This is all below ground. Above the surface is a world of machinery, always to be kept in order—steam engines, air engines, cables, cages, air pipes, pumps, and all the multiplied devices intended to expedite the work and lessen the dangers of mining. Five hundred men have to be lowered into and hoisted from the depths daily. Three hundred cords of wood have to be provided daily for fuel. And there must be no delays, no serious accidents. The needed repairs must be anticipated and provided for; the accidents must be anticipated and guarded against; the explorations must be carried on months in advance; the supplies must never fail. A vast space of forest land, thirty miles away, has to be denuded of its timber, yearly, to fill the insatiate maw of this one mine. It requires 15,000,000 feet of timber, and 100,000 cords of wood, annually, to supply the mine, and to furnish fuel to hoist and reduce the ores. How many can appreciate the ability necessary to carry on this work without any mistakes? Many a man of mind sufficient to accomplish the feat, would fail through sheer lack of physical strength. The work means being up at five o’clock in the morning; means two or three daily journeys into the depths, and when anything unusual happens, it means standing guard day and night, like a ship’s captain in a storm, until the trouble is over. It means a mind large enough to take in the immense work going on at a glance, yet careful enough to include its smallest details, and exact enough to anticipate the wants of the enterprise months in advance. For ten months, the California mine has monthly given up this tremendous yield. [Sidenote: LIST OF BONANZAS.] The following list of the bonanzas of the Comstock will be interesting to all who are watching the marvelous history of that mammoth vein: 1. Ophir and Mexican.—Discovered on the surface, and extended 500 feet in depth. Average width of ore, 15 feet; cubical contents, 112,000 tons; approximate value of ore, $22,000,000. 2. Gould & Curry.—Extended from the surface to the depth of 500 feet. Average width of ore, 15 feet; length along the vein, 500 feet; cubical contents, 190,000 tons; value of ore, $37,500,000. 3. Savage.—This was a continuation of the Curry bonanza, but not so rich. The ore continued down in the Savage claim to the very bottom of that mine, which is now 2,300 feet below the outcroppings. 4. Hale & Norcross bonanza.—This body was struck at a depth of 450 feet. It averaged 10 feet in width, was about 200 feet long, and stretched down to the 1,200 foot level. Cubical contents, 75,000 tons; value, $5,500,000. 5. Chollar Potosi bonanza.—struck at a depth of 500 feet; width of the vein worked, 100 feet; has extended with but few interruptions down to the present bottom of the mine, which is over 1,700 feet. Cubical contents, 1,500,000 tons; value, $24,000,000.