ON THE SUN'S HEAT. 



373 



have no place in science. Their removal is 

 the substitution of true for false statements and 

 thoughts, not always so easily effected as in 

 the present case. The truth is, that it is because 

 the sun is becoming less hot in places of equal 

 density, that his mass is allowed to yield 

 gradually under the condensing tendency of 

 gravity ; and thus from age to age cooling 

 and condensation go on together. 



An essential detail of Helmholtz's theory of 

 solar heat is that the sun must be fluid, be- 

 cause even though at any given moment hot 

 enough from the surface to any depth, however 

 great, inwards, to be brilliantly incandescent, the 

 conduction of heat from within through solid 

 matter of even the highest conducting quality 

 known to us, would not suffice to maintain the 

 incandescence of the surface for more than a 



Lane's conclusion ; and the subject is similarly explained in Ball's 

 Story of the Heavens, pp. 501, 502, and 503, with complete avoid- 

 ance of the "paradox." And now I take this opportunity of 

 correcting my hasty correction of the "paradox" by the insertion 

 of the five words in italics added to lines 8 and 9 of the paragraph. 

 W. T.] 



