Adverting to fig. 16, it will suffice to remark that the two central phases of the rings, opened wide, are to be deemed co-related, or indeed identical in a geometrical sense (so to speak) the difference being that one of them is to be deemed to show the northern side of the ring (which is now in view and will continue in view till 1907) whilst the other represents the southern side, which was in view from 1877 till 1891. The foregoing is a brief statement of the general principle involved in the changes which take place, but the motions of the two planets introduce certain technical complications into the details which would be seen by an observer using a large telescope; with these, however, the ordinary reader will not care to concern himself, and need not do so.
A great deal might be said with respect to the rings treated descriptively. I will now mention a few matters of general interest. Huygens regarded the appendage to Saturn, whose existence he established, to be a single ring, but as far back as 1675, Cassini determined that Huygen’s single ring was really made up of two, one lying inside the other. Cassini in this conclusion outstepped not only all the observers of his own century, but those of the succeeding century, for Sir W. Herschel even 100 years after Cassini, was for a long time unable to satisfy himself, even with his superior telescopes, that the black streaks seen in the ring by Cassini, and regarded by him as indicative of a severance of the ring into two parts, really implied a severance. It is now, however, accepted as a fact that not only are the rings which are known as A and B absolutely distinct, but that A also is itself certainly duplex, that is, that it certainly consists of two independent rings. In addition to this many competent observers armed with powerful telescopes have obtained traces of other sub-divisions, both in A and B; and though there is some want of harmony in the details, as stated by the different observers, yet undoubtedly we must speak of Saturn’s rings collectively as forming a _multiple_ system.
What the rings are is a highly debatable point, but the preponderating idea is that they are not what they appear to be, namely solid masses of matter, but are swarms of independent fragments of matter. Yet “fragment” is not the best word to use, because it implies that something has been broken up to make the fragments. Rather, perhaps, we should say with Professor Young, that the rings are “composed of a swarm of separate particles, each a little independent moon pursuing its own path around the planet. The idea was suggested long ago, by J. Cassini in 1715, and by Wright in 1750, but was lost sight of until Bond revived it in connection with his discovery of the dusky ring. Professor Benjamin Pierce soon afterwards demonstrated that the rings could not be continuous solids; and Clerk Maxwell finally showed that they can be neither solid nor liquid sheets, but that all the known conditions would be answered by supposing them to consist of a flock of separate and independent bodies, moving in orbits nearly circular, and in one plane—in fact, a swarm of meteors.”