20 A CENTURY'S PROGRESS IN ASTRONOMY. 



In c The Edinburgh Review ' Brougham declared 

 that Herschel had devised the word " asteroid," 

 so that the discoveries of Piazzi and Olbers 

 might be kept on a lower level than his own 

 discovery of Uranus. Many scientists would 

 have been much offended at this contemptible 

 insult, but Herschel merely remarked that he 

 had incurred "the illiberal criticism of 'The 

 Edinburgh Review/ " and that the discovery of 

 the Asteroids " added more to the ornament of 

 our system than the discovery of another planet 

 could have done." 



In Herschel's time astronomers were acquainted 

 with three of the outer planets, Jupiter, Saturn, 

 and Uranus, all of which were closely studied 

 by the great astronomer. The belts of Jupiter 

 were supposed by him to be analogous to the 

 " trade-winds " in the atmosphere of the Earth ; 

 while the drifting -spots on Jupiter's disc and 

 their irregular movements were carefully noted. 

 His observations on the four satellites of Jupiter 

 led him to believe that, like our Moon, they 

 rotated on their axes in a period equal to that 

 of their revolution round their primary an 

 opinion shared by Laplace, and by many modern 

 astronomers. 



Herschel's researches regarding Saturn were, 

 however, much more important than those on 



