The morning news. [volume] (Savannah, Ga.) 1887-1900, 1899-08-25
TEMPERATURES IN DEEP MINES
Some Interesting Data Covering IA
Depth of Nearly a Mile.
From the Chicago Inter-Ocean.


Ishpeming, Mich.-George e. Newett OF
this city who recently retired from
the Office of commissioner Of mineral sta
tistics of Michigan, which he ably filed
for two terms. has, after an exhaustive in
vestsation of the subject, replied to the
extensively published statement relative to
the hot copper mines of Michigan. The ar
ticle referred TO stated that at a depth of
$500 feet I'm the Calumet and Hecla mines
1t is so hot that the miners can work only
for a few moments al a time without be-
coming wholly exhausted. the temperature
being constantly 100 degrees Fahrenheit.
In his very interesting statement ex-Com-
missioner NeWett says that the greatest
depth of the Calumet and Hecla is not
within 500 feet Of that named. The deep
est shaft In the world is the Red Jacket
shaft of this mine. II is vertical and Is
l2lax25I2 inside of the timbers. It's loca-
ton is at the northern end Of the mine,
directly in front of shaft No. 4. which rs
inclined and has followed the belt of the
copper-bearng congomerate downward
from the surface. The Calumet congiom-
crate was encountered by the vertical
shaft at depth of 1885 feet below the sur
face, this corresponding with the hfty-sixth
level of the mine, and has been carried
downward past that point to a total depth
of 1890 feet. This VIII be the bottom Of
this opening for the reason that from It's
lowest point the company can secure all
the ore in this end Of its property.
The investigation showed that in sinking
this shaft the atmosphere grew warmer
after the lode was passed through. There
was no ventilation except that artihcially
supplied by the air compressor, but this
was satisfactory. At that time, as ever
since it has been lack of ventilation that
made the temperature in the lower work
f1.s- .Ta mt he .iss
shaft is now connected with No. at sew
eral levels. the connections being made at
every third level. the levels being sixty feet
apart.
Al the bottom of the shaft the temporal
ture Is 50 degrees. The Increase per 100 feet
is very small, but In order 70 determine
exactly what this increase is, a careful
test OF the temperature Of the rock has
been under way Tor the past year. In or
der to make this test holes have been
drilled in the wall rock. In these siOw-reg
islering thermometers have been placed,
and the holes plugged up. In month from
the time Of sealing the holes are opened
and the temperature taken and recorded.
This plan has been followed from the sur
face 10 the bottom Of the shaft, 1t being
the purpose of the company TO make a
thorough and trustworthy test, so that It
may be applied to the future working Of
the property at greater depths than ever
vet attained. II IS desired 10 ascertain COR
rectly The temperature OF the different eie-
vatlons as well as Of the rock strata.
The circula ton Of air in the mine grows
steadily betteISas the sevels are connected
with the workings by crOsscuts. This mine
has twelve shafts upon its conglomcrate,
and an are connected at many levels. In
the upper portion OF the mine, where the
rock which holds the copper has been
mined and sent 10 The surface, the opening
at the end OF the shaft Is walled W. This
is found 10 greatly improve the ventiia-
ton, the circulation of the air being more
free and rapid than If the Cd openings
were not shut Off from The shafts. In this
line Of openings some of the shafts are
downCasts. drawing the air downward
from the surface, while The others are up
CASTS through which the air rises from
the mine 10 the surface This works satis-
factorly. except al a short time during
the warmest portions OF The summer when
the draft into and out OF he mine grows
less rapid.
Al one OF the Iamarack mine shafts,
where an The shafts are vertical. the tenn
peratlte al ne bottom which b. 800 feet
below the eurface is - degrees. Here
The atmospheric condition g. improved to-
cause This shaft Is being connected with
another. Connections have been completed
az me ninth and tenth levels. which are
atoye The cOpHer-l caring c0ngl0merate
lode ans a. the eleventh ana twefh loy-
eis which are below the lode.
IL is claimed that IN no other place ~