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Barrel-welding by Machinery. — The barrels of musquets, birding-guns, &c., or what are called plain, to distinguish them from those denominated stub or twisted barrels, have of late years been formed by means of rolls, a process in which the welding is first effected on a short slab of thick iron, and then the barrel is brought down to its destined length and form, by repeatedly passing it between a pair of rolls, that have been previously grooved to the exact shape of the barrel intended to be made.
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Clonet and Hachette pointed out the three following processes for producing Damascus blades : 1, that of parallel fillets; 2, that by torsion; 3, the mosaic. The first, which is still pursued by some French cutlers, consists in scooping out with a graving tool the faces of a piece of stuff composed of thin plates of different kinds of steel. These hollows are by a subsequent operation filled up, and brought to a level with the external faces, upon which they subsequently form tress-like figures. 2. The method of torsion, which is more generally employed at present, consists in forming a bundle of rods or slips of steel, which are welded together into a well-wrought bar, twisted several times round its axis. It is repeatedly forged, and twisted alternately ; after which it is slit in the line of its axis, and the two halves are welded with their ontsides in contact ; by which means their faces will exhibit very various configuration 3. The mosaic method consists in preparing a bar, as by the torsion plan, and cutting this bar into short pieces of nearly equal length, with which a faggot is formed and welded together ; taking care to preserve the sections of each piece at the surface of the blade. In this way, all the variety of the design is displayed, corresponding to each fragment of the cut bar.

The blades of Clouet, independently of their excellent quality, their flexibility, and extreme elasticity, have this advantage over the oriental blades, that they exhibit in tho very substance of the metal, designs, letters, inscriptions, and, generally speaking, all kinds of figures which had been delineated beforehand.

Notwithstanding these successful results of Clouet, it was pretty clear that the watered designs of the true Damascus scymitar were essentially different. M. Urcant has attempted a solution of this problem. He supposes that the substance of the oriental blades is a cast steel more highly charged with carbon than our European steel, and in which, by means of a cooling suitably conducted, a crystallisation takes place of two distinct combinations of carbon and iron. This separation is, he thinks, the essential condition ; for if the melted steel be suddenly cooled in a small crucible or ingot, there is no damascene appearance. If an excess of carbon be mixed with iron, the whole of the metal will be converted into steel ; and the residuary carbon will combine in anew proportion with a poriion o' the steel so formed. There will be two distinct compounds; namely, pure steel, and earburetted steel or cast-iron. These at first being imperfectly mixed, will tend to separate if while still fluid they be left in a state of repose ; and form a crystallisation in which the particles of the two compounds will place themselves in the crucible in an order determined by their affinity and density conjoined. If a blade forged out of steel so prepared be immersed iu acidulous water, it will display a very distinct Damascus appearance -, the portions of pure steel becoming black, and those of carburet ted steel remaining white, because the acids with difficulty disengage its carbon. The slower such a compound is cooled, the larger the Damascus veins will be. Tavemier relates that the steel crucible ingots, like those of wootz, for making the true oriental Damascus, come from Golconda, that they are the size of a halfpenny roll, and when cut in two, form two swords.

Steel combined with manganese displays the Damascus appearance very strongly.

A mixture of 100 parts of soft iron, and 2 of lamp black, melts as readily as ordinary steel. Several of the best blades which M. Bréant presented to the Société d'Encouragement are the product of this combination. This is an easy way of making cast-steel without previous cementation of the iron. 100 parts of filings of very grey cast-iron, and 100 parts of like filings previously oxidised, produced, by their fusion together, a beautiful damascene steel, fit for forging into white arms, sabres, swords, etc. This compound is remarkable for its elasticity, an essential quality, not possessed by the old Indian steel. The greater the proportion of the oxidised cast-iron the tougher is the steel. Care should be taken to stir the materials during their fusion, before it is allowed to ei:ol; otherwise they will not afford a homogeneous damasc. If the steel contains much carbon it is difficult to forge, and cannot be drawn out excipt within a narrow range of temperature. When heated to a red-white it crumbles under the hammer ; at a cherry-red it becomes hard and brittle ; and as it progressively cools it becomes still more unmalleablc. It resembles completely Indian steel, which European blacksmiths cannot forge, because they are ignorant of the suitable temperature for working it. M. lireant, by studying this point, succeeded in forging fine blades.

Experience has proved that the orbicular veins, called by the workmen knots or Oicrns (ronces), which are seen upon the finest Eastern scymitars, are the result of the manner of forging them, as well as the method of twisting the Damascus bars. If these be drawn in length, the veins will be longitudinal ; if they be spread equally in all directions, the stuff will have a crystalline aspect ; if they be made wavy in the two directions, undulated veins will be produced like those in the oriental Damascus.