164 UKRSCHEL AND HIS WORK 



joined together, making wave or \\a\in^ lines." in 

 1801 ho had advanced to the "strong suspicion tli.it 

 one half of our sun is less favourable to a copious 

 emission of rays than the other; and that its vari tl>l 

 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 follow in 

 50, and three days later above 60. A cloud, ha- 



me of these openings, was seen to move a third <>f 

 the way across the mighty chasm in lifty-ei^ht minutes. 

 Herschel's theory of the sun then may be thus 

 stated. There is first the region of 'luminous 

 clouds" whicli, adding also the elevation of the/*/ 

 cannot be less than 1843, nor much more than J7ii."i 

 miles in depth. These solar clouds he com]>n 

 density with the aurora borealis of our skiea 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 

 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 hon 

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

 idea of unbearable heat in the sun that, in a cou i 

 law, belief in its coolness was at that time quoted 

 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 ifagasint, 1807, p. 



