60 MINING IN CALIFORNIA AND NEVADA.
affording
greater facilities for working systematically, and permitting
low-graded ores to be worked with profit. The rapid progress made in
the tunnel is chiefly doe to the powerful drilling machinery employed,
and the stimulation given to the miners to their receiving a
substantial bonus if a certain number of feet per month were exceeded.
The air compressors used have been erected near No. 2 air-shaft, and
the therein compressed air furnishes the motive-power to work six
percussive drills (Nationals), mounted on a suitable truck or carriage;
the drills strike from 300 to 800 times per minute, with a length of
stroke of 7 inches, each blow falling upon the drill-head with a force
weight of 1,000 lbs. They use from 150 to 200 lbs. of giant powder in
twenty-four hours; all blasts are ignited by means of electric
batteries and detonators ; and that the works are carried on with great
energy and despatch is proved by their driving from 300 to over 400
feet per month, the tunnel measuring "in the clear" 14 feet wide in the
bottom, 13 feet at the top, by a height of 10 feet from the sole-piece;
it is timbered with square sugar-pine logs 12 inches by 10 inches, and
laths 3 inches thick. The grade, adopted for the tunnel, at 12-1/2 feet
per mile, is such as to intersect the Comstock at a vertical depth of
1,922 feet, or about 2,100 feet on the underlay of the lode, below its
outcrop; its direction is due west, and the tunnel has been driven in a
perfectly straight line. Philadelphian mining locomotives are here also
used for traffic purposes, and according to Mr. Sutro's calculations,
since confirmed as correct, each load can be delivered at only 10
cents, or 8d., thus saving, in unproductive mines, the sum of 3 dollars
90 cents on the 4 dollars it costs to hoist, pump, &c, a ton from
below to the surface on the Comstock lode. It is the intention to erect
extensive ore reduction and dressing establishments at the mouth of
this adit after its completion, and to utilize the subterranean water
in the old shafts, properly " bulk-headed," as a motive-power for
pumping and winding engines below the tunnel level, and this Mater in a
similar manner outside, for the working of the crushing mills, pans,
and other ore-reduction machinery.
APPENDIX.
A Wages.—On the Comstock the miners' wages are not less than 4 dots, per day, for seven days
in the week, and by a late agreement come to between most of the mine
superintendents and the very powerfnl "Miners' Union" of Storey
County, Nevada, no miner is employed who does not belong to that
society. At most mines it is customary to dednct one dollar per month
for the hospital fund. Amalgamators, for twelve hours shifts, get S
dols. per diem ; tankmen 4 dols. do.; superintendents receive from 500
dols. per month downwards.
B. Mining and other Laws.—The net produce, or the dividends, of mines in this State of Nevada are subject to taxation.
C Minerals and Ores.—The
Comstock lode furnishes splendid specimens of calcites. The ores
comprise the following, viz.:—Argentite (sulphuret of silver) ;
Proustitc (ruby silver) ; Tetrahedrite (grey copper cum silver = Fahlerz) ; Galenite (sulphuret of lead) ; and Wulfenite (molybdate of lead).
D. Mine Timber ranges from 22 to 35 dols. per thousand feet (limber).
By Authority: Jobs Fmns, Government Printer, Melbourne.
