Anvil, an iron block with a smooth face on which smiths hammer and shape their work. The smallest anvils, called bickerns, are mostly made of steel. The largest, used with tilt, trip, or steam hammers, are of cast iron, and of a very uniform and simple shape. They are truncated quadrangular pyramids, placed with the small end up, the large resting upon a block of wood fixed in the ground. The mid- ' die-sized anvils, on which the forging is performed with sledge hammers, are made of cast or wrought iron. Formerly extra good anvils were made of wrought iron covered with steel, the fibres of which were placed vertically. To do this the bars of steel were cut in pieces about an inch long, which were placed standing side by side, bound by a wire, and welded into a steel plate, which was itself welded to the anvil. The heat necessary for welding very often altered the steel, which was brought back to its original state by the anvil being warmed for a few hours in a box full of cement. It was afterward hardened by pouring a stream of water upon the steel face till the whole block was cooled. The best anvils made in the United States are of cast iron covered with steel: they possess most of the advantages above described, and are comparatively cheap.

The covering of steel is placed at the bottom of a mould, and cast iron is poured upon it. Some makers place a core in the mould so as to leave a deep recess nearly reaching the steel covering in the centre of the anvil. The air penetrates into this recess, and the metal is cooled more uniformly.