742 THE UNIVERSE. 



Although the eye cannot generally perceive these spots, 

 some of them are nevertheless as mnch 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. 



Although the existence of these spots is as easily proved 



32r,. Spots on the Sun. 



as anything can be, yet when they were first j^ointed out, 

 and even after the great Galileo had attested their presence, 

 some theologians, founding their convictions upon false 

 philosojihic ideas, resolutely denied the fact. They main- 

 tained that the pure and radiant star was perfectly immacu- 

 late, and that its pretended blemishes only existed on the 

 glasses of the telescopes of astronomers. 



But though the existence of these is now an incon- 



