New-York tribune., 1873-04-12
LAKE SUPERIOR COPPER MINES.

SS~oi'' i''-' S-o0f1N-' iNAN''N ~ ~ "iV''''
LAKE SUPERIOR COPPER MINES.
The high prices at which copper, and especially
American native copper has ruled for many months
past has attracted much renewed attention TO the
copper mines of Lake Superior; and we have just
received from Boston. where much of the copper
mining interest centers, pamphlet, prepared appa-
rently with much care by Col o, ID. Ashley, giving
very interesting account of the discovery, devel-
opment and present condition Of the Lake Superior
Copper Mines From this little pamphlet it appears
that mining for native copper commenced on
the south Shore of Lake Superior Upper Peninsula
MchiGanl in 1915, about 2S years previous to
which time the supply of copper had been obtained
throughout the world mainly from Sulphurets.
At the commencement the idea that native or pure
copper could be found in any considerable quantities
wa secuted by the learned geOOgists yet the dis
ooverers of TIE metal went forward with their min
ing and in spite Of geological theories found copper
IN masses Of many tons weight, the largest mass,
which was found in the Minnesota Mine, in the
OntOnagon district weighing 800 tons, produc
ing about 90 per cent of ingot copper while many
other masses were found both in the Minnesota and
Cliff Mines weighing from 80 to 200 tons each.
The first decided success won by the famous Cliff
Mine. which returned in dividends the handsome
sum of S2,SS0OOO from original outlay of
$1,000 followed by the Minnesota which returned
Sl275.OOO from assessments of $4,000, stimulated
mining enterprises to such an extent as to induce
many wild investments and the expenditure of
enormous sums Of money from which return was
ever received. To show the extent to which this
sort of thing was carried. it is only necessary to
state that out of 13 companies organized to take up
and work mining locations. and on which assess
ments have been paid TO the extent of S17269,5O0
only nine companies have as yet returned diyi- |
dends. On these, assessments were paid to |
the amount of S2,S71,OOO, and dividends have |
been returned 10 the amount of S11.91OOOO On the |
companies which have declared no dividends |
assessments have been paid ranging from $4,000 to
100000 each, and amounting in the aggregate to |
SI4425.5OO. OF course many of the mines which |
have returned profit have produced considerable
quantities of copper
The native copper of Lake Superior is found in
masses OF various weight as already described in
barrel work running through the adhering rock in
threads Of irregular and jagged formation, but
sufficiently large to be separated from the vein rock
without the use of stamps and what is known
among the miners as stamp stuff" which is found
in very minute particles but generally disseminated
through the copperbearing rock.
la the early history of Lake Superior mining very
little attention was paid to anything except mass
and barrel work for the reason that With the limited
facilities for separating stamp stuff from the rock it
could not be done at profit. After many years of
prosperity on the part of the Cliff and Minnesota
mines they were opened TO depth which made it
Improbable to work them at the then ruling price OF
copper 17 cents per pound and they ceased working
altogether This 20 discouraged mining operations
generally that the business dwnded down to almost
nothing though few enterprises were kept alive
until within few years, when the improved price
of copper and new discoveries of copper-bearing
veins, but especially the great success of the
HI q Il
mining, and materially modified, if they did
not entirely change, the views of mining
men as 10 the ydlre Of mines and the
best modes for obtaining the mineral. For.
while ii the infancy Of the business stamp rock
yielding no than to- per cent Of Copper,
cOmpanied by mass or barrel work, not regarded
As worth working now the experience of the Cal
umet and Heca, which yieldony stamp stuff averag
ing not above per cent of metal or 100 lbs to the
ton shows il TO be the most productive mine in the
world yielding during the year 1872, ais tons of
Copper and paying S2,S00,OOo in dividends to its
stockhOdeIs in single wear. OF course the facili-
ties for mining have been greatly enlarged of late
Economies have been introduced. The drill, driven
by steam or compressed air has taken the place of
the laborions process of hGnd-drilling. Improved
stamps have been adopted and various de-
VICES for saving the copper and for
the more economical handling of the mineral have
been introduced, while the means OF transporting |
supplies and Of copper have been greatly increased
But tie important fact established Is that mines
which yield but jittle OF no mass copper, but are |
rich in stamp rock. are the most productive and |
profitable The mines which are now paying divi- |
dends produced ls.547 tons of copper in 1872 of |
which I217S tons weie derived almost entirely from
stamp copper of wb the richest does not average
over per cent and the poorest only II per cent. |
These facts in connsetion with the high price of |
copper, have reawakened interest in mining, and |
have induced the reopeniog of many partially aban
dened mines in the expectation that they can be |
.orked at profit. The total dividends declared
on Lake Superior copper mines are as follows;
Calumet Heca. ..A,soOoo Yewabic ...... 100000
fqt0 ..-..2 q 10000 National ........... 10000
NJ n6esjta - 10000 Franklin. .......... 2t0eO
D inv ~ iISO 900 Copper Falls....... l0o.O9