yard.
The ground, in both of the last mentioned instances, was surveyed and
the returns per cubic yard are as accurate as it is practicable to
obtain.
Polar Star Mine.—In
the appendix to the " Auriferous Gravels of the Sierra Nevada of
California," Professor W. H. Pettee estimates the value of the top
gravel at the Polar Star Mine to be about 11 cents per cubic yard, and
at Quaker Hill the yield of the top gravel is supposed to approximate 6
cents per cubic yard. The yield of the bottom gravel, however, is not
given, and the estimates of the upper gravel are approximates based on
the statements of others, and not the results of accurate detailed
surveys.
