After being welded, the barrels are carefully examined, and, if needful, straightened by a few blows of the hammer. They are then bored in a machine with an angular plug of tempered steel, which is caused to revolve rapidly within the barrel, while a stream of water is directed upon the outside to check the heat caused by the tremendous friction. The outside is brought to a smooth surface either by grinding on a large grindstone, or turning in a lathe. The breech end of the barrel is bored with a screw-thread, to receive the breech plug, which closes it at that end.
Mandril, with Damascus Barrel in progress. Tool for boring Barrel. Testing Barrel.
The barrels are then proved by being fired at the proof-house, a large building where they are loaded with a charge five times as great as they will have to bear when in use. A great number of barrels are fired at once by laying them upon a strong framework of wood with their touch-holes downwards, and connected with a train of gunpowder which is ignited outside the building. A heap of sand is piled inside the building, opposite the muzzles of the barrels to receive the bullets. Those which bear this test without injury are marked as perfect.
Guns used in field sports are often made with two barrels fixed side by side upon one stock. The barrels are made separately, and each with one flat side, that they may lie close together. They are secured together by ribs running between them from end to end.
The wooden stock upon which the barrel is fixed is generally made of walnut-tree wood. It is first shaped, and afterwards shod with brass or steel; the trigger guard and other fittings are let into the wood, and every part is furnished with the proper screws and fastenings.
With regard to the manufacture of rifles and other small arms in general, the author of the present work some time ago wrote a description of a visit to the factory at Birmingham known as the Toledo Works, and it may be useful to give an extract from that account of what he saw there.
The steel from which the swords are made is supplied in long pieces somewhat tapering at the ends, and having a square portion in the middle, which, being cut through, leaves material for two blades, the bisection of the square leaving a shoulder at one end to receive the iron “tang” by which the blade is afterwards fixed into the handle. The manufacture of these blades is almost entirely effected by the forgers, who hammer them into the required shape upon the anvil, a mould running down the centre of which secures the hollow which in swords extends for about two-thirds of the length from hilt to point. In a little street of smithies the musical clink is being sounded by a score of stalwart arms, either forging the rough steel into form, or hammering the formed blade into perfect shape and symmetry, an operation which requires it to be kept at a certain heat, lest the embryo blade should be injured in the process. Once perfected as to proportion, the hardening commences, and the blade is thrust backwards and forwards into the furnace until it has acquired a proper and uniform heat, at which point it is removed and instantly plunged into cold water. This process, which has obviously suggested the Turkish bath, renders it hard indeed, but at the same time so extremely brittle that we whisperingly suggest the propriety of contracting to supply our enemies with weapons, and neglecting to carry them beyond that particular stage of preparation, when they may be snapped with the fingers. Carefully supported, however, the blade is again subjected to the fiery ordeal until it attains a slaty blue colour, and a beautiful and elastic temper, which has been partially secured by the previous hammering. By the process of forging it has become about six inches longer than the pristine steel shape, and by the tempering it has attained a springy strength which enables it to be bent in a curve sufficient to bring the hand five inches nearer to the point than when the blade is straight.
Many of the best bayonets are forged in the same way as the sword-blades, and, as in almost every manufacturing process, human intelligence has an unmistakable advantage over mere mechanical force, these possess some superior qualities. The greater number of bayonets, however, are made from a square bar of drawn steel, five inches and a half long by nine-sixteenths square. This bar is passed between a series of about sixteen pairs of rollers, which are worked by steam power, and so grooved as gradually to mould the blade to the required shape. Sixteen times the short steel bar undergoes the merciless pressure of a progressively-increased power, until its length is increased from five and a half to twenty-six inches, when some portion is cut off from the point to leave it the regulation length.
The matchets, which are made from bevel-edged steel, passed twice through the rollers, are cut into the requisite shape by means of powerful shears.