As civilization progresses new materials are developed but older ones are rarely discarded; rather are they used more for specialized purposes, particularly if they are comparatively scarce. This was the fate of bronze in Rome, after the introduction of iron smelting about 600 to 700 B.C. In this case the durability of copper and its principal alloy, bronze, and their attractive appearance, ensured continuing use of both metals although on a more limited scale. Moreover, the discovery soon afterwards of a new copper alloy, brass, opened up endless fresh opportunities for the coppersmith's art.
