Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1897-12-10

tailings they are hydraulicked
through sluices set in the bedrock,
the necessary water for bank wash
ings being delivered through pipes.
Where these conditions do not OBJ
tain and large volume of water
is available under the necessary
head the hydraulic elevator is re-
sorted TO.
To the latter class belongs the
deposits of American Hill, where
the hydraulic elevator system of
working has been in successful
operation for period of two
years. This system has found ap-
plication in New Zealand, as we'll
as in this country, in the explora-
ton of shallow placers or placers
laying below the drainage level of
the district. 1t embodies the sail
ent features of hydraulicking as
practiced when ample dump
ground is procurable, differing from
it in that approximately 55 per
cent. of the available water is en-
ployed in elevating the material
derived by bank washing to a
height sufficient to permit Of it's
disposal by gravity. The capacity
of an elevator plant under the
most favorable conditions is there
fore necessarily from 80 to 55 per
cent less than a corresponding
straight hydraulic plant employing
the same sluice grades and water.
OF the many types of hydraulic
gravel elevators on the market
only two can lay claim to being
constructed on proper lines and to
possess an efficiency of from 40 to
40 per cent. These are the Hendy
and Evans types. The former Of
these, modified by the writer to
meet the requirements at Ameri-
can Hill is there used. The latter
which has been recently introduced
in California, has three suction
openings, one main and two auxil-
larry, allowing the water and ma
terial to enter at the back of the
seat, which, it is claimed not only
reduces the wear and tear on the
machine, but also it increases it's
efficiency by allowing the proper
proportion of air to enter with the
water and material, even when the
main suction opening is choked.
Experience at American Hill has
demonstrated that with the Hendy
type of elevator, which has only
one suction opening, chokes of the
nature indicated never occur un.
less an excess Of water is used on
the giant or a crack forms in the
bell-shaped entrance piece, which
tends to weaken the suction at the
main opening. Then only will
sand accumulate to such an extent
in front Of the section opening az
to occasion a choke.
The modified Hendy elevator is
constructed in such manner that
the wear is thrown upon series
of properly proportional steel lin.
ers, placed on the inside of Sec
tional cast iron casting, which is
rendered air tight by means of gas.
kets. Since the introduction Of
this style of construction at Ameri.
can Hill no cracks have formed in
the outer casing and chokes have
been entirely obviated. This ele
vator, operating under 200 #. pres
svre with shin. nozzle, elevates
to a height of % it,, all the water
from a 3s-in. giant with practically
the same head, together with al
the sand and gravel it is possible
to pipe down the sluice with a
grade of g. in, to l2 #. and dis.
charge into the upper sluioe, which
leads to the final dump.
The ditch from which the, water
is obtained is nine miles in length,
has carrying capacity of 1000
miners inches and takes it's water
from American river. From thu
pressure box the water is conveyed
through 1900 #. of 90 in steel pipe
to the giants and the elevator.
Only the lower 20 #. of the de
posit is elevated, the upper 40 it
being worked directly through tn,
upper sluice. The lower line o
sluice has several branches; tn,
operation of the giant is practically
continuous and much time gener
ally lost in cleaning up is econo
mized. The duty of miners
inch of water actually used in pip
ing amounts to 4 Gu. yds. of ma
terial in "a hours.
A Pleasant Anniversary.