The Nevada Mill was built to work the ores of the Hale and Norcross, Chollar and Potosi Mines. It is one of the most substantial mills in the country, and no mill in the State is better arranged. It is lighted with electricity, and the grounds in front are illuminated by means of an arc light on a tall mast.
The Two California Mills.
The California stamp and pan-mills in Virginia City reduce the ores of the Consolidated California and Virginia Mine. The stamp-mill is situated immediately east of the C and C shaft of the mine. It contains eighty stamps. The ore crushed in this mill is amalgamated in the pan-mill, which stands about 1,500 feet further east. The crushed ore is conducted from the stamp-mill to the pan-mill through an iron pipe four inches in diameter. The process of amalgamation is much the same as at the Chollar Mill, except that the pulp goes directly into the amalgamating pans instead of being first received in settling tanks. It flows from pan to pan—the outflow of the first pan passing into the second through a pipe, thence into a third, and so on and from settler to settler, being in all about three hours in passing through the series. This is called the Boss Continuous Process. It is in use in no other mill on the Comstock, as yet. In connection with the Rae electrical process of amalgamation (in which a current of electricity is passed through the settlers) it is found to work satisfactorily. The electric current prevents loss of “floured” quicksilver. Both mills are driven by Pelton water wheels. A single Pelton wheel eleven feet in diameter, placed on the surface, drives the eighty stamps of the battery-mill, and also twelve Boss grinding pans. The water used on the surface Pelton is caught up and conducted to the C and C shaft, where it is used on a series of Pelton wheels of the same size. These wheels are placed in chambers made for their reception 500 feet apart from the top of the shaft down to the Sutro Tunnel level (there 1,500 feet), and by means of steel wire cables, used as belts, the power of all the lower wheels is brought to a main driving shaft on the surface. The whole power is then transmitted to the pan-mill (about 1,600 feet) by means of steel wire cables passing over pulleys placed on a series of tall wooden towers. The cables pass over a considerable depression between the top of the C and C shaft and the pan-mill; three high towers are required in the middle portion.
River and Canyon Mills.
The Mexican Mill, on the Carson River, contains forty-four stamps and a corresponding number of pans, settlers, and other amalgamating machinery. The Morgan Mill has forty stamps. It works ore from the Consolidated California and Virginia Mine. The Brunswick Mill contains seventy-six stamps, the Vivian sixteen, Santiago thirty-eight, and Eureka sixty. All these mills are about and below Empire City, and all work Comstock ores. The Eureka Mill is run on ore from the Consolidated California and Virginia. The Rock Point Mill (thirty stamps), at Dayton, and the Douglas Mill (ten stamps), in Lower Gold Hill, also work Comstock ores.
At and about Silver City are two or three small mills that work the ores of mines in that neighborhood, and on the Carson River are the Douglas and Woodworth Mills, which work tailings.
On Six-mile Canyon, below Virginia City to the east, are several small water mills having an aggregate of about thirty stamps. These work ores from the mines on the canyon and in Flowery District. On the canyon are also one or two small mills that work tailings and the concentrations from blanket sluices.
The Alta Mining Company has a ten-stamp mill, with concentrators, immediately adjoining the hoisting works at their mine. The Justice Company have a new ten-stamp mill near their mine.
Owing to the fact that many mines are now at the same time producing large quantities of ore, a lack of milling facilities is being felt. To meet this demand the Nevada Mill has been enlarged one-third, and the capacity of other mills will be increased, and perhaps some new mills will be erected. Processes by means of which low-grade ores may be profitably worked will no doubt yet be invented or discovered, which will cause many new works to be erected either on the Carson River or in the neighborhood of the mines producing large quantities of such ores.