a furnace where wrought iron or other metal is hammered and fashioned with the aid of heat. This is called a smith's forge. In ships a very convenient kind is the portable truck forge. Forge is also applied to the blast furnace, in which iron ore is smelted; also, where the production of the blast furnace is fused, and afterwards beaten with enormous hammers, or drawn through cylinders of different diameter, in order to render the metal soft, pure, and more malleable and ductile. Such great workshops are otherwise called shingling mills. See IRON-MAKING.

An ordinary smith's forge consists of the hearth or fireplace, which is merely a cavity in masonry or brick-work, lined with fire-clay or brick, and containing ignited fuel, upon which a powerful blast of air is driven through the nozzle of double-bellows, worked by a hand-lever. There are also portable forges, of small dimensions, but answering all the ordinary purposes of a smith's forge. Such are the travelling forges of armies, those used on board ships, &c.