By this severe twisting, the rod of six feet is shortened to three, doubled in thickness, and made perfectly round. Three of these rods are then placed together, with the inclinations of the twists running in opposite directions; they are then welded into one, and rolled down into a rod 11-16ths of an inch in breadth. Being pickled in acid, to eat away the iron, it exhibits the following appearance:--
This iron has long been held in great esteem. It looks pretty; but certainly does not possess either the strength or tenacity of wire-twist iron. It is well known that the strength of a rope may be destroyed by twisting it too much: so is it with this sort of iron. Iron is best when not twisted at all: I speak of the bar. It resembles wood, inasmuch as the strands or fibres run parallel, firmly adhere, and add strength to each other; if you twist those fibres you tear them asunder, and they no longer support each other. So it is with iron.
The objection made to the wire-twist is, that owing to the iron and steel being perfectly separate bodies running through the whole thickness of the barrel, there is a difficulty in welding them perfectly; and, of course there is danger of their breaking across, at any trifling imperfection or mis-weld. This objection is certainly well grounded, as many barrels break in the proving. I have seen a very strong barrel indeed broken across the knee without the slightest difficulty, while, to all appearance, it was perfectly sound. This is the reason why the manufacturers have ceased to make them, except for the American trade.
It may be said that the fibres in the Damascus, after being torn asunder, are welded anew. True; but could you ever glue the fibres of a piece of wood (twisted in the same way) together again, to make them as strong as before? No: cut several pieces of wood across the grain and glue them together, you would not expect them, though equal in substance with a piece in which the grains run lengthwise, to be of equal strength. In short, I hold a Damascus barrel to be little superior to a common barrel, in which the fibres run parallel to the bore.
All the varieties of figured barrels are but modifications of Damascus. The most endless variety possible may be attained; a figure with the carbonised material, showing only the ends or edges of the various laminæ, or portions of the face of that laminæ, may with equal facility be obtained, if the patience of the artist be in proportion. It would be a never-ending task, a subject for many volumes, to endeavour to describe a tithe of the varieties that might be, and have been made.