History of the big bonanza

by Dan De Quille

In some mines many blocks of porphyry and other barren rock are found with the ore, making it necessary to do a great deal of assorting, but in the Consolidated Virginia mine there is no work of this kind to be done, at least not on the 1500-foot level, where they are sloping[sloping] out in the bonanza. There is nothing to do but dig down the rich masses of black sulphuret and chloride ores, shovel them into the cars, and send them to the surface to be taken to the mills, and the same is the case in the California mine.

Samples are taken from each car-load of ore down in the mine, when it reaches the main shaft; at the surface other samples are taken, and at the mills samples are taken of the pulp, every hour, as it runs from the batteries—in short, the ore is sampled everywhere, and at all stages in the handling, from the ore-breasts till it has passed through the mills, and finally appears in the shape of large, shining silver bricks, each weighing a hundred pounds or more. All the samples thus taken are carefully assayed, and the results compared and noted.

An incline is simply an inclined extension of the main shaft, from some convenient point below, or rather at or near the point where the shaft strikes the west wall of the vein. The Comstock lode dips to the eastward at an angle of from thirty-five to forty-five degrees, and as the main working shaft of a mine is always sunk to a considerable distance—a thousand feet or more—to the eastward of the croppings [i. e. that part of the lode which comes to the surface of the earth], the west wall is not reached until the shaft has attained a depth of from 1000 to 1500 feet, depending upon how far east of the croppings it was sunk.

The main incline of a mine is of about the same dimensions as the main shaft, and is timbered in much the same way. In the Consolidated Virginia mine there is as yet no incline, but at the Crown Point mine is to be seen one that is a model in every respect. This incline starts at the 1100-foot level, from the bottom of the vertical shaft, and goes down with the dip of the vein (at an angle of about thirty-five degrees), to the 1700-foot level, its present terminus. A track is laid on its bottom, of ordinary railroad iron, and as neither cages nor a car of the usual pattern can be used in an incline, recourse is had to another device. A kind of car called a “giraffe” is used for hoisting through an incline. It has low wheels in front and high ones behind; thus the body of the giraffe stands level, the same as a common ore-car on an ordinary track.

The giraffe is capable of carrying eight tons of ore—more than eight ordinary car-loads. It is lowered down the track to the bottom of the incline, and hauled up to the foot of the shaft by means of a round steel-wire cable which runs upon a reel at the surface.

The cable passes over a large iron pulley at the top of the vertical shaft, and under a second pulley of the same kind at its bottom. The cable is also supported by rollers, placed in the centre of the track, as it travels up and down the incline, otherwise its great weight would cause it to drag upon the ground. From the upper side of an incline, stations are made, the same as they are made at intervals along a vertical shaft; drifts are then run, and the work of cross-cutting and prospecting the vein goes on in the same way as when the ore-body is approached by means of a shaft. The giraffe has in front and on the “outside” two seats, facing each other, on which six passengers can ride very comfortably. Sometimes there is hitched behind the giraffe a second car of the same pattern, called the “back-action.”

There is not a little of novelty in a ride up an incline on a “giraffe.” The conductor of the “train,” who is seated by our side, gives the signal for starting by pulling a wire and striking upon the engineer’s bell—far away up the incline and up the vertical shaft, and some distance beyond that again in the engine-house—a certain number of strokes. Instantly we start, and soon are darting up the steep iron way at a terrific rate of speed. Lamps are placed at intervals on the sides of the incline; besides, we carry lanterns, and there are lights burning at all the stations. Thus our underground railroad is well lighted up. We have a good view of the track, and can see the rails glistening far ahead of and above us.

We rush up this steep road so rapidly that the posts along the sides of the incline resemble a fine-toothed comb. To look ahead and see before you, and high above you, a hundred yards or more of semi-vertical railroad, up which you are thundering at whirlwind speed, is strikingly the reverse of natural. Going down does not in any way interfere with your notions of the “eternal fitness of things,” for it is quite natural for anything that is loose to run down hill, but this fierce darting up the steep iron rails somewhat unsettles you.

Up this queer railroad you are hurled through the caverns of the gazing Troglodytes, till you reach the foot of the vertical shaft, when they transfer you to a cage, and you are shot out at the top, much as the “Red Gnome,” in the play, is shot up through the trap in the stage-floor of a theatre.

A giraffe is provided with a safety-apparatus somewhat similar to that on a cage. A large wooden rail runs the whole length of the track. Extending from the side of the giraffe, and almost clasping this rail, are two toothed, eccentric wheels. Should the cable break, these wheels would instantly grasp and clasp the rail, and the greater the weight upon the car the more fiercely they would bite into the wood, and retain their hold upon it. This invention has been the means of saving scores of lives.