Gilpin observer., 1899-12-14
SINKING OR riMsERlNo.

SINKING OR TIMBERINo.
Practical Advice to Miners From the En-
cheering and Mining Journal.
In mining, as in other occupations,
things are often done because they are
considered proper, and without any
thought on the part of the miner Men,
in a certain district, get into the habit
of performing certain operations in a
certain way and make no attempt to
see if other methods would not serve
them better. Because certain meth
cd gives n good result in one case it
it too frequently assumed that it will
give good results in other cases where
conditions are entirely different. The
practical miner is apt to know his own
particular mine very well, and this
knowledge gives him certain con-
tempt for biologists, or other trained
observers, who bring wider knowl-
edge and more unbiased judgment to
the work in hand. Perhaps the con-
Scrvatism of the average miner and
prospector in the Rocky Mountains.
or on the Pacific slope, is most evident
in his clinging to the idea that the
best way to find out what there is in
the vein he has located Is to prove it
with depth" by crosscut tunnel.
AS matter of fact. when n miner
has Staked out his claim the first and
most essential thing is for him to de-
termine, as nearly as he can with the
means at his disposal, the direction of
the vein. Thus he will know wheth-
er his location really covers the vein,
thereby very likely saving himself n
heart-breaking lawsuit should the
vein prove valuable. In case the sur
face debris is not deep, say 10 feet or
less, it will not take him very long to
dig some surface crosscuts the whole
width Of the vein. He will find out
also whether the ore that he located
is really in place, or whether it is slide
or float rock from higher up the hill
side. Having determined the general
direction of the ledge, and opened 1t,
II the surface is not too deep, in at
least four places on Il claim; 800 feet
long, the next thing to do is to sink
on the ledge far enough to determine
accurately its dip or the inclination at
which it slopes into the ground. Then
If, as stated, the vein has been open
ed up at at least four points, several
hundred feet apart, careful analysis
of the rock from the bottom of the
different pits or crosscuts will show
whether the vein grows richer in one
direction than in another, or carries
fairly uniform values. Having ascer-
tained this much, the prOspectOr is in
Il position to go to work systematical-
ly. He can decide whether he shall
sink his shaft deeper or run tunnel.
He can also tell where is the best
point to locate his shaft or tunnel so
that it will show up the vein to the
best advantage.
Generally speaking, the best advice
that can be given i'll opening any min
/eral deposit is follow the ore" There
is no other way by which the ground
can be shown up so thoroughly, and
the ore taken out VIII go often long
way toward paying expenses. Even
IL the ore is not rich enough to pay
for shipment, it is always evidence Of
the value of the rock in the vein, and
is a tangible, self-evident thing to show
n prospective investor. Again, shafts
Mvertical or inclined. that follow the
vein, will show up any changes in the
ore and give a large amount in sight.
Thus four shafts fifty feet down OH Il
ledge four feet wide would expose L.
$50 square feet of the vein. A tun-
mel driven 200 feet through rock to
cut the vein would expose but the sec
tiOn, the height and width of the tun-
mel, say 100 square feet To expose
n larger area, dI fling must be done.
and such drifts can be run with better
discrimination at the foot of Il shaft
that has followed the ore.
In the great majority OF cases the
miner, working by rule-of-thumb
methods and disdaining to go ut Il
thing in n scientific way, proceeds In
an altogether different way from that
outlined above. Having staked of his
claim, often located on the strength OF
an apparent outcrop of ore, or on the
showing of single shallow shaft. he
proceeds to run II tunnel. The miner
or prOspector with limited resources
wastes only his own time and money
by such work. 1t is when the practi-
cal miner undertakes to open up n
claim for some company fiOated with
S1.OOO,OOO capital or some other at
tractive figure, that great mischief Is
done. A tunnel Is started to open up
the ledge. say at 200 feet. Now. as
suming that the ledge dips into the
ground vertically. that the slope of the
v/hill is forty-tive degrees. and that the
tunnel Is driven at right angles to
the course of the vein. tunnel 200
feet long will cut the vein at depth
of 200 feet. 1t is easier to tunnel than
TO sink this distance. The dirt and
rock removed can he trammed much
easier than hoisted, the tunnel will
drain itself and If the ground is at all
wet there IL no need of the expense of
pumping outfit.
So much for the advantages: as n
matter of fact. the different factors
are seldom as cited above. The evil
dence that can he gained from an
apparent outcrop or one shaft Is very
misleading. common error Is ia
mistake the slope of the hill. Any or.
dinary hillside Is very much more like.
ly to be n Slonp of twputy-fiye dpprnes
or thirty degrees than fourty-iive de.
grees. and the tunnel to open ground
mt 200 feet may have to he driven 4OO
feet. In n tunnel of this length the
chances are that the ventilation will
he neceSSnrY nfter ench hlnSt work