As the drifts and cross-cuts are advanced, the air-pipes are carried along their roofs or sides, and are in readiness for use in running the Burleigh drills, by means of which the holes are drilled in the face of the drift where the rock requires to be blasted. The air-pipes being in place in all the cross-cuts and drifts, the Burleigh drill may be moved about from place to place as required, and thus a single drill can be used in several different drifts during the day. When a sufficient number of holes for blasting have been made in one drift, the drill is placed upon its carriage and is moved along the car-track to another, where connection is made with the air-pipe, and it is hammering away again with but little loss of time.
In the Ophir mine a small engine, situated at the winze mentioned above as being 365 feet east of the main shaft, does all the hoisting from the 1700-foot level, and in a more satisfactory manner in every respect than the same work was formerly done by the old steam-engine. On the 1150-foot level of the Consolidated Virginia mine a winze was sunk to the depth of 140 feet, with one of these little air-engines, and it could have been sunk to any depth required, but for an influx of water which was too strong to be contended with in that remote part of the mine at that time.
Each year more and more machinery will be run in the mines of the Comstock, by means of compressed air. It is exactly what is needed, as all the air exhausted in the lower levels of a mine is beneficial and is so much ventilation and so much food gained for the lungs of the miners. Compressors, and machinery to be worked by them, are being ordered by all of the leading mines, and are already considered indispensable appliances in modern mining.
CHAPTER XLIV.
UNDERGROUND BUSINESS ARRANGEMENTS.
In order that the reader may obtain something like a correct idea of the appearance of the interior of a first-class mine, let him imagine it hoisted out of the ground and left standing upon the surface. He would then see before him an immense structure, four or five times as large as the greatest hotel in America, about twice or three times as wide, and over 2000 feet high. The several levels of the mine would represent the floors of the building, These floors would be 100 feet apart—that is, there would be in the building twenty stories, each 100 feet in height. In a grand hotel communication between these floors would be by means of an elevator; in the mine would be in use the same contrivances, but instead of an “elevator,” it would be called a “cage.”
Our mine, raised to the surface, as we have supposed, would present much the same appearance as would a large building with the side walls removed, allowing a full view of all of its floors to be obtained. As we should see the elevator stopping at various floors to take on and put off passengers and baggage, so we should see the cage stopping at the several levels to take on and put off miners or full or empty ore-cars.
Upon the various floors of our mine we should see hundreds of men at work, but there would be seen between the floors, in many places, a solid mass of ore, in which the men were working their way up and rearing their scaffolding of timbers toward the floor above.
Not only would the men be seen thus at work, but there would also be seen at work on the various floors, engines and other machinery; with, high above all, the huge pump, swaying up and down its great rod, 2,000 feet in length and hung at several points with immense balance-bobs, to prevent it being pulled apart by its own weight.
Occasionally, too, we should see all of the men disappear from a floor, and soon after would be heard in rapid succession ten or a dozen stunning reports—the noise of exploding blasts.
When blasts are about to be let off in a mine, after the fuses have been lighted and the miners are retreating to a place of safety, “Fire!” is the startling cry that is heard from them, as they fall back along the drifts and cross-cuts. The cry is well understood throughout the mine to mean no more than that fire has been set to the fuses, and that several blasts will shortly go off.