The sun. [volume] (New York [N.Y.]) 1833-1916, 1896-05-17

mir, ring extended from the lnpermost mar
Gin OF the two older rims. half way towart
the globe Of the planet. Prof. Bond was not
howe We destined to enjoy the entire glory 0
this discovery. This new Saturnian feature
WIS simultaneously discovered by an accom-
pllshed English astronomer. Mr.. Dawes. Th'
first comment that Ia apt 10 be made on hear
Ing of the existence Of this new ring Ia Va cN'
press surprise that II hal never been 1iscov'
cred before. This Is not due 10 the fact that
the ring Is not large enough. nor that II does
not occupy n sufficiently conspicuous position
The reason why this new object had escaped
the attention of all preceding astronomers. hot
wlthstar ding that they had observed saturn
40 many hundreds Of times, Is to he found In
tho peculiar character of the new structure.
II IL certainly true TINT the outer rings must
not I've regarded rs solid objects. they are MT
even liquids, but vet they seem uuite solid nb-
Jccts In comparison to the extraordinarily dell
cate feature whicl. was revealed to the pene-
trnting search Of Prof. Bond and Mr.. Dawes.
This new ring has not the brightness OF the
other rings; indeed It's peculiar appearance
Is sufficiently defined I'm the term Grape ring"
ny wbish IL Is generally known. 1t possesses
n semi. transparency resembling that Of Grape.
and this makes Il so faint In comparison
with the brilliant rings and the brilliant globe
Of tho planet that Il had long escaped atten-
ton. with the good telescopes now generally
distributed. II II quite easy to see the craze
ring, and astronomers have come TO regard
II ms n familiar object. II has been sometimes
supposed that changes are In actual progress
in the structure of the APPENDICES of saturn.
and that these changes are of vast magnitude
and proceed with vast rapldity. And II has
been thought that in consequence of these
changes the Grape ring has assumed In these
days a more conspicuous character than 1T
formerly possessed. An attempt has thus
been made to account for the fact that the
Grape ring eluded the penetration of an oh.
server so skilful rs William lerschcl. who
devoted much care. with exquisite and power
full instruments. to the observation OF Saturn.
But I do not think that this affords any ground
for the belief that changes OF apprcciable mag
litude are going forward In the Saturnian sys-
tem. II Is we'll known that after an astro-
nomical object has been discovered, it may then
frequently be seen by an instrument Of greatly
inferior power to that employed In making
the discovery. for when an observer knows
exactly what he has to look for. his chances of
seeing IL become materially increased. This
fact. taken in conjunction with the present
abundance of excellent telescopes. will quite
suffice to explain how 1t comes that the Grape
ring is now so frequently observed, notwith-
Nhu'Aiii IL NV tAiet ~ Nh'ao 49,
up to the year 1850.
AS to the features on the globe of Saturn,
which lies poised in the centre OF the rings,
there is not very much to be said. The astro-
nomical artist who finds such scope for his
pencil in depicting the seas and the conti-
nents, the fee caps or the canals on Mars. sees
little comparatively that he can draw on the
mighty Saturnian ball. No doubt certain belts
or zones are sometimes to be discerned with
moro or less distinctness upon the globe OF
the planet. but they are. even at the best.
only very family marked. One thing is
pc rfectly certain. namely. that Saturn pre-
sents to the observer no indications whatever
of the presence of any permanent features.
1t seems as certain as anything can be with
respect to a globe which is distant from us by
S44, 900, 900 miles, that Saturn as we see 1t IS
not a solid object. What we look at Is
plainly n surface of clouds and vapors so thick
and so dense that our vision has never been
able to penetrate through them toa depth
sufficient to show whether or not there is any
solid interior to Saturn. There cannot be a
doubt that the stupendous envelope of clouds
and vapors which Saturn renders
the physical condition Of that globe totally
in every way from the physical con-
dltions OF such a globe as our earth or as Mars.
There IL also another line of reasoning by which
we can convince ourselves of the fact that the
globe of the ringed planet has been greatly
by volumes of clouds and vapors. by
observations on the moons with which
is attended. II Is possible to determine
the weight of the central orb by whose attrac-
tive power the movements Of the moons are
controlled. The diameter of the planet has
also been measured. and Its volume has thus
been ascertained, and from knowing these
we are able to learn the density Of the
of Saturn. rs compared with those
of other globes, such. for example. as our
earth. 1t is known that this globe of ours is
between five and six times the weight of a globe
OF water of the same size. This has been the
result derived from very careful experiment
In observation. 1t Is, however. easy to per-
GIVE by a little general reasoning that some
conclusion as that we have Just stated
would be extremely probable. For the rocks
which compose the earth's crust are between
and three times rs heavy. bulk for
bulk, as water, while iron, which enters with
out doubt very largely into the constitution
of the earth. is rather more than seven times
as heavy as water.
Common sense would thus seem TO show that
the earth as a whole must be heavier than a
globe of stone the same size. while not so heavy
as a globe Of iron the same size. Hence we
might have anticipated that our globe should
be. as experiment has shown it to be. about
five or six times as heavy as n globe OF water
OF equal bulk. The specially remarkable cir
with regard to the globe of Saturn
is that the materials of which 1t Is made are
very much lighter than the materials Of the
earth. The planet is so vast that II would
GOO globes as large as our earth agglom-
Grated into one to be equal in volume TO the
ball OF Saturn. If this celestial body had been
In the same manner AS our earth
IS constituted, 1t might therefore be reason
ably expected that the weight OF the rinred
planet would be In like proportion to its bulk,
Is TO say. about 600 times as heavy as the
earth. AS a matter OF fact 1t is nothing of the
kind. Saturn does not weigh 100 times ns
much as the earth. There is here n wide dis
crepancy The materials of the great planet
must be, on the whole, far lighter than thos.
of which the earth is built. Our earth. though
not so heavy as an equally large ball Of iron,
Is yet far heavier than an equally large ball OF
stone. saturn. on the other hand, is lighter
than ITS own bulk of water. a globe equally
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