on the joint at the anvil and on the face of the latter itself. Electric welding is largely taking the place of the hand process, but machines are required to maintain the parts in contact during the passage of the current. Butt joints are employed, and a large quantity of power is absorbed, but the output is immensely greater than that of hand-made welds. [Illustration: FIG. 8.] [Illustration: FIG. 9.] [Illustration: FIG. 10.] [Illustration: FIG. 11.] [Illustration: FIG. 12.] Punching. When holes are not very large they are formed by punching, but large holes are preferably produced by bending a rod round and welding it, so forming an eye (fig. 13). Small holes are often punched simply as a preliminary stage in the formation of a larger hole by a process of drifting. A piece of work to be punched is supported either on the anvil or on a ring of metal termed a bolster, laid on the anvil, through which the burr, when severed, falls. But in making small holes through a thick mass, no burr is produced, the metal yielding sideways and forming an enlargement or boss. Examples occur in the wrought iron stanchions that carry light hand railing. In such cases the hole has to be punched from each face, meeting in the centre. Punching under power hammers is done similarly, but occupies less time. Cutting-off. The cutting-off or severance of material is done either on hot or cold metal. In the first case the chisels used, "hot setts," have keener cutting angles than those employed for the second, termed "cold setts." One sett is held in a hole in the anvil face, the "anvil chisel," the other is handled and struck with a sledge. [Illustration: FIG. 13.] The difference between iron and steel at the forge is that iron possesses a very marked fibre whereas steel does not. Many forgings therefore must be made differently according as they are in iron or in steel. In the first the fibre must never be allowed to run transversely to the axis of greatest tensile or bending stress, but must be in line therewith. For this reason many forgings, of which a common eye or loop (fig. 13) is a typical example, that would be stamped from a solid piece if made in steel, must be bent round from bar and welded if in wrought iron. Further, welding which is practically uniformly trustworthy in wrought iron, is distrusted in steel. The difference is due to the very fibrous character of iron, the welding of which gives much less anxiety to the smith than that of steel. Welds in iron are frequently made without any flux, those in steel never. Though mention has only been made of iron and steel, other alloys are forged, as those of aluminium, delta metal, &c. But the essential operations are alike, the differences being in temperature at which the forging is done and nature of the fluxes used for welding. For hardening and tempering, an important section of smith's work, see ANNEALING.