Roman metallurgy the most important being bronze, an alloy of copper and tin. Alloys are mixtures of different metals created either by smelting or by forging. It is important to note that an ore does not necessarily constitute an alloy; ore is a collection of minerals and alloyed metals. As metallurgical technology developed (hammering, melting, smelting, roasting, cupellation, moulding, smithing, etc.), more metals were intentionally included in the metallurgical repertoire. By the height of the Roman Empire, metals in use included: Gold, Silver, Copper, Tin, Lead, Zinc, Iron, Mercury, Arsenic, Antimony (Healy 1978). As in the Bronze Age, metals were used based
Liberty Bell Museum found a considerably higher level of tin in the Liberty Bell than in other Whitechapel bells of that era, and suggested that Whitechapel made an error in the alloy, perhaps by using scraps with a high level of tin to begin the melt instead of the usual pure copper. The analysis found that, on the second recasting, instead of adding pure tin to the bell metal, Pass and Stow added cheap pewter with a high lead content, and incompletely mixed the new metal into the mold. The result was "an extremely brittle alloy which not only caused the Bell