This section is from "The American Cyclopaedia", by George Ripley And Charles A. Dana. Also available from Amazon: The New American Cyclopędia. 16 volumes complete..
Leather (Sax. lether, from lithe, lither, soft, flexible), an insoluble compound of the gelatine and fibrine of hides and skins with tannic acid, though under the general name of leather are included many kinds in which the hide or skin is preserved and made suitable for various uses without such chemical union of the gelatine and tannin, and also where other materials than tannic acid are used in combination with the gelatine and fibrine of the skin. From the most remote periods leather has been prepared for clothing and various useful and ornamental articles. The Hebrews ornamented it by giving it bright colors, as appears by the mention in Exodus of rams' skins dyed red; and they employed it, after the manner of the Egyptians, for vessels to contain water, and for a multitude of other uses. The paintings and sculptures of Thebes represent many of the methods of working leather practised by this people as very similar to those of the present time. Figures of men are seen currying, stretching, and working it, employing a semicircular knife like that of modern curriers, the awl, a stone for polishing the leather, and other implements such as shoemakers now use.
In their shops a prepared skin was suspended as the emblem of their trade, together with ready-made shoes and other articles in leather. For covering harps, shields, etc, their leather was ornamented by embossing and coloring. For strong cords it was cut into thongs and twisted like ropes; and it was also used in the form of straps. For tanning they used the pods of the sont or acacia, the acanthus of Strabo and other writers, and probably also the bark and wood of the rhus oxyacanthoides, and the bark of the acacia seal, both natives of the desert. Of the methods of preparing the leather used by the Romans no accounts are preserved; and the processes of the middle ages also are lost. The Saracens, it is recorded, used alum, the efficacy of which for preserving skins is well understood. The Calmucks at the present time make use of a solution of alum and of statice root, and also of sour milk, in preparing the skins of sheep and other animals. From the largest species of sea carp they have from remote times prepared garments which are nearly water-proof, making use of sour milk, or some astringent, with which the skins, first dried and cleaned, are dressed three times a day, after which they are finished by exposure for several days to a dense smoke.
The Britons exported skins in early times, but afterward learned the art of tanning, and carried it on in establishments of great extent erected on the banks of the streams. Many rude nations now prepare leather by methods of their own. In both North and South America the dried skins, cleaned from the hair, are placed in earthen vessels with the powdered brains and some water, and heated to about 95° F. The cerebrous matter forms a lather, which thoroughly cleans the skins and makes them pliable. After remaining immersed for some time, they are taken out and stretched tightly in a frame, in which state they are rubbed with a smooth stone to expel the water and fat. Sometimes after this they are also smoked, by which they are made to resist better the action of water. In the Pacific countries of North America leather is skilfully tanned by the natives, who' employ some of the vegetable productions of the country for the purpose. The dressing and working of leather in Japan and India are considered the most degrading of all pursuits; the class that practises them is tabooed, and others are contaminated by communication with any of its members. - Hides and Shins. The heaviest ox and cow hides form the principal material from which sole leather is made; those from cattle which are not fully grown, and also those from the smaller cattle of India and Africa, are generally made into what are called upper leathers, in contradistinction from calf skins; upper leather, as known to the trade, including kip, wax kip, grain, buff, and split leather.
Horse hides are used to only a limited extent in the United States, but are largely manufactured in Europe, the leather being known there as cordovan (from Cordova in Spain, formerly famous for its manufacture), and some portions of the hide making a fine, soft leather. The American bison hide somewhat resembles that of the Calcutta buffalo, but does not make as solid sole leather. The supply of these hides has been about half a million a year since 1871, but they will probably cease to furnish material for leather in a very few years. Hog skins make the best saddle-seating, but more imitation hog skin is sold for this purpose than genuine. Sheep skins, of which the supply is very large, furnish probably more kinds of leather than are derived from any other source. The leather has but little strength and no solidity, but it is quickly tanned, generally with alum or sumach, and worked up whole or split, and serves for the cheaper kinds of pocketbooks, bookbinders' leather, shoe linings, hat linings, and a thousand cheap articles; it is also made up into imitations of many other kinds of leather; and since the introduction of aniline colors, which have been very successfully applied in its manufacture, its uses seem to be almost endless.
Goat skins make a stronger, closer-textured leather than sheep skins; this leather, called morocco, furnishes the principal material for ladies' fine shoes. Deer skins are largely used to make what are known as buckskin gloves and mittens, and this leather is often sold for chamois or white leather. The principal sources from which hides for tanning are obtained, besides those which are always available in every locality from the slaughter of cattle in the neighborhood, are the prairies of the west and southwest, principally Texas, New Mexico, and Kansas; Mexico, Central America, the pampas of the country tributary to the Plata river in South America, and various portions of India and Africa. The hides taken off in the United States are nearly all tanned here. The product of Mexico, Central America, and the river Plata is principally sold at New York and Boston, London and Liverpool, Hamburg, Antwerp, Havre, and to a less extent at a few ports on the Mediterranean. The product of India and Africa is principally distributed through the same markets. East India kips form a prominent feature of the English leather market. It is estimated that the total supply of domestic hides of all kinds used in the leather manufacture of the United States amounts to about 7,000,000 annually.
Of the imported hides and skins used in the American leather manufacture, fully four fifths are entered at the ports of New York and Boston. The imports at New York from 1869 to 1873 were as follows:
Other foreign ports......
The total imports of the whole country for the above mentioned period may be roundly estimated at from 500,000 to 700,000 more than these figures for each period named. It must be remembered, however, that this table does not include any portion of the imports of lighter stock commonly classed as skins. The imports of goat skins at the principal markets for the years 1871 - '3 were as follows:
Liverpool is the principal hide market of England, and here most of the imports of hides from South America arrive. English tanners generally take the choicest selections of heavy hides for sole leather. The following table shows the receipts at that port for seven years:
Buenos Ayres and Montevideo.
West Coast and Central America.
N'foundland seal skins.
The importations of hides at London are not more than one fourth as large as those at Liverpool, but in both places there is a considerable business in " market" hides, as those from domestic cattle are called. The most important hide market on the continent of Europe is Antwerp. A summary statement of the trade there for the five years ending with 1873 shows the business in South American hides to have been as follows:
The difference between the exports and imports shows the number of hides, nearly all for the manufacture of heavy leather, which are supplied from this port for the use of German tanners. The calf skins used by the French and German tanners are nearly all furnished from domestic stock; as a rule, all animals are better cared for there than here, and the skins are more carefully taken off, which affords a partial explanation of the superior quality of French and German finished calf skins. - Tanning Materials. Tannic acid is found in almost every plant which grows, and its use in making leather dates back as far as we have any records, and is attested in every sample of ancient leather extant. Among the sources of tannic acid, oak bark has the first place, although in the United States the bark of the hemlock is used even more than that of oak. Hemlock bark makes red leather, because of an excess of coloring matter, from which oak bark is comparatively free. Oak-tanned leather always brings a higher price than hemlock-tanned, because the coloring matter and resin which are to some extent imparted to the latter have a tendency to make it harder and more brittle, and also because of a prejudice against the red color, pure oak leather being often nearly white; but these points are not of so much importance as the fact that, because oak bark costs more, greater care is taken in the selection of the hides and the finishing of the leather.
As for the astringent principle of the bark, which unites with the gelatine and fibrine of the hide to constitute leather, there is no difference between that in oak and that in hemlock bark. The same cannot be said of all tanning substances, for chemists have not yet very closely defined what tannic acid is; and while leather tanned with terra japonica, and some other kinds of concentrated tanning materials, may be restored to a condition very similar to that of raw hide, this cannot be done with bark-tanned leather. To make an accurate analysis of the amount of tannic acid in any given substance is one of the most difficult of chemical experiments; and the results of analyses made by different individuals, and even by the most celebrated chemists, vary so widely that the best informed tanners place no dependence on the figures thus given. The following table embraces all the principal tanning agents now in use, and is arranged with especial reference to the characteristic qualities that each is conceded to have in the leather manufacture; that is, those coming first in the list, before oak bark, make soft, open, mellow leather, and those which follow oak bark make leather more plump, hard, and brittle.
The figures given as showing the percentage of tanning cover only the variations found in excellent samples of the same material:
Percentage of tannin.
Color bad; makes little weight; leather soft and open.
Color light; gives some firmness; makes leather soft and pliable.
Color yellow; makes little weight; leather mellow.
Nearly colorless; gives good weight; makes leather very firm and solid.
Color red; gives good weight; makes leather firm and hard.
Color fair; gives weight; makes leather hard.
Color poor; gives great weight.
Color very red; gives weight; makes leather hard and brittle.
Of the above named tanning materials, a comparatively small amount is used in the American leather manufacture of any except oak and hemlock bark, and sumach, which is used principally in the tanning of goat skins. Hemlock bark is generally found north of the central portion of Pennsylvania, while south of that latitude most of the oak bark is used. In the northwestern counties of Pennsylvania, the northern counties of New York, W. and N. of Lake Michigan, and in Maine and Canada, are now found the principal hemlock forests, which it is estimated will furnish ample tanning materials for at least 50 years to come. Along the Cumberland and Alleghany mountains, and all the lesser ranges of the Blue Ridge through the southern states, are large supplies of oak bark. Maryland and Virginia since 1865 have furnished a large amount of sumach, which, however, is not so highly esteemed as that grown in Sicily, whence considerable importations are made annually. Besides the bark used directly for tanning at or near the localities where it is peeled from the tree, no inconsiderable amount is used in the United States and Canada for the manufacture of bark extract.
This is a process of leaching the bark and then evaporating the principal portion of the water, so that a concentrated solution of tannin is made, which may easily be shipped to distant tanneries; and much of this extract has found a ready market in England within the past five years. It has been a favorite idea with some who are well informed in the business that this trade will ultimately be very large, as oak bark costs in England from £6 to £7 a ton, and the cost of the extract delivered there is only about half as great; but practical difficulties have thus far prevented the expected growth of this business. The following table represents the imports of the principal tanning materials at Liverpool, England, from 1867 to 1873 inclusive:
• * ■ ■
These tanning agents all make cheaper leather than is made with oak bark, and one which is inferior also to that made with hemlock bark; and many devices are resorted to, in the composition of the different tanning agents, and in the process of manufacture, to give the leather a bark-tanned apppearance. When the work is skilfully done, the leather is of most excel-lent quality. .On the continent of Europe coppice, spruce, and willow bark, as well as the wood of the chestnut, are used for tanning; but these substances have very little tannic acid, and the small home supplies of oak bark, with importations of the above named materials and sumach, constitute the principal agents for converting raw hide into leather. Many other substances besides tannic acid may be used to preserve hides and skins and fit them for certain uses; but these do not make leather which will resist moisture or retain its flexibility and softness after frequent wetting. The most extensively used of these is alum, so that the term alum-tanned leather has become a common designation both in Europe and the United States. With this agent is tanned a large proportion of the sheep skins, and lighter glove leathers from deer, lamb, kid, and other skins. - Tanning. As the making of sole leather involves the placing of the greatest amount of tannic acid in the hide, this branch of the business most requires a thorough knowledge of the principles of tanning; for in the manufacture of upper leather as much depends upon the currying and finishing of the stock as upon the tanning, and it is not sought to put the greatest possible amount of tannin in the hide.
The hide or skin is composed of two parts: the epidermis or cuticle, in which the hair is imbedded, and the corium or cutis, the true skin, made up of numberless fibres interlacing in every direction, the interstices being filled with a matter which renders the skin flexible, and renews the substance of the cuticle, and which, as well as the fibres themselves, is shown to be almost pure gelatine. The chemical analysis of dried skin is as follows:
Extractive matter soluble in water, insoluble in alcohol..............
Extractive matter soluble in alcohol.........
Fatty matter and loss..........
The object of tanning is to combine this fibrous and gelatinous matter with tannic acid, and the first process is to wash and cleanse the skin, making it thoroughly soft, and as nearly as possible in the condition it was when taken from the animal. For this purpose the hides are first placed in "soaks," or vats of pure water, where they remain from five to ten days if dry, and about 24 hours if green. Much depends upon the condition of the hide. A dry hide which has been imperfectly cured could not be permitted to remain so long in the soak, as it might begin to decay. When the hide is thus softened, it is ready for the treatment which is necessary to remove the hair. For this purpose there are two principal methods, of acknowledged efficiency and in almost universal use, besides scores of other methods which have their advocates, but have never been generally adopted. The object is so to soften and swell the hide on the surface, where the roots of the hair are imbedded, that the hair can be easily and quickly removed, and the condition of the hide remain as nearly as possible unaltered.
To effect this, liming and sweating are the principal methods; the former being used almost altogether for upper leather, and largely for sole leather, and the latter almost exclusively for sole leather. Great differences of opinion exist as to the amount of lime which should be used; if the lime vat is very weak, a longer time is required to swell the epidermis so that the hair can be easily removed; and if more lime is used, there is danger of burning. The true theory is that the lime shall remove all but the gelatine and fibrine; and in upper leather, as well as in belting and harness leather, the removal also of a portion of the gelatine by the lime tends to make a more flexible leather, with all the strength and toughness that it would have with all the gelatine of the hide remaining to unite with the tannic acid, but with less solidity. The sweating process for the removal of the hair is used in the United States and in Germany on nearly all sole leather stock. In Germany and England the warm sweat is generally followed, and in the United States the cold sweat; the former being at a temperature of about 100° F., and the latter from 50° to 65°. The hide after the soaking is cut through the middle of the back, if intended for sides, as is usual in America, or is rounded by cutting off the pates, bellies, and flanks, if to make butts.
It is then generally put into a hide mill, to further soften it and help to loosen the hair. This hide mill is a simple contrivance, with two arms working in a box to pound the hides, on which a small stream of water is kept flowing. For the cold sweating process the hides are hung in a close vault, and here it is necessary to watch them very narrowly, as the change which has been commenced in the soaks proceeds much more rapidly here. The sweat pits are nearly all under ground and dark (though the light is proved to be not detrimental to the process), and the air is heavily charged with moisture and the ammonia from the hides. The time required to loosen the hair is from one to six days, according to the condition of the hide; but it is of great importance that the hide be removed as speedily as possible after the hair will slip, as it is then in the incipient stages of a very rapid decay. From the sweat pit the hides are first milled, with the water running on them, to soften them further and remove the hair, and then worked over a beam, to take off any remaining hair; they are also, by the more careful tanners, worked on the flesh side to take off any extra flesh or fatty matter which butchers almost always leave on, and then thoroughly rinsed.
By the warm sweating process the same ends are obtained, and in about the same time, though it is with greater danger from more rapid decay in unsound hides. Another object to be attained in this stage of preparing the hide is the swelling or distending of its fibres, to allow of the free admission of the tannin to combine with the gelatine in the cells. When lime is used to unhair, it opens the pores of the hide very effectually, but the lime itself must also be thoroughly removed afterward; this is most commonly done by soaking the hide in what is called a bate, made of hen dung or similar excrement, aided by subsequent thorough washings in water. The swelling of the hide to allow the tanning liquors to enter the pores freely has no little influence in determining the quality of the leather. Some means to effect this are always necessary in tanning hides which have been un-haired by sweating. There are two methods generally followed in America in preparing sole leather, which illustrate the principles adopted by all tanners. These are commonly called the "acid" and "non-acid" processes.
In both methods it is acid that plumps the hide and distends its fibres for the reception of the tan liquor; in the former process, however, a mineral acid is used, either alone, with a large proportion of water, or in connection with more or less of the vegetable acid furnished by the old, sour liquors, to hasten the process of preparing the hides for the tanning proper; while by the latter process the hides, after being unhaired, are handled for several days in the old, sour liquors, but without the aid of the mineral acid (which almost invariably consists of vitriol or sulphuric acid), to effect the same object, that is, distend the fibres and open the pores. In using the vitriol, great care must be observed in the first stages, or the leather will be very dark, and have what is called a very poor grain, i. e., will not make a light-colored bottom for boots and shoes, an object which is very much sought after in all sole leather. The leather is also more likely to be hard and brittle than that prepared by the non-acid method.
The old liquors used, in the latter method are simply the tanning liquors which have become weak by use, and in which the remaining tannic acid has largely been changed to gallic acid by exposure to the air. - The grinding of the bark and the making of the liquors therefrom is a most important part of the work. The bark is stripped from the tree and cut in pieces 4 ft. long; a month or two is generally sufficient to make it dry enough to grind, though if kept two years in a large, close pile, and not much exposed to wet, it will not be materially injured. It is ground in a large mill, not unlike a coffee mill in principle; and about the size of a grain of wheat is considered the proper degree of fineness. To get the tanning principle from the ground bark, leaching with hot water is prejudicial, for in that way resin and coloring matter are also extracted; and leaching with cold water does not extract all the tannin. Both modes are used. Leaching with hot water, or swelling the ground bark with steam before leaching, causes the leather to be darker than that made with liquors which are leached cold. - The vats in which the hides are handled and laid away in tanning are of various sizes, either large enough for whole hides or for sides, and are about 6 ft. deep.
In handling, the hides are sometimes sewed together at the ends, so that they can be reeled from one vat to another; but this is only to facilitate the work in the frequent changes which have to be made. For the first few days the hides are changed every two or three hours from one liquor to another, the first liquors being very weak, and the last liquors in which the hides are thus handled, at the end of 10 or 15 days, having 10 or 12 degrees of strength. From the handlers the hides are placed in what are called layaway vats, a shovelful of ground bark on the top of each hide, and the whole covered with the bark liquor. It is the custom in America thus to lay away the leather in vats six or seven times, the liquors of the first lay-away being the weakest, and the time the leather is allowed to remain, as well as the strength of the liquors, being increased with each successive laying away. For the first layaway a liquor of 10 or 12 degrees would be used, and the time would be from one to two weeks; for the second, 15 to 20 degrees; and two to three weeks; for the third, 20 to 22 degrees, and three to four weeks; for the fourth, 24 to 26 degrees, and four to six weeks; for the fifth, 28 to 30 degrees, or stronger, and the time in this layaway, or for the sixth and seventh, depends on the judgment of the tanner, the quality of the hide, and the kind of leather to be made.
This process, taking about four months, is a fair average of time consumed in America for the actual tanning part of ordinarily heavy hemlock sole leather. Oak tanners generally lay away the leather in bark and strong liquors for a little longer period, and this is also done with all extra-heavy hides. The leather is also much more advanced in the handlers in some cases, and on the proper and thorough opening of the pores here, and the exercise of great care to prevent the tanning from going on too rapidly on the surface, depends the question whether a longer laying away in the bark liquor will add to the weight of the leather. The object in all sole-leather tanning is to get as great weight as possible, where this can be done without detriment. From dry hide about 170 lbs. of leather are made of 100 lbs. of hide; in some cases the writer has seen 195 lbs. of leather made from 100 lbs. of hide; but many poor tanners will make as low as 140 to 150 lbs. In tanning green or wet hides, from 45 to 60 lbs. of leather for 100 lbs. of hide represents about the average production. - The common prejudice that quick tanning is necessarily poor tanning has no sufficient foundation.
The best English tanning, many years since, occupied from nine to 18 months, but the great majority of English tanners now tan in from four to six months. They are also, where valonia, divi-divi, myrabolams, and terra japonica are used, able to make good leather in even a much shorter time. The problem is to feed the tannin as quickly as possible, without too much expense, to every cell and interstice of the hide; and by constant handling and agitation of the hide in liquors of the proper strength and proportioned to its condition, the work which formerly occupied months is now done in weeks, and could be done in days or even in hours if the extra expense incurred in this way were not greater than the profit to be derived from thus expediting the process. Among the many ways of quick tanning proposed, and which have found no small favor in the trade, are the vacuum process for sole and upper leather, and the revolving wheel or drum for upper leather and calf skins. The former proceeds on the principle of pumping out the air, as from a receiver, from the vat in which the hides are placed, and then letting in the tanning liquors; it is asserted that the pores of the hide are then more open, and the tannin will be more quickly taken up.
The wheel or drum for upper-leather and calf-skin tanning is a box nearly filled with a strong tan liquor and the skins, and made to revolve on a shaft, thus constantly agitating the skins, and producing an opening of the pores which facilitates the absorption of the tannin. Neither of these methods, however, has been generally adopted, though each has found favor and is used to a limited extent. - After the leather comes from the last layaway vat, it is scrubbed with a coarse brush, operated either by hand or power, and hung up to dry. Care must be taken at this stage not to hang up the leather where there is too much light, which gives a dark color, and also to have as far as possible a constant circulation of dry air. After drying, the leather is "sammied," as it is called, or slightly moistened and oiled on the grain side, by which it is brought to a flexible, mellow condition, ready to be rolled or hammered, the final process of finishing. In America and England all sole leather is rolled, while in France and Germany it is generally hammered.
The sole leather roller commonly used is of brass, about 5 in. in diameter and from 7 to 9 in. long; it is hung like a pendulum over a solid metal bed with a concave face, in which the roller is worked by means of an arm attached near the lower end. The desired pressure is attained by means of a treadle which raises the bed. A rubber packing is sometimes used under this bed to prevent the pressure from coming too hard upon parts of the side or hide which may be naturally too thick or plump to receive the tremendous weight which can be brought upon it. - In making belting and harness leather, where greater flexibility and the greatest possible tensile strength are sought, the methods of tanning are not essentially different. There is very little difference in the texture and appearance of leather which will wear best for the soles of boots and shoes, and that which will serve best for band leather; and most of the heavy harness leather, if well stretched and finished with less oil or stuffing, would make good belt leather. But in the best belt leather, the original fibre of the hide must be as little disturbed as possible.
An examination with a microscope of the edge of an ordinary piece of sole or belting leather will show how these fibres are interlaced; and, when not disturbed, this constitutes the great strength of a raw hide. In the tanning and finishing of harness leather, the object is to make the stock still lighter than belting leather, and also to give it much more body and strength than any leather which is to be used for the uppers of boots and shoes. With this end in view, the hides are kept longer in the lime, by which more of the gluten is exhausted, and a higher degree of care is consequently necessary to insure the thorough working out of the lime, which would cause the leather to crack, or be hard and brittle. - In the tanning of upper leather and calf skins the time occupied is very much shorter than that used in making sole leather, and the processes embrace a great variety of methods of handling, agitating with a wheel, suspending in vats of tan liquors, etc. Greater care is necessarily taken in selecting and fleshing the skins; and if the lime used to unhair is not thoroughly worked out, the leather will crack quickly. The currying consists in the thorough working of the skins to soften them, blacking, and thoroughly incorporating the oil and tallow used for stuffing.
The latter is generally done in a wheel heated by steam. The blacking is usually of oil, lampblack, and tallow, with a little tan liquor; a cheaper blacking is made of sal soda, lampblack, and soap. Leather finished on the grain or hair side is called grain leather; and imitation grain is made of split leather, which is worked by hand or machine to give its surface the rough look always found on leather finished with the natural appearance on the hair side. Buff leather is where this surface is smoothed off. " Leather board," made of leather skivings and old rope, is manufactured for use in heels, stiffen-ings, and counters of the cheapest boots and shoes. - Japanned leather, generally called patent leather, was first made in America by Seth Boyden of Newark, N. J., 1818-'20. A smooth, glazed finish was first given to calf skins in France, which were sold to a considerable extent in the American market; but the manufacture of japanned leather has now grown to be a large business in Newark, and the amount of these goods imported is very light.
The japanning of calf leather for boots and shoes is most successfully conducted by the French. They furnish the best of the highly glazed brilliant material known as patent leather, and large quantities were formerly produced in the United States. Of late the demand for the finer kinds of calf patent leather has largely fallen off, and its place is in some measure filled by a cheaper article manufactured mostly of kips or larger hides, split or skived down to proper thickness. It is curried expressly for this purpose, and particular care is taken to keep it as free as possible from grease. The skins are then tacked on frames and coated with a composition of linseed oil and umber, in the proportion of 18 gallons of the former to 5 oz. of the latter, boiled till nearly solid, and then mixed with spirits of turpentine to the proper consistency; lampblack is also added when the composition is applied, in order to give color and body. From three to four coats of this are necessary to form a surface to receive the varnish; they are laid on with a sort of knife or scraper. To render the goods soft and pliant, each coat must be very light and thoroughly dried between each application.
A thin coat is afterward applied of the same composition, of proper consistence to be put on with a brush, and with sufficient lampblack boiled in it to make it a perfect black. When thoroughly dry it is cut down with a scraper having a turned edge, when it is ready to varnish. The principal varnish used is made from linseed oil and Prussian blue, boiled to the thickness of printers' ink. It is reduced with spirits of turpentine to a suitable consistence to work with a brush, and is then applied in two or three separate coats, which are scraped and pumiced until the leather is perfectly filled and smooth. The finishing coat is put on with especial care in a room kept closed and with the floor wet to prevent dust. The frames are then run into ovens heated to about 175°. In preparing this kind of leather the manufacturer must give the skins as high a heat as they can bear in order to dry the composition upon the surface as rapidly as possible without absorption, and cautiously so as not to injure the fibre of the leather. - Enamelled leather, now used for carriage tops, was first manufactured by David Crockett of Newark; previous to this, oil-dressed leather, presenting all the appearance of harness leather, was used for this purpose.
This leather is all split by machine, and only large hides are used. By the use of the leather-splitting machine, a hide is split in three or four parts, and what in the old process of shaving would have produced but 50 ft. of leather, is increased to about 125 ft. suitable for glazing, besides a first split that is used for covering trunks. Patent leather differs from enamelled leather in the fact that the former has a smooth surface, and the latter is finished with less composition, leaving the irregular surface given by the natural grain of the skin where the hair has been removed. In enamelled leather American manufacturers take the lead of all others, but they also make much poor stock. The principal cause of complaint against American enamelled leather has arisen from the introduction of powerful stretching machines, by which the size of the hide can be increased from 3 to 7 sq. ft. (The leather is sold by measure, not by weight.) The wet leather is thrown over a bar which is attached to uprights and can be raised or lowered at will; the edges of the hides are attached to a fixed bar, and by the use of two jack screws the movable frame is raised until the leather is stretched to its utmost.
The whole frame is then wheeled into a dry room, where it remains until the leather is perfectly dry, after which it passes through the usual process of blacking and varnishing. Hides treated in this way will shrink more rapidly than those stretched in the usual manner; they will even contract if spread out in the wareroom. Smaller hides are now used for this purpose than formerly, as they retain the enamel surface better owing to their finer grain, and do not shrink so much when exposed to the weather. - Alligator leather was first made about 1855 in New Orleans. In 1870 a much better article was made in Massachusetts, the tanning process occupying about eight months, and a number of firms then engaged in the business. The leather thus made was very costly, and while it was not impervious to water, as was asserted, it had not sufficient firmness to retain its shape when made up into boots and shoes, but would spread out, in ordinary wear, as would be the case with a buckskin upper of a boot or shoe. The irregular and conspicuous checkered pattern of their surfaces made them popular for a brief period; but nearly all of the durable boots of this kind were made with a lining of calfskin, thus rendering them extremely heavy.
In preparing the skins for tanning, great care is necessary to prevent the rotting of the tender crevices between the scales; and, as they must be very carefully treated, twice as much time is required for the tanning and finishing as with calf skins. The skins of the young animals only are fitted for making leather, as the hide of a full-grown alligator is too hard and horny to be of any value. The tanning of alligator skins is, in other respects than those mentioned, similar to that of calf skins. The back of the skin, which is always hard and horny, is gen-erally cut out before shipment, leaving only about two thirds of the whole for use. - Russia leather, such as is used in pocketbooks, travelling bags, etc., has long been highly popular in the United States and Europe, not only for its durability, but more especially for its peculiarly pleasant smell, which it retains after years of use and exposure. For these reasons it has always commanded a high price, and many American manufacturers have striven hard to make a close imitation of the genuine article. The leather is made of the ordinary Russian hides, which, as is the case in all cold climates where the pasturage is generally poor, are large and thin.
These hides are tanned by a very slow process, generally in the weak liquor of the willow bark, which contains not more than 2 or 3 Per cent. of tannin. The leather has very little of the positive bark smell which may always be noticed in more thorough or more rapid tannages; but to give it the particular odor by which it is distinguished, what is called "birch bark tar" is used. The exact manner of using this tar, which is said to be simply a condensed extract of birch bark, is held as a secret by the principal manufacturers in Russia, each one of them having especial modes of their own; but it is certain that they all depend upon this as the means of giving the peculiar odor which characterizes Russia leather. The willow bark used in tanning gives a different color from any other tanning material, and it is supposed that in the finishing process the leather is laid away, after a liberal application of the birch bark tar, to become thoroughly impregnated with its peculiar odor. - The importance of the leather industry in the United States, considering the amount of capital and labor employed in all its departments, is next to that of agriculture.
It is doubtful whether it holds this relative position in England, where the iron and cotton and wool interests are so large, or on the continent of Europe, where the consumption of leather in proportion to population is much less than in the United States. In all other parts of the world besides the United States and British North America, the British islands, eastern and southern Europe, and Australia, the production of leather is comparatively very small, and the product inferior; the raw hides and skins from the excluded sections form no small proportion of the stock from which leather is made in the countries named. The most complete statistics of the leather industry of the United States yet gathered were presented to congress in 1870, as made by Special Revenue Commissioner David A. Wells. The values created by the leading industries are computed as follows: agriculture, $3,282,950,000; railroad service, $360,000,000; leather manufactures, $222,600,000; iron production, $119,-950,000. The value of leather tanned and of leather manufactures, the number of hands employed, and the amount added by labor to the value of the products, are given as follows:
Value of leather tanned and dressed......
Deducting value of hides and skins used as raw material.......
Value added by labor.....
Value of boots and shoes produced.........
Deduct value of all materials used, including leather.......
Added value of boot and shoe industry........
Value of other manufactures of leather, harness, hose, belting, bags, portemonnaies, etc.....................................
Deduct value of materials, including leather.
Added value of above industries..........
Number of hands employed in the manufacture of leather........
Employed in manufacture of boots and shoes..........
Employed in other manufactures from leather........
Value added to hides and skins in the manufacture.........
Value added in manufacture of boots and shoes...........
Value added in other manufactures from leather............
Total added value..............
The value of product in the manufacture of leather is apportioned as follows:
Supplies and repairs............
The value of the product of the boot and shoe industry is apportioned as follows:
Supplies and repairs........
The above statistics were made on a basis of currency prices, with gold at 25 Per cent. premium. By far the larger proportion of the industry to which these figures relate is carried on east of the Alleghany mountains; and while the leather manufacture is of no slight importance in Kentucky and the states north of the Ohio, comparatively little is done in this business anywhere on the Pacific slope. The leather made in all the New England states, and a large portion of that made in New York, finds its principal market in Boston, which is the leading upper-leather market in the United States, and does a large business in sole leather. The following comparative statement, including receipts from New York city, and receipts of rough leather which is sent again to the tanneries nearer Boston to be finished, and thus appears twice in the receipts, represents the business of that city:
New York is the principal market for sole leather and imported calf skins, kids, etc. Nearly all the sole leather received there is hemlock-tanned, which probably constitutes three fifths of the leather tanned in the United States. The receipts of sole leather at New York for the year 1873 were about 4,500,000 sides, and for 1872 not less than 5,000,000 sides. Philadelphia does a large business in oak sole and domestic tanned and finished calf and goat skins. Baltimore and Cincinnati are of considerable importance as oak-leather markets. Buffalo and Chicago have each a large trade in hemlock leather, and are supplied by the tanneries in their immediate neighborhood. There are some considerable tanneries of hemlock leather in Canada and Nova Scotia, the leather finding its market mostly among the shoe manufacturers there; the remainder is principally exported to England. Very little of it comes to the United States, owing to the tariff, which was formerly 25 per cent., and is now (1874) 10 Per cent. on sole leather. Since 1840 American tanners have frequently attempted to supply the English market with sole leather. The hemlock bark principally used for tanning in the United States costs from $4 to $6 a cord, weighing about 2,000 lbs.
The English oak bark costs about $30 a cord, and the amount of tannin it contains is very little greater than that in American hemlock of average growth. As the cost of bark is a leading consideration in the leather manufacture, and the difference in the cost of labor was not very great, it was thought that the American tanner had a very decided advantage over his English competitor. Yet it has taken many years of experiment for the American tanner to obtain any considerable degree of success in this matter. Shipments have not been successful until within the past two or three years, or since the removal by congress, from Aug. 1, 1872, of the 10 Per cent. duty on foreign hides brought to the United States. English manufacturers at first complained that American hemlock leather, being red, was not tanned, but only colored; then that American leather was not so neatly finished, fleshed, and trimmed as that of English make; and this still holds good, so that American hemlock leather, although its substantial qualities are now recognized by the leading English manufacturers of boots and shoes, is sold there only as an article inferior to their best leather, and at a much lower price, but better than the poorer qualities of which the greater portion of their production consists.
The following are the shipments of sole leather from New York to various ports for 1873:
During the year ending June 30,1873, $4,612,-885 worth of leather was exported from the United States, and $6,706,202 imported. About three fourths of this commerce passes through New York. - The leather manufacture of Great Britain is one of its most important industries. English sole leather has long had the reputation of being the best in the world, and its better grades are superior to any other manufactured, if we except a few tannages of similar leather made in the United States. With the increasing demand for leather, however, and the diminishing supply and advanced prices of bark, a poorer quality has largely taken the place of the prime leather which gave English tanners their extended reputation. The following extracts from the latest government returns show the imports and exports:
Hides, raw, cwts..........
,, dressed, lbs.........
Boots and shoes, pairs......
EXPORTS, PRODUCE OF UNITED KINGDOM.
Hides, raw, cwts.........
,, dressed, cwts.........
Boots and shoes, pairs.......
Saddlery and harness........
Other manufactures, lbs........
EXPORTS, FOREIGN AND COLONIAL PRODUCE.
Hides, dry and wet, cwts..
" tanned, dressed, etc, lbs..............
The principal leather market of Great Britain is at Leeds, and at the quarterly and intermediate fairs held here representatives of the principal tanners and leather and hide factors of Great Britain are always to be found. London and Liverpool are also extensive markets. Bristol, Manchester, and Newcastle have each a large business in leather and the shoe manufacture. - On the continent of Europe the sole-leather manufacture is of minor importance, compared with the extent of the industry in England and America, while the manufacture of calf skins, kips, kid skins, morocco, and all kinds of upper leather, is carried on very largely and with great success. The sole leather tanned on the continent of Europe is generally hard and brittle, from an insufficiency of tanning material, and a long process of tanning; but the calf skins and upper leathers, which require but little tanning material and much hand labor in working, are as a rule far superior to those made in England and America. For this reason, the two latter countries are large customers for these goods, and export in return a large proportion of the sole leather used in Europe. Paris is the headquarters of the French calf-skin business, and Milhau is the most important manufacturing centre of the trade in France. At Lyons, Nantes, and Chaumont near Beauvais, the trade is also of considerable importance.
In Belgium, at and near Brussels, there is quite a large production of calf skins. Switzerland, besides numerous small tanneries, has one of the largest calf-skin tanneries in the world, at Lausaune. In Germany, calf skins, calf kids, and kips are made in large quantities at Mentz, Worms, Oppenheim, Offenbach, Dresden, near Frankfort, and near Freiburg, besides innumerable small tanneries everywhere.