Clarke courier. [volume] (Berryville, Va.) 1869-1997, 1907-12-04
THEEARTH'S INTERIOR
Our Planets Core Is Liquid, Yet
It's as Rigid as Steel.
UNDER ENORMOUS PRESSURE
Neither Rock Nor Metal Could Remain
There In the State In Which We See
IL on tho Surface-The Lava That
Breaks Through the Earth's Crust.


The idea that the interior of the globe
Is composed OF flowing lava has long
since been abandoned. but the plcture
that modern science offers of the In
side OF the earth Is hardly less an
paliing. All Investigations unite to
prove that the heat increases as we de-
scend deeper In the terrestrial ernst
at such rate that forty or fifty miles
down no substance with which we are
acquainted could remain unmelted. And
yet the same science tells us that the
core OF the globe is enormously more
rigid than the hardest steel. This an
parent contradiction is due to the ire
mendous pressure inside the earth. No
rock and no metal can remain there i'm
the state In which we see IL on the sur
face Its molecules must lose the adj
herence Characteristic Of solid bodies
in consequence Of the heat. but still
they are not free TO flow like an ordi-
nary liquid. because OF the compression
TO which they are subjected.
The phenomena OF earthquakes have
given wonderful information about the
internal state OF the globe. All OBJ
servations show that the shocks Of
earthquakes are confined TO q thin up-
per she'll They originate at a depth
or only 4 few miles at the most But
the vibrations which they set going
are felt all through the earth. often ex-
tending to the antipodes. The great
core. held rigid by the pressure, is ex-
tremely elastic. and it responds to a
shock like n ball OF steel or of glass.
The density OF the earth increases, to-
ward the center. 1t is only in the up-
per part Of the crust that local move
ments can take place. causing shocks
and changes OF level at the surface.
Deeper down everything is gripped and
immovable. except. rs already re-
marked. that the molecules OF the rocks
ana metals there are subject TO yibra-
ton like those OF bell against which
blow Is struck
But this is not ALL Whenever n local
release from the pressure Is brought
about by changes near the surface the
potentially liquid but effectually solid
core Mt that point may suddenly be-
come fluid and gush forth through a
volcanic throat or other vent But
such effects cannot extend TO any great
depth Nothing comes to us from the
vast Interior mass. That remains a
perpetual mystery. far beyond the
searching hand OF science. Indirectly
however. we may learn much about il
Astronomical considerations throw a
great deal or light upon the subject
We see that through the planetary sys
tenn rotating globes are flattened ut the
poles. The same thing is true OF the
earth. Its equator bulges; its polar
regions are drawn inward. Mechan
ical laws assure us that the cause Is
10 be found in the fact that the earti
and the other planets have assumed
shape under the influence OF the cen
trifugal force OF their rotation. THAI
force is necessarily greatest ut the
equator. Beginning as completed mol
ten bodies. they have commenced to so
lidify Mt the surface after having as
sumed an ellitlordal form due TO theil
rotation.
Another very significant fact is tina
the shape OF the earth corresponds witt
that which globe rotating with IL.
velocity would have IL composed o
materials arranged to their density
that is TO say. growing denser toward
the center. The heaviest materials
must be deep down in the globe; tn,
| lighter materials have remained at tn,
surface This again corresponds witt
the facts OF observation. We know
the total weight. and the averac,
density OF the earth 1t weighs" 81,
sextillions OF tons, and its averag,
density is five and half times that o
water. But the substances cOmposin.
the crust of the earth have an averag,
density OF twice that OF water. 1
follows that the heaviest things in tn,
earth, on the average. exist deep with
In its exterior. For all that we cal
tell, its inner core may be wholly me
tallic. At the center there is probabl,
an enormous aggregation OF dense me
tallic substances.
An indication that the inner parts o.
the earth consist largely If not mainly
or iron Is TO be found In the mag
netism or the globe. The earth is
great permanent magnet. II we coulC
learn the facts it might turn out tina
iron is the most abundant substanc,
In the solar system and perhaps IL
the whole universe. The majority o
the meteorites that fall upon the eartl
consist OF solid iron. Blow the cart
to pieces and in the resulting clou,
OF fragments the rocks that we ar,
familiar With would be almost imper
ceptible. There would be rain O.
iron and other metals descending upoI
the moon and upon any other attract
Ing body in the vicinity.
This view OF the interior OF tn,
globe dispoSeS OF the notion, so pictur
eSquely developed in one Of julie:
Nerne's romanceS. of the existence Of
vast cavernous openings in the int
rior OF the earth. Such void spaces
though on no large scale, may exis
in the upper part OF the crust. but no
at 4 great depth. The earth is eff
fectively more solid than n cannon
ball. and the movable rocks compos
ing its crust are like n film Of rust or
the hard metal.-Professor Garrett T
SQrViSS I'm Nav XorH Ap,ow;co,