make 160 revolutions a minute. The pinion shafts are driven through a
wire rope transmission from an engine located 500 feet distant. The rope
wheels are 15 feet in diameter, and make 160 revolutions a minute. The
engine is 4,700 horse power, and, in addition to driving the pumping
machinery, does the hoisting and air compressing for the Calumet mine.

In the same building with the mine pump gearing is a duplicate
arrangement for operating the man engine. In order to operate the mine
pumps and man engine for the Hecla mine, it was necessary to use rock
shafts, which are made of gun iron, and hollow; they are 32 inches in
diameter outside, with 4½ inches thickness of metal. The pump rock shaft
is 39 feet 4½ inches long over all, in two sections, and weighs 40 tons.
There are rockers placed on each end of this shaft, one of which is
connected with a crank on the mortise wheel shaft, and the other with the
surface rods that work the pump-bobs. These rods are of Norway pine, 12
inches by 12 inches in section, and 1,000 feet long. There are two bobs,
one above the other, with axes at right angles, each weighing about 25
tons. The connection from the upper bob to the lower has hemispherical
pins and brasses to accommodate vibrations in right angled planes. The
slope of the main pump is 39 degrees, and the machinery has been designed
to raise water from 4,000 feet depth. The pumps are of the usual Cornish
plunger type, with flap valves. There is an auxiliary engine, of the
Porter-Allen type, for driving the pumps and man engines when the main
engine is not working. It makes a 160 revolutions per minute, the same as
the rope wheels The seeming complication of the arrangement is due to the
fact that it had to be adapted to existing works, for increased depths,
and put in without interfering with the daily operation of the mine.

The Calumet & Hecla Mining Company has also an extensive pumping plant at
its stamp mills, which are located on the shore of Torch Lake, about four