Omaha daily bee., 1896-05-17

and the physical state of the earth. We
know that the earth contains a vast store
Of heat In its interior and that consequently
1t must once have been hotter, much hotter,
at the surface than it is at present. For as
our globe Is certainly cooling down 1t Is
quite obvious that the further we look back
the hotter do we find our globe must have
been. Indeed, 1t seems impossible to doubt
that at some epoch excessively remote, even
from a geological point of view, there must
have been so much heat that the surface of
the earth was untitled to retain water eX-
cept in the form of steam. We are hence
led to look back to a phase in our earth's
history when the waters at present in the
oceans were in the form of mighty vapors
encompassing our globe. At this time our
earth, though no heavier than 1t Is at pres
ent, must have been enormously larger, and
an outside observer who had the means OF
comparing the bulk of our earth with its
weight would have come to the conclusion
that the density of our globe was compare
lively small. He would. in fact, have found
that the physical condition of our earth in
many respects resembled the physical condi-
ton which the planet Saturn has at present.
II it be. asked why our earth should have
passed through those stages of transforma-
ton by which it has changed from its
primeval condition down to the form In which
We now know it, while Saturn is still in
such an early stage of development, the
answer is no doubt to be found in the cir
eumstance that Saturn is a vast globe. while
our earth is comparatively a small one. We
need only call attention to the somewhat
trite fact that a small body cools down more
quickly than a large one. The earth and
Saturn. both highly heated in the begin
ming, have each been cooling down ever
since; the earth being comparatively small
has parted so freely with It's heat that II has
the form which we now know.
Saturn, on the other hand, being a very large
body, has slowly parted with Its heat, and,
consequently, still retains vast stores in COM
parison with the present state OF the earth.
1t would thus seem that In the present condi-
of the globe Of Saturn wa have a picture OF
what our earth may once have been like. 1t
also seems probale that, as In the course or
ages Saturn gradually parts with It's heat, a
time will at length come when the water at
in the clouds which surround 1t will
be collected into oceans on its surface.
Though It seems almost certain that
is a highly heated globe. yet It IA
not heated sufficiently to radiate forth light
OF its own: all the light which we receive
from thence Is merely reflected sunlight.
There is abundant proof of this In various
ways. 1t is for example demonstrated In an
interesting manner by the fact that the
globe of Saturn appears quite black where
the shadow Of the ring is cast upon II.
This, of course, would not have been the
case II the globe had retained any of it's
luminosity.
THE CHARACTER OF SATURN'S RINGS.
The phenomena of Saturn and his system
present problems of the deepest interest
% astronomers of every class. Especially
has the structure of the ring given rise to
questions which have taxed alike the high
est powers of the observing astronomer, ana
If the accomplished mathematician. The
mechanical character of the ring might at
he first glance appear 10 be a comparatively
simple matter. 1t might be thought that
Zach of the two bright rings was a broad
hin belt OF some solid material. but after
little reflection a mechanical difficulty OF
he gravest character will be seen to present
tself. For think OF the two halves or
alf is a stupendous arch, an arch which
las to Withstand the attraction OF the pom
erous globe in the center. 1t is not difi-
ult to calculate the strain TO which the
OF an arch OF more than 100 900
lilies span would be subjected. Engineers
re well accustomed to the notion that Il IL
for them to erect an arch which )
as a span beyond a certain limit. That