in the mechanical arts, is a cavity artificially cut, with a design to give its form or impression to some softer matter applied therein. Moulds are implements of great use in sculpture, foundry, and other arts. The workmen employed in melting the mineral or metallic ore dug out of mines have their several moulds to receive the melted metal as it comes out of the furnace; but these are different according to the diversity of metals and works. In gold mines they have moulds for ingots, in silver mines for bars, in copper and lead mines for pigs or salmons, in tin mines for pigs and ingots, and in iron mines for sows, chimney-backs, anvils, caldrons, pots, and other large utensils.