The daily sentinel., 1901-08-17
GOLDEN GRAVEL.
San MigueIs Great Placer Enter
Prise Ready for Regular
Work.

commencement OF the washing OF gravel
by the Keystone Hydraulic Mining com
pany marks the inauguration OF placer
mining enterprise unequaled in the
state. The richness Of this placer ground
has been known for years and more than
one attep pt to successfully work it has
been made.
That failure has heretofore accom-
panied the efforts has been due solely to
lack of capital and want OF practical
placer mining knowledge. The present
company was organized by e. l.. Davis,
of Telluride, who brought to the task
the ripe experience of many years. Prior
to this series of thorough prospecting
tests had been made at several points on
the placers, which proved uniformly
profitab BILE, and inspired a strong hope in
the ultimate success OF the projected en-
terprise. This work occupied several
months OF last year, and from one e1ca-
vation carried down to bedrock 5000
yards OF gravel were washed that yielded
$4,000 in gold.
This test was made under unfavorable
conditions, for with but 200 feet OF
sluice boxes and water head Of 500 feet
it was known that at least one half the
gold contained in the gravel was washed
through the sluice and out onto the
dump The plans of the present man.
agement will avoid such losses in the
future, for they embrace total OF 2,2OO
feet of sluicing, and in travelling this dis
tance the smallest particles OF gold will
sink to the quicksilver and be caught by
it, The hume just completed is $500
feet in length and OF 6xI2 feet interior
dimensions. Larger than is necessary to
supply water to two ten.inch giant noz.
zles, but designed to carry the entire
flow of the east fork of the San Miguel
river at any stage of water, and this was
done in order that the old river bed
might be accessible for washing. A
waste fiume will carry the surplus water
around and below the ground being
washed. A hydraulic steel pipe line,
2,20O feet long, takes the water from the
penstock at the lower end OF the hums.
This pipe is twenty-si inches in diam
eter at it's head, and diminishes to six
teen inches at its lower terminal, where
the giant nozzles are attached.
The pipe line on the Keystone has a
fall OF $50 feet, and this gives a pressure
Of 225 pounds per square inch at point
Of esress from the nozzle. The force OF
impact with which ,en-inch stream OF
water would strike a bank of gravel at a
distar ce OF 100 or 200 feet can only be
imagined, and can be compared to moth
ing but solid shot from a sixteen-inch
gun. Since commencing operations there
has so far been but one eightinch giant
nozzle used, and this to prepare a bed on
which sluice boxes will be constructed
A section OF these has been built and
with further extension another eight
inch giant will be installed The one
now at work is effective at distance OF
45O feet, and will throw water $50 feet
but less distances will be used in actual
work. At 200 feet bowlders weighing
up to 300 pounds are thrown out OF the
way like corks, and with two such
streams even heavier ones will be car
ried through the sluice and out onto the
dump. Washing will be stopped and q
clean up OF the sluice boxes made each
month, but for the remainder OF this
season nothing large is expected in re
turns