A foundry is a workshop in which metals are processed by melting and casting in molds. Up until to the 18th century, foundries were usually small, mainly casting gun barrels and bells. From 1760, however, they grew in size as the use of coke provided an efficient fuel to heat large furnaces. Foundries became increasingly sophisticated, especially where iron and steel were concerned, after the innovations of men such as Henry Cort (1740–1800) and Henry Bessemer (see Bessemer process).