The silver messenger. (Challis, Idaho) 1890-1912, 1899-04-25
DREDGING FOR GOLD.

lue IOllOWlnS afCcle from IL.
| N. Bell in Mines and Minerals Civ
ing an extended description OF
the manner in which gold dredg-
es are operated, will be of inter
est to our readers, as one OF
these machines will be put in
operation at Stanley BASIN this
summer.-ED. M.
The perfection to which the
floating dredge placer mining
machine has recently brought is
destined to cut a very important
figure in the rapidly increasing
production of gold in this coun-
try, and is opening up new era
of activity in the placer mining
industry, as it makes available
for profitable handling, thous-
ands of acres of rich gravel beds,
in the vicinity of nearly all the
old placer camps in the west that
were too fiat to be drained, or re-
quired too enormous an outlay OF
capital to cover them with ade-
quate supply of water for hydra
ulicing.
About three years ago a dredge
that had been designed by Mr..
HI. ]. Reiling of Chicago, after
the style of those working in
New Zealand, was built by the
Bucyrus Company of South Mil
waukee, Wisconsin, and put to
work on Grasshopper creek, near
Bannack, in Beaverhead county,
Montana. Owing to the adverse
conditions, the operation of this
machine for the first season was
unsatisfactory, but after a good
deal of tearing down, rebuilding
and readjustment, and after the
outlay of over quarter of mil
lion dollars of capital, and near
ly two years time, Mr.. Reiling
finally got his machine into prof.
table working orGer, and made a
success of gold dredging. This
first boat, named the +. L. GRAY
es, and owned by the Gold Dredg-
ing Company of Chicago, proved
so profitable that another was
built in 1897 for an adjacent mine
under the same management.
which was a success from the
start. Both these machines have
been running steadily the past
season from the 10Th of March
until the ground froze up on the
18th of November. making a net
profit of IRON 81, 900 to 81, 800
per day to each boat, from gcound
so situated that it could not be
mined at profit by anv other
known method.
These boats are built about 100
feet long and 80 feet wide, the
framework is of heavy timbers
closely braced. and they carry
over 200 tons of boilers, engines
and other machinery. Before
launching such a dredge, dam
is built so that sufficient water is
impounded 10 float it. When op-
erationS commence the gravel
when washed is deposited behind
the dredge which moves up the
stream in the excavation thus
made. Steam is generated by
two tubular steel boilers each of
125 horse power of the locomo-
tive type, with CRATES arranged
to use pine and fir wood for fuel.
Immediately in front of the boil
ers is placed a set of engines
which drive the buckets, raise
and lower the bucket-ladder or
frame, and run the guy lines
which are attached at the front
of the dredge and which are
anchored outside, so that the
dredge can be swung in a circle
on the spuds or spile timbers at
the rear end of the boat, which
thus act as an anchored pivot.
These engines are under the con-
troll of an engineer stationed in
pilot house above the upper
deck, from which point he sees
all operations and handles the
machinery levers connecting
with the engi les.
Directly in front of and below
the engineer is the ladder on
which works au endless chain of
36 buckets for digging. The
lower end of the ladder is VERT
cally adjustable for depth bv
means of sdspeusory cables pass
ed over a frame above aud wound
upon a drum at the engine aud
under control of the engineer in
the pilot house. This ladder
permits the blckets to excavste
gravel at a depth of 80 feet, the
buckets being driven by a
sprocket chain gear connected
with 75-horse power engine.
The bucket chain swings loose
on the under side so that each
b0cket has a horizontal drag of