90 Copper and Silver of Kewenaw Point, Lake Superior. 
together at their points of contact. Other specimens exhibit 
square and triangular pieces of silver in the midst of the copper, 
or contain veins of it traversing the latter and firmly united at the 
edges. Crystals of silver, in the form of a regular octahedron, also 
occur, but are notcommon. Fine particles and strings of silver are 
more frequently observed. Glistening scales or fine crystals of an- 
timonial silver ore are found in a part of the lode where the rock is 
most decomposed. Veins of quartz and of calcareous spar traverse 
some parts of the metalliferous rock, and the copper is most highly 
crystallized in the quartz; while the silver is more apt to be found 
in the calcareous spar or in the amygdaloid containing it. 
The first exploration which I made at this place, was at the 
base of the cliff about three feet above the level of the river, and 
the rock was blasted away until the influx of water prevented 
further operations. The cliff is fifteen feet high, and presents a 
mural precipice, in which the metallic copper and silver could be 
readily discovered ; and it was seen that the rock became richer 
as we descended, even though our researches were only to the 
extent of twenty feet from the top of the cliff to the place where © 
we blasted for the last time. I felt confident, therefore, that the 
quantity of metals would increase in the rock to some depth; 
and in order to have this point settled, the miners were directed 
to sink a shaft, beginning on the top of the ledge and going down 
at least forty feet beneath the bed of the river. The shaft was 
then sunk, under the able direction of Mr. Charles H. Gratiot, the 
skillful superintendent of the mines, and its present depth from 
the surface is seventy four feet. By this exploration shaft, the 
value of the mine has been proved, and the proportions of metal 
were found to augment considerably as the work proceeded. 
Several hundred tons of rich ore have been raised, and among the 
fine specimens obtained, is a mass of copper with an ounce of 
pure silver attached to it. The ore raised is probably somewhat 
richer than that extracted by me, and will richly repay the cost 
of exploration. 
Another exploration shaft has been sunk a few hundred feet 
farther from the river, and the ore has been found equally rich. 
These two shafts are now to be connected by a drift or level 
made along the course of the vein; one of the shafts will be 
used for ventilation and the other for the machinery used in hoist 
ing the ore and pumping the water from the mine. 
