Royal Astronomical Society. 477 



giving the dry matter of rules and ordinances, it is brimful of inter- 

 esting details and rich anecdotes ; and there is much intelligence 

 that every English gentleman ought to possess. In the course of so 

 critical an undertaking, there are many topics which required great 

 care and delicacy in their treatment ; and the author has been obliged 

 to shape a middle course between the genius and the temper of New- 

 ton, the honesty and the limited intellect of Pringle, the wealth and 

 the leaden sway of Banks, the good and the evil bias of Davy, and 

 the suaviter and the pliancy of Gilbert. But he has dashed through 

 in good taste, and with a fair spirit ; and his memoirs of the Presi- 

 dents form a valuable addition to British biography. We hope ere 

 long to announce a second edition. 



LXX. Proceedings of Learned Societies. 



ROYAL ASTRONOMICAL SOCIETY. 



[Continued from p. 243.] 



June 9, p|ISCOVERY of a new Satellite of Saturn*. By W. 

 1848. U Lassell, Esq. 



" In communicating to you the particulars attending the discovery 

 of an eighth satellite of Saturn, I shall adopt the proper names pro- 

 posed by Sir John Herschel for the seven hitherto known satellites, 

 namely, Mimas, Enceladus, Tethys, Dione, Rhea, Titan and Japetus, 

 beginning with the closest, and proceeding in order of distance from 

 their primary. The new satellite I have proposed, in conformity 

 with this nomenclature, to call Hyperion. 



"On the 18th of September, while surveying the planet in the 

 twenty-foot equatoreal, and looking out for Japetus (which I ex- 

 pected to find following the planet and not far from the plane of his 

 ring), I remarked two stars exactly in the line of the interior satel- 

 lites. Not being certain at the time which of these was Japetus 

 (although the nearer of the two certainly seemed too faint), I made 

 a careful diagram of their positions with respect to Saturn, and also 

 to some neighbouring fixed stars. 



" The next night, the 19th, proved fine, and I was astonished to 

 find that the two stars had both moved away from the fixed stars to 

 which they had been referred, and were still accompanying Saturn ; 

 the more distant of the two had also gone northward, in conformity 

 with the orbital motion of Japetus, while the nearer and fainter, re- 

 maining precisely in the line of the inferior satellites, appeared to 

 have slightly approached the planet. 



" A consideration of this appearance suggested the idea that the 

 more distant was Japetus, and that the nearer and fainter must be 

 a new satellite of Saturn. To verify the suspicion, I took differences 

 of right ascension between each and a fixed star, and found that in 



* The' new satellite was, it is said, discovered at the observatory of Cam- 

 bridge, U.S., on Sept. 16, but no account has been received from Professor 

 Bond. 



