Royal Astronomical Society. ,^ ^ ^tQ 5 1 9 



which is the mean west declination at St. Helena for the pre- 

 sent year \S^9. 



Mr. Glaisher, of Greenwich Observatory, kindly informs 

 me, that "a/ St. Helena^ IS^S, it was 23° 32' W., dectrasing 

 8' yearly." 



Hence in 1849 it would have decreased about 32', leaving 

 the declination about 23° W., which is only 8' more than our 

 computation. Even this would probably diminish, if not en- 

 tirely vanish, could we obtain the mean declination for the 

 present year. 



Manchester, Nov. 23, 1849. 



LXIV. Pj'oceedi7igs of Learned Societies. 



ROYAL ASTRONOMICAL SOCIETY. 



[Continued from p. 391.] 



Nov. 9, A PPEARANCE of Saturn's Ring, &c, in the Equatoreal 

 1849. ■^ of Cambridge, United States. By Professor Bond. 



" During the period of the disappearance of Saturn's ring in 1848, 

 we often noticed breaks or inequalities in the ring, such as would 

 arise from irregularities in its structure, were the matter of which it 

 is composed unequally distributed in its different parts. 



" Something of this kind has often before been observed, but 

 hitherto only on the illuminated side of the ring. That similar ap- 

 pearances present themselves also on the unilluminated side is a new 

 feature, important in its bearing on the true explanation of these 

 phaenomena, 



" From June to September 1848 the light reflected from the edge 

 of the ring (the only part then visible), instead of being uniformly 

 distributed over a single line, was interrupted on each side of the 

 planet by spaces of some seconds in breadth, where it was barely 

 possible to trace the continuity of the edge. These inequalities were 

 sufficiently abrupt to render it difficult to distinguish at first sight 

 between them and the somewhat similar effects produced by either 

 of the small satellites being projected upon the ring ; their presence 

 could only be detected by their motion, of which the indications were 

 usually decisive in 15 or 20 minutes. On the other hand, the ir- 

 regularities of the ring always retained one fixed position with re- 

 ference to the ball, as long as the earth remained elevated above the 

 southern unilluminated surface. 



" The same appearances were again presented between September 

 and January 1849, while the earth was elevated above the northern 

 unilluminated surface, in all this time retaining one fixed position with 

 respect to the ball. 



" It is an unavoidable inference from our observations that these 

 breaks in the illumination of the edge do not rotate about the globe 

 of Saturn ; a result perfectly in accordance with what Schroeter has 

 established with regard to the corresponding irregularities on the 

 illuminated side. 



