The Republican. [volume] (Oakland, Md.) 1877-current, 1909-02-11

low the surface OF the earth IS
somewhat in excess of half a mil
lion pounds to the square inch.
1t is a safe conclusion that within
large portion of the earth,s crust
there exist pent-up gases, particu-
larly steam, under pressure equal
to that of the most powerful high
explosives. High explosives prob
ably exert pressures ranging from
200, 900 to $50, 900 pounds TO the
square inch.
When a high explosive is de-
tonated the amount of pressure
defends upon the volume of gases
liberated and the temperature of
the gases. Nitro -glycerine, ex-
plOded in a space where it could
not expand, would exert a pres
sure of probably from 500, 900 to
$4,000 pounds to the square inch.
The pressure would certainly be
less than half million pounds to
the square inch, although the tenn
perature of the gases would equal
the boiling point of steel. Conse-
quently, with a 5oo,o pound
force holding in check $4,000
pound force which is continuously
exerting itself in an effort to burst
the earth's crust asunder, it is
reasonably safe to assume that the
stronger force will continue to pre-
vail, for some time to come at least,
and that there is not the slightest
danger of the earth blowing to
pieces.
Unfortunately, as the appalling
record of earthquakes shows, there
are many very weak spots in the
earth S crust. Deep down under
the crust, where water has entered
through faults, to be entrapped and
highly heated. with no room for
expansion, it dissolves the rock,
and as under the enormous pres
sure it forces its WaV through mar
row crevices to new positions, it
cuts new channels in the granite
floors, just as in glacial time sub
glacial sire a ms cut passages
through the ice.
Consequently, when the eruption
of a volcano takes place, relieving
the pressure in the deep passages
under it, there is a rush toward
the outlet of the streams of super
heated water made syrupy with
stone in solution. As these streams
of silica charged water find vent
at the volcano the expansion of the
pent-up stream takes place with
explosive violence, forming vol
Can1c dust and pumice stone, which
are belched forth in stupendous
quantities. Then portions Of the
earth's crust, which have been
resting upon a support of steam I'M
der dynamite pressures, naturally
sag and shift when those pressures
are removed or materially lessened.
The vast amount of solid matter
elected at times from volcanoes is
difficult of comprehension. The
great volcano Krakatoa had been
extinct for ages when, in 1888, its
top blew off with a shock felt
clear through the earth and with
blast that sent a wave Of air
around the earth three times,
while the fine volcanic dust did
not entirely settle out of the at
mosphere for more than two years,
as was indicated by the unusually
brilliant display of red sunsets.
1t is estimated that more mud was
elected from the mountain on that
occasion than the Mississippi river
discharges in $50 years. This was
the greatest volcanic eruption in
historic times. The distance is
not too great nor the time too re-
mote for the eruption of Mont
Pelee to have caused the earth
quakes of San Francisco, Val
paraiso and Kingston, while posi-
bly, Vesuvius may have played a
material part.
Made His Diagnosis.
What diagnosis did the doctor