184 PROGRESS OF SCIENCE IN THE CENTURY. 



tion of an exploded planet can be regarded as tenable, 

 but both served a useful purpose in prompting re- 

 search. They led to the recognition of the minor 

 planets, now known to be very numerous (over five 

 hundred) and the discovery must have served as a 

 useful hint of the complexity of relations which fur- 

 ther study of the heavens was to reveal. The story is 

 of interest in illustration of a scientific prophecy 

 which was rewarded even more richly than its basis 

 deserved. , 



In 1857 Clerk Maxwell proved the truth of what 

 had been several times suggested that the rings 

 around Saturn could not be continuous solid bodies 

 nor liquid zones, but that they behaved as if they 

 were composed of a multitude of small solid bodies 

 revolving independently around the planet, somewhat 

 as- the minor planets do around the sun. This has 

 received corroboration from telescopic and spectro- 

 scopic observations, and is one of the facts which 

 lend countenance to the hypothesis of the meteoric 

 constitution of the heavenly bodies: that meteoric 

 dust, shooting stars, meteor rings, Saturn's rings, 

 comets, minor planets, nebulre, and so on, are all, as 

 it were, terms in an evolution-series. 



Discovery of Neptune. There are few chapters 

 in the history of astronomy more familiar, and, at 

 the same time, more instructive, than the story of the 

 discovery of Neptune. It illustrates the method of 

 science, discovering an anomaly, tracing out the 

 reason for it, and thereby corroborating n general con- 

 clusion. 



In the first quarter of the century it was repeat- 

 edly remarked that the real orBit of Uranus (which 

 Herschcl had removed from among the fixed stars 

 to a place among the planets) was not (to the astro- 



