Popular Technology Volume II Part 23

7. At 510 degrees, the brown becomes dappled with purple spots, which shows the proper heat for tempering axes, common chisels, plane-irons, &c. At 530 degrees, a purple color is established, and this temperature is proper for table-knives and large shears. At 550 degrees, a bright blue appears, which is proper for swords and watch springs. At 560 degrees, the color is full blue, and this is used for fine saws, augers, &c. At 600 degrees, a dark blue approaching to black settles upon the metal, and this produces the softest of all the grades of temper, which is used only for the larger kinds of saws.

8. Other methods of determining the degree of temperature at which the different kinds of cutlery are to be immersed, a second time, in cold water, are also practised. By one method, the pieces of steel are covered with tallow or oil, or put into a vessel containing one of these substances, and heated over a moderate fire. The appearance of the smoke indicates the degree of heat to which it may have been raised. A more accurate method is found in the employment of a fluid medium, the temperature of which can be regulated by a thermometer.

Thus oil, which boils at 600 degrees, may be employed for this purpose, at any degree of heat which is below that number.

9. The _grinding_ of cutlery is effected on cylindrical stones of various kinds, among which freestone is the most common. These are made to revolve with prodigious velocity, by means of machinery. The operation is therefore quickly performed. The _polis.h.i.+ng_ is commonly effected by using, first, a wheel of wood; then, one of pewter; and, lastly, one covered with buff leather sprinkled with an impure oxyde of iron, called _colcothar_ or _crocus_. The edges are set either with hones or whetstones, or with both, according to the degree of keenness required.

10. Almost every description of cutlery requires a handle of some sort; but the nature of the materials, as well as the form and mode of application, will be readily understood by a little attention to the various articles of this kind which daily fall in our way.

11. A process has been invented, by which edge tools, nails, &c., made of cast iron, may be converted into good steel. It consists in stratifying the articles with the oxyde of iron, in a metallic cylinder, and then submitting the whole to a regular heat, in a furnace built for the purpose. This kind of cutlery, however, will not bear a very fine edge.

12. The sword and the knife were probably the first instruments fabricated from iron, and they still continue to be leading subjects of demand, in all parts of the world. The most celebrated swords of antiquity were made at Damascus, in Syria. These weapons never broke in the hardest conflicts, and were capable of cutting through steel armor without sustaining injury.

13. The fork, as applied in eating, is an invention comparatively modern. It appears to have had its origin in Italy, probably in the fourteenth century; but it was not introduced into England, until the reign of James the First, in the first quarter of the seventeenth. Its use was, at first, the subject of much ridicule and opposition.

14. Before the introduction of the fork, a piece of paper, or something in place of it, was commonly wrapped round some convenient projection of the piece to be carved; and, at this place, the operator placed one hand, while he used the knife with the other. The carver cut the ma.s.s of meat into slices or suitable portions, and laid them upon the large slices of bread which had been piled up near the platter, or carving dish, and which, after having been thus served, were handed about the table, as we now distribute the plates.

15. The knives used at table were pointed, that the food might be taken upon them, as upon a fork; and knives of the same shape are still common on the continent of Europe. Round-topped knives were not adopted in Paris, until after the banishment of Napoleon Bonaparte to Elba, in 1815, when every thing English became fas.h.i.+onable in that city.

16. In France, before the revolution of 1789, it was customary for every gentleman, when invited to dinner, to send his knife and fork before him by a servant; or, if he had no servant, he carried them himself in his breeches pocket. A few of the ancient regime still continue the old custom. The peasantry of the Tyrol, and of some parts of Germany and Switzerland, generally carry about them a case, containing a knife and fork, and a spoon.

17. The use of the fork, for a long time, was considered so great a luxury, that the members of many of the monastic orders were forbidden to indulge in it. The Turks and Asiatics use no forks, even to this day. The Chinese employ, instead of this instrument, two small sticks, which they hold in the same hand, between different fingers.

18. The manufacture of cutlery is carried on most extensively in England, at Birmingham, Sheffield, Walsall, Wolverhampton, and London.

London cutlery has the reputation of being the best, and this circ.u.mstance induces the dealers in that city, to affix the London mark to articles made at other places. In the United States, there are many establishments for the fabrication of the coa.r.s.er kinds of cutlery, such as axes, plane-irons, saws, hoes, scythes, &c., but for the finer descriptions of cutting instruments, we are chiefly dependent on Europe.

[Ill.u.s.tration: GUN-SMITH.]

THE GUN-SMITH.

1. It is the business of the gun-smith to manufacture fire-arms of the smaller sorts; such as muskets, fowling-pieces, rifles, and pistols.

2. The princ.i.p.al parts of the instruments fabricated by this artificer, are the barrel, the stock, and the lock. In performing the operations connected with this business, great attention is paid to the division of labor, especially in large establishments, such as those belonging to the United States, at Springfield and Harper's Ferry; for example, one set of workmen forge the barrels, ramrods, or some part of the lock; others reduce some part of the forged material to the exact form required, by means of files; and again another cla.s.s of operators perform some part of the work relating to the stock.

3. The barrel is formed by forging a bar of iron into a flat piece of proper length and thickness, and by turning the plate round a cylindrical rod of tempered steel, called a _mandril_, the diameter of which is considerably less than the intended bore of the barrel. The edges of the plate are made to overlap each other about half an inch, and are welded together by heating the tube in lengths of two or three inches at a time, and by hammering them with very brisk, but moderate strokes, upon an anvil which has a number of semicircular furrows upon it.

4. In constructing barrels of better workmans.h.i.+p, the iron is forged in smaller pieces, eight or nine inches long, and welded together laterally, as well as lengthwise. The barrel is now finished in the usual way; or it is first made to undergo the additional operation of _twisting_, a process employed upon those intended to be of superior quality. The operation is performed by heating small portions of it at a time, and twisting them successively, while one end is held fast.

5. The barrel is next bored with several bits, each a little larger than the preceding one. The last bit is precisely the size of the intended calibre. After the barrel has been polished, and the breech closed with a screw, its strength and soundness are tested by means of a ball of the proper size, and a charge of powder equal in weight to the ball. Pistol-barrels, which are to go in pairs, are forged in one piece, which is cut asunder, after it has been bored.

6. Barrels for rifles are much thicker than those for other small arms; and, in addition to the boring in common barrels, they are furrowed with a number of grooves or _rifles_, which extend from one end of the cavity to the other, either in a straight or spiral direction. These rifles are supposed to prevent the rolling of the ball in its pa.s.sage out, and to direct it more unerringly to the object of aim.

7. The stocks are commonly manufactured from the wood of the walnut-tree. These are first dressed in a rough manner, usually in the country. After the wood has been properly seasoned, they are finished by workmen, who commonly confine their attention to this particular branch of the business. In each of the United States' armories, is employed a machine with which the stocks are turned, and also one, with which the place for the lock is made.

8. The several pieces composing the lock are forged on anvils, some of which have indented surfaces, the more readily to give the proposed form. They are reduced somewhat with the file, and polished with substances usually employed for such purposes. The several pieces of the lock having been put together, it is fastened to the stock with screws. Other particulars in regard to the manufacture of small-arms will be readily suggested by a careful inspection of the different kinds, which are frequently met with.

9. The period at which, and the country where, gunpowder and fire-arms were first invented, cannot be certainly determined. Some attribute their invention to the Chinese; and, in confirmation of this opinion, a.s.sert that there are now cannon in China, which were made in the eightieth year of the Christian era. On this supposition, their use was gradually extended to the West, until they were finally adopted in Europe, in the fourteenth century.

10. Others, however, attribute the invention of gunpowder to Berthold Schwartz, a monk, who lived at Mentz, between the years 1290 and 1320.

It is said, that in some of his alchemistic experiments, he put some saltpetre, sulphur, and charcoal, into a mortar, and having accidentally dropped into it a spark of fire, the contents exploded, and threw the pestle into the air. This circ.u.mstance suggested to his mind the employment of the mixture for throwing projectiles. Some traditions, however, attribute the invention to Constantine Antlitz, of Cologne.

11. The fire-arms first used in Europe were cannon, and these were originally made of wood, wrapped in numerous folds of linen, and well secured with iron hoops. They were conical in shape, being widest at the muzzle; but this form was soon changed for the cylindrical. At length they were made of bars of iron, firmly bound together with hoops of the same metal. In the second half of the fourteenth century, a composition of copper and tin, which was brought to form by casting in sand, came into use.

12. Cannon were formerly dignified with great names. Charles V. of Spain had twelve, which he called after the _twelve apostles_. One at Bois-le-Duc is called the _devil_; a sixty-pounder, at Dover Castle, is called _Queen Elizabeth's pocket-pistol_; an eighty-pounder, at Berlin, is called the _thunderer_; two sixty-pounders, at Bremen, the _messengers of bad news_. But cannon are, at present, denominated from the weight of the b.a.l.l.s which they carry; as six-pounders, eight-pounders, &c.

13. Fire-arms of a portable size were invented, about the beginning of the sixteenth century. The musket was the first of this cla.s.s of instruments that appeared, and the Spanish nation, the first that adopted its use as a military weapon. It was originally very heavy, and could not be well supported in a horizontal position without a _rest_. The soldiers, on their march, carried only the rest and ammunition, while each was followed by a youth who bore the musket.

14. The powder was not ignited with a spark from a flint, but with a match. Afterwards, a lighter match-lock musket was introduced, which was carried by the soldiers themselves. The rest, however, maintained its ground, until about the middle of the seventeenth century. The troops throughout Europe were furnished with fire-locks, such as are now used, a little before the beginning of the eighteenth century.

15. The bayonet was invented, about the year 1640, at Bayonne; but it was not generally introduced, until the pike was entirely discontinued, about sixty years afterwards. It was first carried by the side, and was used as a dagger in close fight; but, in 1690, the custom of fastening it to the muzzle of the fire-lock was commenced in France, and the example was soon followed throughout Europe.

16. Gunpowder, on which the use of fire-arms depends, is a composition of salt-petre, sulphur, and charcoal. The proportion of the ingredients is varied considerably in different countries, and by different manufacturers in the same country. But good gunpowder may be made of seventy-six parts of salt-petre, fifteen of charcoal, and nine of sulphur. These materials are first reduced to a fine powder separately, and then formed into a h.o.m.ogeneous ma.s.s by moistening the mixture with water, and pounding it for a considerable time in wooden mortars.

17. After the paste has been suffered to dry a little, it is forced through a kind of sieve. By this process it is divided into grains, the size of which depends upon that of the holes through which they have been pa.s.sed. The powder is then dried in ovens, and afterwards put into barrels, which are made to revolve on their axis. The friction produced by this motion destroys the asperities of the grains, and renders their surfaces smooth and capable of easy ignition.

[Ill.u.s.tration: FARRIER.]

THE VETERINARY SURGEON.

1. The horse, as well as the other domestic animals, is subject to a great variety of diseases, which, like those affecting the human system, are frequently under the control of medicinal remedies; and the same general means which are efficacious in healing the disorders of our race, are equally so in controlling those of the inferior part of the animal creation.

2. The great value of the domestic animals has rendered them, from the earliest periods, the objects of study and attention, not only while in health, but also when laboring under disease. For the latter state, a peculiar system was early formed, including a _materia medica_, and a general mode of treatment considerably different from those for human patients.

3. Of the authors of this system, whether Greek or Roman, nothing worthy of notice has been transmitted to us, beyond an occasional citation of names, in the works of Columella, a Roman writer, who flourished in the reign of Tiberius Caesar, and in Vegetius Renatus, who lived two centuries afterwards. The former treated at large on the general management of domestic animals, and the latter more professedly on the diseases to which they are liable.

4. Both of these writers treated their subject in elegant cla.s.sical Latin; but neither they nor any other ancient author whose works have reached us, had any professional acquaintance with medicine or surgery. Celsus is the only physician of those times who is said to have written on animal medicine; but this part of his works is not extant.

5. Xenophon is the oldest veterinary writer whose work remains; but his treatise is confined to the training and management of the horse for war and the chase. The chief merit of the ancient writers on this subject consists in the dietetic rules and domestic management which they propose. Their medical prescriptions are said to be an inconsistent and often discordant jumble of many articles, devoid of rational aim or probable efficacy.

6. On the revival of learning in Europe, when the anatomy and physiology of the human body had become grand objects of research in the Italian schools, veterinary anatomy attracted the attention of Ruini and others, whose descriptive labors on the body of the horse have since served for the ground-work and model to all the schools in Europe.

7. The works of the veterinary writers of antiquity were eagerly sought and translated in Italy and France, and the art was extensively cultivated, sometimes under regular medical professors. Every branch of the equine economy was pursued with a.s.siduity and success, whether it related to harness and trappings, equitation and military menage, or the methodical treatment of the hoof, and the invention of various kinds of iron shoes. Evangelista of Milan distinguished himself in the education or breaking of the horse; and to him is attributed the invention of the martingale.

8. The new science having been extended over a great proportion of the continent of Europe, could scarcely fail of occasional communication with England; nevertheless, the medical treatment of horses and other domestic animals continued exclusively in the hands of farriers and cow-doctors, until some time in the first quarter of the eighteenth century.

9. At this period, that branch of this art which relates to the medical and surgical treatment of the horse, attracted the attention of William Gibson, who had acted in the capacity of army surgeon in the wars of Queen Anne. He was the first author of the regular medical profession, in England, who attempted to improve veterinary science; and the publication of his work forms an era in its annals, since his work became, and has continued to the present day, the basis of the superior practice of the English.

10. The eighteenth century was abundantly fruitful in veterinary pursuits and publications. France took the lead; but a zeal for this branch of science pervaded Germany and the states north of that part of Europe, and colleges were established in various countries, with the express view of cultivating this branch of the medical art. It is said that the French have improved the anatomical and surgical branches of the art, and the English, those which relate to the application of medicines.

11. The first veterinary school was inst.i.tuted at Lyons, in 1762.

Another was established at Alfort, in 1766. A similar inst.i.tution was opened at Berlin, in 1792, and in the same year, one at St. Pancras, near London. In these colleges, lectures are given, and degrees conferred. In the diplomas, the graduate is denominated _veterinary surgeon_. A great number of these surgeons have been dispersed in the armies of Europe, as well as through the different countries, where they have been employed in the medical and surgical treatment of diseased animals, to the great advantage of their owners.