CHAPTER I.
DISCOVERY
OF THE
SULPHURIZATION AND VULCANIZATION OF INDIA-RUBBER
IN AMERICA.
It may be safely stated that no chemical discovery within the last century, has produced such wonderful results as those here alluded to. From being a simple gum, the use of which was limited to the erasure of the school boy’s blunder, or the merchant’s mistakes, India-rubber, by the process of vulcanization, has become one of our most important articles of commerce. It is one of the most wonderful products of nature that has ever been applied to the arts.
The first attempt to manufacture caoutchouc or India-rubber into clothing, and articles of daily use in this country, was upon the discovery that the essential oils was a dissolvent of the gum sufficient to spread it upon cloth. This was the beginning of the excitement. The idea of making water-proof clothing took possession of the public mind at once. This was about the year 1834. Spirits of turpentine was the cheapest and most effectual solvent. A company organized and established a large manufactory in Roxbury, Mass., and the shares at $100 par value soon went up in the market to 3 or 4 hundred.
It was soon found however, that they had not sufficiently investigated the matter. In a few months, or perhaps weeks, the manufactured articles which at first presented a substantial face became soft again and adhesive, so much so that masses of clothes adhered together and became almost a solid body. But the excitement continued as the real facts were not made known to the public; companies were formed, and factories were erected to a considerable extent before the bubble burst.
The discovery of sulphurization in the United States was made about the year 1835, by Mr. Nathl. Hayward, a native of Easton, Mass. Mr. Hayward was at this time a resident of Boston, the proprietor of a livery stable. Being of an inventive turn, his mind for a long time had been revolving the idea of applying some substance which would remove the cause of the adhesiveness of the manufactured article so fatal to the success of this great enterprise. Not possessing a thorough knowledge of chemicals or their compounds, Mr. Hayward purchased at random a great variety of drugs to mix with the dissolved rubber. These he placed in the sun hoping that he might, by chance hit upon that substance which would cause the rubber to become hard and retain its consistency. White lead, and all other substances which possessed the virtue of “driers” were successively subjected to his alembic. For months Mr. Hayward prosecuted his investigations, but hitherto without success. Finally, becoming discouraged, he one day collected all the various drugs, etc., which he had purchased, and threw them indiscriminately into a boiler, happening to have some sulphur in hand which he had procured for his horses, he mixed that in with the rest. Nil desperandum—the result of this experiment was the key to the long sought for secret. A fine substantial India-rubber cloth was produced free from stickiness, and presenting the peculiar appearance of sulphurized rubber.
The result was produced, but which of the agencies had caused this wonderful transformation? For months Mr. Hayward pursued his investigations, until at length the mystery was unveiled. Thus by ACCIDENT was this important discovery made.
Yet another discovery was necessary in order to fully complete the magnificent results which Hayward had developed. Sulphurized goods were found to emit a very unpleasant odor, and what was of still greater importance, the goods became rigid in cold weather, and loose and elastic in warm weather. These objections must be removed, or the discoveries of Hayward would lose their chief importance. Vulcanization, subsequently discovered by Goodyear, was the important element to be applied. To Hayward and Goodyear conjointly is the world indebted for the benefits which have followed as a sequence to their discoveries. They stand like the Siamese twins connected by reciprocal inventive faculties, the one equally dependent upon the other for the success which has crowned their united efforts. The intelligent reader cannot fail to see the relative importance which the one holds to the other, and how admirably the genius of Goodyear completed what the untiring energy of Hayward first disclosed. This much is necessary at this point to introduce the reader to what follows concerning vulcanization.
On the 24th day of February, 1839, Mr. Hayward secured a patent for vulcanizing India-rubber by means of sulphur, which patent was assigned to Charles Goodyear—a man of shrewd and future grasping mind. Some idea of the importance of this improvement may be formed from the fact that it has been a subject of continual litigation for a number of years; yea, almost since the day the patent was issued. It is the real vulcanizing substance now used in the manufacture of India-rubber fabrics of every description. The claim is in these words: “the combining of sulphur with gum-elastic, whether in solution or in substance, either by mixing with the digested India-rubber, kneading it, or sprinkling it on the surface of sheets and pressing it in.”
At the time of the famous contest between Goodyear and Day, testimony was produced by which it was endeavored to be proved that the vulcanization of India-rubber was discovered in Germany by F. Luedersdorff, six years before Hayward’s patent was granted. Some doubts have been expressed concerning the statement. Whether true or false, we cannot see why the circumstance should detract in the least from the claims or position of Mr. Hayward, inasmuch as it is very conclusive that his discovery was purely accidental.
A Prussian pamphlet published at Berlin in 1832, describes the experiments made by F. Luedersdorff with India-rubber, and the production of sulphurized India-rubber compounds. The Scientific American in speaking upon this subject, and combating the claims of the learned Prussian has the following:—
“The clamminess of dissolved India-rubber, and its tendency to decomposition are attributed to its resinous properties. On page 28, the following language occurs: ‘After a long series of experiments, in which neither deodorizing or oxidizing substances, neither alkalies, nor mechanical means, which affected the speedy drying, produced the desired result; I succeeded at last in finding in sulphur the substance, which even in very small quantities, perfectly prevented the injurious effect of the resinous aggregation.’ Instructions are given how to prepare the sulphur solution, by heating and stirring three parts of flour sulphur in one hundred parts of rectified oil of turpentine, bringing them to a boiling heat, then dissolving the India-rubber in the solution. By Hayward’s patent, one teaspoonful of sulphur was mixed with that quantity of oil of turpentine required to dissolve a pound of India-rubber, and in this respect, there is little difference between his method and that of the Prussian doctor. It is the sulphur which is the grand agent in the production of vulcanized India-rubber, no matter how combined, in solution, or with India-rubber softened by heat. Leave sulphur out of the question, and we would have no vulcanized India-rubber fabrics.
“The question now arises, what reliance is there to be placed upon the authenticity of this pamphlet, published six years before Hayward’s patent was obtained? We have been assured that the original work is in the College Library, at Providence, R. I.; but it is rather singular, that in the many controversies on this subject, and the numerous suits at law which have taken place, respecting the originality of the invention, that such information was not produced as testimony before some tribunal.
“That Dr. Luedersdorff made the experiments described, we will assume to be true in every respect, but neither is our country or any other indebted to him in the least, for the introduction and success of India-rubber manufactures. To American inventors alone, is the world indebted for the invention of vulcanized India-rubber. Hayward was no doubt totally ignorant of the Prussian doctor’s experiments; he probably could not read German; he made the discovery of sulphurized India-rubber by his own efforts, and he is an original inventor, in this sense of the term.”
We have thus given a brief account of this remarkable discovery. Heretofore but little has been written or published upon the discovery, and the subsequent inventions to which it gave rise. The books which have been published have carefully avoided full and complete statements or facts, and have contained little or no information of value, but on the contrary, have seemed, at least, to deal in generalities calculated to befog and mislead.
In the long and tedious trials which tasked the ingenuity and power of Webster and Choate, it was clearly proven that the articles claimed to be made by specifications there introduced, could not be manufactured by such compounds. To all who are interested in the facts, etc., elicited upon these celebrated trials, we would refer them to “Day’s Bible” if obtainable, containing the Genesis and Revelation of all that could then be said or written upon the subject.
“The profits on the India-rubber business will reach almost two millions of dollars in the year, and the present manufactories cannot supply the demand. Shoes which weigh nine ounces per pair have only about three and a half ounces of rubber, the other materials being worth only from one to six cents per pound. One girl can make from twenty to thirty pairs per day, hence, enormous profits have been derived by the manufacturers of such goods. The best valve packing is made of 30 lbs. of India-rubber, 6 lbs. of lampblack, 22 lbs. red or white lead, and 22 oz. of sulphur; these metalizing substances are all very cheap. India-rubber is easily rendered plastic, and combines readily with almost every substance, such as the oxides of metal, clay, pulverized sand, gums, carbon, saw-dust, ground cork, &c. It is, certainly, one of the most wonderful and useful products of nature that has ever been applied to the arts.”
The importance of the discovery of the vulcanization of India-rubber to the world, can hardly be over-estimated, whether regarded in the light of science, or political economy. But comparatively few years have elapsed since its highest uses were discovered and applied; and even now, with all the success which has thus far crowned the efforts of those engaged in its development, it is yet in its infancy. Like many of the most important discoveries in the mechanic arts, that of vulcanization was imperfectly applied, and millions of dollars were expended in the manufacture of improperly vulcanized goods, mills, machinery, &c.
No sooner had the practicability of manufacturing boots and shoes from India rubber been demonstrated, than the attention of capitalists, and inventors, was turned to this new field of enterprise. Without stopping to test the nature of the gum which was to be moulded in golden ingots, viz., the manufacture of boots, shoes, etc., and the effect of the seasons upon the manufactured articles, the anxious speculator, and the enthusiastic manufacturer plunged boldly into the sea of trade. All classes became interested in its success, stock companies were formed, the shares of which were eagerly snatched up, and visions of untold profits were divided in anticipation. But the “bubble” soon burst, goods manufactured and solarized in April, became a sticky mass of useless rubbish in July. The warm weather literally melted the hopes and expectations of the incautious adventurer. A panic was the consequence, mills were abandoned, thousands of artizans were suddenly thrown out of employment, and this vast field of enterprise so promising but a few months before, was swept as by a hurricane. Hundreds of thousands of tons of India-rubber, both raw and prepared were either given away, or sold at ruinous sacrifices. Hilltops blazed with its ignited masses, and the illuminations of the fourth of July succeeding the failure, were made unusually brilliant by the aid of the India-rubber panic.
As before intimated, the cause of this great loss of money and material, originated in the “indecent haste” of the manufacturer. In the first place, solarization, that is heating in the sun the cloth, or other substance upon which the gum or compound of rubber, and some foreign substances was spread, was an imperfect process, as the heat of the sun was not sufficiently powerful to evaporate the solvent, and form a chemical union between the sulphur and the rubber, which union constitutes perfect vulcanization.
The unfortunate result of the “experiment” was so dearly purchased, that all who were engaged in the traffic, abandoned it without an attempt to profit by experience. It is at this point that we introduce Mr. Charles Goodyear, a man of observation, possessing a larger share of perseverance than is usually found in any single individual, together with fair inventive genius. He saw the sad results of that zeal which is without knowledge, and resolved to find if possible, the thread which should guide him safely through the labyrinth of this mystery. He undertook the task alone, as the severe reverses which had visited the pioneers in the movement, had disgusted them with further attempts to correct, what appeared to be insurmountable objections. Mr. Goodyear seemed to be impressed with the idea that nature never plays practical jokes, and that what had already been accomplished in the uses of rubber was simply an earnest of what might be realized. Acting upon this conjecture, we see him devoting himself to the elucidation of the mysterious problem. Two important points were to be gained. To those acquainted with the India-rubber or gum-elastic, it is well known that after it has been subjected to a certain tension for any considerable time, it loses its elasticity; also, that during hot weather it melts and becomes sticky or adhesive, and in cold weather becomes stiff and rigid, and correspondingly less pliable. These important, in fact, fatal objections must be removed, or India-rubber would become comparatively valueless. Mr. Goodyear engaged in the work with all the enthusiasm of his nature, and notwithstanding he was without money, and the sympathy of friends, and was frequently the subject of privations, hardships, and imprisonments, still he labored on, as though a presentiment of the discovery of the long sought for secret was continually before him, encouraging him to work and he should finally triumph. His persistent efforts were finally successful. The admixture of sulphur with the gum at a heat of about 270°, was the “open sesame” to the treasures which he ultimately realized in the prosecution of his labors.
The Commissioner of Patents of the United States, the Hon. Joseph Holt, in his late decision upon the “extension” of the Goodyear Patent, thus eloquently discourses concerning the early efforts of Mr. Goodyear, in the search of his ultimately wonderful discovery.
“As early as 1834–’5, Mr. Goodyear seems to have formed a most exalted estimate of the capabilities, as a material for manufacture, of the gum known as caoutchouc or India-rubber. This gum had been previously extensively employed in the fabrication of a variety of articles, but, owing to their indifferent quality, all concerned in these enterprises, as well as in those which followed for a series of years afterward, were involved in bankruptcy and ruin. The fabrics thus made could not keep the market, because they were found to grow rigid under the influence of cold, and to soften and become sticky under that of heat, while they rapidly decomposed when brought into contact with perspiration and the animal oils. The applicant was thoroughly convinced that these qualities, which had proved so disastrous to the trade, could be removed, and he set himself resolutely to work to ascertain the process for accomplishing this result. Sulphur had already been advantageously combined with India-rubber by Hayward, so that the discovery had been approached to its very verge. The step, however, which remained to be taken, short as it was, was indispensable, and without it all those which had preceded it would have been unavailing. Science could afford but little assistance in the inquiry, for, as the event proved, the most potent element in the process was too subtle to be disclosed by the severest chemical analysis. The applicant had therefore to pursue the investigation gropingly; but he persisted in it with an ardor and a courage which nothing could abate or daunt. His aim was definite, his conviction as to its attainability complete. As one who searches for a hidden treasure in a field where he knows it is to be found, so pursued he his explorations in quest of this secret. He sought it on the right hand and on the left, by day and by night, in the midst of ceaseless toil and lavish expenditure, and by the light of every form of experiment which his most fertile genius and daring spirit could suggest. He became completely master of everything known in regard to the properties of the material which it was his ambition to improve, and so thoroughly was he imbued with the soul of his inquiry, and so intensely quickened was his vigilance, that no phenomenon, however minute, could meet his eye, no sound, however faint, could fall upon his ear, without his at once detecting and appreciating its bearing upon the great problem whose solution he was seeking. From four to five years were passed in these unremitted labors, when an incident occurred which at once revealed the long sought truth. And it is a singular coincidence, that the spark of light yielded by this incident, was elicited by a collision, so to speak, the result of that intense zeal which, so far as health and fortune were concerned, had been the consuming fire of his life. In one of those animated conversations so habitual to him, in reference to his experiments, a piece of India-rubber combined with sulphur, which he held in his hand as the text of all his discourses, was by a violent gesture thrown into a burning stove near which he was standing. When taken out, after having been subjected to a high degree of heat, he saw, what it may be safely affirmed would have escaped the notice of all others—that a complete transformation had taken place, and that an entirely new product—since so felicitously termed “elastic metal”—was the consequence. When subjected to further tests, the thrilling conviction burst upon him that success had at length crowned his efforts, and that the mystery he had so long wooed, now stood unveiled before him. His history in this respect is altogether parallel with that of the greatest inventors and discoverers who have preceded him. The lamp had swung for centuries in the Cathedral of Pisa, but of the thronging multitudes who worshipped there, none had heeded the lessons which it taught. It was reserved for the profound and observant intellect of young Galileo to extract from its oscillations the true laws of the pendulum, which led to the creation of an infallible measure of time. The theory of universal gravitation loses nothing of its grandeur or value because suggested by the falling of an apple from the tree. In all lands, by teeming millions, this phenomenon had been observed, but to none had it imparted instruction—to none had it spoken of that wonderful secret which lurked beneath its simple features. At length its “still small voice” fell upon the delicate and appreciative ear of one whom it startled into inquiry. The light thus afforded, to which all had been blind, was indeed dim and twinkling; but, following its guidance, as one who traces back the dawn, the great Newton soon plunged into the full-orbed splendors of a discovery confessedly the most brilliant which has gilded and ennobled the annals of science. On all the hearthstones of the civilized world, for thousands of years the kettle had boiled and lifted its lid by the expansive power of its steam; yet for none had this seemingly trite and ever-recurrent incident been significant—to none had it announced that measureless power of which it was the humble but distinct exponent. At length the movement caught the eye of a lonely student of nature, then a prisoner in the Tower of London, and in the soil of his prolific mind it proved the rapidly expanding germ of that steam-engine whose triumphs have changed the social, political, and commercial aspects of the globe. So India-rubber in combination with sulphur may by accident have been exposed to a high degree of heat often before without attracting the attention of any; and it is safe to allege that it might have been thus exposed a thousand times afterwards, without the world’s having been wiser or wealthier for it. The thorough self-culture and training of the applicant and his unwearied researches prepared him at once to seize upon, to comprehend and embody in a practical form, the truth he sought, the moment it presented itself, no matter how dimly, to him. This was his merit—the same in kind with that of the most illustrious inventors who have appeared in the world, and by that of but a few of them surpassed in degree. It is a figure of speech—but an exalted mode of expression—which assigns to man any part in the work of creation.”
The importance of this discovery is well understood. Gum-elastic is thereby made permanently elastic—it resists exposure to heat and cold—is elastic under compression—is impervious to wet—resists the action of solvents to a remarkable degree, and the attacks of vermin of all kinds. It can be moulded into almost every conceivable shape for use, or beauty. In the mechanical arts it has been subjected to a thousand uses, with remarkable success. And here we may remark en-passant, that gutta-percha was discovered subsequently, and is already a formidable rival of India-rubber inasmuch as the latter is affected by oils, and will, in a short time, except as a hard gum, become decomposed, whereas the former (gutta-percha) is not affected in the least by oils or acids, in its pure state; and here is the grand secret of the failure of those shoe manufacturers, who, ignorant of the fact that those shoes or boots cemented by a rubber filament would in a short time become useless, owing to the decomposition of the cement caused by the oil in the leather, were induced to make heavy outlays in the fitting up of large manufacturing establishments which were finally abandoned from this cause alone. Gutta-percha is a firmer and more consistent gum than India-rubber. Gutta-percha when placed in boiling water contracts considerably in bulk, while India-rubber expands. Gutta-percha juice, when taken from the fire, is of a dark brown color, and consolidates in a few moments, and becomes hard like wood. India-rubber sap is perfectly white, and has the appearance 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 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 gum arabic.
Gutta-percha by distillation yields 57? per cent. of volatile matter; India-rubber by the same process, yields 85¾ per cent.
But Mr. Goodyear’s discoveries of vulcanization, as applied to the softer elastic compounds, did not end there. He continued his experiments for the space of five years from the time of his first grand discovery, when he obtained his patent for Vulcanized Hard Rubber. This invention was the crowning result of his long, patient, and laborious researches.
Probably the entire history of inventions cannot furnish an instance of more intense self-sacrificing, entire self-immolation to the elucidation of a great scientific principle, than is shown in the persistent labors of Mr. Goodyear while in pursuit of the crowning discovery of the age. Let us read the glowing account of his toils and disappointments, his defeats and victories, as given by the Commissioner from whom we have previously quoted.
“From the first moment that the conception entered his mind until his complete success—embracing a period of from sixteen to eighteen years—he applied himself unceasingly and enthusiastically to its perfection and to its introduction into use, in every form that his fruitful genius could devise. So intensely were his faculties concentrated upon it that he seems to have been incapable of thought or of action upon any other subject. He had no other occupation, was inspired by no other hope, cherished no other ambition. He carried continually about his person a piece of India-rubber, and into the ears of all who would listen he poured incessantly the story of his experiments and the glowing language of his prophecies. He was, according to the witnesses, completely absorbed by it, both by day and night, pursuing it with untiring energy and with almost superhuman perseverance. Not only were the powers of his mind and body thus ardently devoted to the invention and its introduction into use, but every dollar he possessed or could command through the resources of his credit, or the influences of friendship, was uncalculatingly cast into that seething cauldron of experiment which was allowed no repose. The very bed on which his wife slept, and the linen that covered his table, were seized and sold to pay his board, and we see him, with his stricken household, following in the funeral of his child on foot, because he had no means with which to hire a carriage. His family had to endure privations almost surpassing belief, being frequently without an article of food in their house, or fuel in the coldest weather—and indeed it is said that they could not have lived through the winter of 1839, but for the kind offices of a few charitable friends. They are represented as gathering sticks in the woods and on the edges of the highways, with which to cook their meals, and digging the potatoes of their little garden before they were half grown, while one of his hungry children, in a spirit worthy of his father, is heard expressing his thanks that this much had been spared to them. We often find him arrested and incarcerated in the debtor’s prison, but even amid its gloom his vision of the future never grew dim, his faith in his ultimate triumph never faltered. Undismayed by discomfitures and sorrows which might well have broken the stoutest spirit, his language everywhere, and under all circumstances, was that of encouragement and of a profound conviction of final success. Not only in the United States did he thus exert himself to establish and apply to every possible use his invention, but in England, France, and other countries of Europe, he zealously pursued the same career. In 1855, he appeared at the World’s Fair in Paris, and the golden medal and the Grand Cross of the Legion of Honor were awarded to him as the representative of his country’s inventive genius. Fortune, however, while thus caressing him with one hand, was at the same moment smiting him with the other; for we learn from the testimony that these brilliant memorials passed from the Emperor and reached their honored recipient, then the occupant of a debtor’s prison among strangers in a foreign land—thus adding yet another to that long sad catalogue of public benefactors who have stood neglected and impoverished in the midst of the waving harvest of blessings they had bestowed upon their race. Throughout all these scenes of trial, so vividly depicted by the evidence, he derived no support from the sympathies of the public. While the community at large seemed to have looked on him as one chasing a phantom, there were times when even his best friends turned away from him as an idle visionary, and he was fated to encounter on every side sneers and ridicule, to which each baffled experiment and the pecuniary loss it inflicted added a yet keener edge. The mercenary, naturally enough, pronounced his expenditures, so freely made, culpably wasteful; the selfish and the narrow-minded greeted the expression of his enlarged and far-reaching views as the ravings of an enthusiast; while it is fair to infer from the depositions, that not a few of the timid and plodding who cling, tremblingly apprehensive of change, to the beaten paths of human thought and action, regarded him as wandering on the very brink of insanity, if not already pursuing its wild and flickering lights. Such in all times has been the fate of the greatest spirits that have appeared on the arena of human discovery, and such will probably continue to be the doom of all whose stalwart strides carry them in advance of the race to which they belong. With such a record of toil, of privation, of courage and of perseverance in the midst of discouragements the most depressing, it is safe to affirm that not only has the applicant used that due diligence enjoined by law, but that his diligence has been, in degree and in merit, perhaps without parallel in the annals of invention.”
The change produced in the native gum has been aptly compared to the change which is wrought in the perishable hide by the process of tanning. We can hardly estimate the uses to which this “vulcanite” may be applied, or rather we may say we shall find it quite as difficult to say what uses it cannot be made to subserve. It can hardly be denominated an improvement, but a creation. Daniel Webster in his great plea, Goodyear vs. Day, eloquently remarks that, “it introduces quite a new material into the manufacture of the arts, that material being nothing less than elastic metal. It is hard like a metal, and as elastic as pure original gum elastic. It is as great and momentous a phenomenon occurring to men in the progress of their knowledge, as it would be for a man to show that iron and gold could remain iron and gold, and yet become elastic as India-rubber.” Mr. Goodyear denominates this improvement “metallic gum elastic.” This article is extensively used, and may be wrought into thousand shapes, from massive blocks to the thinnest sheets. It is susceptible of a beautiful polish, and possesses great firmness and durability. It already constitutes an important staple of commerce. Millions of dollars are invested in its manufacture, both in Europe and America. It is largely wrought into imitations of marble, wood, leather, whalebone, shell, horn, &c. The imitation is so perfect as to deceive even a practised eye, and while it so closely resembles the various articles alluded to, it is more durable and permanent than many of them, inasmuch as it remains unaffected by heats or colds, dampness or extreme dryness; no corrosion, oxidation, nor decay. It excels in beauty, nicety of finish, and in durability, those trinkets of glass and jet, which, in the common form, are so liable to instant destruction by children.
Few persons have any adequate conception of the wonderful transformations to which vulcanite may be changed, or its important position in the industrial arts.
Having traced at length the discovery of vulcanization and its contingent results, we now call attention to remarks that have appeared in various English scientific works, of acknowledged authority. The whole process of vulcanization and its application is fully and clearly set forth. And here we would remark that the English have not been backward in publishing with commendable liberality the various discoveries and improvements as they were perfected. On the other hand, all the American inventors have studiously avoided, not only the publication of their discoveries, but have endeavored to obstruct and prevent all investigation, the publication of which would simply make known to the world the results of their genius. The object seems to have been to throw an air of mystery around their discoveries, and by thus preserving to themselves their secrets, be enabled to place an undue value upon the manufactured article. Were they not fully protected in the manufacture and sale of their goods, by the patents which have been so lavishly granted, American inventors would be fully justified in preserving as profound secrets, the results of their perseverance and patient toil, but as it is, we can see no substantial reason for this endeavor to shield from the public eye that which would add to the general stock of scientific knowledge, and could but be honorable to the manliness and genius of the discoverer.
We are indebted to the London Mechanic’s Magazine for many of the valuable thoughts which we shall now introduce to the reader.
CHAPTER II.
VULCANIZATION.
We have attempted to show, that amongst the number of advantages claimed for the hard vulcanized India-rubber, is that of the power of closely imitating almost any article, substance, or material. In doing this, we ought to have referred to the Vulcanite Court of the Crystal Palace for a full corroboration of the position we desired to assume. We are now about to advance a step farther, and shall put forward proofs that hard India-rubber, submitted to a certain facile process, not only has a right to be placed side by side with almost all and every material it affects to imitate, but has a further right to be considered as superior. Of course there are exceptionable cases to this, as in all rules, and these will be pointed out during this attempt to give a thought-bearing digest of the present position of this discovery.
The material produced by vulcanization being as hard as, and capable of a greater amount of wear, than iron, brass, and, in many cases, even than steel, we have the element of durability to start with; and it must be recollected, that this wonderful power of resisting wear, both from friction and the action of the atmosphere is endowed by a process as facile as that possessed by the baker of ship biscuits. That while the mass or dough is in its soft state, it falls into, and as it were, courts the required form of its future existence with a fluency possessed by scarcely any other material. Designs of the most exquisite kind, or of the simplest character, may thus be turned out like tea cakes, and like tea cakes carried to the vulcanizing oven. But here, the simile stops, for these biscuits of Mr. Goodyear defy the teeth of time and the digestion of ages. There are manufacturers, however, that cry out, “we don’t want articles that will last.” This is a narrow view of things. Experience is opposed to so unjust a sentiment. A moment’s thought would forever dispel the illusion. Is there any less demand for iron furniture or iron household utensils, because such articles in that metal will last longer than others? Or is the diamond less prized because it is nearly indestructible? The family of mankind, ever growing and increasing, with its varied wants, its constant changes of fortune and alterations in its tastes, its coquetry, and its caprice, will find for the industry of the world quite enough to keep it employed.
With the introduction of machinery there was to have been a less demand for “hands;” with the introduction of railways, horses were literally to go to the dogs. Need instances be multiplied? Perhaps it would be better to do so, while such a feeling is in the ascendant; but space is imperative, although prejudice is stubborn. But, very naturally observes the reader who has possessed himself of some one or more of the specimens from the Crystal Palace, “this quality of cheapness is a myth.” I for one have put it to the test, and this stick, for instance, cost me 5s. or this pencil 2s. Now, in the first place, the stick or the pencil should be compared with any other sticks or pencils professing all the recommendations of those in question, to arrive at a fair appreciation; and in the next, it should be remembered that those examples are produced from abroad. They bear a duty, and in many cases, they proceed from small and experimental operations. We have made especial inquiries into these facts, and find that such is the case, and that such circumstances are no more than reasonable, as appertaining to every invention upon its first introduction.
The Daguerreotype is a case in point. The inventor, and all those concerned in placing the discovery before the public, take care that the prices shall be kept so that a remuneration shall be obtained before it is let down to the bare cost of production, added, it may be, to interest upon capital employed.
The mass, in its soft stage, does its own work; that is to say, a sheet of it may be laid over a mould, and the bare weight of a shovel full of sand cast upon it will press it into every lineament of the matrix. This sheet of the soft material may have for its components, a large proportion of oxide or of saw-dust, as the desire may be either an imitation of bronze or of some particular wood, or other material. ***
Mr. Charles Goodyear, in an unpublished work upon the subject, states that the first pair of India-rubber over-shoes were made by himself and daughter in a cellar in New York. There are now millions of them made each year at the various India-rubber mills throughout America, France and Belgium. But a singular desire to appreciate and follow sequences, and an indomitable perseverance in conquering difficulties, appears to have acted upon the industrious mind of Mr. Goodyear, in this direction with peculiar force. The India-rubber over shoe perfected, Mr. Goodyear did not sit down quietly to contemplate his work, even when apparently complete, but strongly convinced that there was more to do than covering the feet of nations with a water-proof substance, however symmetrical in its form and comfortable in its fit under almost every circumstance, he felt that if the leather boot or shoe could be altogether dispensed with, and there could be substituted for it an India-rubber boot or shoe, a boon of priceless worth would be conferred upon humanity, the more so as the item of boots and shoes to a poor family, or even to a person of moderate means, was one of considerable importance. To reduce the cost of this article of clothing, and to give to the poor man a pair of boots at one-third of the present expense, and not as now, at more than one-half of his week’s wages, has been one of the special objects of Mr. Goodyear’s untiring life. That he will succeed in this, there now exists not a shadow of doubt. The combinations of the hard, the semi-hard, and the soft vulcanized India-rubber, have given him all the needful elements of success, and ere long, boots and shoes of India-rubber which need not a morsel of leather for their formation, will be as plentiful as over-shoes are now, and even more so. The power of the hard, the semi-hard, and the soft vulcanized India-rubber to resist wear, is one of their extraordinary features. Heels, for instance, made of the soft material, have been put on to shoes of boys at the United Parish School at Norwood, and on to the toes of the same boots iron tips of the eighth of an inch have been secured. The result of this test has been that the iron has been worn out, and the heel, when removed and weighed, has scarcely suffered the slightest appreciable difference in weight or density. Mr. Goodyear has already made arrangements to disperse heels of this material by the hogshead. He fashions them in a circular form making the outer margin of the hard material and the inner circle of the soft. The hard material is smooth and beautifully polished. It does not require blacking, and will keep its lustre a long time. The centre bulb projects beyond the surface of the hard ring, and when trodden upon yields and is flattened by the weight of the body. One of the applications of this form of heel bears directly upon the perfectibility of a boot or shoe wholly made of India-rubber. In the first place, the rotary principle of heel is employed which one might suppose almost an unnecessary arrangement, and in the next, the peculiar form of the bulb or lobe acts when pressed upon as a valve or air-pump, and sends at every step into those shoes or boots properly prepared, a certain amount of air, or perhaps it would be more correct to say, it displaces a certain amount of air which finds renewal from other parts of the boot. Is a boot made unsightly?—not in the least. They are really elegant in form and general contour. Our readers are familiar with the corrugated dress boots. The India-rubber boots we have seen closely imitated these, but it may be added, that in thus copying, Mr. Goodyear copies his own, as the corrugated dress boot was introduced more to prepare the eye for what was to follow, than to give the beau of New York, of Paris, and of London, any particular style of dress boot. In this, Mr. Goodyear displays a consummate knowledge of human nature. Had he brought out a corrugated boot without this avant courier and child of fashion, his invention might have possessed very essential recommendations but that of “optical familiarity,” and the work of years would have been as nought.
We may mention here a characteristic of Mr. Goodyear’s inventive genius. He considers failures as stepping-stones to success. He tells one of the many well selected aids by whom he is surrounded, to do such and such a thing. The mechanician returns after giving his earnest attention to the task, with a something so clumsy or so ridiculous that it either raises the fear of censure or the dread of laughter as the reward of his pains; but neither laughter or censure await him. The result is just what its originator expected; the practical application confirms his views. A dozen failures, perhaps fifty, perhaps two hundred, wait upon these efforts, but with this valuable difference, that each failure approaches, directly or indirectly, the something that the mind desired to arrive at. Thus, each thing is, as it were, hemmed in; it is check-mated by these far-seeing moves, and science, the antagonist in this noble game, renders up the coveted object of an intellectual struggle. In a word, it is a practical exercise of inductive philosophy, or the algebra of mechanics getting at positive and useful facts by means mysterious and unintelligible to ordinary comprehensions.
CHAPTER III.
VULCANIZATION.
Camphine or turpentine, oil of sassafras, and all the essential oils, are faithful tests of the quality of gum elastic, and as certain in their tale-telling as nitric acid is of the genuineness of gold. As the native gums, and also the common manufacture of gum elastic have the same general appearance as those that are vulcanized, more particularly to persons not acquainted with the manufacture nor judges of the goods, these tests are of the utmost importance, not alone to determine whether the goods are genuine, but also to ascertain whether those that are vulcanized are properly done. When these tests are applied to any fabric of native gum, it is rendered very adhesive, and so quickly as to destroy any light fabric almost immediately, while upon goods that are well vulcanized, they should have no such effect. If they do so the manufacture is bad.
Although the manufacture of hard India-rubber goods, by the process of vulcanizing, is extensively known and appreciated in the United States, and in France and Belgium, very little appears to be understood in Great Britain. Indeed, in Birmingham, which is justly termed the “work-shop of the world,” little or nothing, or if anything, a something amounting to a misunderstanding, would comprise the quantity of intelligence upon the subject. There can be little doubt, however, that as the infinite capabilities of the material become known, and justly esteemed, and its amazing applications get manifested, no one thing of late years, surprising as the changes have been in that neighborhood, will have caused so great a revolution in very many of the staple manufactures of that town as will the introduction of this discovery.
As regards the power to be used in the manufacture, steam has a decided advantage over water, as in the plastic state of the mass there exists a variety of proceedings, according to the nature of the material to be made or the object to be imitated, in which steam would have to play a conspicuous part. But it must be in this country as in America and elsewhere, that as the manufacture extends, so will the best and most suitable machinery and power be devised and rendered subservient to its development. When the manufacture is favored with the advantages of steam power, and large capital, the most profitable results have been and are attendant upon it; and perhaps there are few manufactures which require less comparative space, and in which less waste is consequent. There should not be a particle of the substance lost, as all cuttings, sweepings of the factory, and the very dust upon all things around, can be re-worked with profit and advantage. Indeed, it is here that we should make publicly known the fact that every article of vulcanized India-rubber, bears its value according to its make and kind, however old it may be.
As a general impression exists that India-rubber when once vulcanized cannot be again used, this statement should be borne in mind, and the greatest publicity given to it in order that the millions of pounds now lying waste in the shape of galoshoes, &c., may not be heedlessly thrown away. The old Jew clothesmen will at once open their eyes to the fact, and the valet or humble servant girl will find in their collection and sale an increase to their perquisites, in proportion to the consciences of those with whom they deal.
Here, then, we have important elements of economy, at the very beginning and end of the manufacture, if end that can have which has the attribute of a renewal of usefulness. Galoshoes may be called in as worn out sovereigns and shillings are now, and returning to their mint, be melted up and re-stamped for renewed circulation. Another advantage in the manufacture is, that the same tools are employed for its various branches, and the same operatives can be turned from the making of one description of an article to another, without delay or expense. A girl, for instance, who may be engaged as the maker of garments one day, may become the next a trunk, a harness, or a shoemaker; and on the third, find herself occupied in pressing out of the soft and ductile mass brooches, and other articles of adornment, which being afterwards vulcanized, and thus rendered almost imperishable, may serve to encircle the neck, clasp the arm, or hang pendant from the waist of Britain’s fairest daughters. The machinery employed in the manufacture of India-rubber, since the first attempts to work it, has been subjected to variation and gradual improvement. Numerous expedients and divers machines were early tried for chopping, grinding and spreading the gum, and also for flowing it in a liquid or semi-liquid state, which have been abandoned. It is now generally agreed by manufacturers in this business, that the machinery is as near perfection as can be attained; that is to say, they are all satisfied with it. But in this age of improvements, we might see to-morrow one machine doing the work of two or more, and all calculations as to perfectibility obliterated, but to begin again upon fresh data. It must however be admitted that it is of the most simple kind, doing the work well and with astonishing rapidity, although requiring great mechanical power, owing to the toughness and tenacity of the gum. The machine used for cutting and washing the gum is the same as that employed by paper-makers in cutting rags. A large proportion of the India-rubber was nearly useless from the quantity of bark in it until this engine came into use. Gum-elastic or India-rubber can be readily mixed or combined with almost every other substance. It may be mixed with other gums, oils, coal-tar, carbon, and with the earths, and oxides or pulverized metals or ores. It can likewise be combined with all fibrous products.
It is compounded in the manufacture with many of the above substances, for the purpose of obtaining particular advantages for special uses. Ground cork and other light materials are sometimes mixed with the gum to increase the bulk, and make the articles light. The oxides of metals, their filings and pulverized silicas will give imitations of marble. The fibre of cotton, or the dust of different woods will afford simulations of wood of greater or less gravity, as may be required. The combining of plumbago gives the crayon; oxide of zinc, produces lithographic stone, and so on, and on. Pigments and earths are used for color and cheapness, and to increase the weight of the fabric as in the case of carpeting. Bitumen and rosin are sometimes used to give articles a finish, or high lustre. Oxides of some of the metals are used, but white lead and litharge are commonly preferred. From two to four ounces of either of these metals to the pound of gum cause the articles, and particularly those that are thick or massive, to be readily changed or vulcanized, and more completely, or with greater uniformity. Sulphur is applied through the medium of heat in different ways, according to the nature of the articles or fabrics, and their uses. It is generally mixed in the process of crushing or grinding the gum, in the proportion of half an ounce of sulphur to the pound of gum for the vulcanized elastic goods, and about five or six ounces to the pound of gum for the “vulcanite,” or hard goods. In the former case, about 270° of heat are necessary, and in the latter, 300 to 310°. At other times the sulphur is dusted upon the articles in the form of flour of sulphur before they are placed in the heater or oven. This is commonly done in the manufacture of elastic thread and other articles, which possess no extraneous mixture, in which case the gum is penetrated or impregnated with the sulphur, without its being mixed with the gum in the crude state.
Enough has been given in this chapter to permit of the intelligent and thoughtful at once following us, in the manufacture and finish of—we will say for example—buttons. The mass in a tough but plastic state, a toughness and plasticity in combination with which there exists no approachable parallel—having been so rendered by simply plunging it into boiling water, becomes of as easy manipulation as clay. Indeed the material in this stage being so like clay, we can scarcely point to any better illustration than the porcelain button manufacture, which being familiar to most, there can be no need to detail. Treated thus like clay, the moulds may be filled by the gross, and the buttons afterwards submitted to vulcanization. The moulds may bear any impress, and however fine such patterns may be, the material will receive and retain them after vulcanization, to a degree which will defy every power that destroys all other substances short of those of actual cutting, filing, or grinding. Thus a button is produced at an extraordinary economical rate, and with marvellous ease, which, while comparing the facility of its origin to that of the porcelain, possesses the superlative qualities of being comparable with one made with the properties and strength of iron or other metal, and in imitation of bronze, ivory, cameo, and is, indeed, a substitute for any other, and the very best material or thing ever used for button making. In a word, it may possess the closest similitude to the most exquisite carving, with the properties of bronze, ivory, or any hard and scarce material. The applications as far as results are concerned, are attended with like favorable characteristics, whether the article produced be nearly every one of those innumerable and familiar things, which meet us at each turn, either within the palace or cottage, or the many others to be met with out of doors.
The importance of the improvements in gum-elastic for educational purposes, has been previously commented upon in previous portions of these notices, and we would now give a little additional space to some of the many purposes in this direction, which assist in filling up the almost infinite measure of the uses of vulcanized India-rubber. Much has been done to perfect them, but enough has already been accomplished to prove that the causes of education will hereafter be promoted by the use of many articles made of the vulcanized fabrics. The cheapness of some of these articles, compared with the cost of those of other materials, gives double assurance of the correctness of this view. The expensiveness of globes, for instance, which are admitted by all to be by far the best means of imparting and obtaining geographical and astronomical information, has rendered them accessible to few persons, either pupils or teachers. The adaptation and application of gum-elastic to these purposes, will bring within the reach of every youth in the commonest school, a perfect globe, at a price within their means, and maps more durable than leather or parchment, at cheaper rates than paper maps are now made when mounted on linen.
The outline maps which we have seen, are printed upon the vulcanized India-rubber fabrics, both transparent and opaque, and also upon various articles to be used for other purposes besides maps, such as piano covers, crumb cloths, and carpets. Arrangements are being made for this manufacture, which may facilitate the method of teaching from outline maps by printing on this material, maps of the world, upon a scale large enough for “papering” the sides of an ordinary sized room of a school house, academy, public lecture room, or dwelling. The same map, when suspended at a suitable distance from the wall, with lights placed behind it, may be used as a transparency for teaching at night. A series of sectional maps printed on a scale as large as can be conveniently printed upon calenders, after the manner of calico-printing, may be cemented together, and arranged upon rollers.
The globe has heretofore been so expensive, as to be found only in schools of the higher class. No form of map or atlas can give so correct an idea of the surface of the earth, or of the relative situation of places, as a globe. An attempt appears to have been made by Mr. Goodyear to make them of gum-elastic, soon after the discovery of the “acid gas process.” These attempts have been followed up at intervals, until the production of the present process. They are made of various sizes, and when embossed by the method described in the manufacture of hollow ware—by steam and vulcanization—they may be made to supply the present deficiency of globes for the blind.
Their utility and importance to the cause of education need not, we are sure, be insisted upon, when it is understood that any child can be furnished with a perfect globe at a price to come within ordinary means. When used they are inflated with air, and when collapsed, may be folded in so small a compass as to be no incumbrance under any circumstances. When the large sizes are filled with hydrogen they become highly ornamental and beautiful objects.
CHAPTER V.
ADULTERATION OF INDIA-RUBBER—(Caoutchouc.)
Every article of commerce that is susceptible of adulteration is sure to fall into the hands of those who seem to be peculiarly educated to the work of diluting, and reducing by various chemical processes the real value of the article to be counterfeited. No matter how cheap the pure substance can be obtained, some method must be conjured up by which the innocent purchaser or consumer is unconsciously duped. India-rubber and gutta-percha are among the vegetable gums, which have been most extensively adulterated. It long since became a matter of scientific research in England, to ascertain how great a per cent. India-rubber could be reduced, by the admixture of worthless compounds, and the same skill has been thus perverted in our own country.
In Prussia, a law was passed in 1856, making the adulteration of chemicals and articles of consumption by which life shall be endangered, an offence punishable with death. The simple adulteration of food or drink with any deleterious substance, is punishable with fifteen years’ hard labor; and any other adulteration is regarded as cheating (betrug), and is punished accordingly. However severe or stringent these laws may seem to a republican mind, they are nevertheless just. What is the sale of an adulterated article, but the obtaining of money under false pretences, and why should not every rude infraction of the law of right, be visited by some adequate penalty?
A series of letters were published in 1856, in England, under the above caption, which shows very clearly the extent to which the practice of adulteration had then been carried. We herewith give the most important statement contained in those letters. The letters referred to were written by William H. Herbert, Esq., and addressed to the Editor of the London Mechanics’ Magazine.
He commenced the series by remarking that as adulteration by cheap compounds mixed with caoutchouc or India-rubber, are extensively used by engineers, he desires to submit a brief account of the processes, etc., by which they are mixed. Java and Para rubber will float upon water, and all manufactured goods free of foreign matter, are of the same density; and just in proportion as manufactured articles, such as valves, rail buffers, carriage and engine springs, washers, hose, &c., sink in water, so in exact ratio, are they adulterated with some cheap pigment, of which the following are a few, and usually in extent from 30 to 100 per cent. Say then, chalk, Paris white, Cornwall or porcelain clay, barytes, oxide zinc, white and red lead, ivory black, lampblack, black lead, Spanish brown, &c., &c. Interested manufacturers will tell you they improve the article, bear greater pressure, &c.; but as a rule this is a mere trade subterfuge, the truth being, it enables manufacturers to obtain extortionate profits, which, when I submit the exact formulas, will be very clearly seen.
Engineers do not seem sufficiently alive to this question of density. Of course in colored articles, it is necessary to use some pigment, but it is the monstrous excess that I wish to expose, and applies more particularly to the American inodorous system. I think it only fair to Messrs. Mackintosh & Co., to admit, that most of their goods I have examined float on water; but I know nothing, and have no interest whatever in their establishment, but simply state the fact, because I have found they form the exception to this adulterating or mixing system.
What I wish more especially to impress upon the minds of engineers, is the ready mode they have of discovering or ascertaining whose make is best and cheapest, and it is more likely an India-rubber valve of same dimensions at 2s. 6d. per lb., will cost more money than one at 4s. 6d. per lb., arising solely from the extravagant mixture of these cheap pigments, and its great density over the latter. Java India-rubber, which is mostly used, is at this moment about 7d. per lb., and best Para sheet about 1s. 11d. ** If they are fair goods for usual work, then I trust the information I supply may enable contractors to obtain their wants by competition, furnishing their own form. This will realize a great saving to them; but they must not be induced to accept goods of greater density under the plea of being better. The Java gum used in these adulterated articles is ground without undergoing the process of cleansing, but in all articles of light density, the cleaning machine frees it from all gritty matter, and it is usually employed in this cleansed state for such, as well as all gray or white goods.
Messrs. Mackintosh & Co., claim in their patent for vulcanizing all the preparations of sulphur, and without it, so far as I know and believe, no substitute has yet, or is likely to be discovered at a price which can render it commercially available. Indeed, I doubt whether any other than sulphurous bodies will vulcanize, or render fit for the use of the engineers the gum called India-rubber. Hence, the reason why many of the manufacturers are licensed under that firm, and subject to have their goods so stamped. The American inodorous makers attempted to shield themselves, (but on legally trying the point) in vain. The screen against Mr. Mackintosh’s patent was called, as a blind, “hypo.” It is prepared in several ways, but is a compound of sulphur and lead, and when perfect and the lime well washed away, is a very excellent black, costing about 30s. per cwt.; but its whole efficacy rests with the sulphur, and without it would not vulcanize, (though lead works kindly with caoutchouc). This chemical contains about 20 per cent., of sulphur, consequently, five pounds is about equal to twenty-five ounces of sulphur. This extra cost was readily submitted to, rather than to knuckle under to Messrs. Mackintosh’s patent. In many cases it was only said to be used, and what really was used, was white lead or lampblack, oxide of zinc, all in connection with sulphur, according as the color of the goods required, rendered necessary. It was pretended also, by these inodorous manufacturers, that white goods, such as the elastic beds, advertised as “Improved Hydrostatic Beds,” and “Hospital Sheeting,” were vulcanized with sulphuret of zinc, prepared chemically; when, in fact, it is well known that the cost of manufacture is quite prohibitory, and is only of value in proportion to its richness in sulphur. What was in reality used, was, and is, the “yellow sulphur,” and the “pure precipitate of that article.” I mention these things to clear the mystification it may be to the interest of manufacturers to keep up, and as I only write from experience, I have reason to believe your readers, who are interested, will better understand the nature and value of unmixed and mixed caoutchouc, after my fund on this topic is exhausted. With these remarks I will give the recipe for common black packing at 2s. 2d. per lb., in quantity, discount as agreed.
The chemical termed “hypo” is manufactured thus: The sugar of lead is made into a solution with water in a separate vessel. The sulphur and lime are then boiled in water, so as to make a solution of sulphur with the lime. The latter solution (clear) is then poured into the former, which unites with the sulphur, and the precipitate is the “hypo.” The hypo is then washed and dried. The lime merely enables the lead to take up the sulphur.
|
| | | £ | s. | d. |
| Grind | 15 | lbs. Java Caoutchouc at 7d. | 0 | 8 | 9 |
| Grind | 15 | lbs. Para Caoutchouc at 2s. | 1 | 10 | 0 |
| Grind | 15 | lbs. Oxide of Zinc at 3d. | 0 | 4 | 0 |
| Grind | 16 | lbs. China or Cornwall clay | 0 | 0 | 3 |
|
| | | | |
| Total, | 16 | lbs. | | | |
| 28 | oz. Yellow Sulphur | 0 | 0 | 3 |
| Mill-costs at 3d. per lb., on 73 lbs. | 0 | 18 | 3 |
| | |
|
|
|
| Total, | | 3 | 5 | 3 |
| Costs therefore, 10½d. per lb. | | | |
The above is 110 or 112 per cent. of adulteration.
I should here remark, there is also a kind of packing in use, which perhaps is practically best known as “Rag Packing,” made principally from the useless cuttings in the manufacture of India-rubber coats, where the gum is run or spread on calico foundations, which is usually the case with water-proof garments offered for sale at the shops. It is made as follows:
Rag packing for valves, bearing springs, or in sheets of any thickness, where less elasticity is required, and great pressure.
| | | £ | s. | d. |
| Grind | 35 | lbs. Useless scraps, say | 0 | 3 | 0 |
| Grind | 18 | lbs. Black Lead, at 2¼d. | 0 | 3 | 4½ |
| Grind | 16 | lbs. Java Gum, at 7d. | 0 | 9 | 4 |
| Grind | 1 | lbs. Yellow Sulphur, | 0 | 0 | 1½ |
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| |
|
|
|
| Total, | 70 | lbs. | | | |
| Mill-costs at 4d. per lb. on 70 lbs. | 1 | 3 | 4 |
| | |
|
|
|
| Total, | | 1 | 19 | 2 |
This is sold at 2s. per lb. in very large quantities, or 1s. 6d., if a shrewd man, net, or a small discount for cash.
Our gardens, fire engines, brewers, and pump-makers (for suction, &c.,) have found the value of this gum, and the following is the form used with success, and perhaps the adulterations are the best substitutes for pure caoutchouc that the cheap compound market offers.
| | | £ | s. | d. |
| Grind | 20 | lbs. Java, at 7d. | 0 | 11 | 8 |
| Grind | 10 | lbs. Para, at 2s. | 1 | 0 | 0 |
| Grind | 14 | lbs. White Lead, at 3d.} | 0 | 7 | 0 |
| Grind | 14 | lbs. Red Lead, at 3d.} | | | |
| Grind | 1½ | lbs. Yellow Sulphur, | 0 | 0 | 3 |
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| | | | |
| Total, | 59 | lbs. at 3d. per lb., Mill-costs, | 0 | 14 | 9 |
| | |
|
|
|
| Total, | | 2 | 13 | 8 |
| Consequently costs 10½d. per lb. | | | |
This is spread upon flax cloth, (Messrs. Richards & Co., Broad Street, are manufacturers,) which weighs 10, 16, and 32 ounces to the square yard, and is about the same cost as the compound, so that the weight is the truest criterion of cost, and is so calculated by the manufactory. ****
Excepting garments every other description of black goods are made from such forms as I have figured, with very little variation according to the requirements of the engineer, and which needs very little judgment or experience to meet. To those who cling to these heavy goods, the formulas I have rendered will enable them to have supplies at a fair competing charge according to quality, and it is their own fault entirely if they persist in purchasing 100 per cent. of cheap powder at the same charge as for “pure caoutchouc” of a third of their density.
Your readers must be good enough not to lose the fact of “specific gravity,” and test all the above goods made with pure, unadulterated India-rubber, by their floating on water. Any deviation from this is a proof of some cheap stuff unfairly introduced. It will be just in proportion as they keep themselves well posted up in this matter, that manufacturers will be sly of throwing into their caoutchouc such mad and infamous proportions of cheap adulterations, and drive them (for they will not volunteer) to the necessity of manufacturing from the pure gum, and thus place better disposed traders upon a more just footing, and enable the latter to compete (if need be) upon their own terms, or upon recipes supplied by the engineer. Another fact must not be lost sight of, and that is the use of “light carbonate of magnesia,” which, mixed with the gum, does not increase its density, as will in some measure be illustrated by the recipe I shall now figure out, merely remarking that a somewhat heavy carbonate was used, as well as in an unroasted, and hence the somewhat increased density. This article is worth the attention of buyers of rubber goods, as in a moderate quantity it reduces the costs without correspondingly injuring the manufacturer. (Light buffer spring just sinks in water.)
| Grind together | 25 | lbs. Clear Java Rubber, |
| 5 | lbs. Para Rubber, |
| 10 | lbs. Common Magnesia, |
| 25 | oz. Pure Sulphur. |
| Costs 19 cts. per pound—Sells for 60 cts. per pound. |
This is brown at first, but in a few days the sulphur blows over the surface grey or white, and would lead an amateur to judge they were of that color throughout. Buffer springs and other moulded goods from this compound are a little heavier than Messrs. Mackintosh and Co.’s. A density railway spring, at 4s. per lb. gross, and were made at first to meet it, also sold at 2s. 6d. per lb. net. It is a most useful spring, and in competition should be bought at 1s. 3d. to 1s. 6d. per lb. net, but I should strongly recommend that engineers try a substitute of all “Java gum,” by obtaining a few away from their usual manufacturer, ON TRIAL, as I believe their quality as a spring would not be injured, and the price would be reduced, and, moreover, it would guard against the manufacturer being left tempted to do so, without reducing the charge.
For the guidance of engineers, I remark, that a spring of this quality and dimensions, 4½ × 2½ × 1, pressed to half an inch, showed 3½ tons on the dial, and one with equal quantities of oxide of zinc and magnesia, of same size, &c., indicated 1½ tons on equal pressure, while the quality of Mackintosh and Co.’s, referred to before, and of which this was an intimation, marked 1¾ tons on the dial; of course, a spring with a smaller bore than 2½ inches would show greater tonnage.
The next recipe is for grey packing, which is largely and exclusively used by some dealers for marine engines, &c., as well as in sheet; and if the price (3s. 6d. per lb.) was not excessive for so much adulterated matter, I would pass it over in silence as a very fair and useful article, and if approved, my form will enable the engineer to obtain it much cheaper by competition.
Say then,
| Grind together | 25 | lbs. Para Rubber, |
| 5 | lbs. Cleaned Java, |
| 16 | lbs. Oxide of Zinc, |
| 6 | lbs. Carbonate of Magnesia, |
| 3 | lbs. Porcelain or Cornwall Clay, |
| 2 | lbs. Red Lead, |
| 30 | oz. Pure Sulphur. |
So that it costs 25 cts. per lb., and hence I submit that 75 cts. per lb. is excessive, with discount from 10 to 20 per cent. Unless the magnesia in this packing is well calcined it will cut porous, but does not show its valves cut to shape before vulcanizing. It may seem I lay too much stress upon high prices, and if the goods were bought in trifling quantities, it would carry argument; but as the orders are usually large, and show good monied invoices, there is a wide margin for reduction; besides in many cases these long prices prohibit the use of caoutchouc. The prices are about right if the goods were of pure India-rubber.
I ought to remark that in all formulas which I use, Para rubber is used, which is now nearly four times the cost of Java, and is frequently more. This circumstance has for some time been attracting the attention of manufacturers, and bids fair to shut out almost the use of the former in all goods confined in moulds to vulcanize. I would call the especial attention of engineers to this fact, as Java materially reduces the cost, and needs very little judgment on their part to adopt it in these forms, in place of the expensive kind. I do not say it is so strong a gum as Para, but I feel certain that the manufacturers will be awake, and use it, without perhaps yielding the advantage out of their own factories, and therefore it is necessary for consumers to try how far they can “assist themselves” without their benevolence, especially as “Java gum” is now so readily and cheaply cleansed of all dirt or gritty matter. These remarks apply to the recipe I now hand, which is termed—best pure spring, or washers, &c.
| Grind together | 30 | lbs. Para Gum, |
| 5 | lbs. Oxide Zinc, |
| 2 | lbs. Carbonate Magnesia, |
| 3 | lbs. Common Chalk, |
| 2 | lbs. Porcelain or Cornwall Clay, |
| 30 | oz. Pure Sulphur. |
This costs about 33 cts. per lb. and is sold at $1 per lb., and though heavier, is intended to meet Messrs. Mackintosh and Co’s. article at $1 12½. The difference in density renders the latter the cheapest to the consumer, while the reduced price of the former catches the unsuspecting trader in these goods, and frequently obtains his preference.
The companion quality to the above for large valves, and packing sheets, is made as follows, and is styled—best pure packing.
| Grind together | 30 | lbs. Para Rubber, |
| 5 | lbs. Oxide Zinc, |
| 5 | lbs. Porcelain or Cornwall Clay, |
| 28 | oz. of Pure Sulphur. |
This costs about 31 cts. per lb. and is sold at $1 per lb., and is a trifle heavier than the pure spring quality.
It will be perceived that sometimes pure sulphur is used, and sometimes the common flour of sulphur; the former is thought to render the goods more soft and velvety, but the difference in their relative cost is very wide, and the writer will not undertake to say how far the marketable value of the goods is improved, but thinks it will be admitted that their intrinsic value to engineers is not altered in any way.
I may here observe, that carbonates work best in all moulded goods, but not otherwise, and it is necessary they should be retained therein until quite cold, or they swell out of shape; but in packing, &c., vulcanized openly, oxides should be selected, as there is little or no chemical action with sulphur or heat. I have made no mention in these papers of very finely pulverized talc, or French chalk, which, from its cheapness, if well bought, and its being unaffected by heat, and its slippery nature, is invaluable as a top dressing, well rubbed in, upon the surface of all white goods for open vulcanizing, as well as dusting the sheet zinc upon which they are laid. It is equally valuable in all goods cured in rolls, such as medical sheeting, &c., and renders entirely unnecessary the rays of the sun afterwards, needing only to be wiped off with a dry cloth after vulcanizing.
There are many most respectable manufacturers, and these should have their sense of honorable integrity acknowledged, and, as far as possible, be protected from their inferiors in morality. In writing these papers off hastily, one is really tempted to get into a violent rage with this vicious system; especially when one calls to mind that, no sooner does an ingenious man invent something really valuable and useful, but these kidnapping and adulterating traders counterfeit the same instantly, and render their make to all appearance (and to the unsuspecting) equally good, though, in reality, not so, being merely cheapened by this adulterating and tricky system. Added to which, if the originator is not very sharp in obtaining his protection for the really valuable service he has rendered to science, and to the sale of which he is looking very naturally and justly, as a remuneration of what may have probably cost the inventor many days and nights of weariness, and possibly involved the spending of his money capital, and perhaps, even besides, months of labor, disappointment, poverty, and sorrow, I say, if he is not very quick in his protection, the unblushing effrontery and impudence of these “second hand people” will rob him of the whole. I believe no pen can sufficiently protest against those individuals who thrive “and make haste to become rich” from the oozings of other men’s brains. Theirs is the basest class of felony our laws cannot reach, and, consequently, their infamous and nefarious habit continues unheeded and untouched, and often (because unknown) unscorned. This applies to caoutchouc. Special reference to particular manufactures must be discussed another day; but, if I am rightly informed, Mr. C. Goodyear especially, and others, to some extent, have suffered from these copyists very egregiously and seriously. Though my testimony would be confirmed by our best men in every branch of trade, where there is scope for genius. I must not digress, and trust you will excuse my hasty protest against this counterfeit coin.
I will therefore, at once, hand you the formula for
COMMON WHITE BUFFER-RINGS, WASHERS, ETC.
| Grind | 30 | lbs. Java caoutchouc, |
| Grind | 18 | lbs. Oxide of zinc, |
| Grind | 6 | lbs. Carbonate of magnesia, |
| Grind | 6 | lbs. Clean chalk or whiting, |
| Grind | 2 | lbs. Flour of sulphur. |
This costs about 13 cents per lb., and is sold at 50 cents per lb., and, as you will perceive, contains about 110 per cent. of adulterating matter. Considering the mass of foreign substances in the above formula, (and yet sold under the name of “caoutchouc,” which should be pure Java gum, of less than half the density, for a great deal less than 50 cents gross price), one is almost astonished that the “gum-elastic” should retain any of its original liveliness, mixed up with so much dead weight; but so it is, as I shall show, by stating that a buffer-ring (4½ × 2½ × 1 ins.) of this quality exactly, and of the same size as those of which I gave the tonnage in your Magazine of the 24th of October, indicated, on the same being pressed to half an inch, 4½ tons on the dial. Of course the weight of the ring was fully double those then remarked upon, arising from increased density by adulteration. Pursuing the same subject of density, I have observed that these manufacturers have been compelled to charge less than the actual weight of their goods, as the people at Berlin would not pay caoutchouc price for so much rubbish. This in the “good old red-lead time,” when the manufacturers, with more faith than judgment, considered they could not include too much of that metal, but they have since become more crafty and subtle, and use it less madly. I weighed a cylinder or spring some few months since, of which a like quantity are now in use by the London and North-western Railway, and, I expect, at their station at Wolverton, which contained at least, 100 to 130 per cent. of cheap, heavy adulteration; and yet they paid 1s. 6d. per lb. in quantity nett. The size was 6½ × 2½ × 4, and weighed close upon 6 lbs. I should say, if the charge had been 9d. per pound, no manufacturer could need a better trade, hence I have chosen to throw a little a “free trade light” upon the subject.
The washer trade is a very lucrative one to the manufacturers, being principally cut from the spare or waste ends unavoidable in the make of springs, cylinders, and buffer-rings.
I will now give you the formula for what is termed
HYPO-CLOTH FOR WATER-PROOF COATS, &C.
| Grind | 30 | lbs. Clean Java gum, |
| Grind | 5 | lbs. Lamp black, |
| Grind | 11 | lbs. Dry chalk, or whiting, |
| Grind | 5 | lbs. Sulphuret of lead. |
Costing about 12½ cents per pound.
Sometimes the Para gum is used in this mixture; but, though better, its use is not considered imperative if the Java caoutchouc is well cleansed. A cured coat, well vulcanized, is a great improvement in all respects upon the filthy naptha or varnish coat, and should, when competition is thrown into the market, exceed it very little in charge. As long as the calico upon which these are run is covered, the thinner that covering the better; and by far the best I have seen are made by Messrs. Mackintosh and Co., Moulton & Co., Moses, Son & Davis. I have seen some very bad ones, ill-shaped, non-vulcanized, and altogether only useful in bringing the better make into unjust dislike by the public. The sooner these latter daubs are improved, or withdrawn from sale, the better for the reputation of the India-rubber garment dealers. The cloth upon which the material is spread weighs about four ounces by the yard, and therefore the quantity of gum on each article is readily assessed, and the scale will determine which are lightest and best for a storm.
The article termed “sulphuret of lead” in the formula, is the chemical I have before remarked upon, and the screen or blind, nick-named (for reasons therein explained) “hypo,” and is only useful in so far as it is an excellent black pigment, which is only of importance in the garment branch of the trade.
ADULTERATION OF INDIA-RUBBER, IN CONNECTION WITH THE MANUFACTURE OF INVALID WATER MATTRESSES AND CUSHIONS.
There is no necessity for the monstrous charges at present made for these goods, and hence I desire to open up the subject fearlessly. The amount of adulteration necessary to bring up the desired color, is from 4 to 10 per cent. of the pigment termed oxide of zinc; but the formula used for the manufacture of the water or air mattresses and cushions referred to, contains about thirty-five per cent. of this cheap substitute for India-rubber. In writing thereon I take leave to state at the outset, that, like the “air,” or Mackintosh cushions or pillows we have known for so many years, they can be had of any size or shape, and differ from them in being of pure caoutchouc, or elastic gum, (minus the adulteration) instead of only a thin coating of pure gum, upon a cloth or non-elastic foundation. Hence their increased value to medical men in preventing bed sores, &c.
In my judgment, what is understood in these days by the word “humbug,” has gained such ascendancy over common sense, that honorable people, who disdain to practice it, are so out-distanced by the many who do, that they lose thereby several of the chances of trade. This “popular pet humbug” is, therefore, largely dealt in by puffing advertisers (even in these articles) who perpetually issue illustrated catalogues, &c., under the word “patent,” where none exists, “Improved Hydrostatic Water Mattresses,” “Inventor” and “sole manufacturer,” and a host of other fanciful and attractive names, through our Post Office, to the whole medical profession in the United Kingdom, as well as to the staff of medical men connected with all the Hospitals, Poor Law Union Infirmaries, East India and other companies, &c., and these mattresses are now in use at most of such establishments; and if the retail prices were not highly extortionate, and altogether beyond all reasonable limit, I would not throw the “sunshine” upon this valuable medical appliance. It just strikes my memory that there is a quiet notification in the interior of the envelopes of these circulars, that a discount of 12½ per cent. is allowed to the “profession,” (but which some refuse.) I may as well add, that these dealers, of course, have no exclusive right to the above names, as they would lead the public to infer, the manufacture being as free as the air we breathe; and of “hydrostatics,” they understand about as much as they do about general “chemistry,” and I am quite sure that of the latter exquisite science they know only just as much as the letterer can actually embody and make inherent in the words he may be instructed to paint on the door posts or facia outside. It is a melancholy truth, that this lettering is now accepted as proof that the “professor” inside, is in fact, a “practical” or “operative chemist,” though he may live and keep shop at the west end of the metropolis, and exhibit a framed notification, that he is a member of the “Pharmaceutical Society of Great Britain,” but without examination.
It is incredible, moreover, how these people, by their presumption, even seem to deceive medical practitioners, judging from the numerous “good names” they append to some of their valueless compounds of exhausted roots. In many cases beyond the capacity of informing an enquirer why, in “camphorated spirit” the addition of “water” precipitates free camphor, (to use a figure) they know no more of chemistry than the writer’s “foot;” and yet if one had not daily experience and proof that true science is modest and retiring, one would be liable to put these “professors” down as real living “Faradays,” “Herapaths,” “Redwoods,” and other equally illustrious chemists instead of quacks. Excuse the digression, but these characters who disgrace an intellectual science, will cross one’s mind in writing.
Returning to the water mattresses, I will show in figures, in the manufacturer’s price in 1850, and the manufacturer’s charge in May, 1856, (and it must be less at this moment,) and the uniform retail price, and to this latter I invite the special attention of your readers, and ask them carefully to note the retailer’s profit on each, and decide the advantage to be derived from purchasing of the manufacturer. I have no personal interest in any of them. I will show also their usual sizes, and their weight, as they are all sold by the manufacturers, on this basis.
I trust this may stir up increased demand for so useful and necessary an article for the alleviation of human suffering, the use of which the immense retail profits have hitherto prohibited among the middle and humbler classes.
The formula for water mattresses and cushions—(India-rubber) is:—
| | s. | d. | |
| 1 lb. | Fara Gum (in sheet,) | 2 | 0 | |
| (Present cost, 1s. 7d., per lb.) | | | |
| 6 oz. | Oxide Zinc, | 0 | 1½ | |
| 1 oz. | Pure Sulphur, (common equally good,) | 0 | 1½ | |
| Mill costs, | | 3 | |
| |
|
| |
| | 2 | 5 | |
| Or 1s. 7d. per lb. | | | |
| Say of the above compound, | 1 | 0 | |
| Making waste, | 0 | ? | |
| Grinding, running, cleaning and vulcanizing, | 0 | 6 | |
| Add 36? mill profit, or | 0 | 10 | |
| is | 3 | 2 | per lb. |
This is the price per pound the weight should be estimated at. The mattresses vary in size from 8 + 14 inches to 48 + 72—some with cells—some without cells. The retail profits on these goods, over the manufacturer’s prices, in 1856, ranged from 13s. 6d. to £7, 6s.—according to the size of the mattress. Or in American currency, from about $3.00 to $36.00 profit on single mattresses.
Should so serviceable an article be thus clogged and fettered by such immoderate charges by the retail shop-keepers? It may probably be a guide to some of our readers to state, the best size pillow is 17 + 22, and that the celled mattresses 27 + 30, and 30 + 40, are found most useful, and of adequate length to support the trunk of invalids, and admit the other portion of the body to rest upon the usual feather bed, and thus steady a weak patient; as a full length mattress of elastic gum, 33 + 72 is beyond the safe control of such invalids.
The retailer, for obvious reasons, recommends the larger mattresses, and which are not returnable, even if the patient dies before they reach him.
CHAPTER VI.
VALUABLE RECIPES, ETC.
PURIFYING GUTTA-PERCHA.
H. H. Day, of New York, has obtained a patent in England for extracting from gutta percha a peculiar etheric oil which it contains, preparatory to its being subjected to the process of vulcanization, by submitting it to the action of a liquor which dissolves out the etheric oil, and also, at the same time, by acting upon the woody matter, disengages the sand or other foreign substances held therewith. This liquor is composed of caustic potash (hydrate of potassa) dissolved in water, with an ether formed from a solution of chloride of lime and alcohol added, and after the crude gutta-percha is placed therein the whole mass is heated to a boiling point, and so kept for about nine hours, and then treated between rollers under water, in the ordinary manner. When taken out, the gum will consist of a pure and solid mass, resembling India-rubber, and fully equal to it in fineness, and in the readiness with which it may be worked to prepare it for the additional process of vulcanization.
PURIFICATION OF GUTTA-PERCHA,
By James Reynolds, of New York City. Gutta-percha, in the raw state in which it is imported, contains large quantities of bark, dirt, and foreign substances. In the common processes of manufacture these cannot be extracted, and bad results often ensue. For example, in the covering of telegraph wires, holes are often left wherever foreign substances are present, and thus the insulation is impaired. The only method heretofore employed, for preventing the quality of the manufactured article from being too much injured by the presence of these impurities, has been to reduce the bark and dirt into fine particles, by long-continued and tedious grinding, and then incorporating them with the gum.
The object of the present improvement is to effect the entire extraction of the bark and other foreign particles, and thus improve to a very great degree the quality of the manufactured article. The invention consists in first cutting the gutta-percha into extremely thin slices or sheets, and then submitting it to heating, rubbing, and screening operations. Under this treatment the foreign matters, are almost entirely extracted, and the gutta-percha left pure. This is a valuable invention.
MARINE GLUE.
Take one pound of India-rubber and then dissolve it in the exact quantity of naptha, or oil of tar to render it moderately thin, (about a gallon) to which is added shellac, and the whole allowed to macerate for ten days, until it attains to a cream like consistency. After which more shellac is added to make it pretty stiff, when it is heated and then poured out into plates. It is heated to 250°, when applied. The mixture is that of India-rubber and shellac dissolved in naptha. It is insoluble in water and not affected by the heat of the sun.
INDIA-RUBBER ARMOR.
In Paris a new kind of cuirass for the use of the army, is shortly to be tried. This cuirass is of vulcanized India-rubber, about half an inch thick. The thickness, it is stated, is more than sufficient to resist the action of a ball projected from any kind of firearm. All the experiments tried have proved entirely successful. The force of the ball is completely broken by the elasticity of the India-rubber, and it falls on the ground at the feet of the person against whom it was sent.
NEW GUTTA-PERCHA COMPOSITION.
Alfred H. Gaullie, Paris, patentee. This improved composition is formed by mixing together equal parts of gutta-percha and of Roman cement reduced to a pasty consistence with ox-gall. The operation of mixing is to be performed while the gutta-percha is in a heated and plastic state, and the two ingredients must be well masticated so as to cause them to combine intimately together. Any kind of coloring matter may be combined with the materials according to the effect desired to be produced.
A. Ford, of London, has obtained a patent for making solutions of India-rubber and gutta-percha, which solutions can be used for water-proofing as a varnish. The India-rubber or gutta-percha, is dissolved in warm turpentine or naptha. The turpentine, or naptha, is prepared by mixing a caustic alkali, such as potash, in it—one pound to the gallon—then agitating them in a suitable vessel, and allowing them to stand for about three days, when a dark colored residuum is found at the bottom. The clear liquor is then poured off and used for dissolving the India-rubber. It is stated that this makes a very beautiful varnish.
WATER-PROOFING OIL.
A patent has been obtained by Alex. Parkes, of Bury Port, Wales, for a preparation of oils similar in its nature to the improvement of Mr. Daines. He treats oils with the chloride of sulphur, which changes their character, rendering them similar to vulcanized India-rubber, and insoluble in mineral naptha and sulphuret of carbon. He heats about 2 parts by weight, of the chloride of sulphur with 8 parts, by weight, of oil, up to about 250°, when the combination of the two is effected. This vulcanized oil, it is stated, can be mixed with gutta-percha or India-rubber, to cheapen the manufactured articles made from these materials. This, apparently, is also an important invention.
Mr. Parkes has also taken out a patent for a varnish made of gun cotton dissolved in alcohol, or any solvent of gun cotton. This varnish is transparent, and he applies it to coat silk, sewing cotton, thread, leather, plaster, wood, &c., to render them water-proof. Gun cotton dissolved in chloroform is a well known varnish.
INDIA-RUBBER TEETH.
This article, in the form of purified white India-rubber, has been patented in England, for making artificial teeth, gums, and palates. By its adoption, many advantages hitherto impossible to be attained, have been introduced. The adhesion is complete, it can be moulded with perfection, to suit every inequality of the gums and teeth, and supplies an artificial periosteum, as it were, to the teeth, when become painful by the wasting away of the gum, added to these is the elasticity of the material, which completely obviates the inconveniences that arise from any motion with artificial teeth, as made by other means.
EMERY PAPER.
The Moniteur Industriel mentions an ingenious method of obtaining fine emery paper for polishing metals. Strips of paper coated with fresh starch-size are hung on ropes at different altitudes in a small room, which is afterwards carefully closed. A quantity of fine emery is then blown in by means of a ventilator, through an aperture left for the purpose, by which means a dense cloud of emery dust fills the room, but only the finest particles rise in the air to a sufficient height for them to be deposited on the upper slips; those of the second row receive a somewhat coarser sort, and so on, while such particles as are too heavy, and therefore too coarse for delicate polish, fall to the ground at once. Thus emery paper of different degrees of fineness may be obtained by a single operation, and sorted with mathematical certainty.
SULPHURIZED OIL PAINT.
At a recent meeting of the Society of British Architects, J. B. Daines stated that by subjecting eight parts (by weight) of linseed oil and one part of sulphur, to a temperature of 278°, in an iron vessel, he obtained a species of paint possessing singularly preservative properties. Applied to the surface of a building with a brush, it effectually keeps out air and moisture, prevents deposits of soot and dirt, and preserves the beauty of the stone, wood, or brickwork to which it is applied. It has long been known that a portion of sulphur can be dissolved in oil, but until recently such a composition, as a paint or varnish, has attracted no notice; in fact, its preservative and impervious qualities when dry, were unknown. It is well known to chemists that sulphur, (the substance employed to give body to the oil,) is unalterable in the air, and is not acted on by moisture; hence its quality as a preservative for coating the outside of structures exposed to the weather. It is capable of preserving plaster of Paris figures exposed to the air, also monuments, and buildings of the brown freestone, which are liable to detrition, from the action of the weather. It is stated that it improves the color of the stone to which it is applied, as well as preserves it; therefore it is a most useful paint, and deserves to be very generally employed.
INDIA-RUBBER AND COAL TAR.
Mr. C. Goodyear has recently taken out a patent in England, for a new compound, composed of India-rubber and coal tar vulcanized with sulphur. Coal tar is heated in an open boiler until it acquires the consistency of melted rosin, when it is mixed with India-rubber, in proportions which may vary according to the character of the material to be produced for a specific purpose. It is mixed with sulphur and then heated to vulcanize it.
LIQUID GLUE.
Dissolve two pounds of strong glue in one quart of water, in a glue kettle, or in a water bath; when the glue is entirely melted, add little by little to the amount of ten ounces of strong nitric acid. This addition produces an effervescence due to the disengagement of hyponitric acid; when the whole of the acid is added, remove the vessel from the fire and leave it to cool.
Glue thus prepared, kept in a stopped flask, will remain good for two or three years.
ENORMOUS STRENGTH OF GUTTA-PERCHA TUBING.
A series of interesting experiments have just been concluded at the Birmingham Waterworks, relative to the strength of gutta-percha tubing, with a view to its applicability for the conveyance of water. The experiments were made (under the direction of Henry Rolfe, Esq., engineer,) upon tubes three-quarters of an inch in diameter and one eighth of gutta-percha. These were attached to the iron main, and subjected for two months to a pressure of 200 feet head of water, without being in the slightest degree deteriorated. In order to ascertain if possible, the maximum strength of the tubes, they were connected with the Water Company’s Hydraulic Proving Pumps, the regular load of which is 250 lbs. on the square inch. At this point the tubes were unaffected, and the pump was worked up 337 lbs., but to the astonishment of every one the tube still remained perfect. It was then proposed to work the pump up to 500 lbs., but it was found that the lever of the valve would bear no more weight.
The utmost power of the hydraulic pump could not burst the tubes.
The gutta-percha being somewhat elastic, allowed the tubes to become slightly expanded by the extraordinary pressure which was applied, but on its withdrawal, they resumed their former size.—London Mechanics’ Magazine, Vol. LI.
CHEAP AND SIMPLE METHOD OF MAKING LEATHER WATER-PROOF.
Two pounds of tallow, a pound of hog’s lard, a half pound of turpentine, and the same quantity of bees-wax are melted together in an earthen pipkin. The boots and shoes are dried and warmed, and the composition is well rubbed into them with a piece of tow dipped into it; the articles being held near a hot fire until they have imbibed as much as they can take up. This mixture is used with very good effect by sportsmen.
Another mixture for the same purpose, which is much used by fishermen, is applied in the same way. It consists of a pound of bees-wax, a half pound of rosin, and the same quantity of beef-suet.—Morfit.
