[Sidenote: YIELD OF THE COMSTOCK VEIN.] The yield of the Comstock vein, in ten years, is estimated at two hundred and twenty millions of dollars, or an average yield, annually, of thirteen millions, seven hundred and fifty thousand dollars. In 1874, the yield exceeded twenty-two millions, and in subsequent years it was larger. The mines have been subject to the usual accidents of similar works in all parts of the world. Many men have lost their lives there, from falls through the shafts, from the breaking of cables, from falls of rock, and various other causes. The mines have been on fire several times, the gases generated from the earth assisting the burning of the immense masses of timber. The heat in the mines is, at all times, very great, and consequently the wood becomes exceedingly dry, and liable to ignite at the slightest opportunity. Some of the fires are attributed to spontaneous combustion, but it seems more probable that they are the result of carelessness. Virginia City, which stands above the mines, has also suffered very greatly from the same cause, and on one occasion, almost the entire settlement was swept away, involving a loss of millions of dollars. But in spite of accidents, calamities, the rise and fall of stocks, Washoe “zephyrs,” and other things, the work goes steadily on, and the mines of Nevada, year after year, continue to hold their place as the greatest and most remarkable silver mines in the world. [Sidenote: WORKING A MINE.] During the month of April, 1877, the shipments of the California mine have been $1,600,000. If we read the brief announcement, every month, on a certain day, that a certain mine has paid a dividend of $1,080,000, we have not the slightest idea of what is necessary to be done in order to make such an announcement possible. Every one who ever owed a note in a bank, knows that thirty days is a very brief period of time. To cause a mine to produce $60,000 in a single day, is a tremendous feat; to continue this product daily, through weeks and months, almost without variation, is a marvel. It takes forethought, endurance, judgment, and nice calculation, such as very few men possess in this world. The ore from which this mighty yield is extracted, lies hid away almost a third of a mile below the earth’s surface. It lies where consuming heat and baffling waters join their forces to try and drive away the invading miner. While the ore is being hoisted, every month, 1,250,000 feet of lumber has to be lowered and put in position, to keep safe the weakening caused by the mighty excavations. While one level is being worked, another has to be explored, for a drain of 500 tons of ore per day would soon level a mountain down. Then the Comstock is an uneasy fissure. In a single week, sometimes the swell of the ground shivers into splinters fourteen-inch square timbers. Shafts and drifts and inclines and tracks have to be watched incessantly, for a mine, like a glacier, seems ever to be working.