Nevada and Placer.—South of Yuba and Butte is Nevada, the richest mining county of the state. Within its limits the tom, sluice, under-current sluice, and crinoline hose were invented, and the ditch and hydraulic power were first applied to placer-mining; and quartz-mining was first undertaken extensively. In 1859 there were thirty-two quartz-mills in the county, and twenty-eight mining-ditches, with an aggregate length of three hundred and ninety-four miles. No part of the mineral region of the state is better supplied with water than Nevada county. The richest quartz district is in the vicinity of Nevada City, which has fifteen mills, and Grass Valley, five miles distant, has seventeen. The great Allison mine, which has the richest lode in the state, is in Grass Valley.

The quartz mines here are much troubled with water, and during the winter of 1860-61, many of the mills were compelled to stop for weeks until the shafts could be drained by steam engines, after having been filled by a long and heavy rain. The annual gold yield of Grass Valley has been estimated at four millions of dollars. North San Juan has the finest hydraulic claims, and Sweetland the largest tail-sluices. The Eureka Lake Ditch Company has more ditching and water than any other company in the state. Their main ditch is seventy-five miles long, and there are one hundred and ninety miles of branches, making a total of two hundred and sixty-five miles, which have cost nine hundred thousand dollars. The daily sale of water is six thousand inches, with a weekly income of six thousand dollars. The principal mining towns are Nevada, Grass Valley, North San Juan, Rough and Ready, Orleans Flat, Moore's Flat and Humbug City.

INDEX.

Chief Industry [ 3] River-Mining [ 24]
Metals obtained [ 3] Beach-Mining [ 26]
Gold Mines [ 3] Mining-Ditches [ 27]
Placer Mines [ 5] Prospecting [ 27]
The Sluice [ 7] Quartz-Mining [ 27]
Amalgamation [ 9] Distribution of Gold in Quartz [ 28]
Cleaning up [ 11] Prospecting Quartz Rock [ 30]
Riffle-Bars [ 12] The Divining Rod [ 31]
Double Sluices [ 13] Quarrying Quartz [ 31]
Rock-Sluices [ 13] Arastra [ 32]
Hydraulic Mining [ 14] Chilean Mill [ 34]
Blasting [ 16] Stamps [ 34]
Tail-Sluice [ 16] Separation [ 34]
Tunnel-Sluice [ 17] Sulphurets [ 36]
Ground Sluice [ 17] Chief Quartz-Mills [ 36]
Long Tom [ 17] Silver Mining [ 37]
Cradle [ 18] Quicksilver Mining [ 38]
Pan [ 20] Platinum [ 39]
Dry Washing [ 22] Del Norte and Klamath [ 39]
Dry Digging [ 22] Siskiyou [ 40]
Puddling-Box [ 22] Trinity and Shasta [ 40]
Quicksilver-Machine [ 23] Plumas and Sierra [ 41]
Tunnel-Mining [ 23] Yuba and Butte [ 43]
Shafts [ 24] Nevada and Placer [ 44]