278 REPORT ON THE DISCOVERY AND NAME 



could only be distinguished from the satellite by their not partaking 

 of the motion of Saturn. 



Oct. 13th, 7h. 40m., x follows Saturn's centre 202". 

 " 14th, 7h. Om., " " 152". 



" The motion of x among the stars was sensible in three hours. 



Oct. 15th, 9h. 35m, x follows Saturn's centre 92.4". 

 " The foregoing positions are approximately satisfied by a pe- 

 riodic time of twenty-one days. 



" The orbit is nearly coincident with the plane of the ring." 



In the letter of Mr. Bond addressed to Mr. Everett, above re- 

 ferred to, it is stated, that the light of the newly discovered 

 satellite is fainter than that of the two interior satellites discovered 

 by Sir William Herschel in 1789, which have ever been spoken 

 of by observers as objects beyond the reach of any but the most 

 powerful instruments. The discovery of the Messrs. Bond is, 

 therefore, peculiarly satisfactory, as a test of the capacity of the 

 new telescope at Cambridge, toward the purchase of which the 

 Academy has contributed. 



While this addition to the planetary system is justly to be re- 

 garded in itself as an event of high interest in astronomical 

 science, it is rendered peculiarly so by the fact, that the same 

 discovery was made almost at the same time by Mr. Lassell, at 

 Starfield, near Liverpool. The committee have been permitted 

 to incorporate in their report the following copy of a letter from 

 this distinguished observer to Mr. Bond. 



"Starfield, Liverpool, 30th September, 1848. 

 " Dear Sir, — I have the pleasure to inform you, that I have 

 discovered an eighth satellite of the planet Saturn. 



" In relating to you the mode of its discovery, I shall, in speak- 



