ings," and which for several years furnished nearly half of the
gold yield of the state, are now, with a few unimportant exceptions,
exhausted, or left to the attention of the Chinamen.

The purpose of all placer miners is not to catch all the gold in the
dirt which they wash, but to catch the greatest possible quantity
within a given time. It is not supposed that any process used in gold
mining catches all the metal. Part of it is lost; in some processes a
considerable proportion. The general estimate in California is, that
one-twentieth of the gold in the dirt which is washed is lost. Many of
the particles are so very small as to be invisible to the naked eye,
and so light that their specific gravity does not avail to prevent them
from being carried away by the water like sand. The larger pieces will
sink to the bottom and resist the force of the water; the smaller the
particles, the greater the danger that it will be borne away. Many
devices have been tried to catch all the gold, but none have succeeded
perfectly, and some which have caught a portion of what escaped from
the ordinary modes of mining, have been found to cost more than their
yield. The miner does not grieve about that which he cannot catch. He
is not careful to catch all that he could. His purpose is to draw the
largest possible revenue per day from his claim. He does not intend to
spend many years in mining, or if he does, he has become thriftless and
improvident. In either case, he wishes to derive the utmost immediate
profit from his mine. If his claim contain a dollar to the ton, and he
can save five dollars by slowly washing only six tons in a day, while
he might make ten dollars by rapidly washing fifteen tons in a day, he
will prefer the latter result, though he will loose twice as much of
the precious metal by the fast as by the slow mode of working. The
object of the miner is the practical dispatch of work, and his success
will depend to a great extent upon the amount of dirt which he can wash
within a given space of time. He regrets that any of the gold should be
wasted, but his regret is because it escapes from his sluice and his
pocket, rather than because it is lost to industry and commerce.

_The Sluice._--The board-sluice is a long wooden trough, through which
a constant stream of water runs, and into which the auriferous dirt is
thrown. The water carries away the clay, sand, gravel and stones, and
leaves the gold in the bottom of the sl