History of the big bonanza

by Dan De Quille

The air will even go down a shaft and crawl out through a tunnel when that tunnel runs in a southerly direction! When the Union tunnel connected with the old Ophir mine the air did not draw through the tunnel and pass up and out through the main shaft, but came out of the mouth of the tunnel. When the old Best and Belcher works connected with the Gould and Curry tunnel, the same thing was seen—the air went down the shaft and passed out at the mouth of the tunnel. About the next connection of the kind made on the lead was between the Crown Point and Belcher, at the depth of 160 feet; and the current of air went down the higher shaft, moved southward, and came out at the Belcher. Next the Yellow-Jacket and the Crown Point connected, and the draught was southward to the Crown Point. The Alpha and the Imperial next connected, and the draught went south to the Jacket. When the Gould and Curry and the Savage connected, the draught went south to the Savage. When connection was made between the Ophir and the Consolidated Virginia, the air went south to the Consolidated. The only places I know of on the lead where the air moves to the northward are between the Gould and Curry and the Consolidated Virginia, and between the Hale and Norcross and the Savage, and here it probably would not move north but for strong inducements.

The latest instance of this tendency of currents of air to move southward in mines is seen in the Overman mine. When that mine was connected with the Belcher, the draught was southward, out through the Overman shaft, though it stands much lower than any of the shafts connected with the Belcher mine.

From the facts given, it will be seen that there are some curious things connected with the ventilation of mines, and that it is not altogether impossible that Sutro’s big tunnel may draw backwards, when completed.

A great deal of machinery is now beginning to be used on the lower levels of the principal mines on the Comstock. Some years ago steam-engines were set up in the lower levels of some of the leading mines, with boilers, furnaces, and all, just as on the surface. This would not do. The heat of the furnaces, boilers, and steam, added to the heat of the mine, could not be endured by the engineers and others whose duty it was to “stand watches” about the machinery.

A few years since an engine was set up on the 1000-foot level of the Gould and Curry mine, and steam was conducted to it from boilers situated on the surface. When this engine was started up there was a popping of champagne corks away down there in the bowels of the earth, and a good time was had drinking to the success of the experiment. But it was not a success after all—it wouldn’t do. The ground began swelling, the timbers were crushed and twisted, the engine bed could not be kept level three days at a time—it was like a boat in a rough sea, now on this end, and now on that—and the experiment was a failure.

The latest attempt to use steam machinery underground was at the Ophir mine. A boiler and engine were set up on the 1465-foot level, near the main shaft, up which was extended a sheet-iron smoke-stack reaching to the surface. This engine was used in sinking a winze (situated 365 feet to the eastward) to the 1700-foot level, and also in doing some work on the level last named. The furnace and boiler heated up the level to such a degree that it was “killing” to the men. The boiler still stands where it was set up, but is now used as a reservoir for compressed air.

The introduction of engines and machinery to be run by means of compressed air, was a grand forward stride in the science of mining.

In the Consolidated Virginia and California mines are to be seen at work a number of small engines that are run by compressed air, furnished by two powerful compressors that are constantly in operation on the surface. The air is carried down the main shaft in a large iron pipe, and from this smaller pipes branch off in all directions, and are carried along the roofs of the drifts and cross-cuts, as we see gas-pipes running through buildings in the upper-world.

Thus is the compressed air carried down into all parts of the mine where work is being done. In places we see small engines at work at the top of winzes, where they do all the hoisting, and effect a great saving of both money and muscle. At other points, in passing along a drift, we suddenly come upon a small chamber constructed on one side, and sitting in this we see a “cunning” little engine, industriously at work at running a blower (a machine such as we see in foundries for furnishing a blast to the cupola, where metal is melted), which blower is sending a stream of fresh air through a pipe to men working in some far-away, heated cross-cut or upraise.

There are quite a number of these little engines and blowers in various parts of the mine, and instead of heating they greatly assist in cooling those parts of the mine in which they are used.