The Evolution of the Sciences 



Ages. They were then accounted for in the most 

 natural manner by admitting that the moon did 

 not entirely cover the solar disc, and this inter- 

 pretation prevailed until it became possible, 

 by the use of the telescope, to measure angles 

 accurately. It was then placed beyond doubt 

 that in some eclipses the apparent diameter of 

 the moon distinctly exceeds that of the photo- 

 sphere. 



Some other explanation was therefore re- 

 quired. Kepler, with the intuition of genius, 

 suggested the existence of an atmosphere of 

 inflamed ether near the sun; but he soon joined 

 all the astronomers of the time in adopting the 

 hypothesis of a lunar atmosphere, illuminated, 

 from behind by the sun, during an eclipse, in such 

 a manner as to form the corona. This opinion 

 was still supported in the eighteenth century 

 by a distinguished astronomer, Louville, who 

 was commissioned by the Academy of Sciences to 

 observe at London the eclipse of 1715. Louville 

 fancied he noticed that the plumes of the halo 

 followed the direction of the rays of the moon 

 and not of the sun; and carried away by his 



hypothesis, to which he attempted to connect 



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