$25,000,000; Nevada, $25,000,000; Idaho, $8,000,000; Oregon, $3,000,000; Utah, $2,500,000; British Columbia, $2,000,000; Arizona, $1,500,000; and Washington Territory, $1,000,000. Estimating the gold and silver product of California, since the discovery of gold in 1848 to the year 1872, at $1,000,000,000, and the product of all the other sections of the Pacific coast, from the discovery of gold in them to the year 1872, at $200,000,000, would give an aggregate yield for the whole coast of $1,200,000,000, to the period ending January 1, 1872.

In 1851, gold was discovered in Australia; and, from that period forward to the present, mines, both in placers and quartz, have produced abundantly of the precious metals. In 1852, the gold-mines of Victoria produced $44,375,640; and, in 1856, produced the largest amount of any single year since the discovery— $59,719,820. California's greatest yield was in 1853$65,000,000. Since 1856, there has been a marked decline in the product of the Australian mines; but these mines produce more at the present time than do the gold-mines of California. The gold-fields of Australia extend over Victoria, New South Wales, New Zealand, and Queensland; and the mines of these regions, from the year 1851 to 1872, have produced an aggregate of gold equal to the whole product of California from 1848 to 1872-$1,000,000,000. The figures following exhibit the result of the periods named, and the product since these last dates is estimated, and is as nigh correct as can well be ascertained.

Victoria, from 1851 to 1868, yielded $711,369,000; New South Wales, from 1851 to 1868, $148,314,125; Queensland, from 1860 to 1867, $2,424,850; New Zea

land, from 1853 to 1867, $74,924,280: showing a total within these dates of $937,032,255.

It will be observed in the table of annual yield of gold in California that the amount from the discovery of gold to 1872 is but $961,000,000. Amounts, going from the mines into the hands of private parties, and not easily accounted for, have been estimated to swell the amount in the table to $1,000,000,000; and the estimated aggregate amounts obtained from the Australian mines and the amounts passing into private hands, since the last reports above, will swell the total product of Australia to a little over the entire yield of California.

The approximate value in the yield of the precious metals in California and Australia, considering the large amounts and that the dates of discovery in each country are so close to each other, is something most remarkable in the history of gold-mining and the gold product of the world.

The government of Victoria collects for miners' licenses, miners' rights, leases of gold and mineral lands, and other mining taxes; while in the United States no collections are made, except in a few instances where local governments impose a small tax upon Chinese, and that in violation of the laws of the national government.

In the seven leading mining-districts of Victoria, namely, Ballarat, Beeckworth, Sandhurst, Maryborough, Castlemain, Ararat, and Gippsland, there are 2,431 miles of water races constructed, at a cost of $1,551,350. The area of land held as claims in the same districts is 133.575 acres; and the estimated value of the claims in these seven districts is $44,347,520. The number of

machines employed in alluvial mining are 441 steamengines, 1,887 pumping machines, 298 whims, 320 whips, 261 cradles, 19,346 water-wheels, 643 stamps crushing cement; and the number employed in quartzmining are 602 steam-engines, 66 crushing machines, 5,977 stamps, 512 whims, 436 whips. The value of all the mining machinery and appliances used in mining in Victoria is estimated at $10,752,160.

The number of men engaged in mining in Victoria, in 1851, was 19,300; the largest number in 1860, 108,562; and the number in 1868 was 64,658.

In 1857, there were 36,327 Chinamen working at the mines in Victoria. In 1868, the number was reduced to 15,300. The remainder have nearly all returned to their native land. Only fifty-six of the 15,300 were working at the quartz mines; the balance were working on the alluvial mines.

In 1852, the average earnings of miners was $1,310; in 1862, it fell to $336; in 1868, the average rose to $520 per man per annum.

Gold, of all metals, has a peculiar charm for the human family, and the real value of the baser metals is often ignored in the thirst for the circulating medium as it comes glittering from the mine or the mint. Great Britain does not produce the precious metals, yet her annual yield of minerals far surpasses all the gold of California, and that in such magnitude that there is no comparison. The annual value of the mineral products of Great Britain is about three times as great as the greatest annual yield of gold in California, and eight times as great as the mines of California produce at the present period. The value of the minerals taken from the mines of Great Britain, in 1869, was $176,269,000.

If we calculate this amount by twenty-four, the years of the existence of the gold-mines of California, and in which they have produced $1,000,000,000, we will have the aggregate sum of $4,230,456,000 worth of iron, lead, copper, tin, and coal in Great Britain, against $1,000,000,000 of gold produced from all the mines of California within the same period. A feature worthy of notice in connection with this subject is that, while the yield of the precious metals in California is steadily on the decrease, the production of the mines of the British islands is steadily on the increase. But it is doubtless only a question of time when the supply from the earth must give out.

The minerals raised from the earth in the United Kingdom, in 1869, were of the value of no less than $176,269,000. This amount exceeds that of the preceding year by upwards of $8,000,000. The coal produced in 1869 was 107,427,557 tons. The returns for 1868 showed only 103,141,157 tons produced, being less than in 1869 by above four million tons. The production of iron ore in 1869 advanced to 11,508,525 tons, of the value of $16,000,000; the quantity is about 1,340,000 tons more than the year preceding. The great increase is in North Staffordshire and in Scotland. The tin ore amounted to 14,720 tons, and copper ore, 129.953 tons.

CHAPTER XXI.

Tunnel-mining-Sutro tunnel-Canals- Ditches-AsphaltumCement-Coal-Copper-Cobalt-Nickle-Diamonds-Electrosilicon-Gypsum-Iron-Lead-Petroleum-Quicksilver-Salt -Sulphur-Tin-Marble-Granite-Caves-Mining laws-Mining laws of Spain and Mexico-Geology and mineralogy-Great mines of the world.

TUNNEL-MINING.-Tunnel-mining is carried on to a considerable extent in California: mountains are pierced through granite and slate, for great distances and at great expenditure of time and money, in order to reach quartz veins; the object being to strike the lode as low down as possible, so as to drain the mine of water and extract ore: when the lode is reached, drifts and branch tunnels enable the miner to quarry the quartz, which finds its way through the main tunnel to the surface or the mill, where it is ground and the metal extracted. Mountains are also often pierced in order to reach the deposits of gold dust in the beds of ancient rivers and basins, which in many instances have proven very rich.

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SUTRO TUNNEL.-The grandest project in tunnelmining in America is the Sutro tunnel, at Virginia City, in the State of Nevada, intended to cut the famous Comstock lode, and pass under Mount Davidson at a depth of 7,827 feet from its top, which is 1,622 feet above Virginia City.

The Comstock lode will be reached by this tunnel at a distance of twenty thousand feet, or three and onefourth miles, from its mouth, and be cut at a perpendicular depth of 1,900 feet-or 2,900, following the dip