state of unstable equilibrium in reference to the body of the planet.
These difficulties, along with new observations, led to the idea that the rings were all fluid. The concentric structure seemed to change; divisions, seen plainly at one time, were not seen at another; and this was so frequently noticed, that the inference seemed natural, that there was a real fluctuation in the divisions of the fluid system. The idea of fluidity was certainly an advance, as it allowed each portion of the system to assume its appropriate period of rotation. A slow ring was not yoked to a fast one. The idea of fluidity has, however, given way to one which more naturally explains the phenomena, and brings this part of the solar system into harmony with other parts. The theory in question is, that the rings are composed of meteoric matter, each particle moving as an independent planet in its own orbit. It is not at all necessary to suppose that the particles are very minute. There may be meteorites of considerable dimensions, but, at the distance of the earth, they can appear only as a continuous mass. The rings of Saturn would thus correspond to the zones of meteoric bodies and asteroids encircling the sun.
A remarkable confirmation of this theory is afforded by the history of the rings. Saturn, above all the other planets, is full of interest, in this respect, that it furnishes proof of great organic changes. It
