Of course these mines cave in, in places, occasionally, and then it is worth one's while to take the risk of descending into them and observing the crushing power exerted by the pressing weight of a settling mountain. I published such an experience in the Enterprise, once, and from it I will take an extract:
AN HOUR IN THE CAVED MINES.--We journeyed down into the Ophir mine, yesterday, to see the earthquake. We could not go down the deep incline, because it still has a propensity to cave in places. Therefore we traveled through the long tunnel which enters the hill above the Ophir office, and then by means of a series of long ladders, climbed away down from the first to the fourth gallery. Traversing a drift, we came to the Spanish line, passed five sets of timbers still uninjured, and found the earthquake. Here was as complete a chaos as ever was seen--vast masses of earth and splintered and broken timbers piled confusedly together, with scarcely an aperture left large enough for a cat to creep through. Rubbish was still falling at intervals from above, and one timber which had braced others earlier in the day, was now crushed down out of its former position, showing that the caving and settling of the tremendous mass was still going on. We were in that portion of the Ophir known as the "north mines." Returning to the surface, we entered a tunnel leading into the Central, for the purpose of getting into the main Ophir. Descending a long incline in this tunnel, we traversed a drift or so, and then went down a deep shaft from whence we proceeded into the fifth gallery of the Ophir. From a side-drift we crawled through a small hole and got into the midst of the earthquake again--earth and broken timbers mingled together without regard to grace or symmetry. A large portion of the second, third and fourth galleries had caved in and gone to destruction--the two latter at seven o'clock on the previous evening.
At the turn-table, near the northern extremity of the fifth gallery, two big piles of rubbish had forced their way through from the fifth gallery, and from the looks of the timbers, more was about to come. These beams are solid--eighteen inches square; first, a great beam is laid on the floor, then upright ones, five feet high, stand on it, supporting another horizontal beam, and so on, square above square, like the framework of a window. The superincumbent weight was sufficient to mash the ends of those great upright beams fairly into the solid wood of the horizontal ones three inches, compressing and bending the upright beam till it curved like a bow. Before the Spanish caved in, some of their twelve-inch horizontal timbers were compressed in this way until they were only five inches thick! Imagine the power it must take to squeeze a solid log together in that way. Here, also, was a range of timbers, for a distance of twenty feet, tilted six inches out of the perpendicular by the weight resting upon them from the caved galleries above. You could hear things cracking and giving way, and it was not pleasant to know that the world overhead was slowly and silently sinking down upon you. The men down in the mine do not mind it, however.
Returning along the fifth gallery, we struck the safe part of the Ophir incline, and went down it to the sixth; but we found ten inches of water there, and had to come back. In repairing the damage done to the incline, the pump had to be stopped for two hours, and in the meantime the water gained about a foot. However, the pump was at work again, and the flood-water was decreasing. We climbed up to the fifth gallery again and sought a deep shaft, whereby we might descend to another part of the sixth, out of reach of the water, but suffered disappointment, as the men had gone to dinner, and there was no one to man the windlass. So, having seen the earthquake, we climbed out at the Union incline and tunnel, and adjourned, all dripping with candle grease and perspiration, to lunch at the Ophir office.
During the great flush year of 1863, Nevada [claims to have] produced $25,000,000 in bullion--almost, if not quite, a round million to each thousand inhabitants, which is very well, considering that she was without agriculture and manufactures. Silver mining was her sole productive industry. [Since the above was in type, I learn from an official source that the above figure is too high, and that the yield for 1863 did not exceed $20,000,000.] However, the day for large figures is approaching; the Sutro Tunnel is to plow through the Comstock lode from end to end, at a depth of two thousand feet, and then mining will be easy and comparatively inexpensive; and the momentous matters of drainage, and hoisting and hauling of ore will cease to be burdensome. This vast work will absorb many years, and millions of dollars, in its completion; but it will early yield money, for that desirable epoch will begin as soon as it strikes the first end of the vein. The tunnel will be some eight miles long, and will develop astonishing riches. Cars will carry the ore through the tunnel and dump it in the mills and thus do away with the present costly system of double handling and transportation by mule teams. The water from the tunnel will furnish the motive power for the mills. Mr. Sutro, the originator of this prodigious enterprise, is one of the few men in the world who is gifted with the pluck and perseverance necessary to follow up and hound such an undertaking to its completion. He has converted several obstinate Congresses to a deserved friendliness toward his important work, and has gone up and down and to and fro in Europe until he has enlisted a great moneyed interest in it there.