280 REPORT ON THE DISCOVERY AND NAME 



reasonable errors of observation during so short a period. More- 

 over, the point a being precisely in the line of the interior sat- 

 ellites, I took micrometrical measurements of his position with 

 respect to the others at two epochs, differing four hours, and 

 was perfectly satisfied that, during that interval, no perceptible 

 change whatever in his position took place. As the motion of 

 Saturn southwards during this interval would amount to 18", it 

 must have left the point x obviously behind, if it had been a fixed 

 star. I could not then escape the conclusion that a; is a new 

 satellite of the planet. 



"The 21st and 22d have been the only evenings since the 

 19th on which any observation could be got; it was then ap- 

 proaching Saturn. A season of cloudy weather has now set in, 

 which is very unfortunate, as another clear night would have 

 enabled me to ascertain something respecting the satellite's pe- 

 riod. In conformity with Sir J. Herschel's nomenclature of the 

 older satellites, I have proposed to call this Hyperion.^'' 



It will appear from the comparison of dates in the preceding 

 accounts of the observations of Mr. Lassell and the Messrs. 

 Bond, that the discovery of the new satellite by these eminent 

 observers was nearly simultaneous. It was first noticed by the 

 Messrs. Bond on the 16th, and by Mr. Lassell on the 18th of 

 September, and the discoveries had been publicly announced in 

 each country before the accounts from the other had been received. 

 This circumstance leaves to each astronomer the credit of an 

 original discovery. It is unnecessary to state that nothing but 

 an instrumental power of the highest order, applied with con- 

 summate skill, would have sufficed for its achievement. 



The first discovery of a satellite of Saturn was made by Chris- 



