IF*, Article/
PLACER GOLD
III
"SLUICING"
/3v Seoree T. ifesurv/
The 3luice box is a long trough on series of troughs varying from 50
to several thousand feet in length. Hie width is seldom if ever less than
one foot, the height of the sides from on half foot up, depending on its
width.
Water is usually diverted into the sluice by means i a flume* Hie flume
of Porcupine Greek was 24 to 30 fe6t wide and wver a mile long, the sides
being six feet in height, maintaining a grade of about five inches to. the
hundred feet; that of Glacier Creek was eight feet wide, five feet deep and
1950 feet in length with a grade from six to ten inches per twelve feet*
The sluice is usually made in sections from 10 to 15 feet in lengthf
each section having one end wider than the other so that sections may be
fitted together like stovepipe* These sections rest on trestles so that they
form an even grade from the upper end at pay dirt to 'Che lower end whose
grade is lessened in order to catch the finer gold. This fall or grade is
called according to the slant or drop per foot of trough or sluice, i.e., a
fall of eight inches is called :fan eight inch grade”, of ten a ”ten inch
grade,'1 etc. The gn&de is determined according to the material in which
the gold i9 found and the quickness in which this material disintegrates.*.
In general the average pay dirt is completely disintegrated in the first 200
feet of a moderately graded sluice. Across the flooring of the sluice are
placed riffles, these being of two classes: first, the flooring of the sikikice
is covered with block riffles cut across grain so that the fibres stand up
right in the box as in a tree. These blocks are placed close together as
in street paving and have two purposes, to save wear and tear on the floor
ing and to catch the gold itself; second, cross bars are placed laterally
at intervals, over which the water flows, the gold being detained because
of its weight. Pay dirt is choveled or' "tailings” are hydrauliced direct
ly into the sluice box at the upper end, this is carried over the riffle
blocks by the mter, the gold andother small heavy material fall through the
interstices between the riffle blocks or retarded by the riffle barsf the
large stones, etc*, being carried off at the mouth by the water.
Ihe clean up i3 made by stopping the feed of pay dirt, allowing the
water to flow until clear, then shutting off the v/ater and, beginning at the
upper endj the riffle blocks are lifted out and the entire sluice cleaned.
Mercury is usually used in operating sluices by injecting a snail quantity
at regular intervals into the upper end of the sluice* Ihis amalgamates as
descrived in my previous article*
It is of interest to note that the sluice of Glacier Creek was four
feet wide, three feet deep, 128 feet long and na floored with 60-pound stefcl
rails set cross wise for riffles. uset}
Pbrcupine used the block riffles for about 2000 feet. 3oth/hydraulie
power to place their "tailings” into their sluices.
Bie trip to this placer district can easily be made from here, going
on Saturday and returning Sunday, by auto. I’he sluices of Porcupine will,
according to report, be worked this summer, and members of the Post should
take advantage of the opportunity offered in order that they may visualize
these articles written for their edification.
__ _ ,.r.(3h_e, Efld),, ______,__
CGliPMr F OKIES A Sid RAGE;
a race on skis from the building formerly known as the Guard
House to the road in front of the Hospital was held by Company Fas part .of
the Physical Training Schedule Monday morning# Private Say was the winner,
with Pvt# Chapman second and Pvt# Butler third.
Copporal Russell officiated as photographer#