Round rods, and those of a square or flat shape, that are required more perfect in their figure, and with a smoother surface than those which are split by the process described, are made by rolling with small rolls that are case-hardened, and have their grooves very nicely formed. They are usually from six to seven inches in diameter, and make from 230 to 260 revolutions per minute, and the rods, whilst between the rolls, are drawn through them at the same velocity. They are rolled of great lengths, sometimes upwards of forty feet, and are afterwards cut to the required lengths, and tied into bundles of 56 lbs. each. Round rods are thus rolled so small (about three-sixteenths of an inch), as to form a very useful and cheap substitute for wire. It is extensively used by wire-workers, and in making " invisible fences;" also by tinmen, coppersmiths, and other trades; but especially in those cases where it is covered over, and employed to stiffen flexible substances.

Red-Short, is a term given to bar iron that has the defect of cracking or breaking, when punched or bent, while at a red heat. It is generally very strong when cold, and therefore useful in that state; and when it is worked, care should be taken by the smith not to subject it to severe strains at that peculiar heat in which it is disposed to give way.

Cold-Short, is that kind of iron that readily breaks when cold, but is easily wrought under the hammer when heated.

Testing the Quality of Iron is usually performed by cutting a nick on one side of it with a cold chisel, then bending it down, or giving it a blow with a sledge hammer. If the iron be bad, or cold-short, it will break, and exhibit a resplendent, crystallized fracture; if, on the contrary, the uncut part bends back, and exhibits the appearance of a bundle of silky-looking fibres, such iron will probably stand the heated test of bending it double whilst at a cherry-red heat, first in the direction of the pile, and afterwards at right angles to it If the iron does not crack by these tests, it is neither cold-short nor red-short, but of a tough good quality. We have now given a pretty general outline of the process of making common malleable iron, but there remains to be explained in what respect the processes differ in the preparation of the superior kinds.