For your interest Bro. Bonny
"The Irish Industrial Exhibition of 1853: A Detailed Catalogue of Its Contents"
John Sproule, 1854
http://books.google.com/books?id=cNKl8YYZejsC There are two processes by which a bar of iron is converted into a tube for the purposes of the gunsmith. First the simple though imperfect method of employing a flat bar, equal in length to the required barrel, and in width somewhat exceeding its circumference, and rolling it up until the edges overlap, to be finally welded along its entire length. Of late years an improvement has been effected in this method by the introduction of steam-power. A short bar is turned up and welded at one heat, and is then drawn out to the required length bv passing it through successive rollers. Such barrels are only used for the plainest work, and an much inferior to those produced by the second method. In this more perfect process the bar of iron, now called a strand, is coiled round an iron rod or mandril of the same size as the required bore; and the spiral so formed having been brought to a welding heat, and struck on the end to join the edges, becomes a continuous tube in which the grain of the material runs round the barrel, thereby insuring the greatest amount of resistance to the expansive force of the charge. The advantages of the latter method are numerous. The fibres of the iron, instead of being torn asunder by bending the bar parallel to its length, are rather condensed and closed together; and, accordingly, the better description of barrels have been manufactured in this manner for a long period. Among these are included the varieties called stub-twist, plaited-twist. laminated steel, Damascus, &c., which all partake so far of the common character that they are forged according to this process, but differ in the preparation of the strand. Thus, in stub-twist, a bar of iron is made as follows: — A quantity of stubs, i. e., small pieces of iron or steel, are raised to a welding heat, and consolidated by a few blows, and then drawn down between rollers to the required size. The excellence of the material depends on the quality of the stubs employed; that being in most repute formerly which was manufacture I from horse-nail stubs, or old horse-shoe nails collected by the farriers. Of late years these have deteriorated in quality, and it became necessary to apply, in the preparation of the strands, other processes which have for their object the purification of the iron, by twisting and hammering, and the introduction of carbon by a partial admixture of steel. The first of these — that of making plaited twist — is conducted as follows: — Two square bars of stub iron are separately twisted at a red heat until the whole rod has the appearance of a four-threaded screw, the threads being formed by what were the angles of the bar in its untwisted state, the one having a right-hand turn, the other a left. These rods, so prepared, are welded side by side to form the strand, and the grain of the iron presents, when finished, that feathered or plaited appearance whence it derives it’s name.
Steel barrels are made in a somewhat similar manner as just described, the material instead of stub iron, being prepared from soft steel, which is decarbonized in the course of manufacture.
The process of making Damascus barrels is more complicated, as involving a greater number of stages. The strand in this case is composed of three or four twisted rods instead of two, and they are all generally twisted in one direction; but it is in the manufacture of the rods themselves that the essential difference consists. These are no longer stub iron or decarbonized steel, but are formed of from twenty to four-and-twenty alternate layers of iron and steel welded together. The effect of this arrangement is, that when the barrel is finished, and an acid applied to the surface, the iron layers are rapidly eaten away, while the steel remains comparatively intact; and the whole presents that beautiful pattern, celebrated (long before the method of production was understood) as some secret prowess known only to Eastern armourers, and supposed to have originated in Damascus.
The credit of rediscovering it in these countries a due to a Dublin house, a Messrs. Rigby, of Suffolk- street, whose experiments were brought to a successful result in the year 1817.
