140 LIGHT SCIENCE FOR LEISURE HOURS. 



how he could have been deceived. But he admits that 

 he was unable to watch any of these satellites through 

 a considerable part of its path, or to identify any of 

 them on different nights. All he felt sure about was 

 that certain points of light were seen which did not 

 remain stationary, as would have happened had they 

 been fixed stars. No astronomer, however, has since 

 seen any of these four additional satellites, though Mr. 

 Lassell has discovered two which Herschel could not 

 see (probably owing to their nearness to the body of the 

 planet). As Mr. Lassell has employed a telescope more 

 powerful than Herschel's largest reflector, and has 

 given much attention to the subject, no one has a 

 better right to speak authoritatively on the subject of 

 the four additional satellites. Since, therefore, he is very 

 confident that they have no existence, I feel bound to 

 represent that view as the most probable ; yet I am 

 unable to pass from the subject without expressing a 

 hope that one of these days new "[Iranian satellites will 

 be revealed. 



The four known moons travel backwards; that is, 

 they circle in a direction opposed to that in which all 

 the planets of the solar system, and all the moons of 

 Jupiter and Saturn, as well as our own moon, are 

 observed to travel. Much importance has been attached 

 to this peculiarity; but in reality the paths of the 

 Uranian moons are so strangely situated with respect 

 to the path of Uranus, that the direction in which they 

 travel can hardly be compared with the common direc- 

 tion of the planetary motions. Imagine the path of 



