The Black Hills union. [volume] (Rapid City, Pennington County, Dakota [S.D.]) 1889-1904, 1903-08-14

terial to work on when it's mill is
ready to start again, which should be
before the middle of the present
month.
The Interstate Mining company have
good crew at work on the Blue
Bird group which has an excellent
belt of veins bearing gold some of
which are very high grade. The deep
est shaft which has attained depth
of something over 60 feet, has cut
through the vein it was designed to
strike, and having revealed the infor-
dip and richness of the vein at that
point the miners will now be changed
to another place where another shaft
has been started. When this has been
sunk to satisfactory depth another
will be started and still another until
they have line of shafts all along the
outcrop Of the main vein. 1t is con-
sidered more desirable at this time to
prove the continuity of the ore body
than to gain depth in one place. The
object in view is to get ore enough in
sight in the least possible time to JUS
tify putting plant on the ground
With this end in view we think that a
line of shafts all along the vein is the
best policy, as it will go further in de-
velopment, and show the most ore in
sight with less expense and less time
than deep sinking. There is every
evidence that these veins are true
assures and will go down to profound
depths, but it is quite as essential to
know how far they extend through the
claims. They have another group
called the ''Lacota," consisting of six
claims in length and two wide. These
claims have some very promising veins
cropping above the surface from
which some high grade ore has been
taken but the amount of development
on this group is quite meagre at pres
ent. The whole group, however, is
covered with a fine growth of large
timber fit for the saw, which will all
be needed in the mines when they
come to be worked to the deep
Chronicle.
In testing cassiterite with blowpipe,
first powder, it being infusible and re-
fractory. Then heated with soda will
give small malleable globules of me-
tallic tin. These globules are at first
as white as silver, but soon tarnish.
With little nitric acid in watch
glass the buttons yield an insoluble
white powder of tin oxide.
German silver is an alloy of copper
zinc and nickel, of white color. and is
| used as limitations of silverware. II
can be readily covered with silver by
plating. The commonest variety OF
| this alloy contains about eight parts
| copper, three to five of zinc and TIVE
OF nickel. The more nickel added
makes the finer alloy.
| Rock drills are not efficient machines
when operated under low pressures
This is true commercially or mechani.
cally. Under such conditions a rock
drill will work very slowly, but the la
Dor required will be the same as if I
were working at full pressure. The
| cost per foot of hole is therefore in
/ creased. Mechanically speaking, the
friction of the machine is practically
constant whatever load Hence with
low pressures the ratio of friction tc
useful effective load is greater than
with high air pressures.
James Conzett's force of miners OF
the Portland mine of the Ruby com
pany has large amount of ore ex.
posed, and more than enough to keel
the plant which is being built on the
property running for long time ever