Speculum metal metal mixtures usually contain two parts copper to one part tin along with a small amount of arsenic, although there are other mixtures containing silver, lead, or zinc. The knowledge of making very hard white high luster metal out of bronze-type high-tin alloys may date back more than 2000 years in China although it could also be an invention of western civilizations. Such metals were used in sculpture and to make more effective mirrors than the more common yellow easily tarnishing bronze mirrors. In that era mirrors of speculum metal, or any precious metal, were rare and only owned by
American Brass Company Inc., the next largest brass manufacturer, was able to expand its market share significantly as American Brass lagged. Despite its managerial challengers, American Brass was still a highly innovative company. It developed and patented a process for constructing hollow and ventilated busses from rectangular copper bars. The company also developed numerous new and unique metallurgical processes and alloys. On January 1, 1912, the companies held by American Brass were dissolved and all of the firm's divisions began operating under the name of the American Brass Company. The company also expanded, taking over the Chicago Brass Company of Kenosha, Wisconsin; Waterbury