Lyon County times. [volume] (Silver City, Nev.) 1874-1907, 1879-08-02

two of these mines. | believe these
discoveries we're made about 600 feet
below the 1850 level, and it 10 posi-
Bile that The continuance Of the Com
stock as a producer of ore in depth
may be decided already in the affirma.
tive. But leaving out of considers
ton these discoveries, of which I
have no definite knowledge, and con.
flung our attention to those facts
which were known and capable Of
scientific examination in 1877, it
must be acknowledged that below
the 1600-level all the mines but one,
or possibly two, were barren for .
depth of 600 feet, and most Of them
for as much as 800 and 900 feet. and
even more. If the sources Of the
ore and the forces which placed it In
position were existing in undimin.
ished vigor, a. il 10 my purpose to
impress upon you, there must be-
some other antagonistic cause in
operation which has prevented the
formation of ore bodies at this par.
ticular depth and produced q barren
zone.
Such . change of conditions 10 dis.
cernible. and though . complete
retrospect Of the mode in which the
great lode u as formed would occupy
too much time, l can point out to
you one of the most striking facts
which the study of the lode has
brought out.
Through the whole Virginia Sec
ton, and also in q large portion of
the Gold Hill ground, the ore-bearing
portion of the lodc has a very steep
pitch. Angles of IS, so, and go de-
grees we're common. The great boz
nanzas may be said to stand vertically /;
for, while they dip throughout their
whole height. this dip is both east
aud west on alternate levels, and the
result is not far from perpendicu-
larity. The characteristic of the pro-
ductive ground then is steep alp.
Barren ground is marked by just
the opposite popularity, and wber-
ever the dip has fattened, whether
near the surface or at a great depth,
the fattening of the lode has been
followed by cessation of ore. Very
marked instances of this are shown
in the Yellow jacket, Gould & Curry,
and other mines. This is precisely
the state of things now found in the
existing great barren zone, and to
this fattening l trace the disappear
ance Of ore. There is no reason to
suppose the change permanent one,
or to deny the probability of ore
making gain in depth just as it has
repeatedly made at higher levels
when fiat dip has been followed by
sleeper inclination.
1t is on account of this fattening
that the new shafts have been placed
so far to the east. Whether the dis
lance selected, about one half-mile,
has been sufficient, must be proved
by the results; but the conclusion to
which the history Of the lode neces-
sarily leads US is, that, if they find
the lode increasing in dip at the point
of their intersection with it, tile pros
poets for a line of bonanzas on q
new front removed half mile from
the old one will be just as good as if
it were one or two thousand feet
nearer the surface. The added depth
is not likely to decrease the results,
and the chances on the new line will
be just as good as they were on the
old one.
But the theoretical probabilities of
finding ore are not the only elements
in the problem Of constructing these
deep shafts. New conditions have
come in-new not only on the Com
stock but novel in the world. In the
first thousand feet of depth, the
mines we're often close and hot and
the ventilation poor. Since that was
worked out, the ventilation has been
so improved that the works would
be quite comfortable if the rock had
remained as cool as it was above.
But it has become hot, and is steadily
growing hotter. The men work in
an atmosphere of 1859 to 1879 in =
great many drifta. The rock at the
2OOO-foot level is 1909 Fahr., and,
ominous of future events, water of
1859 Fair. has entered at least one of
the mines.
At the same time, the guam.
tity of water in the rocks has in
creased. A we'll $500 feet deep will
drain q large territory; and when,
from the bottom of that we'll, gal
lery is run two miles each way, north
and south, and at numerous points in
its course other galleries are cut
through the rocks, quadrupling the
length Of the main drift, the whole
network forms drainage system vast
in extent and Of the most perfect
arrangement.
Already the mines are raising not
less than 1850, 900 or 100000 tons
of water year, and the upcast shafts
through which the air-current leaves
the mines send out whirling column
Of vapor forty feet high. Will the
water increase SO as to make mining
Improbable, or the heat increase %
as to make labor impossible 10 these
deep shafts
The popular fancy Is more i'm