Schoolcraft on the Copper of Lake Superior. 45 
from the main land, forming a route of communication 
which is generally passed i in light canoes. . There is a por- 
tage of only two hundred and seventy-five rods from the 
source of this river, to the shore of the lake west of the 
point, and the distance saved by the route is commonly es- 
timated to be ninety miles. Se 
This is the channel nurse by the expedition through 
the upper lakes in 1820, and consequently we were preclu- 
ded from making any personal observations upon the ex- 
tremity of that point of land. Heavy barges, such as are 
rea noapenes by the fur traders, cannot, however, cross 
t 
his p ut are compelled to keep out in the open 
lake ed tra versing around this peninsula, they must pass 
a small bay and point of rock known among the Canadian 
bene by the name of La Roche Vi erte, which is, in fact, 
the vein of copper ore, of which aeons: are ants — 
it a out abruptly‘apon jthedele: 
whom 5 ed to to procure are these. apec 
mens sek this place early in the month of May last, but fae: 
ing other pursuits likewise in view, did not return until with- 
in a short time. He reports, that the vein of ore is about 
one fathom in width, rising with a broken, hackly surface 
out of the water, ond that it extends in a direct line from 
the lake into the interiour—its course being marked upon 
the bed of the lake by a broad green stripe reflected th 
the water, and upon the shore by parallel = of the 
enclosing rock, which constitutes the matrix of the ore. 
He further represents that this peninsula rises into conical 
mountains of considerable elevation, and that the strata fre- 
quently. show themselves. in precipitous cliffs upon the wa- 
ter’s edge. From the specimens of this formation which 
lie before me, and the best information I have 
procure, I am led to conclude that the entire peninsula con- 
sists of a spine of granite, with sandstones, a 
secondary trap deposited around its base. t, red- 
dish brown, ferruginous rock, which ps in con 
with the ore, is probably allied to the former strata. No 
experiment has been made to determine the quality of the 
ore. It appears from external characters, to be the com- 
pact Malachite of authors ‘which is stated generally to yield, 
at sani mines of Cornwall and Saxon aay fifty-six to sev- 
enty percent, of oxid of copper, the cinder ating chief- 
