Our country, the marvel of nations; its past, present, and future, and what the Scriptures say of it . mile, at a speed of fifty-five miles an hour. Originally the copper-mine operators introduced gravity stamp jiiills ; butthese proved totally inadequate, and latterly steam mills have been provided ofsuch power in some instances that an average of 350 tons of ore can be crusheddaily at a single miil. The equipment of a large modern copper mine alsoincludes powerful air compressors, capable of supplying fifty air drills, and fansthirty feet in diameter, with a capacity of one hundred thousand
Our country, the marvel of nations; its past, present, and future, and what the Scriptures say of it . mile, at a speed of fifty-five miles an hour. Originally the copper-mine operators introduced gravity stamp jiiills ; butthese proved totally inadequate, and latterly steam mills have been provided ofsuch power in some instances that an average of 350 tons of ore can be crusheddaily at a single miil. The equipment of a large modern copper mine alsoincludes powerful air compressors, capable of supplying fifty air drills, and fansthirty feet in diameter, with a capacity of one hundred thousand cubic feet ofair a minute for underground ventilation. Some of the older copper mines in the United States rank among the deepest holes in the world. The Red Jacket shaft district, for instance, an opening about five feet in size, has been sunk j to a depth of nearly five tJwusatici^^ T is claimed to be deepest shaft of its class i n t Ji e world. This shaft has a vertical dei^tli of nearly one mile; and branching out from the main in the Lake Superior twelve feet by twcnty- vertic ally feet; and. Coal Miners 6o THE MARVEL OF NATIONS shaft are innumerable cross-cut channels, through which the copper ore iscarried to the main artery of communication, and hoisted to the surface in ten-ton cages, each ofwhich makes half adozen round trips inan hour, enabling thehoisting of more thanfive thousand tons ofore from tliis onemine every workingday in the year. Of the profitsof copper mining-,xM r. F a w c e 11 says:— If the coppertaken from the groundin America during anaverage year is esti-mated to be worth^100,000,000, it issafe to credit ^50,-000,000 as net prof-its. Europe, hesays, consumes anenormous quantity ofcopper, and for aheavy proportion ofit she must dependupon the UnitedStates. In the
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectprophec, bookyear1901
