Page:Encyclopædia Britannica, Ninth Edition, v. 11.djvu/293

SMALL AKMS.] GUNMAKING wheel, which, when released by the trigger, spun round, rubbing against the pyrites and causing sparks, which set fire to the priming. The wheel-lock was, however, found to be complicated, expensive, and uncertain, so that the match-lock remained in use till the middle of the 17th century, when it was displaced by the flint-lock, the earliest form of which, the " snaphaunce," seems to have been invented about the end of the 16th century in Germany. Tn this lock the priming pan was provided with a steel cover and the cock held a flint; on pulling the trigger the cock fell, the flint struck the steel cover, forcing it back from the pan, evolving at the same time sparks, which fired the priming. During these developments of the lock the shape of the barrel was gradually changed; in 1621 the length of that of the musket was 4 feet, and the size of the bore such that twelve bullets weighed 1 fib. Soon after this the infantry soldier was supplied with a dagger. FiQ. 1. Haud-Gun. which fitted into the muzzle and served as a pike. This was improved at Bayonne into the bayonet, and during the latter part of the 17th century was still farther improved by the addition of a socket, so that the musket could be fired while the bayonet was fixed ready for use. Little change in firearms took place in the 18th century, but in 1807 a Scotch clergyman named Forsyth obtained a patent for priming with fulminating powder, an invention which, though it slumbered till 1834, was destined to cause a complete revolution in the mechanism of firearms. Early in the present reign its value was fully recognized ; the magazine of detonating composition and the priming pan used by Mr Forsyth were improved into the cap and nipple, and the flint-lock was entirely superseded. At this point, the progress of invention renders it necessary for us to treat separately the two branches of the subject, and to divide sporting from military arms. For sporting purposes smooth-bored shot-guns and grooved rifles are employed. Both are nearly always double- barrelled, and of late years the old muzzle-loaders have been almost entirely supplanted by the many breech-loading systems recently invented, which enable the sportsman to reload with greatly increased rapidity and uniformity, the latter quality being specially important in rifle shooting. The chief parts composing the arm are the barrel, the lock, and the stock. Barrels for sporting arms are made of four different kinds of material Damascus twist, laminated steel, stub iron, and mild cast-steel; besides these, common material is worked up into cheap barrels for exportation. Damascus twist consists of alternate rods of iron and steel placed one upon another ; usually six of each kind are thus arranged ; they are then forged and thoroughly welded to gether into a solid bar, which is afterwards rolled into rods, having a section about f inch square. The rod thus formed is raised to a brightish red heat, and one end of it is placed in a revolving chuck, while the other remains fixed ; the turning of the chuck subjects the rod to a severe twisting throughout its whole length, so that at last -it acquires the appearance of a screw having a very fine thread. Three of these rods are then placed together, the twist of one being in a contrary direction to that of the other two. They are then welded together into a bar, and rolled into a strip about f inch in width. The thickness of this strip depends on the part of the barrel it is intended to form ; if for the breech end it is made ^ inch thick, if for the centre y inch, if for the muzzle |- inch. These strips are now ready for coiling, which is performed by raising the strip to a bright red heat, fixing one end of it to a hook projecting from a taper mandril, which is placed in a machine and provided with a handle. On turning the handle the strip is wound round the mandril into a coil about 10 inches in length. The coil is then welded by about 3 inches at a time till the spirals unite to form a hollow cylinder ; it is then hammered on a small mandril till the welding is complete. Three coils welded together end to end form a barrel, to which the three different thicknesses of metal above m entioned give a slightly conical form, approximating to the ultimate shape. About three- fourths of the material is cut away in the making; 16 tt> of iron are used in the first instance to make a pair of barrels, which weigh only 8 Bb when the welding is finished, and only between 3 and 4 ft) after boring and grinding, In the manufacture of laminated steel barrels the best quality of steel scrap, after thorough cleaning in a revolv ing drum, is mixed with a small proportion of charcoal iron. The mixture is heated in a furnace, and puddled into a ball, which is well worked up under a forge hammer. It is then drawn out under a tilt hammer, and rolled into strips of the required length and thickness, after which it is treated as above described. This material is much esteemed for its hardness and closeness of grain, but it does not possess the elegant marking and appearance of the Damascus twist. Stub iron for barrels was formerly made by putting a quan tity of old horse-shoes or stubs into an iron ring, welding them into a solid mass, and then rolling them out to strips of the requisite dimensions. Now a mixture of best wrought scrap, and sometimes steel scrap with stubs, is preferred, as giving more hardness and durability to the barrels. A description of the manufacture of cast-steel barrels will be found below, in connexion with military rifles. A sham-twist barrel is apt to impose on the purchaser ; plain iron is cheaper than twisted iron, and sometimes a thin coil of twist is rolled round a plain inner tube ; the whole is then welded together, and has all the appearance of a genuine twisted barrel. Other cheap barrels are made by rolling up strips of iron plate, and welding them together so that each barrel has a weld running down its whole length. As the breech end is thicker than the muzzle end, these barrels are usually mode in two lengths. In the rough state just described the barrels are sent Boring from the forge to the gunmaker, w r ho bores them carefully a ?d st: out to nearly the finished size. He then turns them pl down at intervals, obtaining correct surfaces by means of inside and outside gauges. The barrels are then "stripped" that is, turned down the whole length to correspond with the bore. For double guns two barrels are now brazed together, near the muzzle and near the middle. At the breech the barrels are separated by a "steel lump." The axes of the barrels are not quite parallel to each other, but are usually adjusted to cross at about 40 yards from the gun. When packed together, a rib is soldered on down the

entire length, and they are sent to be proved at the proof-