They are crushed to egg-size in a rock-breaker, and pulverized to pass a 40-mesh sieve in a California stamp-mill, which treats in 24 hours about 3 tons per stamp. A 10-stamp mill is fed by one rock-breaker, and discharges the liquid pulp into 10-15 wooden settling tanks, 9 by 5 by 8 ft., the settled contents of which are shovelled out and charged into the pans.
Mesh in the clear, supported upon a 3-in.
21 the sand rests on small gravel of such degree of coarseness that the whole of the grains would be retained on a sieve of a-in.,mesh and rejected by a sieve of z-in.
Both the state government and the national government have established hatcheries within the state, and state laws protect the industry by regulating the size of mesh in the nets used, prescribing the size of fish that may be taken and kept, establishing close seasons for several kinds of fish, and by other limitations.