000 pounds; but the most perfect specimens are of smallsize, as some accident is sure to overtake the larger ones before theyacquire their growth, to interfere with their symmetry or transparency. This you will see abundantly illustrated by the examples which I haveprepared, as also the constancy of the angles of like faces. Chemicallyspeaking, the crystal is always a perfect chemical body, and can neverbe a mechanical mixture. This fact has been of great value to thescience of chemistry in developing the atomic theory, which hasdemonstrated that a body can only exist chemically combined when adefinite number of atoms of each element is present, and that there isno certainty of such proportions existing except in the crystal. Ihold before you a crystal of common alum. Its chemical symbol would beAl_{2}O_{3}, 3SO_{3}+KO, SO_{3}+24H_{2}O. If we knew its weight and wishedto know its ultimate component parts, we could calculate them morereadily than we could acquire that knowledge by any other means. But theelements of this quantity of uncrystallized alum could not be computed. Then we may define crystallization to be the operation of nature whereinthe chemical atoms or molecules of a substance have sufficient polarizedforce to arrange themselves about a central attracting point in definitegeometrical forms. 

Fresenius defines it thus: "_Every operation, or process, whereby bodiesare made to pass from the fluid to the solid state, and to assume_certain fixed, _mathematically definable, regular forms_. " It would befolly for me to attempt to criticise Fresenius, but I give you bothdefinitions, and you can take your choice. The definition of Fresenius, however, will not suit our present purpose, because the crystallizationof wrought iron occurs, or seems to, _after_ the iron has acquired a_solid state_. 

Iron, as you all know, is known to the arts in three forms: cast orcrude, steel, and wrought or malleable. Cast iron varies much inchemical composition, being a mixture of iron and carbon chiefly, asconstant factors, with which silicium in small quantities (from 1 to5 per cent. ), phosphorus, sulphur, and sometimes manganese (e. G. Spiegeleisen) and various other elements are combined. All of these havesome effect upon the crystalline structure of the mass, but whatevercrystallization takes place occurs at the moment of solidification, orbetween that and a red heat, and varies much, according to the timeoccupied in cooling, as to its composition. My own experience leads meto think that a cast iron having about 3 per cent. Of carbon, a smallper centage of phosphorus, say about ½ of 1 per cent. , and very smallquantities of silicium, the less the better, and traces of manganese(the two latter substances _slagging_ out almost entirely during theprocess of remelting for casting), makes a metal best adapted to thegeneral use of the founder. Such proportions will make a soft, evengrained, dark gray iron, whose crystals are small and bright, and whosefracture will be uneven and sharp to the touch. The phosphorus in thisinstance gives the metal liquidity at a low temperature, but does notseem to influence the crystallization to any appreciable extent. The twoelements to be avoided by the founder are silicium and sulphur. Thesegive to iron a peculiar crystalline appearance easily recognized byan experienced person. Silicium seems to obliterate the sparklingbrilliancy of the crystalline faces of good iron, and replace them withvery fine dull ones only discernible with a lens, and the iron breaksmore like stoneware than metal, while sulphur in appreciable quantitiesgives a striated crystalline texture similar to chilled iron, and verybrittle. Phosphorus in very large quantities acts similarly. The form ofthe crystal in cast iron is the octahedron, so that right angles withsharp corners should be avoided as much as possible in castings, as themost likely position for a crystal to take would be with its faces alongthe line of the angle. Steel, to be of any value as such, _must_ be madeof the purest material. Phosphorus and sulphur _must_ not exist, exceptin the most minute quantities, or the metal is worthless. If either ofthese substances be present in a bar of steel, its structure willbe coarse, crystalline and weak. The reason of this is unknown, butprobably their presence reduces the power of cohesion; and, that beingreduced, gives the molecules of steel greater freedom to arrangethemselves in conformity with their polarity, and this in its turn againweakens the mass by the tendency of the crystals to cleavage in certaindirections. Carbon is a constant element in steel, as it is in castiron, but is frequently replaced by chromium, titanium, etc. , or is saidto be, though it is not quite clear to me how it can be so if steel isa chemical compound. However this may be, we know that a piece of goodsoft steel breaks with a fine crystalline fracture, and the same piecehardened when broken shows either an amorphous structure or one veryfinely crystalline, which would indicate that the crystals had beenbroken up by the action of heat, and that they had not had sufficienttime to return to their original position on account of the suddencooling. The tendency of the molecules of steel after hardening toassume their natural position when cold seems to be very great, for wehave often seen large pieces of steel burst asunder after hardening, though lying untouched, and sometimes with such force as to hurl thefragments to some distance. If a piece of steel be subjected to a brightyellow or white heat its nature is entirely changed, and the workmansays it is burnt. Though this is not actually a fact, it does wellenough to express that condition of the metal. Steel cannot be burntunless some portion of it has been oxidized. The carbon would of coursebe attacked first, its affinity for oxygen being greatest; but we findnothing wanting in a piece of burnt steel. It can, by careful heating, hammering and hardening, be returned to its former excellence. Then whatchange has taken place? I should say that two modifications have beenmade, one physical, the other chemical. The change chemically is thatof a chemical compound to a mixture of carbon and iron, so that in achemical sense it resembles cast iron. The change physically is that ofcrystallization, being due partly to chemical change and partly to theeffect of heat. I have procured a specimen of steel showing beautifullythe effect of overheating. The specimen is labeled No. 1, and is a pieceof Park Brothers' steel (one of the best brands made in America). It hasbeen heated at one end to proper heat for hardening, and at the other iswhat is technically called "burnt. " It has been broken at intervalsof about 1½ inches, showing the transition from amorphous or properhardening to highly crystalline or "burnt. " Malleable or wrought ironis or should be pure iron. Of course in practice it is seldom such, butgenerally nearly so, being usually 98, 99, or even more per cent. It isexceedingly prone to crystallization, the purer varieties being as muchsubject to it as others, except those contaminated with phosphorus, which affects it similarly with steel, and makes it very weak to crossand tensile strains. I have never estimated the quantity present in anyexcept one specimen, a bar of 1½ round, which literally fell to pieceswhen dropped across a block of iron. It had 1. 32 per cent. Of phosphorusand was very crystalline, though the crystals were not very large. Ironwhich has been, when first made, quite fibrous, when subjected to aseries of shocks for a greater or less period, according to theirintensity, when subjected to intense currents of electricity, or whensubjected to high temperatures, or has by mechanical force been pushedtogether, or, as it is called, upset, becomes extremely crystalline. Under all of these circumstances it is subjected to one physicalphenomenon, that of motion. It would seem that if a bar of iron werestruck, the blow would shake the whole mass, and consequently therelative position of the particles remain unchanged, but this is not thecase. When the blow is struck it takes an appreciable length of time forthe effect to be communicated to the other end so as to be heard, if thedistance is great. This shows that a small force is communicated fromparticle to particle independently along the whole mass, and that eachatom actually moves independently of its neighbor. Then, if there beany attraction at the time tending to arrange it differently, it willconform to it. So much for theory with regard to this important matter. It looks well on paper, but do the facts of the case correspond? Ifpractically demonstrated and systematically executed, experiments failto corroborate the theory, and if, furthermore, we find there is nonecessity for the theory, we naturally conclude that it is all wrong, or, at least, imperfectly understood. Now there is one other qualityimparted to iron by successive shocks, which, I think, is independentof crystallization, and this quality is hardness and consequentbrittleness. One noticeable feature about this also is, that as"absolute cohesion" or tensile strength diminishes, "relative cohesion"or strength to resist crushing increases. Specimens Nos. 2, 3, and 4 arepieces of Swedish iron, probably from the celebrated mines of Dannemora. Nos. 2 and 3 are parts of the same bolt, which, after some months' useon a "heading machine" in a bolt and nut works, where it was subjectedto numerous and violent shocks, (perhaps 50, 000 or 60, 000 per day), it broke short off, as you see in No 2, showing a highly crystallinefracture. To test whether this structure continued through the bolt, Ihad it nicked by a blacksmith's cold chisel and broken. The specimenshows that it is still stronger at that point than at the point whereit is actually broken, but the resulting fracture shows the samecrystalline appearance. I next had specimen No. 4 cut from a freshbar of iron which had never been used for anything. It also shows acrystalline fracture, indicating that this peculiarity had existed inthe iron of both from the beginning. 

I next took specimen No. 3 and subjected it to a careful annealing, taking perhaps two hours in the operation. Although it is a 1-1/8 boltand has V threads cut upon it we were unable to break it, although bentcold through an arc of 90°, and probably would have doubled upon itselfif we had had the means to have forced it. Now what does this show? Havethe crystals been obliterated by the process of annealing, or has onlytheir cleavage been destroyed, so that when they break, instead ofshowing brilliant, sparkling faces, they are drawn into a fibrouslooking mass? The latter seems to be the most plausible theory, to whichI admit objections may be raised. For my own part, I am inclined to thebelief that the crystal exists in all iron which is finished above abright red heat, and that between that and black heat they are formedand have whatever characteristics circumstances may confer upon them, modified by the action of agencies heretofore mentioned. 

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