Elmore bulletin. [volume] (Rocky Bar, Idaho) 1889-1906, 1891-11-07
Rocky Bar, November 7, 1891.


life of a prospector when If he had
MT hand some means ofcrushing the
ore which he comes across he could
bring back with him, as the result
of his summers work. enough OF the
precious metal to we'll repay him
for his toll and labor.
Heretofore the only means by
which the prospecting miner could
separate the gold from its rocky
gangue was by using hand mortar
and pestle, or else by crushing the
ore between two rocks. But these
methods, although very good in their
Wv are too Glow ard laborous to
produce large results.
The prospector who was going
over a rough and rocky country
could not very well carry with
him the small mills which have for
some years past been upon the mar
ket. Their weight, although not
excessive when one considers the
work they will do, was more than
he cares to pack on his animals. Be-
sides, the expense Of such mills was
more than most miners could afford.
The mortar, which he could buy
for dollar or 50, and which weigh
ed only few pounds, was his sheet
anchor. The great objection TO
crushing in mortar is that as the
material is pulverized II naturally
sits down to Che bottom, and there
being no way to remove II without
emptying the contents of the mortar,
each successive blow is deadened
by this already finished product.
There has to be just so much
dead work" done. This difficulty
in crushing is removed by any con-
trivance which will allow the pull
verified material to drop out the
way as soon as it is Of sufficient
fineness. All modern crushing ma
chinery tends tothis end. The COM
struction of the Blake and similar
rock breakers or ore-crushing ma
chimes is known TO all practical
miners. The rock is broken bv
being crushed between powerful jaws
which are given their opening and
closing motion by various contri-.
vances. These. however, have only
been used for comparatively coarse
crushing. They cannot work the
ore 10 sikty or eighty mesk.
There is a small portable ore
erusher manufactured by San
Francisco house which meets all the
demands of the prospector. First
of all its cost is MISUNDERSTANDING
five dollars is not much when we
take in consideration all the advau-
tages of the machine. 1t. weighs
only 100 pounds, and SO can be
easily packed on an animal. Its
crushing capacity depends, Of causs1s &.
on the hardness and desired fineness
Vi the rock 4nt with rock of moder-
ate hardness it can easily work
from 100 to 200 ounds per hour to
n ten TO twenty mesh. A point to
he observed in the working of this
machine TO obtain the quickest re-
sults, ia not to crush coarse at first,
and gradually to reduce the open
ing of the jaws. II, for instance, we
have fifty pounds Of ore to crush,
and we set the jaws apart for a
number four mesh, probably ten
pounds of this ore will be crushed
TO a twenty mesh or finer. A great
mistake ia made in attempting to
crush all the ore the desired fineness
ut once.
The machine works on the prln-
ciple of a jaw-crusher. The dis
lance apart of the jaws is regulated
l,y tnrn-screw conveniently placed.
r'he stationary jaw is straight. and
is at the end opposite to the opera
TOR. The movable jaw has it's lower
hart beveled at an angle to its plane.
The face of both jaws is corrugated,
20 as to facilitate the ore in working
down. The jaws are worked by q
hand lever, and have an opening OF
about three by two inches. A COW
err goes over the feed opening so as
10 prevent any pieces Of ore from
flying out while being crushed.
For the purpose for which this
crusher ia designed II Is unequalled.
1t is of great service in assay offices
or sampling works. where small
quantities of ore have to be crushed
Gsafaannan