The Evolution of the Sciences 



protuberances of the lunar contour, like a string 

 of beads; then the sun disappears. "Im- 

 mediately/' says Father Secchi, " the scene 

 changes in a sudden and complete manner; in 

 the midst of a lead-coloured sky stands out a 

 perfectly black disc, surrounded by a magnificent 

 glory of silvery rays, among which scintillate 

 rose-coloured flames." The stars, and the planet 

 Venus, shine in the sky, but the general darkness 

 is far from being complete ; some light is emitted 

 both from the bright corona which surrounds 

 the moon and from the regions of the terrestrial 

 atmosphere situated outside the cone of umbra. 

 It is possible, with difficulty, to read a book 

 printed in large type, but it is almost impossible 

 to tell the hour on a watch, and observers are 

 obliged to keep lighted lamps near their instru- 

 ments in order to be able to read their scales. 



The irradiation surrounding the dark disc 

 of the moon occupies an expanse of the sky 

 which varies considerably from one eclipse to 

 another, but it is generally more or less equal 

 to that of the sun itself. First, reddish masses 

 are to be seen, distributed irregularly around 

 the solar disc, and situated principally in the 



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