ish in May of that year. No doubt, with our modern
calculations founded on long-continued and accurate observation, we are
now enabled to make forecasts as to the appearance or the disappearance
of Saturn's ring with far greater accuracy; but, remembering the early
stage in the history of the planet at which the prediction of Huyghens
was made, we must regard its fulfilment as quite sufficient, and as
confirming in a satisfactory manner the theory of Saturn and his ring.

The ring of Saturn having thus been thoroughly established as a fact in
celestial architecture, each generation of astronomers has laboured to
find out more and more of its marvellous features. In the frontispiece
(Plate I.) we have a view of the planet as seen at the Harvard College
Observatory, U.S.A., between July 28th and October 20th, 1872. It has
been drawn by the skilful astronomer and artist--Mr. L. Trouvelot--and
gives a faithful and beautiful representation of this unique object.

Fig. 64 is a drawing of the same object taken on July 2nd, 1894, by
Prof. E.E. Barnard, at the Lick Observatory.

The next great discovery in the Saturnian system after those of Huyghens
showed that the ring surrounding the planet was marked by a dark
concentric line, which divided it into two parts--the outer being
narrower than the inner. This line was first seen by J.D. Cassini, when
Saturn emerged from the rays of the sun in 1675. That this black line
is not merely a black mark on the ring, but that it is actually a
separation, was rendered very probable by the researches of Maraldi in
1715, followed many years later by those of Sir William Herschel, who,
with that thoroughness which was a marked characteristic of the man,
made a minute and scrupulous examination of Saturn. Night after night he
followed it for hours with his exquisite instruments, and considerably
added to our knowledge of the planet and his system.

Herschel devoted very particular attention to the examination of the
line dividing the ring. He saw that the colour of this line was not to
be distinguished from the colour of the space intermediate between the
globe and the ring. He observed it for ten years on the northern face of
the ring, and during that time it continued to present the same breadth
and colour and sharpness of outline. He was then fortunate enough to
observe the southern side of the ring. There again could the black line
be seen, corresponding both in appearance and in positio