1 64 HERSCHEL AND HIS WORK 



joined together, making waves, or waving lines." In 

 1801 he had advanced to the "strong suspicion that 

 one half of our sun is less favourable to a copious 

 emission of rays than the other ; and that its variable 

 lustre may possibly appear to other solar systems, as 

 irregular periodical stars are seen by us." In the same 

 paper he records in his observations that he counted at 

 one time 45 " openings " or spots, on the following day 

 50, and three days later above 60. A cloud, hanging 

 over one of these openings, was seen to move a third of 

 the way across the mighty chasm in fifty-eight minutes. 

 Herschel's theory of the sun then may be thus 

 stated. There is first the region of "luminous solar 

 clouds " which, adding also the elevation of the faculce, 

 cannot be less than 1843, nor much more than 2765 

 miles in depth. These solar clouds he compares in 

 density with the aurora borealis of our skies. Under- 

 neath this envelope of brightness is the sun's atmo- 

 sphere, which may be so clouded as to shield the body 

 of the sun and the beings, who live there, from the 

 intense heat and glare above. The body of the sun 

 lies still lower, and " is diversified with mountains and 

 valleys." Some may deem it the horrid abode of lost 

 souls ; others may see in its cool retreats the home of 

 blessed spirits. But so imbued is man's mind with the 

 idea of unbearable heat in the sun that, in a court of 

 law, belief in its coolness was at that time quoted as a 

 proof of insanity, and of incompetence in a man to 

 manage his own affairs. 1 This, in short compass, is 

 Herschel's view of the constitution of the sun. It is 

 largely founded on the theory of his friend Wilson, 

 the Professor of Astronomy in the University of 



1 Scots Magazine, 1807, p. 329. 



