The Bull engines, from their strength and simplicity, give very little
trouble, working year after year with astonishing freedom from accident
and slight cost of repair. No attempt is made to economize fuel, which
consists mainly of culm, which would otherwise be wasted. Of late, direct
acting steam pumps placed under ground have found much favor with mine
operators, on account of their portability and small first cost. They
usually range in size from 8 inch steam and 5 inch water cylinders by 12
inch stroke to 80 inch stream and 14 inch water cylinders by 36 inch
stroke. Great numbers of these pumps are in use all over the United
States.

A pumping engine that is remarkable for its size and peculiarities of
construction is located at the Lehigh zinc mine, at Friedensburg, Pa. It
was designed by Mr. John West, the company's engineer, and built by
Merrick & Sons, of the Southwark Foundry, Philadelphia. It is a beam and
fly-wheel engine, the steam cylinder being 110 inches in diameter, with a
stroke of 10 feet. There are two beams on the same main center, from the
outer end of which a double line of bucket and plunger pumps is operated.
The crank-shaft is underneath the steam cylinder; and there are two
fly-wheels, one on each end of said shaft, the crank-pins being fast in
the hubs of the same. There are two connecting rods, which are attached
one to each end of an end beam pin 28 inches in diameter. The main center
and crank shafts are also 28 inches in diameter; each of the two plunger
holes is 24 inches by 30 inches in section; and all the working parts are
in proportion to those heretofore mentioned.

Perhaps no mining district has ever had to contend against greater
difficulties in pumping than have faced the engineers of the celebrated
Comstock lode, Virginia City, Nev. The mines are of great depth, in some