CHAPTER I.
IMPORTANCE OF THE BOOT AND SHOE TRADE.

The great importance of the Boot and Shoe Trade in the New England and Middle States, and the vast amount of capital devoted to its development, the energy, brains, and perseverance of its leading men, place this branch of the mechanic arts high on the list of the great industrial interests of the age. It is, therefore, a matter of surprise, that some work has not appeared which should contain important scientific, statistical, and practical information concerning the rise and progress of the Shoe and Leather interests. Works upon Tanning have been published, covering many of the collateral branches of that science, and fugitive articles occasionally appear, giving accounts of new discoveries, or new applications of old methods, concerning the preparation of leather, &c.; but in the manufacture of boots and shoes, no work has ever appeared which would enable the shoemaker to make any advancement in his calling, other than that which his own observation or genius might suggest. The Boston Board of Trade publish annual Reports in which appear able articles upon the Shoe and Leather interests, but these, of course, are mainly statistical and financial in their character. There is published, also, in Boston, New York, and Philadelphia, simultaneously, the Shoe and Leather Reporter, by J. D. Field & Co., a valuable journal, devoted exclusively to the trade in boots and shoes, leather, hides and its collateral branches, also market reports and correspondence from various portions of the world. This paper is the only organ, we believe, devoted exclusively to the shoe and leather interests. Systems of measurement, the cutting of patterns, preparation of stock, all of which can be gained by study and application, have been, as it were, sealed from the direct investigation of the inquiring mind. In other branches of the mechanic arts, volumes have been published, and the ambitious student pursues his investigations from primary principles to ultimate results in regular gradations.

In the science of shoe manufacture, we must refer for information principally to English works; and even these are collateral, rather than direct, in their application. Dodd’s British Manufactories, Brande’s Encyclopedia, Dictionary of Arts and Sciences, Penny Cyclopedia, Results of the Late Exhibition, (London,)—all these are the repositories of much that has been written upon the leather interests; sources of information which none but the man of leisure, or the enterprising compiler, would be likely to trace out.

It may be said that the simplicity of this branch of the mechanic arts does not require that degree of study and investigation which the more abstruse and complicated sciences demand, and hence there is no necessity for works upon the subject. This objection is only true in part. It requires the nicest adaptation of skill to make a perfectly fitting shoe or boot, and no man, unless he who is fully conversant with the rules and principles which enter into the preparation of the stock, the correct measurement of the foot, the “cutting out” of the several parts of the stock, the lasting and fitting of the shoe or boot, can be successful in his profession. The making of an easy, elegantly fitting boot, requires a knowledge of the anatomy of the foot, a familiar acquaintance with the angles, lines and curves, which are involved in the perfect adjustment of part to part, and their relative positions. Most shoe manufacturers, and ordinary village shoemakers, learn their trades from their fathers, and the knowledge has been handed down from generation to generation, without change or improvement, and shoes are made to fit lasts, rather than the feet which are to wear them. Hence intelligent instinct has taken the place of intelligent knowledge, and progressive investigation. The workman knows nothing of the anatomy of the foot, the science of pattern cutting, and therefore works on as though all feet were cast in one mould, with the simple difference which the “sizes” indicate. These “sizes,” as is clearly shown in another portion of this work, are regularly incorrect. Hence, in the absence of a correct standard, the system of boot and shoe making is simply the following of established mechanical rules, upon a false foundation.

We refer in these remarks to the manufacture of what is known as “sale work.” There are many, very many, “custom workers,” who proceed by correct rules, and upon scientific principles; men who understand how to adapt the shoe or boot to the foot, so that when the customer first draws the boot or shoe on, it fits naturally and easily, adapting itself to any, and every deformity or slight irregularity which the foot may present. We make general statements, which every intelligent shoemaker, or large manufacturer, will at once acknowledge. The whole trouble arises from the want of some correct standard by which to be guided in the preparation of the stock for the workman. All this cannot be gained but by study, patient investigation, and the practical application of scientific rules.

The French are generally acknowledged to understand the art of boot and shoe making better than those of any other nation, and they have carried the science to a degree of perfection not yet attained by ourselves, except in a few comparatively isolated cases. The whole secret of their success is their patient perseverance, and artistic skill in understanding the rules which are vitally essential to success.

In another chapter we have devoted considerable space to the elucidation of the principles of measurement, pattern cutting, and such instructions as will enable the manufacturer—and in this term we comprise all who are engaged in this important branch of our industrial interests—to become a scientific proficient in his vocation.

This work, however, as its title indicates, is devoted more specifically to the application of Gutta-Percha, and the various Rubber compounds, in the manufacture of boots and shoes. Yet we regard the principles of their manufacture, as equally important, and as vitally essential, to the perfect fitting of the boot or shoe, whether sewed, pegged, or cemented.

The Boot and Shoe Trade of New England is of comparatively modern date. The first vessel, the sloop Delight, ever freighted at Boston with a full cargo of boots and shoes, sailed for the port of New York, in the month of May, 1818, consigned to Spofford & Tileston, then the largest boot and shoe jobbers in New York. This firm then commenced supplying the shipping demand from that port, instead of Boston. The manufacture, then, was confined to the New England States, but it soon commenced to take a wider scope. The trade increased rapidly, but eleven years later, 1829, there were only four jobbing houses in New York. In Boston, the centre of the trade, the whole jobbing trade for 1828 did not exceed but little over one million of dollars. The trade has increased to an almost wonderful extent. It now forms one-third of the whole manufacturing power of the country; New England and Pennsylvania retaining two-thirds. In the city of Boston there are about two hundred and eighteen wholesale and jobbing boot and shoe houses, doing business to the amount of fifty-two millions of dollars annually. In New York there are about fifty-five jobbing houses, whose aggregate sales reach from fifteen to sixteen millions yearly. The domestic and foreign boot and shoe trade of the State of Massachusetts alone, amounts to between fifty-five and sixty millions annually. The shipments from Boston to San Francisco for 1856, were $2,100,000.

The manufacture of boots and shoes is the largest domestic trade in the States, and there is no country or nation that can successfully compete with us, either as regards prices or quality. Common styles of goods, such as men’s pegged boots and brogans, women’s pegged and common sewed shoes and gaiters, are manufactured in the following villages of New England, viz: Lynn, Haverhill, Worcester, Milford, Natick, Randolph, Abington, the Readings, Danvers, Georgetown, Stoughton, Woburn, and several other towns in Massachusetts. The amount of capital employed in the city of Worcester, in the boot and shoe business, is one hundred and seventy-six thousand dollars; the annual value of boots and shoes manufactured, about one million of dollars. The total value of boots manufactured in Milford, Mass., in 1857, was upwards of two millions of dollars. The amount would have greatly exceeded that estimate had not the financial troubles of the country prostrated this, in common with every other manufacturing interest. According to present indications, the manufactories of Milford, this year, 1858, will nearly, or quite, reach the value of four millions of dollars. The city of Lynn, Mass., has employed in this business, about five thousand workmen, and its sales for the year 1857, exceeded four millions of dollars.

Each New England village, town or city, where this industry is carried on, is devoted to one kind of boot or shoe, and whole communities are built up by this special industry. Some idea of the importance and extent of the boot, shoe and leather interest may be inferred from the fact, that there are forty-one thousand men in Massachusetts who work upon leather, either in manufacturing the article or moulding it into various forms. Every eighth man in the State is a shoemaker.

The Shoe and Leather Trade of Boston takes its date, as a prominent branch of commerce, about the year 1830, caused principally by the change made in conducting the business. It was formerly the custom for Manufacturers and Dealers in Boots and Shoes to seek a market for their goods, by consignment on their own account, to New York, Philadelphia, Baltimore, Charleston, Savannah, New Orleans, Havana, and other West India Islands. It was found to be remunerative for a while, but on the increase and competition of trade, it became a losing business. The leading houses failed. Since 1828 and 1829, an entire change in the method of conducting the shoe business has taken place. Manufacturers and Dealers now sell their goods on their own account instead of consigning them to other States. The consequence is that Boston is made not only the head-quarters for nearly all the manufactories of New England; and although the city of Lynn and the towns of Haverhill, Danvers, &c., sell a large portion of their goods at home, a large number of the manufactories have offices in Boston for the sale of their goods. If the domestic trade of Boston had been conducted on the home principle, the expansion of the city would have greatly exceeded its present limits.

The great industrial and trading interest is a correct type of New England thrift and industry. No branch of our mechanical pursuits is conducted with so much safety, energy and intelligent perseverance, as is the great Boot and Shoe interest. When convulsions come which rend in pieces other commercial or internal trading interests, the boot, shoe and leather trade, is the last to succumb, and the first to reinstate itself. The great financial crisis of 1857, thoroughly tried the strength of this branch of trade, and nobly did it sustain itself, even extending the helping hand to such as required assistance. Especially applicable is the latter remark to the merchants of Boston. All this demonstrates the soundness of their basis—the back-bone which enables the Shoe and Leather interest to hold itself up under a pressure which easily crushes all departments of trade and commerce built up on a paper foundation.

The peculiar characteristics of the boot and shoe trade, its democratic elements, its freedom from all monopoly, gives it a strength and power which corporations can never wield. Every man is his own director, and as all interested are subject to, and dependent upon, their individual shrewdness and enterprise, it is very seldom that success fails to crown their efforts. The day is not far distant when all our industrial interests will be conducted upon a like basis, and corporations cease to exist.

The almost numberless uses to which this remarkable gum has been, and is applied, has awakened an interest in the public mind concerning its discovery, and its uses, and especially the different applications, and their methods.

The discovery of Gutta-Percha is comparatively recent. The first that was known of this wonderful production by Europeans, was in the year 1845. Dr. Montgomerie, an English gentleman, residing at Singapore, observed in the hands of a Malay woodchopper, a strange material used for a handle to his axe. Curious to learn its nature, he questioned the native, and ascertained that he procured it from a tree in the form of sap; that upon exposure to the air it became solid; also, that in immersing it in hot water it became soft and plastic, and could be moulded into any desired form. Dr. Montgomerie at once obtained samples of the material, which he forwarded to the London Society of Arts and Sciences, with a description regarding it. After subjecting it to various tests, the Society were unanimous in their opinion concerning its great value. They awarded to Dr. M. a gold medal for the valuable knowledge thus communicated to the manufactories of the world.

It is observable, however, that this substance may be said to have had two European discoverers, independent of each other; for the tree, and the gum which exudes from it, were discovered or observed by Mr. Thomas Lobb. This gentleman visited the islands of the Indian seas in 1842–3, on a botanical mission, as agent to Messrs. Veitch, the scientific and energetic florists of Exeter; and it was during his rambles that he became acquainted with the gutta-percha tree.

In proportion as the value of this substance has become known, so has a desire extended to ascertain the range of its growth in the East. It is now known that the gutta-percha tree abounds in that extreme south-eastern point of Asia, which obtains the name of the Malay Peninsula; in the neighboring island of Singapore; in the important Bornean island, which Rajah Brooke has been the means of making so familiarly known to us; and in various islands which constitute the Eastern Archipelago. There seems very little cause to apprehend any failure in quantity; for even if the present supply from the neighborhood of Singapore should be exhausted, the capabilities of more distant islands are quite beyond present calculation.

It appears that percha (of which the pronunciation is pertsha, not perka or persha) is the Malayan name for the tree which produces the gum; while gutta is a general name for any gum which exudes from a tree. The tree belongs, of course, to the group in which botanists place sapotaceous or gum-exuding genera. The wood of the tree, being soft and spongy, is applied to many useful purposes. The fruit yields a thick oil, which is used by the natives with their food; and either from this or some other parts of the tree an ardent spirit is capable of being distilled. But it is the sap which forms the most valuable product of the tree. It circulates in small vessels which run up between the bark and the wood.

Thrifty methods are teachable to rude islanders, as to more civilised men, when the advantages have been once made apparent. The natives around Singapore, when they first found a market for the solidified gum, proceeded ruthlessly to work; they killed the bird which laid the golden eggs, by cutting down the trees in order to obtain the gum. But they have now been taught better; it is shown to them how, by tapping or cutting notches in the branches at certain intervals of time, the sap may be made to flow, without endangering the life of the tree. Experiments are now being made to determine whether the gutta-percha tree can be planted so as to maintain a continuous and inexhaustible store of gum or sap; should these attempts succeed, the supply would equal any imaginable demand.

The gutta-percha is sold at Singapore by weight, according to the apparent quality of each lump; but, when the consignment reaches England, it is not unfrequently found that a large stone or a piece of heavy wood is imbedded in the heart of it, to increase the weight. It would entail a serious loss of time to cut open each lump at the time of purchase; so that at present Oriental honesty is rather an important element in the commercial value of this article. There is, too, a great amount of difference in the quantity of bark, leaves, and dirt, which become accidentally mixed up with the gum.

The crude gum is imported to the extent of about two millions of pounds annually.

GUTTA-PERCHA IN THE FACTORY.

The extensive and highly interesting establishment of the Gutta-Percha Company, situated near the City Road Basin of the Regent’s Canal, is worthy of attention even beyond the general average of such centres of industry, for the peculiar character of the substance operated upon necessitates the employment of new processes, new machines, and new tools. An incessant course of invention has marked the manufacturing history of this material during the brief period of its existence. If the gutta-percha is to be applied to some new useful purpose, tools and processes of novel character have to be employed; if an ornamental application is determined on, methods are adopted for developing any natural beauty which the grain of the substance may present; if an attempt be made to supersede leather, or wood, or papier-mache, or metal, by this singular gum, great pains are bestowed on a study of the special qualities to be imitated, and the process of imitation often requires operations and tools differing considerably from those before employed.

The first process consists in cutting the block into slices. There is a vertical wheel, on the face of which are fixed three knives or blades; and while this wheel is rotating with a speed of two hundred turns a minute, a block of gutta-percha is supplied to it, and speedily cut into thin slices—much on the same principle as a turnip-cutter performs its work. Woe to the steel edges if a stone be imbedded in the block.

These slices show that the gutta-percha is by no means uniform in different parts, either in color or texture. To bring about a uniformity is the object of the shredding or tearing process. The slices are thrown into a tank of water, which is heated by steam to such a temperature as to soften the mass; dirt and heavy impurities fall to the bottom, leaving a pasty mass of gum; and the mass being thrown into another rotating machine, is there so torn and rent, and dragged asunder by jagged teeth, as to be reduced to fragments. The fragments fall into water, upon the surface of which (owing to the small specific gravity of the material) they float, while any remaining dirt or impurity falls to the bottom. These fragments are next converted into a dough-like substance by another softening with hot water, and the dough undergoes a thorough kneading; it is placed in hollow heated iron cylinders, in which revolving drums so completely turn and squeeze and mix the now purified mass, that all parts become alike, and every particle presents a family likeness to its neighbor.

The kneaded state may be considered the dividing line between the preparatory processes and those which relate to the fashioning of the material. The soft ductile mass may be formed either into sheets or tubes. In forming sheets the mass is passed between steel rollers, placed at a distance apart corresponding with the thickness of the sheet to be made—whether for the heels of a rough-booted pedestrian, or for the delicate “gutta-percha tissue,” now so much employed by surgeons. By the time that the substance has passed through the rollers it has cooled sufficiently to assume a solid, firm consistency. By the adjustment of a few knife edges, the sheet may be cut into bands, or strips of any width, before leaving the machine. In making tubes and pipes, the soft mass of kneaded gutta-percha is passed through heated iron cylinders, where a singular modification of the wire-drawing process reduces it to the desired form and dimensions.

From the sheets and tubes thus made, numberless articles are produced by cutting and pressing. Machines, somewhat like those used in cutting paper, are employed to cut the gutta-percha into pieces. If for shoe-soles, a cutting press produces a dozen or so at one movement; if for string, or thread, narrow parallel slips are cut, which are then rounded or finished by hand; if for producing stamped decorative articles, the sheets are cut into pieces, and each piece is warmed and softened to enable it to take the impress of a mould, or die. But the mode of casing copper wire for electro-telegraphic purposes is, perhaps, one of the most singular applications of the material in the form of a sheet. Several wires are laid parallel, a strip of gutta-percha is placed between them, another strip is placed above them, and the whole are passed between two polished grooved rollers; the pressure binds the two surfaces of the gutta-percha firmly together and to the wires, while the edges between the grooves indent the gutta-percha so deeply, that it may easily be separated longitudinally, each slip containing its own core of copper.

GUTTA-PERCHA BOATS.

When Lady Franklin fitted out an expedition in search of her gallant husband, a year or two ago, Captain Forsyth, the commander of the vessel, took out with him a gutta-percha boat, presented for that purpose by Messrs. Searle. His account of the behavior of this boat, under the rough usage to which it was subjected in the ice-bound regions of the north, is most laudatory. He states that “whilst the other boats constructed of wood suffered much by the cutting of the young ice, the gutta-percha boat was not in the least damaged, and returned to England in almost as good condition as when she left, although she underwent all the rough work of the voyage.” Mr. Snow, who had especial charge of the gutta-percha boat belonging to the ‘Prince Albert,’ has detailed in a clear manner the remarkable way in which this material resists the rude buffetings of those regions. It must be remembered that the boat had a skeleton of wood and a covering of India rubber. Mr. Snow says, “The severest trial it endured, and endured successfully, was on both my visits to Whaler Point, Port Leopold. To those unaccustomed to the nature of such ice as was there met with, it will be impossible fully to conceive the position a boat was placed in. The mere transit to and fro, among loose masses of ice, with the sea in a state of quiescence, would have been quite enough to have proved or not the value of gutta-percha boats; but when, as in the present case, those masses were all in restless agitation, with a sea rolling in upon an opposing current, it might have been well excused—and without deteriorating from the previously attested goodness of the article—if it had not been able to have resisted the severe shocks it received.... Sliding through and over the ice; sometimes lifted completely out of the water by the sudden contact of a resistless floe; and at others thrown side-ways upon an adjoining craggy piece; I think it would have been next to impossible for any other kind of boat to have been otherwise than crushed or stove on the instant.” It was in a right spirit that the explorers gave the name of “Gutta-Percha Inlet” to the spot where the boat had rendered them such important service.

GUTTA-PERCHA—MISCELLANEOUS APPLICATIONS.

A rare catalogue we should present, if all the useful applications of gutta-percha were duly set forth. We should have to speak of breast-coating for waterwheels, of galvanic batteries, of shuttle-beds for looms, of packing for steam-engines and pumps, of cricket and bouncing balls, of felt-edging for paper making, of curtain rings whose merit is noiselessness, of window-blind cord and sash lines, of clothes’ lines (recommended to the laundress as defying all attacks of weather,) of bosses for flax-spinning frames, of whips and sticks, of policemen’s and ‘special constables’’ staves, of flax-holders for heckling machines, of skates, of fencing sticks, of washers for the axles of wheels, of plugs or solid masses used in buildings, of buffers for railway carriages, of gunpowder canisters (which ‘keep the powder dry,’) of sheet-covering for damp walls, of linings for ladies’ bonnets, of jar covers, of sponge bags, of foot baths, of funnels, of goldsmith’s bowls, of bobbins for spinning machines, of covers for rollers, of book covers, of moulds for electrotypes, of coffin linings, of sounding boards, of portmanteaus, of beds for paper-cutting machines, of fine and coarse thread, of envelope boxes, of powder flasks, of portfolios, of a stopping for hollow teeth—a tolerable list, this, which shows how multiplied are the applications for which this singular vegetable product is available.

GUTTA-PERCHA—ORNAMENTAL WORK.

When softened by heat, this substance will take the impress of a mould or stamp with delicate precision; and in the course of a few minutes it reassumes its tough state, retaining permanently the pattern given to it. The power of application is thus unlimited, or limited only by the inclination of the purchaser. Whether the mould be of copper or of brass, of pear tree or of box, an impress can equally well be obtained from it. In practice, all these four materials are employed, and sometimes others. The mould being carved and in a state of readiness, the piece of gutta-percha (always, or nearly always, in the form of sheet) is laid upon a marble slab, which is heated by steam from beneath; and the gum being thus brought into a pliant and yielding state, it is placed on or in the mould, a counter mould is laid upon it, and the action of a press forces the material into the minutest parts of the device. If the pattern be deep and the relief bold, a hydraulic pressure of a hundred or a hundred and fifty tons is brought to bear upon it; but if of lighter and simpler character, a hand-press is brought into requisition.

In this way, aided by minor manipulation, are produced the varied and ever-increasing specimens of ornamental gutta-percha work. Trays are produced of every imaginable (or at least of every usable) form and pattern: bread trays, biscuit trays, cotton or work-table trays, counter or card-table trays, pen trays, pin trays, card trays, soap trays, shaving trays, &c. Then there are work-baskets and hand baskets, flower vases and bouquet holders, plates and platters, decanter stands and watch stands, bas-reliefs and alto-reliefs. The desk fittings admit of much beauty in this material; inkstands are produced in most diverse forms; while pen trays, paper weights, wafer boxes, envelope boxes, &c., are beginning to establish a formidable rivalry to the similar articles made in papier-mache. Beauty, pattern, graining, clouding, or whatever we may choose to term it, is produced in a very remarkable way on the surface of gutta-percha. Some specimens of gutta-percha are darker than others, and all have a tendency to darken by age; and the workman dexterously avails himself of these varying tints to produce a pattern. He softens two or more pieces, of different tints, passes them between two rollers to thoroughly unite and amalgamate them, and then presses them into the mould; leaving it to the freaks of chance to bring out the wavy lines, the curls, the streaks, the knots, which the intermixture of tints produces. This diversity is not very apparent at first; but it becomes developed when the substance is polished, and considerably enhances the beauty of the article produced.

GUTTA-PERCHA PIPES AND TUBES.

Water-pipes have had a few vicissitudes in their history. Those who remember the arrangements for the water-supply of London, in past days, will have been familiar, with the wooden pipes, formed of bored trunks of trees, which were wont to be laid down beneath the paving of the streets. These gave way to iron. The smaller pipes have chiefly been made of lead; but zinc in one quarter, brown ware in another, glass in another, have invaded the domain of lead. A new competitor now enters the field. Gutta-percha claims to be not merely an efficient material for water-pipes, but to possess certain sanitary qualities very important in this sanitary age of ours. It is very strong and tough (say the patentees); it possesses much durability underground; it stoutly resists frost; and it leaves the water as pure as it finds it. Hence it is applied to pump barrels, to ships’ pumps, to locomotive feed-pipes, to syphons and mine-pipes, and to fire-engine pipes. But if the testimony of medical men is to be deemed authoritative, the substitution of gutta-percha for lead as a material for water-pipes is a matter of yet higher import. Dr. Thomas Smith, of Cheltenham, states that “Many serious and alarming disorders, such as mania, epilepsy, sudden death, nervous affection, paralysis, consumption, hydrocephalus, heart disease, &c., owe their origin in some instances, their intractable character in others, to the gradual and continuous infinitesimal doses of lead, copper, &c., introduced into the system through the channel of our daily drink.” It appears that the carbonic acid contained in water has a tendency to combine with the lead of the pipe which contains it, and to generate a compound possessing poisonous qualities. That gutta-percha resists such action, all authorities agree; and although at first the gum imparts a slight taste to the water, this effect seems speedily to disappear.

There are many other circumstances which render tubes of this material very advantageous for the conveyance of water. It bears an amount of friction and hard usage which is frequently surprising. At New York there is a gutta-percha pipe a thousand feet in length, which conveys the water of the great Croton Aqueduct to Blackwell’s Island; the pipe lies along the bed of the intervening river, and is kept down by upwards of a hundred small anchors, and yet it resists both the friction of the bed and the weight of the anchors. With an immense pressure of water, gutta-percha pipes have been found to remain unharmed, where leather hose would be disrupted. It resists the action of marine insects, which would soon make ravages on stout timber. If water be contained in a gutta-percha pipe, it remains liquid at a temperature which would produce ice in almost any other pipes. For watering gardens and roads, for sprinkling malt in a kiln, for applying water from a fire engine, these pipes appear to be singularly well fitted, since, with a great power of resisting pressure, they may be bent, or twisted, or lengthened, or shortened, in any required degree. Nor is this material, per se, the only efficient part of such pipes; for a gutta-percha pipe may be firmly united to a metal pipe in five minutes, with no other cement than warm water; the end of the pipe being softened in warm water, and drawn over the end of the metal, the gum contracts on cooling so as to grasp the metal tightly, and thus form an impenetrable joint.

But if water be conveyed thus effectively through tubes of gutta-percha, the qualities of the material are still more remarkably displayed in the conveyance of chemical liquids. Few persons are so ignorant of chemistry as not to be aware that the stronger acids and alkalies play sad havoc with the vessels and tubes which contain them. On the other hand, there is an obstinacy of constitution about this singular substance which enables you to battle a whole host of formidable opponents. It does yield, certainly, to concentrated sulphuric and nitric acids; but if these acids in a weaker state be the liquids in question, or if muriatic, acetic, or hydrofluoric acids, or chlorine (all of which have a very destructive action), then the gutta-percha stoutly resists them, and renders good service. Carboys, pipes, dye-vats, flasks, funnels, bowls, ladles, syphons, troughs, measures, buckets—all are now made of this material, for use in chemical works, print works, dye and bleach works, and other establishments where strong chemical liquids are employed.

CEMENT EXPERIMENTS.

The chemistry of cement is a curious one; for the stony particles adhere with a force which is in some instances almost equal to the power of stone itself. The so-called Roman cement has long been famous for its cohesive property; but the Portland cement recently introduced far excels it. In an experiment lately conducted, two solid blocks were prepared, one of Roman and the other of Portland cement; and they were placed in such positions that weights might be suspended from them. The Roman cement yielded to a disruptive force of eleven hundred pounds, but the Portland cement stoutly maintained its integrity till rent asunder by a weight of nineteen hundred. But this cement has still more strikingly shown its strength when used as a mortar in brickwork. On a recent occasion in Hyde Park, a brick beam was built up with Portland cement as a mortar. The bricks were hollow, and were so ranged as to form a beam about four feet in height by two in width. This beam was rested at the two ends on supports more than twenty feet asunder, and weights were suspended from the centre; and not till the astonishing weight of nearly seventy thousand pounds was thus applied did the beam yield and break. It was not the actual binding power of the cement alone that resisted this enormous force, for thin slips of iron were introduced at different parts; but the experiment was intended to show how much strength might be obtained by hollow bricks and Portland cement, aided by a little iron.

STEREOTYPING FROM GUTTA-PERCHA.

Mr. Muir, of Glasgow, has invented a mode of stereotyping, managed in the following way. A page of common type is first set up, and well fixed: a warm cake of gutta-percha is applied to it, screwed down tightly, and allowed so to remain a quarter of an hour; when this gutta-percha mould is removed, it is brushed over with fine black-lead, and an electro-copper cast taken from it; the printing is then effected from this cast. It is found that gutta-percha constitutes a very convenient and efficient substance for the mould, owing to the readiness with which it can be softened, and its toughness when cold; while the electro-copper cast is said to bear the action of the printing press throughout a much greater number of copies than an ordinary stereotype plate.

The same inventor also practices a plan in which the gutta-percha performs not only its own work but that of the electro-copper also. A mould is taken from an engraved wood-block, in gutta-percha; and this mould, when brushed over with black-lead, is made to yield a cast also in gutta-percha, in an exactly similar way; and from this cast the impressions are printed. It seems difficult to conceive that, after this double process, all the delicate lines of a wood engraving should be preserved on the surface of such a material as gutta-percha; and yet, without this preservation, the method would be practically valueless.

ACOUSTIC USES OF GUTTA-PERCHA.

The conveyance of sound is, perhaps, the most extraordinary service which gutta-percha tubes have yet rendered.

There are two qualities required in a speaking tube; first, that it shall concentrate a large amount of sound into a small space; and secondly, that it shall not stifle the acoustic vibrations within the tube itself. Any material will answer equally well, so far as the first-named quality is concerned, for it requires simply a trumpet-shaped mouth at one end, and a very small orifice at the other; but gutta-percha possesses rare qualities in respect to the second kind of service. Whether it is the smoothness of the texture, or the peculiar kind and degree of elasticity, or the relation of the substance to heat or electricity—whatever may be the cause, a tube of gutta-percha preserves sonorous vibrations with a surprising degree of clearness and equability; and the modes in which this quality are brought into useful requisition are also very numerous.

There is, for example, the long ear-trumpet, with a wide orifice at one end and a small one at the other; and there is the portable ear-trumpet, differing from the former only in bringing the speaker and the hearer closer together, by a ‘French-horn’ system of twisting in the tube. There is the ear-cornet, so small and neat that one may be almost invisibly attached to or near each ear. There is the paraboloid trumpet, in which the sound is echoed from a large concave receiver before it enters the tube. There is the trumpet with a long flexible tube, or with several tubes, so that several persons round a table can communicate in turn with the user. In short, there have been almost as many useful variations of the principle as there are variations in the social inconveniences of those who require such aid.

A different group altogether is formed by those contrivances which are intended to aid—not partially deaf persons—but those whom noise or distance would otherwise disenable from conversing together. Drivers of omnibusses now sometimes communicate with the conductors, and captains of steamboats with the engine-men, by gutta-percha tubes. But these are trifling services compared with such as the tubes render at greater distances. The Domestic Telegraph, as it has been called, is simply a gutta-percha tube conducted from one apartment to another: it is employed as a medium of transmitting messages, and saves many a weary footstep to those who are at the beck and call of others. The Medical Man’s Midnight Friend (a lack-a-daisical sort of a title) is a gutta-percha tube extending from the ‘doctor’s’ street-door to the doctor’s bed, by which a message can be transmitted to the awakened practitioner, instead of merely the sound of his bell. In factories and large establishments such speaking tubes are advancing extensively in favor; for the communication between distant buildings is most complete. In printing offices, spinning and weaving mills, in union poor-houses, in hospitals and infirmaries, and in various other establishments of magnitude, the advantages are so self-evident that the use is becoming very general.

The church acoustic apparatus is in many respects the most interesting and remarkable of these highly curious applications. Let us conceive, for clearness of illustration, that in a remote pew of a church is a person who, though not deaf, yet fails in ability to hear what is said in the pulpit or reading-desk. A gutta-percha tube is laid down either on or beneath the floor from the pulpit to the pew—the material bends so easily that it may be carried in any form—and a small ivory or hard wood ear-piece is attached to one end, while the other end expands in trumpet-form. Now the remarkable circumstance is, that the required effect is brought about without necessitating the approach of the speaker’s mouth to the tube; his head may be two or three feet above, or below, or behind, or at the side of the trumpet-mouth; and yet the sound will reach the remote end of the tube in audible quantity. The truth is, that if the tube receives a mouth-full of sound (which it can in any direction round and near the speaker), that quantity is so economised, and so faithfully conveyed to the other end, that it becomes condensed to an audible pitch; if the trumpet-mouth be large, and the ear-piece very small, we may liken the action to the condensation of many threads of sound into one; and the ear of the auditor becomes sensible to this condensed power. In practice, the trumpet-mouth is usually fixed to the front of the pulpit, mouth uppermost, and is stamped or moulded in an ornamental form consistent with the decorations of the pulpit. Beyond all this, the sound may be laid on, like gas, to any pew or any quarter of the church; for there may be a tube (which we will call the main-pipe) laid along the centre aisle, and lateral tubes may spring from this to any required spot. Some clergymen have what they call a deaf pew; that is, a pew in which those are congregated who may be collectively benefitted by this admirable apparatus. This contrivance has been used at some of the great meetings (four thousand strong) at Exeter Hall, by those to whom the speeches would otherwise have been little else than dumb show.

Gutta-percha has been discovered in the British province of Mergui, and though not precisely identical with the gutta-percha of commerce, it possesses all the valuable properties of that substance, including plasticity in hot water, and the power of insulating electric currents.

The tree from which the true gutta taban is produced (erroneously misnamed gutta-percha, a gum yielded by a different tree,) is one of the most common in the jungles of Johore and the Malay Peninsula. It is not found in the alluvial districts, but in undulating or hilly ground. There is a great uniformity in the size of the full grown tabans, which rise with perfectly straight trunks from sixty to eighty feet in height, and from two to three feet in diameter, the branches being few and small. The natives, after felling the tree, make an incision round it, from which the milk flows. This is repeated at distances of six to eighteen inches along the whole trunk. It appears that the taban, or milky juice, will not flow freely like India rubber, but rapidly concretes. Its appearance in this state, before being boiled, is very different from that of the article as imported and shipped. It has a dry, ragged look, resembling shreds of bark, and instead of being dense and tough, is light, and possesses so little cohesion that it is easily torn to pieces.

Various statements are made as to the produce of each tree, which is somewhat surprising, considering the uniform size of the trees. It takes twenty trees to produce one picul of 133 lbs., and as the exports of gutta-percha, from the commencement of the trade up to the close of 1853, amounted to 3,107 tons, it follows that upwards of one million trees must have been destroyed to obtain that quantity in nine years. The natives, however, do not appear to be under any apprehension that the trees will be extirpated, and smile at the probability when suggested; for it is only trees arrived at their full growth, or at least at a very considerable age, that repay the labor of felling them and extracting the gutta; and those of all inferior ages which are therefore left untouched, will, it is supposed, keep up the race.

The collection of the gutta has widely extended, embracing now the Johore Archipelago, Sumatra, Borneo and Java. Unfortunately, the quality has deteriorated by the admixture of other inferior gums, the products of different trees, which are often used to adulterate the taban.

Gutta-percha, as a cement, was first introduced to our notice in 1849. A medical gentleman having received a severe cut upon one of his fingers, dissolved a portion of the gutta-percha in chloroform, then with a fine brush, first immersed in the solution, passed several times around the finger in order to produce the required thickness; then, immersing his finger in water for a short time, thus formed a neat and durable covering, air and water proof. Thus protected, it healed quickly without soreness or farther trouble. With this cement and crude gutta-percha, we first applied it to Boots and Shoes, and found it held very firmly the fibres of cloth and leather together. A sample in sheet form, we applied with a warm iron. It held with great tenacity, and with an additional quantity, we applied it with entire success, in the repairing of about five hundred pairs of shoes. These shoes had cloth uppers, without “foxing” around the heels, and were badly cut in taking out the “raw” in finishing the knife work around the heel. We have continued the use of gutta-percha as a cement for shoes, also as a water-proofing substance between the inner sole and the outer sole, and our experiments were fully successful. This process also prevented the boots and shoes from “squeaking,” that horror of nervous temperaments, at the same time adding greatly to the durability of the leather.

OBSERVATIONS CONCERNING GUTTA-PERCHA AND RUBBER IN THEIR USES IN THE MANUFACTURE OF BOOTS AND SHOES.

Among the many advantages we have observed in our experiments in the use of gutta-percha in the manufacture of boots and shoes, are its exceeding fine grain, its perfect water and oil repellent properties, which render it far superior to all rubber cements and combinations ever offered to the public. Gutta-percha is proof against water, acids, and oily substances, dampness and decomposition. It is very tenacious, clean, and sweet, and will stand all weathers, and will not become sticky. The boots or shoes made with it, may be worn in damp or dry localities, through water, oily or acid combinations, without injury to the cement. These statements are corroborated by actual tests of the severest nature.

No one will doubt who will investigate the subject of the application of gutta-percha to boots and shoes. It is worthy the study of all engaged in the manufacture of these articles, and will amply repay the closest study and investigation. Nor can it be doubted that it is destined, in a very brief period, to supersede all other improvements in the manufacture of boots and shoes.

In 1855, the “The North American Patent Boot and Shoe Co.” tested gutta-percha as a cement after they had abandoned a rubber filament or cement as useless. They continued to manufacture boots and shoes by the use of gutta-percha, and found, after a long and satisfactory trial, through all seasons of the year, that it remained firm and uninjured, not being in the least affected by the oleaginous substances or fluids used in preparing the various kinds of upper leather or sole leather. The oily matter here referred to, destroys all the rubber cements, and the Company found that gutta-percha continued as firm and tenacious after their tests, as when first applied to the shoe, and was not affected by other chemical combinations used in the construction of the shoe. That Company spared no pains or expense in perfecting part of the manufacture of the shoes, whereby they were enabled to produce a quality of goods never before equalled in lightness, style, or practical utility, exceeding, as they did, the most sanguine expectations of all interested. They fully demonstrated that shoes thus manufactured were far superior to the sewing or pegging process, or rubber cements; thus proving conclusively that the process is destined to produce an entire revolution in the manufacture of every description of fine shoes and boots.

Gutta-percha cement applied to sole leather renders it water-proof just in proportion as it is mixed with its fibres, and the quantity applied; at the same time improving the leather more than one hundred per cent. as it adds to its solidity and durability. The mixing, mingling, or saturating the fibres of the leather, or other fibrous substances, as cloth, with the cement, gives it its firm and tenacious hold on the various substances to which it is applied in the manufacture of boots and shoes, and all other combinations that require a tenacious cement.

PROCESS FOR MANUFACTURING BOOTS OR SHOES BY SIMPLY CEMENTING THE EDGES OF THE IN SOLE AND OUTER SOLE.

Objections are sometimes urged against the gutta-percha sole as being liable to sweat the feet. This objection we regard as purely mythical, as no such result will follow unless the feet are encased in rubber or gutta-percha. The top of the foot being covered with leather, thus allowing the perspiration to escape, the gutta-percha sole acts only as a protection, thus avoiding the unpleasant effects realized in wearing India-rubber shoes. Shoes or boots may be made, if desired, by cementing the edges of the inner sole and outer sole only. This process obviates the objection just alluded to. We have manufactured shoes in this manner, which have worn at least one-third longer than when pegged or sewed, the materials being the same. For perfectly dry walking they are a very desirable article. Only about one-fourth the quantity of cement is required when manufactured in this manner.

Belts of leather may be put together by this cement, which adds greatly to their wear and durability, not being in the least affected by dampness, neither by the oils which may come in contact with them from the machinery. In cutting up belt for harness leather, there is usually great waste and loss of stock, as portions of the sides are very thin, and unfit for use. But by this process every particle may be saved. Cut the stock the proper width, stretch it, then raise a strong thick fibre on all the thin parts and the laps. Apply the cement hot with a brush to all the thin portions and laps. Let it dry until the solvent has evaporated; then heat the parts sufficiently, and press together with a vice or clamps. On all the thin places apply a piece of the cemented leather until the belt is of an even thickness; press firmly together, then shave off the projections with a knife or cutting machine. Trim the edges: you will thus produce a firm, smooth belt, without a stitch, rivet, or lacing. All portions of a harness or saddle may be cemented in the same manner. This process is exceedingly simple, at the same time economical—a saving of time and money, and adds greatly to their durability.

GUTTA-PERCHA IN ITS APPLICATION TO WOOD WORK, &C.,—IMPORTANT TO SHIP AND BOAT BUILDERS.

It may be applied to vats, drains, cisterns, sinks, etc., to great advantage. All square joints should be first prepared by raising a fibre, as in veneering work. Apply the cement hot, as glue is spread. In a few hours the solvent will evaporate; then heat the parts sufficiently to melt the cement; press together firmly. The gutta-percha will be found to be an excellent cement for all leaky places in stone, brick or wood work. Mix it with sand, or any fibrous substance, apply hot, or melt it in with a hot iron. The pure gutta-percha will cement broken stone, marble or brick, so firmly that it will remain for years. It is undoubtedly the best cement ever yet discovered. Ornamental work, centre-pieces, etc., may be thus cemented to their position.

It is a well known fact, that sub-marine wires, enclosed in the gutta-percha tube, are indestructible, as all sea insects, worms, &c., never molest it. In caulking all ships, boats, &c., oakum, or any fibrous substance, may be saturated with pure gutta-percha, and then pressed hot into the joints with a hot iron. This process renders the joints proof against all agencies. The joint thus cemented is made more firm and solid than the plank itself.

The application of gutta-percha soles for boots and shoes have been extensively and satisfactorily tested, its merits having been acknowledged by all who have worn them. Indeed, experience has proved that gutta-percha soles wear twice as long as leather, with great additional personal comfort, and remain perfectly impervious to wet until worn through.

Gentlemen: I write to thank you because I can speak confidently of the advantages of gutta-percha over leather soles. I made the first pair last October, and wore them eight months before I wore the soles through. I had them heeled six times, and one pair of extra fronts I put to the same soles. I only kept one pair in use to see how long they would last. I will never wear another leather sole so long as I can obtain gutta-percha soles, and I walk from twelve to twenty miles a day.

Patent Gutta-Percha Soles.—The applicability of gutta-percha soles for boots and shoes having been extensively and satisfactorily tested, we can unhesitatingly recommend the material prepared for the purpose, its merits having been acknowledged by all who have tried it. Indeed, experience has proved that gutta-percha soles wear twice as long as leather, with great additional personal comfort, and they remain perfectly impervious to wet, until quite worn through.

Gentlemen:—I have given the gutta-percha boot soles what may be considered a fair trial, namely: three month’s constant wear on a rough, gravelly road, and can bear testimony to its usefulness. With proper care in putting them on, and a little attention afterwards, I am persuaded that it will last longer than leather, and being impervious to wet, will be found invaluable to persons subject to damp or cold feet.

Dear Sir:—It is with pleasure that I bear testimony to the good qualities of gutta-percha soles. You are aware that my occupation requires me to be on foot a great deal, upon all kinds of roads, and in all weathers, and since I began to wear gutta-percha soles, I have not had to complain of wet or cold feet. The pair I have on now have been in almost daily use for more than four months, and my fear is, that the upper leather will be worn out first. I am quite sure that I save from thirty to fifty per cent., in the cost of shoes, in consequence of my family wearing gutta-percha soles, and, so long as I can get them, I intend to wear them in preference to anything else I have seen.

Gutta-percha Boot and Shoe Soles for Summer Wear.—The fact of the total imperviousness of these soles to water, enables the most delicate, by the use of them to escape the suffering which the proverbial uncertainty of our climate, even in summer, so often inflicts upon the incautious. All injurious effects may be entirely prevented by a sole so thin and light, as to afford to the wearer a degree of ease and comfort, unattainable in conjunction with security against damp. At the same time the remarkable nonconducting properties of gutta-percha, afford a most valuable protection to those who are subject to suffering or inconvenience by walking upon heated pavements. No instance of failure has ever come to the knowledge of the company, which may not be ascribed to the neglect of the wearer.

The following article from the London Weekly Despatch will be read with interest. The writer has, evidently, not only a knowledge of the subject upon which he writes, but an appreciation of the value of gutta-percha, and its invaluable importance in the mechanical arts.

“We have lately visited the extensive works belonging to the Gutta-Percha Company, in Wharf-road City-road, and confess that we were delighted and astonished. The premises in which the business of the company is carried on cover a large area of ground. Several floors of the building are devoted to the operations of the workmen, amounting to nearly one hundred and seventy individuals, including a sprinkling of stout, hearty-looking boys. The basement is occupied by two steam-engines, without whose presence the works would by no means be complete. These groan from “early morn to dewy eve,” in turning lathes in the engineering department, in kneading the gutta-percha, cutting out soles and heels for boots and shoes, rolling out driving bands of every dimension, and heating the steam-chests by which the gutta-percha is rendered pliable and fit for the hands of the workmen. On the principal floor there are several hydraulic presses, used in the process of manufacture; and we had the good fortune to witness the production of a complete dessert service of the most chaste and elegant pattern, and in imitation of gnarled oak. The subjects of adornment were brought out in high relief, and after undergoing the process of varnishing, were surprisingly beautiful, light, and incapable of being fractured or broken by a fall or blow.”

Some of these sets were of the vine-leaf pattern, in close imitation to nature. These things were pressed out with some rapidity, but not without great manual labor, notwithstanding the aid of the powerful presses alluded to. Inkstands of the most beautiful character were also fashioned in a short time; indeed, all sorts of ornaments, elaborated with the most ingenious devices, were made during our stay. We observed a vast deal of ornamental work, intended to supersede the labor of the carver. There were frames of large dimensions ready for the reception of pictures. We were particularly struck with the appearance of one intended for a large pier-glass. The foliage was of the most sumptuous workmanship, and possessed a sharpness and finish which the hand of man could scarcely accomplish. A design for a bible cover was exhibited. The subject harmonized with the nature of the book it was intended to enclose, and was in bold relief. It is believed that gutta-percha will, in a short time, be in general use among book-binders, not only in the shape of massive covers, but to supersede the present cotton binding which has so pretty an appearance, but is not of that lasting character as to induce persons to adopt it in cases where strength and durability are required. In other portions of the factory, workmen were employed in making instruments used by surgeons, to be employed in cases of a delicate nature; others were finishing off the numerous objects just turned out of the moulds. Amongst the other articles of curiosity, we observed several yards of gutta-percha rendered exceedingly thin by machinery, and intended for ladies’ dresses. It was of a light pink color, by no means displeasing to the eye, and possessed of great strength. By the aid of delicate machinery, the gutta-percha was run out into thread, to be used in the manufacture of ladies’ work bags, fishing nets, and for a hundred other purposes.

Large tubing, and some with an inconceivably small bore, was run out to lengths of various dimensions. Wagon and cart harness, of enormous strength, combined with lightness, we observed hanging up in the establishment, besides gentlemen’s riding-whips, and things of every kind. Greatly as we were delighted with all these things, we had yet another treat to come, which infinitely surpassed anything we had seen. We were shown several specimens of enormous panelling, on which the carving of the original design was brought up with remarkable fidelity. Considering that gutta-percha is an indestructible material, we have little hesitation in stating, that the mansions of the nobility will soon be decorated with ornamental work produced by this new system of multiplying objects, produced by the ancients to their glory and eternal honor.

This important gum is known by a variety of names. Caoutchouc, gum-elastic, and India-rubber. It is a product of the syringe tree of South America. This substance was first brought to Europe in 1735, by some French astronomers, who were sent to Brazil to make astronomical observations. It is found abundantly in Peru, Brazil, and Quito, and has recently been discovered in Asia. Considerable quantities of it are now obtained in Java, Penang, Singapore and Assam. In some places hundreds of miles are covered with trees. They are very lofty, rising to the height of fifty or sixty feet, without branches, but covered with a rich tufted foliage. The bark is exceedingly smooth, its leaves deep green, thick and glossy, and six or seven inches in length. The fruit consists of white almonds and is regarded by the natives as very delicious. The process of obtaining the liquid is very simple. A longitudinal gash is cut in the bark of the tree with a hatchet, a wedge is then inserted to keep the aperture open; the gum then oozes out in the form of a milky juice. A small clay cup is attached to the tree into which the sap flows. In the space of four or five hours the milk ceases to run, and the quantity received is about five table spoonsful. The cups are now emptied and the process of smoking is commenced; this with the forming process must be done as soon as the milk coagulates. A fire is built upon the ground made of the nuts of the wassou palm tree; over this fire an inverted earthen pot, with a hole in the bottom is placed, from whence issues a jet of pungent smoke. The smoke changes the color of the gum very slightly at first, but by exposure to the atmosphere it becomes first brown, then quite black, presenting the appearance which we see it has in articles of commerce. The sap of the tree is laid on a mould in successive layers, which are allowed to dry, and are formed into bottles and cakes, in which form it is exported. The natives of South America are very ingenious in the uses to which they apply it. Boots, shoes, syringes, and tubes, are among the many articles of domestic use into which it is converted. The tubes they use as torches, which burn very clearly, and emit but little odor. According to the celebrated chemist, Faraday, its composition is carbon, 87.2, hydrogen, 12.8—a hydro-carbon. It melts when exposed to a heat of 248°, and is resolved into vapor at 600°, and can be condensed into a liquid called caoutchoucin. In 1770, a cubic inch of India-rubber was sold in London for seventy-five cents, to erase pencil marks. It was not used to make water-proof fabrics until about the year 1800. These were first invented by Charles Mackintosh, of Glasgow, who applied a naptha solution to the surface of two pieces of cloth, then laid them together, passed them between rollers and thus cemented them together.

A “Mackintosh” was the name applied for many years to a water-proof coat. Dr. Ure, although well aware of Mr. Mackintosh’s invention, coldly passes it over in his dictionary. It is supposed that personal feeling was the cause of this, as Dr. Thomson and Ure were once rival chemists in Glasgow, and Mackintosh was the friend and pupil of the former. The fabrics of Mackintosh had a most disagreeable smell, still he was the first person who established India-rubber manufactures in Britain, and perhaps the world. He afterwards removed his factory to Manchester, England. Various kinds of goods made of India-rubber soon afterwards began to be manufactured in England, but they were all decidedly objectionable to use, until the grand discovery of sulphurization was made; for this the world is indebted to an American inventor, Nathaniel Hayward of Woburn, Mass.

This substance, or rather, compounds of it, is now manufactured into so many articles of beauty and usefulness, that it forms an object of no small wonder to witness the rapidity with which such manufactures have sprung into existence.

The following description of the India-Rubber tree and its fruit is given by Chevalier D. Claussen, inventor of the flax cotton. He says that in the course of his travels in South America, he had occasion to notice the different trees which produce the India-rubber, and of which the Hancornia speciosa is one. It grows on the high plateaux of South America, between the tenth and twentieth degrees of latitude south, at a height of from three to five thousand feet above the level of the sea. It is of the family of the SapotacÆ, the same to which belongs the tree which produces gutta-percha. It bears a fruit, in form, not unlike a bergamot pear, and full of a milky juice, which is liquid India-rubber. To be eatable, the fruit must be kept two or three weeks after being gathered, in which time all the India-rubber disappears, or is converted into sugar, and is then in taste one of the most delicious fruits known, and regarded by the Brazilians (who call it Mangava) as superior to all other fruits of their country. The change of India-rubber into sugar, led him to suppose that gutta-percha, India-rubber, and similar compounds contained starch. He therefore tried to mix it with resinous or oily substances, in combination with tannin, and succeeded in making compounds which can be mixed in all proportions with gutta-percha or India-rubber without altering their characters. By the foregoing it will be understood that a great number of compounds of the gutta-percha and India-rubber class may be formed by mixing starch, gluten, or flour with tannin and resinous or oily substances. By mixing some of these compounds with gutta-percha or India-rubber, he can so increase its hardness that it will be like horn, and may be used as shields to protect the soldiers from the effect of the Minie balls, and some of these compounds in combination with iron, may be useful in floating batteries and many other purposes, such as covering the electric telegraph wires, imitation of wood, ship-building, &c.

A description of the various uses to which India-rubber is applied, will be found exceedingly interesting and instructive. The English have thus far succeeded more perfectly, or rather more generally in their application of it, than we, although since 1856, rapid strides have been made in perfecting the manufacture of the various fabrics in which it is used in our country, especially New England. It must not be forgotten that to an American is due the discovery of the process of sulphurization, which discovery immediately gave a new value, and a new impulse to the application of this wonderful product of the forests of South America.

The following account of the various uses to which India-rubber is applied, is taken principally from English sources, and refers to the manufactures of that country.

The India-rubber, or caoutchouc, now imported to the enormous extent of six or seven hundred thousand pounds annually, reaches this country in masses of varied shape, but mostly of a dark color. In its imported state it is used for very few purposes; considerable modifications being necessary for its adaptation to practical service. It requires to be transformed into cakes, or sheets, or tissues, or tubes, or solutions, preparatory to its ultimate use; and this transformation requires operations of a somewhat peculiar kind, owing to the necessity of rendering the whole mass homogeneous in substance.

The bottles, and masses, and fragments, as imported, have much inequality in texture, and are, moreover, contaminated with much dirt and refuse. To separate these, the India-rubber is first cut into very small fragments, and then steeped in warm water, by which the dirt is precipitated. The fragments are dried, and are then thrown into a kind of kneading machine, where immense pressure is employed to bring them to one homogeneous mass. The India-rubber, though put in cold, becomes so hot by the agitation that it could not be safely touched by the hand; it is necessary to supply the machine with cold water, which is made nearly to boil by the caloric driven out of the elastic mass. So thoroughly is the mass pressed, rolled, pricked, cut, and kneaded, by the severe turmoil which it undergoes, that all dirt, air, water and steam are expelled, and it presents the appearance of a dark colored, uniform, smooth mass. It is put into cast iron moulds of great strength, and brought, by hydraulic or screw pressure, to the form of blocks, slabs, or cylinders, according to the purpose to which it is to be applied.

MACKINTOSH CLOTH.

The manufacture of the Mackintosh cloth is a singular one. The material is merely two layers of cotton cemented with liquid India-rubber; but the junction is so well effected, that the three become to all intents and purposes one. The stout and well-woven cloth is coiled upon a horizontal beam, like the yarn beam of a loom; and from this it is stretched out in a tight state and a nearly horizontal position. A layer of liquid or rather paste-like solution is applied with a spatula, to a considerable thickness, and the cloth is drawn under a knife edge, which scrapes the solution and diffuses it equally over every part of the cloth, which may be thirty or forty yards long. The cloth is then extended out on a horizontal framework to dry; and, when dried, a second coating is applied in a similar way; and a third and fourth may be similarly applied if necessary. Two pieces, thus coated, are next placed face to face with great care, to prevent creasing or distortion; and, being passed between two smooth wooden rollers, they are so thoroughly pressed as to be made to unite durably and permanently. Cloth, thus cemented and doubled and dried, may be cut and made into garments which will bear many a rough trial, and many a deluging before rain or water can penetrate.

It is as a sheet and as a thread that India-rubber meets its most extensive application; and both of these are made by cutting from the blocks and slabs. A block is cut into sheets by an ingenious machine, in which a sharp knife-edge has a rapid vibratory motion in a horizontal plane, so adjusted as to cut a thin film from a block of India-rubber supplied to it by a steady motion. The knife requires to be kept cool by a flow of water, or it would adhere to the India-rubber. In this way thin sheets may be cut, or thicker sheets from which stationers’ India-rubber may be obtained, or sheets of any thickness, great or small, according to the purposes required.

The separation of the material into shreds or narrow strips is a very pretty operation, exhibiting much nicety of manipulation. A continuous strip may be cut from a bottle or any other curved mass of the India-rubber. The bottom of the bottle is cut off, and is pressed into a round and tolerably flat form. The cake thus fashioned is fixed to the end of the horizontal shaft, or lathe-axis, and is made to revolve with great rapidity; and while so rotating, a circular knife, rotating at high speed, cuts through the substance, and advances steadily towards the centre of the disc; thereby separating the disc or cake into one continuous spiral thread. This thread can be easily drawn out straightly, and can even be separated into two or more finer threads, by drawing it through a hole where one or more sharp-cutting edges encounter it. If a bottle or any other hollow piece of India-rubber can be drawn over a cylinder of uniform diameter, it may be cut into a continuous thread, by a modification of the same machine; the cylinder being made to revolve, a steel cutter is placed against it, and as the cylinder has a slow longitudinal motion given it, the gum is cut spirally from end to end—just on the same principle as a worm or thread is cut on a bit of iron by the screw-cutting machine. Machines of this kind were invented in France more than twenty years ago; but the machines used in our own country are of English invention and of later date.

INDIA-RUBBER LIQUID.

When once it was discovered that India-rubber may be dissolved in petroleum, in naptha, or in oil of turpentine, it was speedily seen that a new and extensive sphere of utility was given to it. The coarsest pieces, as imported, the waste from the kneading operations, and the parings and cuttings from other manufacturing operations, are placed in a close iron vessel, to which the liquid solvent is added. A brisk agitation is kept up, and the heat thereby generated in the elastic gum warms the liquid and increases its solvent power, until at length the whole of the gum is dissolved. This operation is conducted on a somewhat extensive scale; for the iron vessel is large enough to contain more than half a ton of India-rubber, which requires three days of constant agitation for complete solution. The liquid thus produced has a consistency which fits it to be used as a varnish, or as a water-proofing medium, or as a cement, or for many other purposes which the sagacity and self-interest of manufacturers have enabled them to discover.

INDIA-RUBBER BRAIDS AND WEBS.

If we glance among the stores of the India-rubber manufacturers and retailers at the present day, we find the braids and cords, webs and bands, form no inconsiderable portion of the wares exposed for sale. These, in most cases, require that the India-rubber should be first made into blocks or cakes, next cut into sheets, and then separated into threads, or cords, or narrow strips. Supposing these preliminary cuttings to be effected, the making of braids and webs is exceedingly curious, for it involves a combination of the India-rubber with other materials. Let us briefly trace the processes. In the first place, the narrow cords are stretched by a kind of wheel, and kept extended till nearly deprived of their elasticity, and till they form a thread of the desired thickness. The thread is then put into a braiding machine which is a complicated and very ingenious apparatus, whereby a sheathing of cotton, silk, flax, or worsted, is wound round the India-rubber thread. In such a machine several threads are twisted round each other, from three to nearly thirty in number; each thread has its own bobbin, and all the bobbins revolve round a common centre, giving out their threads in the proportions and order required. Generally speaking, the braiding machine is employed in making stay-laces, braid, upholsterers’ cord, &c.; but it is also applicable to making the numerous elastic cords and webs which owe their elasticity to India-rubber. When an envelope of cotton, silk, flax, or worsted, has been given to the thread of India-rubber by the braiding machine, the threads are laid as warp in a loom, and woven into the required kind of web, whatever it may be. Then comes a curious development of the properties of the material; in the preliminary stretching, the India-rubber was made somewhat stiff and unyielding; but by now exposing it to the action of a hot smoothing iron upon a table, the elasticity is restored, the riband or web contracts in length, and the sheathing or envelope corrugates or wrinkles up on the surface. The web thus produced is very soft and elastic. The warp threads may be alternated with others of non-elastic character; and the weft-threads may be either elastic or non-elastic, so that any desired degree of elasticity may be obtained.

INDIA-RUBBER VULCANIZED.

Why a piece of India-rubber, when it has been somewhat modified by heat and chemical action, should be deemed vulcanized, it is for the inventor to say. Let us take the name simply as an expression of a fact, that fire or heat has been brought to bear upon this substance as a means of affecting its qualities. The method was invented by Mr. Hancock seven or eight years ago, and it has been the means of giving a wide extension to the use of India-rubber.

This vulcanized India-rubber is in fact a compound of sulphur with the vegetable gum. When a sheet of India-rubber is immersed in liquid sulphur, a marked change takes place in its qualities; the sulphur acts upon the gum and combines with it; and indeed the two may almost be said to form a new substance. The methods by which the combination is brought about are varied, but the effect is in all cases very remarkable. The strength of the India-rubber is increased to an extraordinary degree. The elasticity is rendered more permanent, analogous in some respects to that of gutta-percha. The new substance will absorb essential oils without injury, whereas such oils would dissolve India-rubber. It retains its properties at a temperature so low that India-rubber would be too much hardened for use; and at a temperature so high that India-rubber would be destroyed. Later experimenters have found that antimony, and many other substances, may similarly be combined with India-rubber; and it is reasonable to expect that many useful novelties are in use for us in this “vulcanized” rubber.

INDIA-RUBBER OR (CAOUTCHOUC) AND GUTTA-PERCHA—COMPARISON OF THE CRUDE MATERIALS.

Much ignorance exists in relation to the intrinsic merits of gutta-percha and India-rubber. It is generally supposed that there is so little difference that it is hardly perceptible, and that the one or the other may be used for the same purposes, with the same results. In order to correct this impression and convey an intelligent idea of their relative properties, we here give an analysis of the two gums:

Gutta-percha when immersed in boiling water contracts considerably in bulk, whilst India rubber, when immersed in boiling water, expands and very materially increases in bulk. Gutta-percha juice also is of a dark brown color, and consolidates in a few moments after exuding from the tree, when it becomes about as hard as wood. India-rubber sap, on the contrary, is perfectly white, and of about the consistency of thick cream; when it coagulates it gives from four to six parts water out of ten. Gutta-percha first treated with water, alcohol, and ether, and then dissolved with spirits of turpentine and precipitated, yields a substance consistent with the common properties of gutta-percha; but India-rubber similarly treated, results in a substance resembling in appearance the gum arabic. Gutta-percha by distillation yields 57? per cent. of volatile matter; India-rubber by the same process, yields 85¾ per cent.

India-rubber, or caoutchouc, is produced from a milk-white sap taken chiefly from the Sephonca Cahuca tree, afterwards coagulated, and the whey pressed out or dried off by heat—the residue is the India-rubber of commerce.

Gutta-percha is produced from the Isonandra, or Gutta tree; is of a brownish color, and when exposed to air, soon solidifies, and forms the gutta-percha of commerce.

India-rubber of commerce, is of a soft, gummy nature, not very tenacious, and astonishingly elastic.

Gutta-percha of commerce is a fibrous material, much resembling the inner coating of white oak bark, is extremely tenacious, and without elasticity, or much flexibility.

India-rubber, when once reduced to a liquid state by heat, appears like tar, and is unfit for further manufacture.

Gutta-percha may be melted and cooled any number of times, without injury for future manufacture.

India-rubber, by coming in contact with oil or other fatty substances, is soon decomposed and ruined for future use.

Gutta-percha is not injured by coming in contact with oil or other fatty substances—in fact one good use of it is for oil cans.

India-rubber is soon ruined for future use, if brought in contact with sulphuric, muriatic, and other acids.

Gutta-percha resists the action of sulphuric, muriatic, and nearly all other acids—in fact one great use of it is for acid vats, &c., and other vessels for holding acids.

India-rubber is a conductor of heat, cold and electricity.

Gutta-percha is a non-conductor of electricity, as well as of heat and cold.

India-rubber, in its crude state, when exposed to the action of boiling water, increases in bulk, does not lose its elastic properties, and cannot be moulded.

Gutta-percha, in its crude state, when exposed to the action of boiling water, contracts and becomes soft like dough or paste, and may then be moulded to any shape—which shape it will retain when cool.

India-rubber is vulcanized to reduce its elasticity and give it more firmness than is natural to the crude material.

India-rubber, vulcanized, is not so perfectly a repellent of water, as before being vulcanized.

India-rubber is not a perfect repellent of water, but is more or less absorbent, according to quality.

Gutta-percha has an exceedingly fine grain, and its oily property makes it a perfect repellent of liquids, oils, acids, and all oleaginous substances, so that when united to tanned leather, the oil in the leather will not affect the adhesive properties of the gutta-percha. Whereas oil in leather will decompose any India-rubber cement that may be applied to it.

Pure gutta-percha is without smell or disagreeable odor, and whenever it is found to produce any but a perfectly sweet odor, it arises from its impurities, and may be regarded as a test of its quality.

India-rubber when vulcanized has an odor about it very disagreeable. It will decompose, become sticky like tar, and much of it becomes entirely useless. It is vulcanized to reduce its elasticity and give it more firmness than is natural to the crude material, and when exposed to friction, even after vulcanization, it rolls up a dirty, sticky mass.

The foregoing analysis is so simple and clear, that the attentive reader will at once comprehend the natural as well as chemical differences existing in gutta-percha and India-rubber, being not only chemically, but mechanically and commercially different.