pounds of copper'in '1951. Three large mines were responsible for practically,' all of it. They ...,Fufther developments andIefinements in mining and milling methods have great.. ly increased the ore reserves of both major companies. Bet~een 1906, when J. Parke Channing examined the deposits at Miami and ex ploratory shafts were started, and 1911, when the Miami Copper Company began to ...