142 The Planet Saturn. 



picturesque and "beautiful than straight ones. We cannot 

 conclude our notice upon this able report without one more 

 quotation from it, and bestowing our sincerest congratulations 

 to the Commissioners of Sewers for the City of London upon 

 possessing so accomplished and efficient an officer in the 

 Surveyor and Engineer : — 



" That looking to the future as well as the present necessi- 

 ties, and having regard to the fact that the cost of present 

 improvements will probably be in a degree cast upon a future 

 generation, they should be planned and carried out upon the 

 broadest and most comprehensive scale, that no obstacle should 

 be allowed to interfere with this principle; and that such 

 course is true economy. 



" It should be held in mind that where the need for public 

 improvements arises from the increase in the numbers, 

 business, and wealth of the population, it may generally be 

 inferred that the population is able to pay for them.'" 



THE PLANET SATURN. 



(continued.) 

 BY THE EEV. T. W. WEBB, A.M., F.K.A.S. 



In our last No. attention was drawn to the insufficiency of the 

 evidence by which the period of rotation of the ring has 

 hitherto been considered to be determined. It will be at 

 once understood, that no idea is entertained of throwing doubt 

 upon the fact of rotation. The reader is in possession of 

 the means of showing the insufficiency of the objections of 

 Schroter, Schumacher, and Schwabe ; and if such a motion 

 is not a necessary condition of equilibrium, it would be 

 entirely beyond the power of the writer to show it to be 

 otherwise.* What has been said amounts merely to this, 

 that the period must still be considered as unascertained, 

 so far as observation is concerned : even its theoretical value 

 is rather uncertain, for Secchi has given 14 - 238 hours as 

 the period of a satellite revolving a little within the external 

 ring, A. One thing is evident, that it must differ, theoreti- 



* There are some curious observations by De-Vico which are worthy of 

 mention. On several successive nights in 1840, an extremely minute point of 

 li^lit, like one of the smallest satellites, was seen in the E. ansa, immovably 

 attached lo the edge of the ring (B), then widely open. A similarly -situated 

 pretty bright point was again seen 1842, Oct. 17, Ball's alone among the divisions 

 being visible, but that very distinct. It is diilicult to explain Has in connection 

 with rotation. 



