The morning call., 1893-07-21
MINES FLOODED.

The dispatch announcing that the
pumps are to pc taken out of the Henri
eSta and Maid of Erin mines at Leadville
must be received cum grano. II tie state
ment be true. it probably means that at
the extreme depth which the shafts in
those mines have reached there is no ore
that will pay to work. For when the
pumps in deep mine are stopped, the
works are drowned. the timbers give way.
the rock caves, and the mines are practi-
cally abandoned. We know how it was
when the pumps were hauled up on the
Comstoek.
In the course of the last twenty years
we have learned that ore bodies contained
in veins or consecutive deposits deterior-
ate in quality as depth is gained. The rich
est ore is near the surface, and as the body
is followed downward the percentage Of
precious metal gradually dimnishes. That
is the lesson of the COmstock and of the
Leadville carbonates. The highrgrade ores
which were taken out of both were found
at no great distance below the surface of
the ground, and in both, when great
depths were reached, 1t was always a
question for thu assay er whether the ore
was worth mining and hauling to the top.
This occurred, though in neither case were
true veins found. At Leadviie the ore
lay In horizontal deposits between the
limestone and the conglomerate; on
Mount Davidson it was discovered in
lenticular bodies scattered through an
enormous vein of clay and rock. But the
deposits of the lenticular bodies obeyed
the rule which applied to regular assure
L.
they were.
Both on the COmstock and at Leadville
miners have accepted the situation and
have endeavored to prolong the life of
their respective camps by mining ores
which in the days of the boom were not
deemed worth extracting. At Mount
Davidson sixteen or seventeen years ago
an ore which carried less than $50 worth
of gold and silver was passed by or thrown
upon the dump. Now when ore is found
which nets 50 a ton over and above the
expense OF mining, hosting and milling
it is gratefully welcomed. So this very
Henrietta at Leadville was supposed ten
or twelve years ago to contain an mex
haustible deposit of SIS ore, where as
lately it has always been gamb whether
the monthly balance sheet would show a
profit or loss on the thirty days opera
lions Such condition of affairs has
compelled mining managers in both camps
to resort to economies which were not
thought of in the days OF the boom; even
now they are faced with the alternative
Of cutting down expenses still further and
closing the mines. 1t would seem that the
Leadville mine-owners have taken advan-
tage of the present silver scare to shut
down.
1t is often asked why our mines don't
last as long as the mines in Europe. There
are mines in Spain which were worked
when Carthage flourished The tin mines
OF CORNWALL were in operation in the time
OF Julius Cesar. Some mines in the Hartz
Mountains have been in continuous eX-
ploitation Tor 400 years. Indeed, one need
not cross the ocean to find mines which
have lasted for centuries. They can be
met with in Mexico and Peru. The differ
ence between those iong-lived mines and
our short-lived mines mainly arises from
the TACT that the latter are worked
with machinery which the former coulo
not command. Without the steam engine
and pumps now in use it was impossible IN
hoist ore or water below q certain dentb
When the shaft got down to that point the
main work had to stop. but the mine was
kept alive by pecking at stringers on the
sides of the shaft. Again, there are mine,
where the ore is not inclosed In a vein o.
defined deposit, but Is distributed through
mass Of rock which may be enormous