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98 G, P. Bo7id on the Rings of Saturn, 



saw two or three divisions outside of the center of the ring; a 

 figure is given in Lalande's Astronomy. In June, 1780, Sir W^ 

 Herschel noticed, on four different nights, a division near the in- 

 ner edge. From its never, either previously or subsequently, 

 having been seen by him, it is probable that the subdivisions are 

 not permanent; otherwise they could scarcely have escaped de- 

 tection under the scrutiny to which he subjected every thing 

 appertaining to the system of Saturn for thirty or forty years. 

 This inner division is figured and described in the Philosophical 

 Transactions for 1792. In Gruithuisen's Astron. Jahrbiich, for 

 1840, pp. 103-105, mention is made of lines seen on both 

 rings in 1813 and 1814. Quetelet, at Paris, with an achro- 

 matic of ten inches' aperture, saw the outer ring divided in De- 

 cember, 1823. 



On the 17th of December, 1825, and on the 16th and 17th of 

 January, 1826, at least three divisions were seen on the outer 

 ring by Captain Kater. A full accountj illustrated with engrav- 



mgs, 



Memou' 



the Royal Astronomical Society. This contains also a collection 

 of the accounts of previous observers. Two reflectors of the 

 Newtonian form were used, of between six and seven inches' 

 aperture. 



At Berlin, on the 25th of April, 1837, the outer ring was seen 

 by Professor Encke, with perfect distinctness, divided into two 

 nearly equal parts, and several divisions were recognized on the 

 inner edge of the inner ring. The great equatorial of the Berlin 

 Observatory was used with an achromatic eyepiece. 



On the 28th of May, the place of the outer secondary interval 

 was determined. The great optical capacity of the telescope, 

 and the eminence of Professor Encke as an observer, give the 

 highest value to these observations. They are found in the 

 Asir, Nachr,^ No. 338. No. 357 of the same volume has a no- 

 tice of several divisions on both rings, seen by De Vico. at Rome, 

 with the equatorial of the Roman College, the object-glass of six 

 inches, by Cauchoix, A letter from M. Decuppis, Comptes Ren- 

 dnSj vol. vii, gives a description of several divisions seen at 

 Rome, in May, Jane, and July, 1838. 



On the 7th of September, 1843, a division of the outer ring 

 was detected by Messrs. Lassel and Dawes, at Slarfield. They 

 employed a Newtonian reflector of nine inches' aperture ; the de- 

 tails are to be found in vol. vi, of the Monthly Notices of the 

 Royal Astronomical Society. 



The newly discovered inner ring of Saturn cannot properly 

 be classed with the subdivisions of the old ring, as it lies within 

 its inner edge. 



We have, then, the best assurance in the number and reputa- 

 tion of those who have described the phenomena in question. 



