Considered as a system, the rings are distinctly more luminous than the planet, and of the two bright rings, the inner one is brighter than the outer one; and the inner one is less bright at its inner edge than elsewhere. It is also to be noticed that when seen edgeways just about the time of the Saturnian equinoxes, when the Sun is shifting over from one side of the ring to the other, and the ring is dwindling down to a narrow streak, its edges (forming the _ansæ_ as they are termed) do not disappear and reappear at the same time, and are not always of the same apparent extent. One ansa, indeed, is sometimes visible without the other, and most commonly it is the Eastern one that is missing. To what causes these various peculiarities are due is unknown. Many physical peculiarities have been either noticed or suspected with reference to the bright rings. For instance, on comparing one with another, some persons have thought that their surfaces are convex, and that they do not lie in the same plane. The existence of mountains on their surface has more than once been suspected. Again, it has been fancied that they are surrounded by an extensive atmosphere. It seems hardly likely that the rings would have an atmosphere and not the ball (or _vice versâ_), and, therefore, no wonder that we have no observations which countenance the idea that the ball does really possess an atmosphere. This, indeed, seems to flow from Trouvelot’s observation, that the ball is less luminous at its circumference than at its centre. The circumstances of ring C, otherwise called the “Dusky” or “Crape” ring are as curious historically, as they are mysterious physically. In 1838, Galle of Breslau, noticed what he thought to be a gradual shading off of the interior bright ring towards the ball. Though he published a statement of what he saw, the matter seems to have attracted little or no notice. In 1850, G. P. Bond in America perceived something luminous between the ring and the ball, and after repeated observations in concert with his father, came to the conclusion that the luminous appearance which he saw, was neither less nor more than an independent and imperfectly illuminated ring lying within the old rings and concentric with them. Before, however, tidings of Bond’s discovery reached England, but a few days after the discovery in point of actual date, Dawes suddenly noticed one evening as Bond had done, a luminous shading within the bright rings, which he was not long in finding out to be in reality a complete ring, except so far that a portion of it was of course hidden from view behind the ball. He, and O. Struve likewise, noticed that this new Dusky Ring was occasionally to be seen divided into two or more rings. The Dusky Ring is transparent, though this fact was not ascertained until 1852, or two years after Bond’s discovery of the ring.