Hydraulic
mining used jets of water to break down gravel banks and to
wash the gold-laden soil, sand, gravel, and cobble through gold-separating devices (sluices and
under-currents). Hydraulicking dominated the California gold
mining industry from the mid-1850s until 1884, when it was halted by a federal injunction.
During its 30-year heyday, hydraulic mining yielded over $100 million in gold, or one-third of
all gold produced by California in that time.
This
BookWebCD includes the page images and searchable text of A
Practical Treatise on Hydraulic Mining in California by Augustus
J. Bowie. Bowie's book was the most thorough contemporary
description of the hydraulic mining industry of California. It was first published in
1885, just a year after the collapse of this premier gold mining sector,
and at a time when the industry hoped to revive itself by lobbying, or by
building dams to control mining debris.
Bowie
describes the industry, literally from top (with diversion of rivers
at high elevations many miles from the mines) to bottom (with discharge of tons of debris
from the sluices). He tells of the rock dams, wood flumes,
and earthen canals built to store and deliver water to the pits.
Bowie gives details of the powerful hydraulic monitors and the drifting
and blasting methods used to bring down and break up the cemented
gravels. He describes the use of mercury and other mining
practices that made hydraulicking pay at "an ounce of gold per ton
of gravel." And he tells of the long hard-rock tunnels that
were required to drain the pits and to house the sluices and
undercurrents that caught the gold.
Bowie's
book was reprinted ten times by 1910, guiding the development of
hydraulic mines in other states, Alaska, Canada, South Africa, South
America, and
Australia.
