MINING. 295 
ceipts $251,426, showing a clear profit of $74,441. The next 
year, after the water had fallen, the company commenced its 
labors again; spent $160,000 and received $115,000, and thus 
lost $45,000. North of Oroville is a “table-mountain” with 
a top of basalt, covering a rich deposit of auriferous clay. 
§ 222. 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’ under- 
taken extensively. In 1859 there were thirty-two quartz-mills 
in the county, and twenty-eight mining-ditches, with an aggre- 
gate 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 hy- 
draulic claims, aud 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. 
Placer county lies next to Nevada going southward. The 
