The interior of the proving-house is very happily arranged for the purpose to which it is put. On the right-hand end of the building as you enter, and extending across it, is a platform of cast-iron, containing grooves in which the muskets are placed when loaded. A train of gunpowder is then laid on the back side of this platform, connecting with each barrel, and passing out through a hole in the side of the building near the door. A bank of clay is piled up on the opposite side of the room, into which the balls are thrown. Only one fatal accident has occurred at the armory during the last two years, and this occurred in the proving-house. When the muskets are brought in, they are placed upright in frames, which, when full, are laid down upon the platform. Five barrels are placed in a frame, and these five exploded while the man was putting them in the proper position for laying them down, and ten balls were plunged into him. No satisfactory explanation could ever be obtained of the cause of the premature explosion.
About one per cent. of the barrels burst under this trial, although under the old process of welding there was a loss of nearly two per cent., or one in sixty.
The pieces that fail are all carefully examined, to ascertain whether the giving-way was owing to a defect in the rolling, or to some flaw or other bad quality in the iron. The appearance of the rent made by the bursting will always determine this point. The loss of those which failed from bad rolling is then charged to the operative by whom the work was done, at a dollar for each one so failing. The name of the maker of each is known by the stamp which he put upon it at the time when it passed through his hands. As the workman gets but four cents for rolling a barrel, he loses the work done upon twenty-five for each one that fails through his negligence. The justice of this rule will be apparent, when it is taken into account that that amount of cost has been expended upon the barrel prior and subsequent to the work done by the roller, all of which has been lost through his remissness. Besides, he is paid so liberally for his work, that he can well afford to stand the loss. This system of accountability runs through the entire work, and tends greatly to the promotion of care and fidelity in the various departments of labor.
There are forty-nine pieces used in making up a musket, which have to be formed and finished separately; only two of these, the sight and cone-seat, are permanently attached to any other part, so that the musket can, at any time, be separated into forty-seven parts, by simply turning screws and opening springs. Most of these parts are struck in dies, and then finished by milling and filing. The process of this manufacture is called swaging,—the forming of irregular shapes in iron by means of dies, one of which is inserted in an anvil in a cavity made for the purpose, and the other placed above it, in a trip-hammer, or in a machine operated in a manner analogous to that of a pile-driver, called a drop. Cavities are cut in the faces of the dies, so that, when they are brought together, with the end of a flat bar of iron, out of which the article is to be formed, inserted between them, the iron is made to assume the form of the cavities, by means of blows of the trip-hammer, or of the drop, upon the upper die. About one hundred and fifty operations upon the various pieces used in the construction of the musket are performed by these dies. Some of the pieces are struck out by one operation of the drop, while others, as the butt-plate, require as many as three, and others a still larger number. The hammer is first forged, and then put twice through the drop. Four men are kept constantly at work forging hammers in the rough, while but two are required to put them through the two operations under the swaging-machine. Sometimes, however, the work presses upon the droppers, and they have the alternative either to work double time—that is, night and day—or to allow other hands to work with them; and as they work by the piece, and are anxious to earn as much as possible each month, they will frequently work night and day for several consecutive days. I have known instances where workmen have worked from Monday until Thursday, night and day, without any intermission, excepting the hour and a half at the morning change of hands, one hour at noon, one at tea-time, and half an hour at midnight,—four hours out of the twenty-four. By this means they will sometimes earn as much as one hundred and fifty dollars per month, although this would be an extraordinary case. The average pay in the dropping-department is about three dollars per day.
There are twenty-four simple and seven compound dropping-machines in constant operation. Some of the pieces are pressed into shape under these drops when cold,—this being the case with the triggers, which were found to use up the dies too rapidly when they were swaged while heated; but, as a general rule, the swaging is done while the piece is at a red or white heat. The operations of the various dropping-machines are exceedingly interesting, and the amount of labor they save is perfectly marvellous.
A large number of men are kept constantly at work making dies for the various pieces required.
When the pieces come out of the swaging-machines, they have more or less of surplus metal about them, which is cut off or trimmed by passing them through machines designed for this purpose.
The bayonet-blade is first forged under a trip-hammer, and then rolled to the proper shape, by an operation similar to the barrel-rolling. The socket is forged separately, and afterwards welded to the blade under a trip-hammer. It is then passed twice under the drop, then milled and polished, when it is ready for use. The ramrod is cut from steel rods about the size required. It is then ground in the same manner as the barrel, and the hammer is swaged on by two operations under the drop. The screw-cutting and polishing are very simple, and executed with great rapidity.
The cone-seating, like every other part of the work done upon the musket, is very interesting. The barrel, after it comes from the rolling-mill, is placed in a forge and heated to a white-heat. A small square block of iron, cut under a trip-hammer to the proper size, is also heated to a white-heat, and then welded to the barrel by half a dozen strokes under the trip-hammer,—the whole operation occupying less time than is required to describe it. An iron rod is meanwhile inserted within the barrel to maintain the continuity of the bore.
The sights are struck in dies, and placed upon the barrel in slots cut for the purpose. They are then brazed upon the barrel, pieces of brass wire, half an inch long, being used for this purpose. Three men are employed in brazing on the sights for the establishment.