Part 18

6. In the shop represented at the head of this article, sledges and hammers are used as forging instruments, and these are wielded by the workmen themselves. The head workman has hold of a piece of iron with a pair of tongs, and he, with a hammer, and two others, with each a sledge, are forging it upon an anvil. The two men are guided in their disposition of the strokes chiefly by the hammer of the master-workman.

7. In ordinary blacksmith shops, two persons commonly work at one forge, one of whom takes the lead in the operations, and the other works the bellows, and uses the sledge. From the part which the latter takes in the labor, he is called the _blower_ and _striker_. A man or youth, who understands but little of the business, can, in many cases, act in this capacity tolerably well.

8. The iron is rendered malleable by heating it with charcoal or with stone coal, which is ignited intensely by means of a blast from a bellows. The iron is heated more or less, according to the particular object of the workman. When he wishes to reduce it into form, he raises it to a _white heat_. The _welding heat_ is less intense, and is used when two pieces are to be united by _welding_. At a red heat, and at lower temperatures, the iron is rendered more compact in its internal texture, and more smooth upon its surface.

9. The joint action of the heat and air, while the temperature is rising, tends to produce a rapid oxydation of the surface. This result is measurably prevented by immersing the iron in sand and common salt, which, uniting, form a vitreous coating for its protection. This coating is no inconvenience in the forging, as its fluidity causes it to escape immediately under the action of the hammer.

10. Steel is combined with iron in the manufacture of cutting instruments, and other implements, as well as articles requiring, at certain parts, a great degree of hardness. This substance possesses the remarkable property of changing its degree of hardness by the influence of certain degrees of temperature. No other substance is known to possess this property; but it is the peculiar treatment which it receives from the workman that renders it available.

11. If steel is heated to redness, and suddenly plunged into cold water, it is rendered extremely hard, but, at the same time, too brittle for use. On the other hand, if it is suffered to cool gradually, it becomes too soft and ductile. The great object of the operator is to give to the steel a quality equally distant from brittleness and ductility. The treatment by which this is effected is called _tempering_, which will be more particularly treated in the article on the cutler, whose employment is a refined branch of this business.

THE NAILER.

1. Nail-making constitutes an extensive branch of the iron business, as vast quantities of nails are annually required by all civilized communities. They are divided into two classes, the names of which indicate the particular manner in which they are manufactured; viz., _wrought nails_ and _cut nails_.

2. The former are usually forged on the anvil, and when a finished head is required, as is commonly the case, it is hammered on the larger end, after it has been inserted into a hole of an instrument formed for the purpose. Workmen by practice acquire surprising dispatch in this business; and this circumstance has prevented the general introduction of the machines which have been invented for making nails of this description. Wrought nails can be easily distinguished from cut nails, by the indentations of the hammer which have been left upon them.

3. In making cut nails, the iron is first brought into bars between grooved rollers. The size of the bars is varied in conformity with that of the proposed nails. These bars are again heated, and passed between smooth rollers, which soon spread them into thin strips of suitable width and thickness. These strips, having been cut into pieces two or three feet in length, are heated to a red heat in a furnace, to be immediately converted into nails, when designed for those of a large size. For small nails, the iron does not require heating.

4. The end of the plate is presented to the machine by the workman, who turns the material over, first one way and then the other; and at each turn a nail is produced. The machine has a rapid reciprocating motion, and cuts off, at every stroke, a wedge-like piece of iron, constituting a nail without a head. This is immediately caught near the head, and compressed between _gripes_; and, at the same time, a force is applied to a die at the end, which spreads the iron sufficiently to form the head. From one to two hundred can be thus formed in a minute. This fact accounts for the low rate at which cut nails are now sold, which, on an average, is not more than two cents per pound above that of bar iron.

5. On account of the greater expense of manufacturing wrought nails, they are sold much higher. It is said that nine-tenths of all the nails of this kind, used in the United States, are imported from Europe. We thus depend upon foreign countries for these and many other articles, because they can be imported cheaper than we can make them; and this circumstance arises chiefly from the difference in the price of labor.

6. The first machine for making cut nails was invented in Massachusetts about the year 1816, by a Mr. Odion, and soon afterwards another was contrived, by a Mr. Reed, of the same state. Other machines, for the same purpose, have likewise been constructed by different persons, but those by Odion and Reed are most commonly used. Before these machines were introduced, the strips of iron just described, were cut into wedgelike pieces by an instrument which acted on the principle of the shears; and these were afterwards headed, one by one, with a hammer in a vice. The fact, that the manufacture of this kind of nails originated in our country, is worthy of recollection.

7. In 1841, Walter Hunt, of New-York, invented a double reciprocating nail engine, which is owned by the New-York Patent Nail Company. This machine works with surprising rapidity, it being capable of cutting five or six hundred ten-penny nails in a minute. One hand can tend three engines, as he has nothing more to do than to place the heated plate in a perpendicular position in the machine.

8. This manufacture includes, also, that of tacks and spikes; but since, in the production of these, the same general methods are pursued, they need no particular notice. The different sizes of tacks are distinguished by a method which indicates the number per ounce; as two, three, or four hundred per ounce. Spikes are designated by their length in inches, and nails by the terms, two-penny, three-penny, four-penny, ten-penny, and so on up to sixty-penny.

THE CUTLER.

1. Under the head of cutlery, is comprehended a great variety of instruments designed for cutting and penetration, and the business of fabricating them is divided into a great number of branches. Some manufacture nothing but axes; others make plane-irons and chisels, augers, saws, or carvers' tools. Others, again, make smaller instruments, such as table-knives, forks, pen-knives, scissors, and razors. There are also cutlers who manufacture nothing but surgical instruments.

2. The coarser kinds of cutlery are made of blistered steel welded to iron. Tools of a better quality are made of shear steel, while the sharpest and most delicate instruments are formed of cast steel. The several processes constituting this business may be comprised in forging, tempering, and polishing; and these are performed in the order in which they are here mentioned.

3. The general method of _forging_ iron and steel, in every branch of this business, is the same with that used in the common blacksmith's shop, for more ordinary purposes. The process, however, is somewhat varied, to suit the particular form of the object to be fashioned; for example, the blades and some other parts of the scissors are formed by hammering the steel upon indented surfaces called _bosses_. The bows, which receive the finger and thumb, are made by first punching a hole in the metal, and then enlarging it by the aid of a tool called a _beak-iron_.

4. The steel, after having been forged, is soft, like iron, and to give it the requisite degree of strength under the uses to which the tools or instruments are to be exposed, it is hardened. The process by which this is effected is called _tempering_, and the degree of hardness or strength to which the steel is brought is called its _temper_, which is required to be _higher_ or _lower_, according to the use which is to be made of the particular instrument.

5. In giving to the different kinds of instruments the requisite temper, they are first heated to redness, and then plunged into cold water. This, however, raises the temper too high, and, if left in this condition, they would be too brittle for use. To bring them to a proper state, they are heated to a less degree of temperature, and again plunged into cold water. The degree to which they are heated, the second time, is varied according to the hardness required. That this particular point may be perfectly understood, a few examples will be given.

6. Lancets are raised to 430 degrees Fahrenheit. The temperature is indicated by a pale color, slightly inclined to yellow. At 450 degrees, a pale straw-color appears, which is found suitable for the best razors and surgical instruments. At 470 degrees, a full color is produced, which is suitable for pen-knives, common razors, &c. At 490, a brown color appears, which is the indication of a temper proper for shears, scissors, garden hoes, and chisels intended for cutting cold iron.

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 _polishing_ 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 mass 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 fashionable 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 circumstance 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 coarser 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.

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 principal 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 class 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 workmanship, 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 passage 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, assert 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 circumstance 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 balls 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 class 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 homogeneous mass 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 passed. 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.

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.