HERSCHEL THE DISCOVERER. 31 



first class being " bright nebulae," the second 

 "faint nebulae/' the third "very faint nebulae," 

 the fourth " planetary nebulae," so named by 

 Herschel from their resemblance to planetary 

 discs, the fifth class contained " very large 

 nebulae," the sixth "very compressed and rich 

 clusters of stars," the seventh "pretty much 

 compressed clusters of large or small stars," 

 and the eighth " coarsely scattered clusters of 

 stars." 



At first Herschel believed all nebulae to be 

 clusters of stars, the irresolvable nebulae being 

 supposed to be farther from our system than 

 the resolvable nebulae. As many of the nebulae 

 which Messier could not resolve had yielded to 

 Herschel's instruments, Herschel believed that 

 increase of telescopic power would resolve the 

 hazy spots of light which remained nebulous. In 

 the paper of 1785, in which Herschel dealt with 

 the construction of the heavens, he stated his 

 belief that many of the nebulae were external 

 galaxies universes beyond the Milky Way ; and 

 in 1786 he remarked that he had discovered 

 fifteen hundred universes ! 



Arago, Mitchel, Nichol, Chambers, and other 

 writers quite misinterpreted Herschel's views on 

 the nebulae when they said that he believed 

 them to be all external galaxies. In 1785 



