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

SATURN, IN THREE POSITIONS.
The SMALL CIRCLE REPRESENTS THE COMPARATIVE SIZE OF
THE EARTH.
From a lantern slide II. the collection Of II, Columbia
College Observatory.
astronomers has done its best to explain more
fully the marvellous features of this ringed
system. The stream of discovery has thus
flowed onward continually. Indeed, n very i'm
important step has been made only quite re-
Gently In illustration of the ultimate texture
of the ring.
After the achievement of Huyghens. the
next great advance In our knowledge of the
Saturnian system Is due to J. E. ID. Cassini,
who discovered the now we'll dark
line of division which marks the ring into two
regions, namely, the inner ring and the outer
ring. The existence Of this important feature
was announced In 1878. No doubt Is now
entertained that this dark line Is not merely
a mark, but that II is a veritable separation Of
the ring into two distinct portions. Up tu the
present. however, II does not seem to have
been quite demonstrated that II is possible to
see clearly through the line OF Cassini. There
would be only one really satisfactory method
of testing the question as to the dark mark be-
ing actually q void space. but the opportunity
for putting this test into practice does not as
yet appear to have arisen. As Saturn moves
across the heavens II must occasionally pas
between the earth and certain of the fixed
Fbnics ~ ~ ohcuIt c " iiNlptl Una IN DlhleU
passed over a sufficiently bright star. it would
DO extremely interesting to observe whether
the star could be discerned through the dark
line. II that line were really an actual open.
ing, as we have good reason to believe. the star
should be seen shining with undiminished
brilliance through the narrcw aperture.
Besides this division SO well known to every
observer, there is another much fainter line
which marks the outer ring into two nearly
--..
the extremitles most remote from the planet.
Evidently in this case there Is not a complete
division through the substance of the ring.
There can also be no doubt that under circum.
stances exceptionally favorable for observation
many other divisions are to be discerned In
both rings besides those more prominent ones
which we have here mentioned. In fact.
glimpses of Saturn have been occasionally OBJ.
tained which seem to show the rings divided
into a series of ribbons of bright material sep.
Arated by narrow dark lanes. No doubt such
a theory OF ring formation can hardly be re.
garded as thoroughly we'll established; at the
same time It must be observed that what we
certainly know rs TO the structure Of the ring,
and this Is q point which will be dealt with
presently, leads us to tho belief that some such
subdivision OF the broad Hat rings into multi
tubes of narrow concentric rings is possible.
One reason why cur knowledge of the
features or Saturn and its rings has been gath
ered so slowly Is connected with the long
period required by this planet to accomplish a
revolution around the run. Saturn takes no
less than thirty wears for each of these great
Journeys. As there are only particular parts
Hf lis orbit in which certain Of the phenomena
can be studied 20 advantage. II necessarily fol.
lows ths much time may often have TO elapse
in the complete calculation Of any particular
point, Thus. for instance, on the question of
visibility through tho dark lines there Is a GER.
tain position In which the planet is some.
times placed which might throw much light on
the matter. II will occasionally happen In tho
course Of Saturn's movement around the sun
that the plane OF the ring passes between the
earth and the sun. In such q case II would not
be the sun-illumined side which would then
DO turned toward the earth. as Is generally
tho case. The face on which the sun does not
shine would he that which was then exposed
10 our inspection. Such an occurrence would
AFFORD a very interesting object for those who
arc provided with good telescopes So slo Wy
docs the planet move, however, that we must
wait until the year 1907 before the necessary
opportunity arises.
A very remarkable extension was given TO
our knowledge of the planet In 1850, Up To
that timo II had been supposed that the rInRed
system consisted simply OF the two well-known
bright objects divided by the conspicuous line
OF Cassini. But in the year We have named.
Prof. Bond, tho distinguished astronomer OF
Harvard College Observatory, Cambridge,
Mass, made an announcement which r.veted
tho attention OF the astronomical world. lie an
nOuncsd that besides the two well. known rings
there was yet another which had eludrd the
penstrsGon e All previous Gsu Onon ere. IhIs