ON THE RINGS OF SATURN. 121 



an accumulation of disturbances, of which the absence of inequalities lessens the proba- 

 bility, bring the rings together, the velocities at the point of contact will be very nearly 

 equal, and the two will coalesce without disastrous consequences. 



If in its normal condition the ring has but one division, as is commonly seen, under 

 peculiar circumstances it might be anticipated that the preservation of their equilibrium 

 would require a separation in some regions of either the inner or outer ring ; this would 

 explain the fact of occasional subdivisions being seen. Their being visible for but a short 

 time, and then disappearing, to the most powerful telescopes, is accounted for by the re- 

 moval of the sources of disturbance, when the parts thrown off would reunite. 



Finally, for a fluid ring, symmetrical in its dimensions, there is not the same neces- 

 sity for a state of unstable equilibrium, with reference either to Saturn or to the other 

 rings, which obtains in the case of a rigid coherence of its particles. 



VOL. V. NEW SERIES. 18 



