24 A CENTUKY'S PROGRESS IN ASTRONOMY. 



to confirm his belief. As Mr Gore says, some 

 of the satellites " must, therefore, have been 

 either optical 'ghosts' or else small fixed stars 

 which happened to be near the planet's path at 

 the time of observation. Herschel also suspected 

 that he could see traces of rings round Uranus 

 like those round Saturn, but his observation 

 was never confirmed, either by himself or other 

 observers." 



Although Herschel made several important 

 observations on the Moon, and measured the 

 heights of the lunar mountains, he was not 

 a devoted student of our satellite. Caroline 

 Herschel remarks in her memoirs that if it 

 had not been for clouds or moonlight, neither 

 her brother nor herself would have got any 

 sleep ; adding that Herschel on the moonlight 

 nights prepared his papers or made visits to 

 London. However, he did make some investiga- 

 tions, and in 1783 and 1787 believed himself 

 to have witnessed the eruption of three lunar 

 volcanoes. He afterwards concluded, however, 

 that what he believed to be eruptions was really 

 the reflexion of earth - shine from the white 

 peaks of the lunar mountains. Herschel never 

 discovered a comet, leaving that branch of 

 astronomy to his sister, who discovered eight 

 of these objects. He was, however, much in- 



