The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1899-11-23
How to Prospect for Mineral De-
posts That Do Not Crop.
PAysTREAks EASILY FOUND.


When the prospector has, by following ur
Indications, determined to his satisfaction
that certain piece OF ground lie underiald
with body OK ore. or deposit Of minerals
that 1t VIII pay him to open, the next
problem before him Is how he can de-
termine the value Of hts fna wi.f the least
expense to himself In case tha minerai
deposit does not ouicrop. but In overiaid
by an unknown depth OF soil or debris,
there arc variety OF ways by which he
can find out the depth of this surface COW
erfne and get some idea OF the character
OF the mineral below. ,She quickest way In
case the soil II not full OF powders. ard
does not contain bodies Of qoicksand. or OF
fine sand which. while containing no
water. will oil Up hole made In II almost
AZ easily as auicksand. Is by some device
that viii make a small hole.
The simplest instrument for this purpose
r. an ordinary posthoie digger. THIS can be
made by q blacksmith out Of a piece OF
sheet-steel. say one-sixteenth inch thick
and two feet wide. bent into a cylinder,
FIVE or six inches In diameter. and fasten-
ed to tho end OF a stout rod as a f1and.e.
With this continuance holes can be- put
down quickly TO depth OF Nn, fifteen
or twenty feet through ordinary soil. and
fairly sim clay: and II the ninera, sought
fs soft or diSntegfated, samples OF the
ledge can be brought up from over twenty
feet. A consriyance Of this kind devised
by the superintendent OF a Florida phos-
phate mining company. has come into gen.
erhI use for prospecting for phosphate rock
In that state.
For reaching greater depth. or for work
In country where the soil Is filed with
powders. and contains qucksand as In
many OF the mining regions OF the United
States. other methods must be used. The
simplest OF these IN a spring-oole drill. a
heavy drill three inches or more wide. sus-
pended from one end of a pole made Of
springy sapiing. Two or three men with
such drill can do good work as deep as
fifty feet. or 80. and going down into any
kind Of ledge. BY means Of sandbuck-
ct. piece Of hollow pipe slightly smaller
than the hole. with valve In the bottom.
samples Of drillings from the edge can be
brought up. Quite accurate results can be
obtained from anatyzing a number OF such
samples In case very hard bowIder Is
struck. II Is an easy matter TO change the
position Of the driii. In case fine sand or
auicksand gives trouble. the hole II kept
open by driving down n piece Of pipe TO
follow the progress Of the drill. In holes
OF moderate depth this pipe can be pulled
out again without much difficulty.
What II Necessary For Deep Holes.
For putting down still deeper holes a
heavier drill OF the same type Is commonly
used Such drills get their persuasive
motion from n rope passing over pulley
and motor at the other end 10 giva
stroke If varying length. TIE source OF
power may be horse or steam or saso-
line engine The capacity OF the outfit
VII vary With its size A small RIG VIII
do sood work Tor 100 feet or more. while
larger drills. with steam power. such AZ
are used In the Pennsylvania oil fields.
win work down 10 s.eeo feet. Drills OF this
type have been used In testing the COM
parative shallow iron ore bodies on the
Mesabi Iron Range In Minnesota. and are
the regular devices employed in hunting
for pockets of lead and zine ore In the
Joplin district Of Missouri. Az these per-
russion drills chip the rock Into bits 10
be brought up by The sand~pump. the sSs-
tlmony they hiring from below may be-
misleading. In the case ~ an iron ore body
the bits az steel worn from the driif itseif
may make the pulyerix"d ere brought; up
assay too high In iron. In the case of any
deposit, particularly II II contains layers
% hiah grade and low grade rock. The
record Of thS drisIings may prove very
unreliable.
To get an accurate record of the ground
passed through. dril that brings up soc
tens Of rock is necessary. The diamond
ariil = the best known Of this class and
has become necessary adjunct all ever
the world
In tais drill. tubular hlt Of soft s,ee!
has set In It's lower face varying number
Of diamonds. These are not gem stones.
which are expensive and liable Ia break.
but the tougher black diamonds or horts
The rotating diamonds shave OF thu rock
A stream OF water forced down from sur
face removes the cuttings. and the cylf-
sirieal core left Is broken Of by a special
contrsvance aud hoisted. with the htt from
trpe al
made are 10 be driven by hand power, ana
will take cores from hole 80 feet deep.
I - largest drills will cut ceres as large
a. four inches. and have teen constructed
30 hring up sections 81 rock from 4 depth
OF ore mile.
Need of Stand-rfpc or shaft.
The diamond irtll Garnet * through
gravel or broken quartz without danger ~
injnriug the cutting saccs nf the diamond
or tearing them out ~ the hi; altogether
Consequently. IN prospecting I; is usual To
drive an iron stand pipe through shs sur
face soil or gravel SO the ledge, or In ease
the sell IS fGli ef howlaers of granite or
other hard rock 20 sink "A shaft 20 the
ledge before the aysli is ready for work
Another type es rotary sarilI. ,,sot ~.th
success sor several kinds ~ work has for
it's cutting edge a series " steel teeth ~
peculiar shape. we'll tempered These -. n
when pressed against The rock . she am
revoives break off bits ~ the rock which.
like the diamond drill rock FhsvatgS are
removed from the circular rat<uss Nv
stream Of wafer sarSed town sregn surface,
In rsNck that Is aot too hard Ehls caiyx
tri... as II = caiied. has aoas some remark
able work. The cose~ tia, K brings up
are 81 larger diameter than those made hy
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