Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1896-07-17
Working Flat Placcrs.

to the search for new deposits, but
also to revived interest in the ex-
ploitation of ground long well
known, but hitherto not utilized
because of disadvantageous con.
ditions. 1t may fairly be ques,
toned whether there are not bet.
ter opportunities in developing old
territory now made available by
improved methods and economies
than in prospecting for entirely
new discoveries. AS to placer
ground, the probabilities of coming
across important deposits overlook
ed by the earlier prospectors are
not very encouraging, at least
within the limits of the United
States, since the ground has been
gone over pretty thoroughly and
the methods of prospecting and
testing are so simple and general
ly understood that whatever is
worth it is seldom likely to escape
notice. On the other hand, there
are numerous known and proved
occurrences, especially in the older
gOld-mining areas of the Pacific
Coast States, toward which the
eyes of mining men have long been
turned with longing, but which
have for the most part baf1led at
tempts at profitable working.
In the region just indicated there
are large tracts of good placer
ground-that is, good so far as the
tenor in gold goes-where there is
plenty of water at hand or avail
able from nearby sources, but
which, for want of sufficient fall
for dump room, are unfavorably
located for hydraulicking or wash
ing by any system involving the
disposal Of large volumes of tail
ings. When the ground is I'M
usually rich, SO that relatively
small quantities of material have
to be handeled, operations have
been carried on in a desultory
manner for the last three or four
decades, but never on a very i'm
port scale or very successfully from
the investors point of view. Yet
in this particular line of mining
there are evidently good opportu-
mites under present improved con-
ditions.
Ground which runs much below
a dollar yard, with the pay con-
centrated in well-defined stratum,
will not pay for working by the
drift system, which involves sub
stantial timbering and often heavy
pumping; and, besides, drift min
ing needs some fall and moderate
amount of dump room for washing
the material and afterwards dispos-
ing of it. The sort of proposition
we now have in mind is interme-
date between ground suitable for
drifting and that workable by the
usual open hydraulic method; that
is, the gold content may be too low
for drifting, but still high enough
and contained in fair mass of ma
terial to be available for means
considerably more expensive than
by draulicking. Much of
this ground is unsuitable for drift
ing, for reasons wholly apart from
the question of cost.
of all the numerous systems pro-
posed, many of which have been
tried on a working scale with vary
ing degrees of success or want of it
the prominent ones rely upon either
hydraulic elevators or steam SHOW
els. In the former case the ma
terial is taken up high enough for
feeding in at the head of a string
of sluice boxes; in the latter the
preference is usually to wash in
some form of appliance provided
with close grizzlies and medium
screens, with rifles and copper
plates, mercury troughs, ETC., and
often having shaking motion i'm
parted by power. This needs less
and fall, less dump room
because the great bulk of the ma
5erial is kept back by the grizzlies
md retained near the source, and
rhe washing machines generally
'equire much less water than con-
sluices. In whichever
way the dirt is raised and handled,
here is generally no conflict with
any debris laws, for the amount of
material is not only much less than
in the big open hydraulic workings
but does not need to be moved far.
Under reasonably fair circum-
stances of water supply and power,
or water enough for washing and
cheap fuel for power, ground run
ming, say, 25 cents a cubic yard
ought to pay, if there is enough of
it. Any system to be successful
on a large scale must adhere to
the underlying principle of hy-
draulicking-the reducing of man.
ual labor to the very smallest
minimum. Most of the operations
thus far in this line have been on
too small a scale to be
very profitable, hence another les
son must be borrowed from ny