History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c14.s1.1

v1.c14.s1.1

A great number of coins carry devices, which are not as sharply cut or clear as those on a great number of archaic coins including the ‘punch-marked’ series. These devices seem to have been impressed on coins not by hard striking, but by casting metal in moulds bearing the required impression in negative. The process of manufacturing these coins involves preparation of mould(s), melting of metal and casting of the latter in the mould(s). The negative of the intended coin-type could have been engraved or etched on a blank mould made of heat-resisting plastic clay or on a mould in cast metal. It was perhaps technically also possible to have the metal mould with the intended impression by casting the required amount of molten metal in a clay mould bearing the positive of the impression in relief. Similarly, according to an alternative and possibly more convenient method of preparing a clay mould for producing coins, the intended coin-device could have been carved in relief on a lump of clay or on a piece of metal. It was not difficult to rectify the positive impression, if it was found necessary. The latter, made either in clay or metal, served as a model. By pressing this positive impression on a lump of heat-resisting plastic clay, specially prepared according to the shape (round, rectangular, square, etc) and size of the intended coin, a mould was made, consisting of the intagliated negative impression. The mould with raised rim around the coin-socket was then baked.