The Ohio Democrat. (Logan, O. [Ohio]) 1886-1906, 1889-06-29
The RINGS oE SATURN.
Prof Darwin Explains How They Are
Viewed by Science To-day.

Viewed by Science To-day.
1t has been shown by several lines o.
investigation that Saturn's rings consist
of Independent meteorites, moving,
each in its orbit, about the planet, and
this conclusion may be safely accepted
as correct. But every field Of though,
is now seething with the evolutionary
ferment, and as we can not rest salts
fed with any conclusion as o finality,
we here merely find ourselves at the
starting point of new speculations.
What, then, is the history OF these
rings, and what their future fateP
They are clearly intimately related to
the planet, and their history would be
complete If we could with the mind 8
eye watch their birth from the planet
and follow their subsequent changes.
Now although the details of such his
tory are obscure, yet at least shadowy
outline of it may be confidently &C
cepted as known.
In the remote past all the matter
which now forms the Saturnian system
of planet, satellites and rings was far
more diffused than at present. There
was probably nucleus of denser mat
ter round which slowly revolved mass
of rarefied gases and meteorites. The
central portion was intensely hot, with
heat derived by condensation from a
state of still greater dispersion.
AS this nebula cooled it contracted,
and therefore revolved more quickly.
If you watch the water emptying itself
from common wash hand basin when
the plug at the bottom is removed, you
will see an example of such quickened
rotation. When the basin is full, the
water is commonly revolving slowly in
level falls and the water approaches
the hole, it spins more quickly, and the
last drops are seen to whirl around
with violence.
The revolving nebula is fattened at
the poles like an orange, and the
amount of hattening increases as it
contracts and spins quicker. AT GER
tain stage it can no longer subsist in
continuous mass, and an annular portion
is detached from the equator, leaving
the central ball to continue its contrac-
ton.
We are pretty safe in saying that
the rings of Saturn took their origin in
some such mode as this. But it can
not be maintained that we understand
it all, for we have not more than a
vague picture of the primitive nebula,
and the mode in which the matter aggre-
gated itself into ring and detached it.
selfis obscure. NJ. Roche has done per-
haps more than any one else to impart
mathematical precision to these ideas,
but even he has not been wholly sue
cessful.
This theory, commonly called the
nebular hypothesis, was advanced in
dependently both by the philosopher
Kant and by Laplace. Various mod
itiications have been suggested by 9th
ers, but the theory, in whatever form,
is replete with difficulties, and must at
present be only regarded as an ap-
Proclamation TO the truth.
If the past history of the ring is not
wholly clear, it is at least more ascer-
tainable than its future development.
1t is nearly certain that the ring now
presents markedly different appear
ance from that which was seen by its
discoveries. Indeed the only doubt
lies in the uncertainty as TO the amount
difference of observers and of instru-
ments. Huygens described the inter
val between the bright ring and the
planet as rather exceeding the width OF
the ring, but this is now hagrantly in
correct. 1t is improbable that Huy-
gems was incorrect, although, on the
other hand, by the most delicate micro
metric measurements Struve has been
unable to detect any change in an in.
terval of thirty years of this century.
We may call to mind that Maxwell
showed that spreading of the rings
both outward and inward was a thoret-
ical result of the inevitable impacts be-
tween the constituent meteorites,
which he used TO describe as shower
of brickbats. Thus, whether or not
the immense changes suspected since
1869 are true, it remains almost certain
that changes Of this kind are in prog
resS.
/ venture, then, to hazard few
words of speculation as to the future OF
the rings. The outward spreading
will in time carry many meteorites be-
yond Roche's limit; here there will no
longer be an obstacle to aggregation
into celestial body, such aggregation
will probably ensue. and ninth satel-
lite will be formed. The inward
spreading will in time carry the me.
teorites to the limits of Saturn's atmos-
phere, where, heated by friction as
they rush through the air. they will
and fall on to the planet as
dust. After time, of which no esti-
mate can be formed, the ring will have
vanished, leaving the ninth satellite
as its descendant. But it must be ad-
mitted that all this is highly specula-
tive, and we can only hope that further
will give US frmer
grounds for a forecast. Prof. George
Howard Darwin, in Harper's Magazine.
A Gain and Yet a DANCE r.