176 Copper Mines of Lake Superior. (April, 
The scimpings are not clean. They carry from 1°40 per 
cent. to 1°80 per cent of copper, 0°40 to 0°80 of which is as 
oxide. ‘Twelve tons of copper, therefore, are thrown away 
daily. 
The Calumet Company publishes no report, but the 
following figures are, if not quite, very nearly correct. 
There are 1600 hands employed, 260 contracts are set in the 
Calumet, and a somewhat greater number in the Hecla. 
The cost of breaking a fathom of ground varies from 20°00 
to 22°00 dols., and it yields 21 tons of rock; the cost of 
dressing exceeds that at the Quincy mine, standing at 
1°17 dols. per ton. In 1872 the mine produced 9717 tons of 
ingot. The quantity of ore raised daily was about 740 tons, 
or 266,400 tons per year of 360 days; and, therefore, as it 
produced 9717 tons of ingot, the ore actually yielded 3°6 per 
cent of copper. ‘This large amount of work was rewarded 
by profit in proportion; for there was distributed among the 
shareholders, in 1872, 2,750,000 dols.; and during that same 
year large sums were expended in permanent improve- 
ments. The result in every respect is unparalleled in 
the history of copper mining; and all owners of copper 
mines with no such brilliant promise can only hope that it 
may not be repeated ; for the effect of a very few such mines 
would be most depressing. 
Adjoining the Hecla another mine is being opened by the 
Osceola Mining Company, which, from surface indications, 
will be very rich. The Allonez near by is expected to turn 
out well, and on the Isle Royale attention is again being given 
to long-neglected conglomerate beds, and the prospect of 
success is there good also. The Royale, though belonging 
to Michigan, lies close to the Canadian shore. As already 
pointed out, the copper formation is largely developed from 
Michipicoten to Thunder Bay on the main land and on 
Canadian Islands. 
With the experience gained on the south shore, explora- 
tions could now be conducted on the north, with better 
chance of success than heretofore. What little has been 
done has revealed the existence of deposits that would not 
have remained unworked had they been situated on the 
opposite shore. 
The following statistics, officially corre@t, are taken from 
the annual circulars published by the ‘‘ Portage Lake Mining 
Gazette. 
The production of all the mines on the promontory for 
the year ending Nov. 30, 1873, was as follows :— 
