ield of mineral percubic fathom of ground broken, 1,130 pounds; yield of refined copper per ton of rock stamped, 5278 pounds; percentage of copper in stamp rock, 75 pounds average. During 1895 the Calumet and Hecla mill treated on anaverage 4,000 tons of rock per day, which yielded anaverage of… … 0£E DOGES OF THE CALUMET AND HECLA MINE. twenty feet wide and one hundred feet deep, and youmay form some idea of the openings which the annualproduct necessitates. Many persons will wonder how long the mine canlast with such a great production. But when they aretold that the mine is at present,…
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