The morning call. [volume] (San Francisco [Calif.]) 1878-1895, 1890-12-08
THE CENTER
OF THE EARTH
All the Evidence Points to the Be.
lief That It Is Hollow.
Thickness Of the Crust-Proof Gathered From a
Long Series Ct Well Known Facts-Prcba-
bilities as to the Interior.

Without assuming anything for granted
and accepting only such conclusions as come
from the evidences inevitably, as we pass
along. let US survey the earth and endeavor
to ascertain the character of its internal
economy. The surface features that first
impress us are the great water and land
areas. Calculations, says writer in the
Plttsburg Dispatch, have proved that three
fourths of the surface is water and ice; the
remaining fourth is land. The water is of
varying depth, but occasionally reaches dis.
tances of from four to six miles. This is
deeper than any land point is high.
Huge ribs, known as mountains, dispose
themselves on all continental areas, and are
generally ranged in lines parallel with the
coasts. At irregular intervals along these
mountain ranges openings, known as volca-
noes, penetrate down into the earth, through
which, from time to time vast quantities of
molten and gaseous matter are poured out,
thousands of islands of considerable area
having been formed in this way. These
openings bear every indication of being
vents, some of which have closed from dis
use, and some. after having been inactive
Tor centuries, again become alive. These
vents are more frequent in the vicinity of
coasts. anu are also found on islands.
THE BOTTOM OF THE SEAS
From what we know, the bottom of the
seas presents about the same typographical
features as the dry land, as beneath the
water-line are mountains, hills. pateaus,
valleys, ETC., etc. Extensive and impossible
Ice areas cover the polar districts, and here
also we find volcanoes and the evidences of
volcanic action. We thus figd this volcanic
feature in pretty general distribution all
over the surface of the earth.
Having now briefly surveyed our globes
exterior and noted the chief physical char
acteristics, what are the phenomena pre-
scented, so far as we may absolutely know.
beneath the surface? What NAV we be
able 10 determine as to its physical interior?
Shaiting and drilling to whatever depth
disclose layer after layer of rock stratifca-
ton and the temperature rises uniformly
with increasing depth. The temperature, if
the rate of increase be sustained, would
reach the melting point at less than thirty
miles. AS 1t Is about 1000 miles to the
earth's center, we find that this shell, if we
accept thirty miles as its thickness, is con-
slderabiy less than one pei cent of the dis
tance.
Now, since there is strong indication of
some kind of molten interior, is there any
corroborative evidence OF such condition?
EARTHQUAKES AND VOLCANOES.
There are occasional Earrings or shakings
that are difficult to reconcile with the theory
OF a solid interior, but which are readily ex-
plainable on the assumption that the earth
is only solid shell with plastic or igneous
interior. These Earrings. which are known
as earthquakes, have some connection with
the volcanic openings, as they are generally
affected when earthquakes occur and their
activity is often IremonitiOn of vibrations
Of some kind. Now, if the earth's interior
be really molten OF gaseous, and if these be
vents through which any molten or gaseous
substance is thrown in considerable uuanti-
fiaS what Qffact Wnn1t
long continued, have on the surfacep
Simply that of subsistence to the precise
measure of the matter emitted from the in
terror. Then what? As the she'll is cold,
is of immense thickness, of great weight and
lateral firmness, as it has to gradually ac-
commodate itself to slightly smaller
sphere, it follows inevitably that this shell
must exhibit bulges or wrinkles on its sur
face, and if such result is TO follow such
condition we may conclude that mountain
ranges are thus formed, being such bulges
or wrinkles.
FACTS AND THE THEORY.
But, is there any evidence of erupted mat
ter anywhere in sufficient quantities 10 lend
plausibility to the view that the wrinkles
known as mountains are the measure of
such subsistence? Yes; the Hawaiian group
of islands in the South Pacific Ocean affords
a striking instance of the immense volume
of solid matter that may be expelled bv vol
canc action. These islands are wholly vol
canic, rise up where the water is $1,000 feet
deep and the peak of Mauna Loa is still
1900 feet above the water level, so that
here is an instance of $1,000 feet of perpen-
dicular upheaval, or nearly six miles. When
1t is considered that the bases of these
islands are all continent, some idea may be
derived Of their quantity of matter, which
does not include any estimate of the
merely gaseous or volatile portion of the
outpour.
This theory would demand eruptive and
shaking phenomena over the water areas,
and these we also find, though they are not
so apparent as on the land. Tremendous
volumes of matter may pour forth and
spread over the ocean floor, where the
depth is great, without any commotion on
the surface. But tidal waves and many
other marine phenomena can thus be read
lily accounted for.
is THE CENTER A VACUUM?
Now, as regards the problem of pressure
Mt the center OF the earth: Has any one
demonstrated that grayitatiOn extends its
full force to the center? Is there any like
lihood that the maximum of pressure may
be found some distance this side of the CEN
ter? Is there anything to cause US to sus-
pect that there may be simply nothing at
attraction where there is nothing to attract?
There is fairly conclusive evidence that
ring forms of matter may occur in the pro-
cesSes of nature. May hollow shell, then.
form in somewhat analogous manner, and
would such form of material be lust as eco.
nomic?
Ii we conceive OF mass of incandescent
matter whrlng for millions of years, will
there be tendency for the matter to move
toward the surface, and will such movement
create central vacuum? But this is too
big question for this article