THE SIDEREAL UNIVERSE. 



709 



extent of its surface, but in reality of vast extent relatively 

 to the dimensions of our globe. Although the eye cannot 

 generally perceive these spots, some of them are, neverthe- 

 less, as much as 75,000 miles in diameter; and if we suppose 

 that they represent gaps in the solar envelope, the earth 

 might be engulfed in them with the greatest facility. 



fill': Jj J?- # ' U 



257. Spots on the Sun. 



Although the existence of these spots is as easily proved 

 as anything can be, yet, when they were first pointed out, 

 and even after the great Galileo had attested their reality, 

 some theologians, founding their convictions upon false phil- 

 osophic ideas, resolutely denied the fact. They maintained 

 that the pure and radiant star was perfectly immaculate, 



