Bronze is an alloy of copper, to which other metallic substances are sometimes added, especially zinc. It is a finegrained metal, taking a smooth and polished surface, harder and more fusible than copper, but not so malleable. In various parts of the world weapons and implements were made of this alloy before iron came into use, and hence the bronze age is regarded as one coming between the stone age and the iron age of prehistoric archeology.
Both in ancient and modern times bronze has been much used in making casts of all kinds, medals, bas-reliefs, statues, and other works of art; and varieties of it are also used for bells, gongs, reflectors of telescopes, and formerly for cannons, etc.
Bronze is of a reddish, brownish, or olive-green colour, and is darkened by exposure to the atmosphere. Ancient bronze generally contains from 4 to 15 percent of tin. The alloy of British bronze coinage at the start of the 20th century consisted of 94 parts of copper, 4 of tin, and 1 of zinc. An alloy of about 85 parts copper, 11 zinc, and 4 tin is used for statues. Bell-metal consists of 78 of copper and 22 of tin. An alloy called phosphor bronze, consisting of about 90 percent of copper, 9 of tin, and from .5 to .75 of phosphorus has been found to have peculiar advantages for certain purposes. The addition of phosphorus increases the homogeneousness of the compound, and by varying the proportion of the constituents the hardness, tenacity, and elasticity of the alloy may be modified at pleasure. Research Bronze
Abbreviations
SciTech
Research Bronze