Title: The American Museum journal
Identifier: americanmuseumjo17amer (find matches)
Year: c1900-(1918) (c190s)
Authors: American Museum of Natural History
Subjects: Natural history
Publisher: New York : American Museum of Natural History
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: Biodiversity Heritage Library

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The i)resfnc>' of iii:iii\ ovnaiiiriit.s .-iiid impli'iiuMits of Iironzi- in prehistoric Peruvian b.irials litis raised much discussion as to whether tlie ancients knew the secret of combining copper and tin in proper proportions to make the harder metal or whether its production was accidental. Among the articles found ai'e ktiivrs. nccdl-s. Iiattli' axes, chisels, and shawl i)iiis Prehistoric Bronze in South America 15v (HA I( L H S \V. M H A 1) Tl I Fj (lisfovery by i^rimitive man that certain kinds of stone or mineral would yield a niotal on application of heat, made possible an advance in civilization relatively as important as any that has fol- lowed. Metal implements superseded the more clumsy and inadequate tools of stone, and metallurgy became an established sci- ence. Bronze, an alloy of copper and tin, is obtained by smelting these metals together in proportions which may be varied accord- ing to the nature of the product required. The addition of tin to copper makes a combination which not only is more fusible than copper alone, but also harder and less malleable. It is therefore more suitable for casting and more useful for making imple- ments. Copper and tin are reduced quite easily, unlike iron, which requires a greater application of heat to separate it from its ore than it was possible to obtain by primi- tive methods. In the hands of the ancients these metals ai-e responsible for what is generally known as the Bronze Age of cul- ture. 574 It has seemed probable that the original discovery of bronze and its advantages over copper were a matter of chance. It is pos- sible that the metals often found in copper of the early bronze age were not intention- ally added but were the result of smelting impure copper ore. Later, when experience had shown that the combination of copper with other metals yielded a product superior in many ways to copper alone, the additions were made purposely. Strictly speaking, the term "copper" should be applied to all implements which contain ninety-six jier cent or more of this metal, the remaining four per cent being a mixture of two or more other metals in varying proportions, with occasionally some sulphur and less than two per cent of tin. Such alloys come under the accidental category, although in exceptional cases, such as the tin and copj^er ores of Cornwall, a much larger proportion of tin may be acci- dental. It has been af3firmed by some that bronze could not be produced by smelting a copjier ore containing tin. Experiments with the

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