The Evolution of the Sciences 



had the intuition that the time had come for 

 studying the worlds, not only with the eyes of 

 the astronomer but also from the physical 

 point of view. And at that time physics, 

 thanks to the impulse of Gay-Lussac, Cavendish, 

 Faraday, Fresnel and of a band of scientists, 

 unequalled in any other age, had just established 

 its fundamental law. The nature of light was 

 known, and that was the main point, as light 

 forms our sole means of communication with 

 the ultra-mundane regions. Photography had 

 just been discovered, and spectroscopy was on 

 the point of being created by the strenuous 

 efforts of Kirchhoff and Bunsen. But above 

 all the habit of method and of scientific procedure 

 had been learned, which rejects approximations 

 and demands precise verification. 



As a matter of fact it is from the eclipse of 

 the 8th July 1842 that the true progress of solar 

 astronomy dates. Observed in France, Italy and 

 Austria b> Airy Arago, Bailey and Fusinieri, 

 it enabled a clean sweep to be made of all the 

 hypotheses which the eighteenth century had 

 been unable to criticise ; henceforth there could be 



no question of the effects of diffraction, or of a 



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