The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-05-17

ern Telescope.
body has but slowly parted with its
heat. and consequently still retains vast
stores in comparison with the present
state of the Earth. 1t would thus seem
that in the present condition of the
globe Saturn. we have a picture of
what our earth may once have been
like 1t also seems probable that, as i'll
the course of ages Saturn gradually
parts with its heat, a time will at
length come when the water at pres
ent in the clouds which surround 1t,
will be collected into oceans on its sur
face.
Though it seems almost certain that
Saturn is a highly heated globe, yet it
is 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. II is
for example demonstrated in an inter
esting manner by the fact that the
globe of Saturn appears quite black
where the shadow Of the ring is cast
upon it. This, of course, would not
have been the case if the globe had re-
tanned any of its original luminosity.
THE CHARACTER OF sATURN'S
The phenomena of Saturn and his
system presents problems of the deep
est interest TO astronomers of every
class. Especially as the structure of
the ring given rise to questions which
have taxed alike the highest powers
of the observing astronomer and of
the accomplished mathematician. The
mechanical character of the ring
might at the first glance appear to be
a comparatively simple matter. 1t
might be thought that each of the two
bright rings was a broad, thin belt of
some solid material, but after little
reflection mechanical difficulty of the
GraveSt chara cter will be seen to pre-
sent itself. For think of the two
halves of which each ring is COM
posed. Each such half is a stupen-
dous arch, an arch which has to with
stand the attraction of the ponderous
globe in the center. 1t is not difficult
to calculate The strain which the ma
terials of an arch of more than 600
miles span would be subjected. Engi-
neers are well accustomed to the no.
ton that it is impossible for them to
erect an arch which has a span beyond
a certain limit. That limit is dictated
by the circumstance that the pressure
upon the stones or other materials of
which the arch is built, increases
with every increase of the span. Con-
sequently a point would be sometimes
reached when the pressure to which
the stones are subjected is so great
that any further increase in span
would be attended with the danger
that the structure would collapse with
its own weight This considerat ton
defines the limit of the arch which
would be constructed out of terrestrial
materials. We can calculate the pres
sure that would have to be withstood
by the materials in an arch such as
that made by one-half of Saturns
ring. 1t is quite easy to prove that
this pressure would be so great that
even if the materials were many thou
sands of times tougher than the
toughest steel, or any other known
substance, it would be utterly impos-
sibe for the ring to resist the tendency
to collapse. No doubt the strain on
the structure would be somewhat
nghtened by the fact that the ring is
spinning round rapidly. The centrifu
gal force thence arising must to a
certain extent neutraliZe the effect of
the attraction of the planet. The cir
cumstance, though it may lessen, yet
it does not remove the difficulty, for
the ring has very considerable width.
If the centrifugal force were so adjust
ed as to neutralize the strains in the
middle portion of the ring, it would be
too great for the inner portion while
it would not be great enough for the
outer portion. Looked at in whatever
way we please, it would seem quite
impossible, on mechanical principles,
that each ring of Saturn would be
composed of a thin belt of solid ma
terial
The explanation of the character of
this curious structure was first given
by the late Professor j Clark Max
well. He conducted this memorable
research by means of that instrument
which is often more subtle than the
telescope of the astronomer. l mean
the pen of the mathematician He
thus showed that the rings of Saturn
must be composed of myriads of little
objects, each so minute that it is quite
impossible for US to see it separately,
at its present distance from the Earth.
These little objects are, however, in
such incalculable myriads, and they
lie so close together, that we can see
the mighty shoals which they form,
though we are not able to discriminate
the individual members. By this sup
position the difficulty as to the me-
chanical condition of Saturn's rings
has been found TO disappear. Each of
the little particles may be regarded as
Moon or satellite in attendance on
the great planet. Each such moon re-
wolves around the central globe pur-
suing its own track in complete in
dependence of the movements of its
neighbors, everv one of which is also
guided and held in its course by the
supreme controlling power of the
mighty Saturnian mass
And now we are able to understand
what would seem otherwise inexplica-
BILE, and that is the exquisite structure
of the Grape ring. For it is character
istic of this most extraordinary fea-
ture in the solar system that it is semi
transparent; in fact under certain cir
cumstances the globe of the planet can
be seen right through the Grape ring,
though this ring, like the two bright
rings, is said to be quite thin, yet we
must remember that the thinness is of
a relative description. 1t is thin rela-
lively to it's breadth or to the gigantic
size of the planet, but measured in
more familiar standards, the rings are
doubtless hundreds of miles in thick
ness. Here then we have a structure
of membrane, or whatever we may call
it, hundreds of miles in thickness
which nevertheless is sufficiently trans