Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1918-08-30

%If the ball travelling through the
earth had eyes and a more leasurely
journey. what would it see?"-Harry
-. Young. Chicago.
T.his refers to an article of mine
about the dropping of a ball through
. hole supposed to be bored diam
SrVically through the earth's center.
Excluding the effect of air resis-
tance and of the earth's relation, and
other disturbing elements of the
problem. I showed that the ball
would drop to the center in about
twenty-five minutes. then rise in the
same time to the opposite surface,
then return to the starting point.
fro through the earth like a pendu-
lum bob.
I may here add the curious fact
that, assuming the earth to be hon.
oSeneous. the time required would
be the same whether the ball started
from the earth's surface or from
any point within the earth, however
close to the center.
AS to what the ball or a suppo-
see on its journey, only more or
less probable assertions can be made
because our knowledge of the state
of things prevailing in the interior
of the arth is still very imperfect
and uncertain. There are four or
five different theories on the sub
iect, no one of which may represent
the actual facts. We know more about
t. Irface of the Moon. or even of
SLf "er. than we do about the in
sioe Of tie earth. because. we can
re-, though we cannot reach, the
foi me-, while we can neither see
nor reach the latter.
OF course, we do know by inspec-
ton, and by pretty certain inference.
a good deal about the upper layers
of the earths crust. but after all,
this knowledge relates only to a
kind of epidermis.
The deepest mine in existance
goes down less than a four-thou-
sandth of the distance from the
surface 10 the center of the earth
and even the deepest boring pene-
trates only 1880 of that distance
and is but little over two inches
diameter at the bottom.
1t used to be generally believd
that below 2 depth OF twenty or thir-
ty miles the earth was composed of
molten liquid rock. This was based
on the fact that, as we go down,
the temperature increases about a
degree Fahrenheit for every sixty
feet of descent (the rate varying in
different localities): but for reasons
into which I cannot here enter. the
general opinion is that the inter-
for is rigid, even. perhaps. on the
average as rigid as steel, owing TO
the pressure, although the heat may
be great enough to liquify or even
TO vaporize all rocks and metal not
subjected to such pressure.
picturesque idea is that of the
swedish chemist. Arrehnius, who
thinks that the central core of the
earth about 5000 miles in diameter
is probably composed of iron in a
potentially gaseous condition. l. e,
so hot but for the pressure it would
flash into gas. Above this he depicts
shell about 500 miles thick of
rock substance in the same poten- /
tial gaseous state. then a stratum
about $50 miles thick of similar
substance in a white-hot hduid con-
dition, and finally theupper crust. |
not over 100 miles in average thick
ness on whos surface we COM
fortably dwell.
Let US assume that this scheme
represents substantially the real con-
dition OF the earth's interior, and
further that hole could be driven
straight through the entire mass
without producing any local effects
upon the state of the various LAYERS.
Then, as the ball started on its
Journey 1t would at first be passing
through what we might call the geo.
logical realm, consisting of broken
and pictured layers of rock that
like torn leaves contain the frag- !
mentary geological history of the
earth. If only the hole could be
bored along a diameter where the
successive leaves lay in true histor- I
zeal order, (if such thing were pos
lplel, the eyes in the decending ball /!
would behold the whole story of the |
development Of terrestrial life dis |
played in reverse, going back through
the aeons of time from man and
and MS contemporaries through the
great Neozoic, Cainozoic Mesozoic
and Paleozoic eras to the dark Azoic |
when no life had yet appeared.
Starting from the wall of the
tube through which the ball dropped |
WouIo appear in succession the skele- /
tons OF prehistoric men, of primal
men, of ape men, of man apes. of !
the mysterious common ancestor of
the primates and the anthropoids
and after that only OF simple brlltes' |
physlcaI giants. many of them |
fighter, destroycrs. mere living me-
cnines' with no foregleam of intel |