THE SIDEREAL UNIVERSE. 731 



the firmament, only gives us an impeifect idea of the 

 grandeur of the heavenly regions. Nmuber and distance 

 weaken the impression. It seems as if the stars, so 

 abundant and apparently so heaped together, could only 

 be luminous points! It is science that gives objects their 

 real importance by calling calculation to our aid. In 

 order to give the dimensions of one of these bodies 

 with precision, we will quote the exact words of M. A. 

 Guillemin: "Wollaston," he says, "afiirms that the aj^j^a- 

 rent diameter of the most brilliant star in the sky, Sirius, 

 is not equal to the fiftieth part of the second of an arc. 

 But we may at once say that this calculation would still 

 leave a large margin for the real dimensions of this 

 star, seeing that at the distance at which it is from us, 

 an apparent diameter so small would yet represent a real 

 diameter of 4,500,000 leagues, which is twelve times that 

 of our sun." 



Does not this simple quotation prove that the phe- 

 nomena of nature possess proportions not less extra- 

 ordinary than unexpected ? Thus when man begins the 

 study of the sciences, it is with profound astonish- 

 ment that he recognizes that the marvels which they 

 reveal to him far surpass the most audacious fictions of 

 antiquity. 



Let us prove it by a few instances. 



The ancient philosophers thought they gave a grand 

 and majestic idea of the sun by comparing its dimensions 

 to the superficies of the Peloponnesus. But what a mean 

 comparison! This torch of the world, this lucerna mundi, 

 as Copernicus called it, is of such proportions that if we 

 supposed the earth placed in its centre, the mass of the 

 sun would extend beyond the orbit of the moon, and our 

 satellite would only accomplish its revolutions while still 



