STAR-ISLANDS OR WORLD-SYSTEMS 233 



have followed in his footsteps with a better equipment 

 of instruments, if not with a richer endowment of 

 insight or genius. Others still have looked upon his 

 lifelong quest as an attempt to reach the foot of the 

 rainbow ladder, or to master the secret of the philo- 

 sopher's stone. His papers remain a wonderful monu- 

 ment of ingenious research and marvellous discovery, 

 of lofty imaginings and reasoned conclusions. 



These nebulae and clusters of stars Herschel called 

 milky ways, different from the great Milky Way, in 

 which our solar system is imbedded. He held at first 

 that they are in no respect connected with our milky 

 way, but are star-islands or world-systems, perhaps 

 only in process of formation, at immense distances from 

 our sun, outlying provinces of creation, as it were, in 

 the vast ocean of ether, or constructions only begun in 

 the realms of space. He is supposed to have fallen 

 from this opinion in his later years, and to have 

 imagined that all these milky ways and star-clusters 

 were connected with ours. His latest papers give no 

 indication of this change of view. He appears indeed 

 only to have changed his view in so far as to have 

 regarded our milky way as the greatest of all the 

 milky ways, visible in our telescopes : but on this point 

 he was scarcely justified in speaking, as the distance of 

 the nearest nebula not only was and continues to be 

 unknown, but the means of determining the distances 

 of these white clouds have not yet been discovered. It 

 is thought that the great nebula in Orion, if not the 

 nearest to us, is among the nearest. Herschel main- 

 tained this. He had some grounds also for believing 

 that changes had taken place in the positions of the 

 nebulous matter during the thirty-seven years he 



