74 THE SUN. 



the chemical products have to be disposed of. In the 

 case of gun cotton, it has been calculated that, if the sun 

 were made of it so condensed as 'only to burn on the 

 surface, it would burn out, at the rate of the sun's ex- 

 penditure of light and heat, in eight thousand years. Any- 

 how fire, kept up by fuel and air, is out of the question. 

 There remain -only three possible sources of them, so far 

 as we can perceive electricity, friction, and vital action. 

 The first of these was suggested by the late Sir William 

 Herschel in 1801; the second, at least as a possibility, 

 though without indicating any mode by which the neces- 

 sary friction could arise, by myself, in a work* published 

 in 1833. The theory at present current of it is founded 

 on what may not unfairly be considered a further develop- 

 ment of this idea, the friction being supposed to arise 

 from meteoric matter circulating round the sun, and 

 gradually subsiding into it, and either tearing up its sur- 

 face, or ploughing into its atmosphere. But on this we 

 cannot dilate, as nothing has been hitherto said about 

 the appearance of the sun in telescopes, and the strange 

 phenomena its surface, so examined, exhibits. 



(33.) One of the earliest applications of the telescope 

 was to turn it on the sun. And the first fruits of this 

 application (which originated about the same time in 

 the year 1611, with Harriot in England, Galileo in Italy, 

 and Fabricius and Scheiner in Germany), was the dis- 



* "Lardner's Cabinet Cyclopaedia," Astronomy, s. 337, p. 212. 

 Aristotle was earlier in making this suggestion : but such random- 

 guesses as those of the ancients can hardly merit the name of 

 tific suggestions, 



