The manufacture of a gun is performed by the follow ing workmen, viz. barrel forger, borer and filer, lock for ger and filer, furniture filer, ribber and breecher, rough stocker, scrcwer together, polisher, and engraver, in all ten different persons, few of whom can execute any other branch of the art but one. :lost of the principal towns in England have one or two master gun-makers, but none of them earry on the business in all its different branches, except London, Birmingham, and Edinburgh. The ma kers of the first and last cities have the highest prices for their guns, single fowling-pieces being from 15 to 30 guineas, and double ones from 35 to 70 guineas ; indeed, to such a perfection has this insrument been brought, of late years, by the British artists, that it cannot be doubted but that they arc greatly superior to every other nation in Europe ; although we have learned that, at the Versailles manufactory, under the first consul's special patronage, fowling-pieces were made at the high price of 800 guineas. Instances, however, can be produced where London makers have had a thousand guineas for one gun. The variety and ingenuity in the construction of small arms, in order to gain peculiar advantages, are so various and extensive, that it would be very difficult to enter into any details up on the subject : We shall, however, enumerate a few of the different kinds of guns which are in use : guns with one barrel, to discharge from one to three balls successively ; magazine guns that prime and load by one motion, and dis charge from 10 to 20 balls in succession ; double guns, with their barrels placed perpendicular, horizontal, and to turn round a centre ; three, four, and seven barrelled guns; harpoon guns ; muskets and carabines, &c.
The gun barret—The length, shape, and bore of gun barrels have materially changed, as the instrument became more generally used and better understood. Hence we find, in different countries and at different periods, their length fluctuating from six feet to 25 inches, and their diameters from half an inch to one and a quarter inch : They are generally cylindrical, but in some instances square, internally and externally, with chambers at the breech to contain the powder, as is the case with all the Asiatic matchlocks of most ancient construction. The Spaniards were the first people in Europe who excelled in the manufacture of barrels, remarkable for lightness and safety : Possessing finer iron from tt.eir .;melting di& ores with wood ; and being sensible that the more it is wrought by heating and hammering, the purer it becomes, they naturally resorted to the old nails extracted from the shoes of their horses and mules. Juan Sanchez di Mirve pa, is the first that forged the barrel in separate pieces, in the reign of Philip 1V.; and so highly were the Madrid maket s esteemed, in 1720, that the French gave 1000 livres, or 43/. 13s. sterling, for the barrels of Nicholas Biz, Juan Beier, and Juan Fernendcz. About the year 1650, we find Lazerino Cominazio, of Brescia, in high repute. France has also had her eminent workmen, such as Nicol le Clcrc, Des Champs, Jean Franc Relict, and Henry Renet, all of Paris, whose barrels are still much prized. The British are now, however, confessedly much superior to every other people in the manufacture of this article. They have, of late, introduced many ingenious improvements, such as patent steel barrels, and narrow and wire twist barrels, with a beautiful application of the fibres of the metal in welding, so as to resemble exactly the Damascus steel of Persia, or what is seen in the finest arms of Indian work manship. At first the European barrels were all of one diameter throughout, until within these 30 years, that a London tradesman obtained a patent for a chambered breech, which, though it possessed peculiar merit, was no thing but a copy from the principle of the carronade, and both are obviously borrowed from the Indian matchlock ; hence his privilege of original invention being untenable, this construction became general in a few years, and still continues, with some slight variation, to the present period.
In forming the common gun barrel, the workmen begin by heating and hammering out a bar of the best iron, into the form of a flat ruler, thinner at the end intended for the muzzle, and thicker at that for the breech, the length, breadth, and thickness of the whole plate being regulated by the intended length, diameter, and weight of the barrel. This oblong plate is then, by repeated heating and ham mering, turned round a cylindrical rod of steel, called a mandril, whose diameter is considerably less than the in tended 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 hammering it, with very brisk but moderate strokes, upon an anvil which has a number of semicircular furrows in it, adapted to barrels of different sizes. The heat required for welding is the bright white heat which immediately precedes fusion, and at which the particles of the metal unite and blend so intimately with each other, that when properly managed, not a trace is left of their former separation. Every time the barrel is with drawn from the forge, the workmen strike the end ofit once or twice gently against the anvil in an horizontal direction; this operation, which is called jumping, serves to consolidate the particles of the metal more perfectly, as well as to dis engage the scoria from the inside and outside of the tube, and to obliterate any appearance of a scam. The mandril is then introduced into the bore, or cavity ; and the barrel being placed in one of the furrows or moulds of the anvil, is hammered very briskly by two persons ; the forger all the while turning it round in the mould, so that every point of the heated portion may come equally under the action of the hammer. These beatings and hammerings are repeat ed until the whole of the barrel has undergone the same operation, and is rendered as perfectly continuous as if it had been bored out of a solid piece. Twisted barrels are now generally used for the finest fowling-pieces, the me thod of fabricating of which is as follows. Four bars of stub iron, two feet in length, half an inch in breadth, and the first two bars half an inch thick or more, according to the size of the barrel, arc previously prepared. An old barrel being welded to the extremity of one of those bars for a handle, it is heated and turned round like a cork screw, by means of the hammer and anvil ; after this, the turns of the spiral are united by heating the tube two or three inches at a time to a bright white heat, and striking the end of it several times against the anvil in a horizon tal direction, with considerable force: This is called jump ing the barrel, and the heats given for that purpose jump. ing heats : A mandril is immediately introduced into the cavity, and a quick light hammering is kept up on the welding part, until the ridges raised at the seams by the jumping are flattened, and the piece appears sound. As goon as one bar is rounded and jumped in this manner, another is welded to it, and treated in the same way, until the four pieces are united and form one tube : The old barrel is then cut off as being no longer requisite, and the operation of heating and hammering is frequently repeated in its whole length, until its external figure is correctly acquired, and the metal has arrived at the utmost closeness of fibre in. all its parts. It is a circumstance of considera ble importance with respect to a gun barrel, that it should be forged as nearly as possible to its weight when finished, so that very little may be taken away in the boring and filing ; for as the outer surface, by having undergone the action of the hammer more immediately than any other part, is rendered more compact and pure, the less that is removed the better will the barrel be.