1874.| Copper Mines of Lake Superior. E75 
The Ball stamps may influence the result, through the 
volume of water required for their efficient working, and 
which, not being separated from the suspended ore, may in 
some cases flood the hutches. 
The annual reports of the Quincy Mining Company are 
models, presenting the work done and the cost of doing it 
in clearest detail. From the report for 1872 we summarise 
the following particulars. During the year, there were 
stoped 5165 fathoms, and sunk in shafts and winzes 808 feet 
—say 150 fathoms, and driven 1974 feet—say 329 fathoms. 
Assuming the specific gravity of the rock to be 2°7, and 
that therefore there are 18 tons to the cubic fathom, there 
were broken 101,592 tons of rock. As there were 60,828 
tons stamped, about 4-roths of the rock was separated by 
hand-picking. The mining, raising, and picking cost for 
the year amounted to 283,487°30 dols., or 2°79 dols. per ton 
of rock raised, while the milling cost was 64,783°79 dols., or 
1°06 dols. per ton of rock stamped. This large amount of 
rock yielded 2,804,954 lbs. of concentrated mineral, which 
produced 2,276,308 lbs. of ingot. There was recovered, 
therefore, only 1°12 per cent of copper from the rock mined, 
and yet there were divided, as the year’s profits on working, 
210,090 dols. 
In 1872, copper brought an exceptionally good price, 
selling at 324 cents per lb., but as a set-off, wages were 
high, the average wage of miners on contract being 60°62 
dols., and the yield of the ground per fathom lower than its 
wont. 
Distributing the cost over the mineral produced, we find 
that, as 2,804,954 lbs. of mineral—which, without making 
an allowance for the slight loss in smelting, must have con- 
tained 81°r per cent of copper—were obtained at a cost for 
mining and concentrating of 461,147°83 dols., each pound 
cost 16°44 cents; but when the cost of smelting, trans- 
port, insurance, and commission was added, each pound 
of ingot cost 22°93 cents U.S. currency, or, say, 20 cents in 
gold. Copper has fallen to 25 cents U.S. currency, but as 
wages have declined proportionately, and the cost of pro- 
duction therefore has been lessened, there is not likely to be 
a very serious decrease in the profits. Besides distributing 
this large sum among the shareholders, there were added to 
construction account,—for permanent improvements likely 
to lessen the cost of future produ¢tion,—67,227°65 dols., so 
that the real profits of the year were 277,318°35 dols., which 
certainly could have been realised only by good manage- 
ment and by the employment of every possible labour- 
