SUN SPOTS 161 



undoubtedly rxr.-ll.-nt ol..s-r\ ali.,ns ! %s ^ t-,,, |, a -r, t , 

 ho then wrote, and too ruth in the conclusions 



.on drew. But let it be recorded to his honour 



to him belongs the credit of first sending the 

 beams of Sirios and other sunny stars through a prism, 



iie purpose of determining whether their light s - 

 H or not It was a most brilliant idea, 

 carried out before tho world wan ready to reoeivi 



e great question Herschel set himself to solve 

 regarding the sun was, What is it ? He knew, as ail 

 men had known, that it was a vast fiery ball ruling 



i and sky , Uit ho saw, as they saw, nothing save 

 the outaide ; .ill. Was it n mi-hty furnace 



within as it was without ? In Newton's days, two or 

 three generations earlier, there were people who 

 "supposed tho sun to be cold," although Newton easily 



d that, to "a body hard by the sun, his heat 



I be 50,000 times greater than we feel it in a hot 



Miniiui r -lay. which is vastly greater than any heat we 



know on earth." l Herschel was aware that the spots, 



the black spots on its face, were vast dark holes in its 



brightness, so large that they would let the 



live in, and be at a thousand miles' distance 



and from tho burning, blazing clouds. But while 

 lie knew this, he had also learned from the writings of 

 others tint these black riftewere careering over its face 

 from west to east at the rate of more than a mile 

 very second What <li<l it all mean, was the qtu 

 he wished answered. Fabricius in 1611, and Galileo 

 about the same time, divide between them the honour 

 of discovering these spots on the sun's face. 

 former tells tho story of his first Might of a spot, of his 



1 firewater, Lift, ii. 458. 



