Omaha daily bee., 1896-09-18
A VILE STRAIGHT DOWN.
Great Depth of n SHAFT of One of thc
Michigan Copper Mines.

MICHIGAN copper Mines.
A French engineer proposed last year to
the directors Of the international EXPOSE
tion to be given in the French capital in
the year 1900 the digging of a hole to the
depth of one mile. The idea was favorably
received. but on investigation the magnitude
of the undertaking became so apparent that
the idea has been dropped. 1t will. there
fore, be necessary for those who desire TO
descend a mile into the bowels of the earth,
says the Minneapolis Journal, to come to
Calumet, for nowhere else on earth are there
available openings Of such depth. Within
less than a mile Of each other in this min
ing town there are three vertical shafts
each nearly ore mile in depth. The deepest
of this trio Is the Red Jacket shaft OF the
Calumet and Hecla copper mine, which has
reached its full depth OF 1900 feet. Five
Eifel towers could be dropped down this
hole were 1t wide enough, and the top OF
the fifth would reach above the surface
only to such a height as would allow 1t to
be easily covered by the steel shaft house
now being built over the monstrous hole.
This shaft was begun in 1889, and it has
taken seven full years to sink 1t, showing
an average progress of 700 feet annually,
nearly all of which has been in blue trap
rock, one of the most refractory OF minerals.
The conglomerate carrying copper was the
bed of an ancient sea, and Is composed OF
pebbles and gravel worn by the action Of the
water. such as are seen on sea beaches or
lake shores. cemented into a solid mass
of Gale and silica. BY the percolation Of the
waters and the decomposition of certatr
constituents of the rock little cavities WEI
FORMED, in which were deposited small
nodules Of copper by the water.
The Red Jacket shaft is 1914 by % feet
in size inside of the timbers, and contains
six compartments. being fully equal in
working capacity to half a dozen mining
shafts OF ordinary size. The shaft is solidly
/, n,I.rA r rho nlon ntipn frfnnpgg nt inc
rock renders II secure for all time to come,
the timbers being merely to carry the traffic
of men and mineral, of water and electric.
ity, which serges between the sunlight and
the bottom. In four compartments viii slip
up and down the ponderous cages. car
rying ten-ton loads of rock at the speed OF
express trains. Up and down these cages
will also ride the men who mine the rock
from the old sea bed. In one compartment
will be the great iron pump pipes. and down
another descends the steady current of COM
pressed air, which runs the drills a mile be-
low the engine house. Bunched in slender
cables are the copper wires which convey
to light the recesses of the mine,
threads of wire that afford telephone COM
munication from the most remote drift to
any other portion of the property, for the
and Hecla has a telephone exchange
of its own which in size and perfection
of equipment puts to blush the facilities
of many pretentious towns. and which
reaches every Office on the surface and every
portion of the great mine. There are fire
alarm wires, too, for the Calumet and Hecla
spares no cost to make its employees as safe
as skill and lavish outlay of money can
them.
The sinking of this shaft possesses deep
interest from a scientific standpoint. OBJ
servers ascending to great heights In bal
looms have been able to secure data of
surprising Importance regarding meteoro-
logical conditions and observations made at
the depth of a mile affect positive inforlna-
ton. The Red Jacket shaft has shattered
some of the deeply cherished theories, and
there are text books now eXtant in the higher
institutions of learning which must be over
hauled because facts have succeeded theory.
The mines Of the Comstock lode in Nevada
were the deepest in the world. The mines
were very hot, and on the deeper levels
some of the more pious miners were quite
positive that they smelled sulphur, and re
fused to go further down for fear OF en-
croaching upon the dominions of the devil.
According to deductions. the bottom of the
Red Jacket shaft should be about the proper
temperature to boil eggs. Careful tests have
determined that the normal temperature OF
the rock is SIG degrees Fahrenheit at the
tcttom. The rock temperature at the depth
of los feet was SO degrees Fahrenheit, show
ing an access of ESQ degrees in 4,795 feet.
There was, however, a gain of s degrees IN
temperature in the last 500 feet sunk. a
much more rapid increase than at lesser
depths.
notwithstanding the beneficial effects Of
ventilation and compressed air, men work
ing at the bottom of the deep shaft do not
have an especially easy berth, though
literally paid. They are compelled to wear
rubber boots and rubber coats, as the water
found in the mine at that great depth is
most corrosive on the human body.