116 BAILLY. 



are beyond all criticism. But the question has been suffi- 

 ciently discussed in a passage of The Exposition of the 

 System of the World, on which it would be useless to 

 insist here. Whatever came from the pen of M. de La- 

 place was always marked by the stamp of reason and of 

 evidence. In the first lines of his magnificent work, 

 after having remarked that " the history of Astronomy 

 forms an essential part of the history of the human 

 mind," Bailly observes, "that it is perhaps the true 

 measure of man's intelligence, and a proof of what he 

 can do with time and genius." I shall allow myself to 

 add, that no study offers to reflecting minds more striking 

 or more curious relations. 



When by measurements, in which the evidence of the 

 method advances equally with the precision of the results, 

 the volume of the earth is reduced to the millionth part 

 of the volume of the sun ; when the sun himself, trans- 

 ported to the region of the stars, takes up a very modest 

 place among the thousands of millions of those bodies 

 that the telescope has revealed to us ; when the 38,000,000 

 of leagues which separate the earth from the sun, have 

 become, by reason of their comparative smallness, a base 

 totally insufficient for ascertaining the dimensions of the 

 visible universe ; when even the swiftness of the lumi- 

 nous rays (77,000 leagues per second) barely suffices for 

 the common valuations of science ; when, in short, by a 

 chain of irresistible proofs, certain stars have retired to 

 distances that light could not traverse in less than a mil- 

 lion of years ; we feel as if annihilated by such immensities. 

 In assigning to man, and to the planet that he inhabits, 

 so small a position in the material world, Astronomy seems 

 really to have made progress only to humble us. 



But if, on the other hand, we regard the subject from 



