32 LIGHT SCIENCE FOR LEISURE HOURS. 



hands of the President of the Imperial Academy at 

 Paris. Five minutes before, however, the president 

 had read a communication from Mr. Warren De La 

 Hue, announcing that an English observer had lighted 

 independently upon the same discovery. 



Let me briefly indicate how this had come about, 

 premising that what we have yet to learn from future 

 eclipses is so intimately associated with the history of 

 what we have already learned, that it would be im- 

 possible rightly to present the hopes of astronomers 

 respecting the eclipse of next December without con- 

 sidering the progress of past research. 



Mr. Huggins, the eminent spectroscopist, had in 

 1866 examined the light of a star which blazed out 

 suddenly in the constellation of the Northern Crown. 

 He had found that this star owed its great increase of 

 lustre to an outburst of hydrogen flames ; for he could 

 distinctly see the bright lines belonging to the spectrum 

 of glowing hydrogen, superposed on the rainbow-tinted 

 streak crossed by dark lines, forming the ordinary 

 spectrum of a star. 



It occurred to Mr. Lockyer that if the spectrum of 

 a glowing gas can thus be recognised in the case of a 

 distant star, we might be able to detect masses of 

 glowing gas on our sun, which is relatively so near to 

 us; so that, if the prominences are of this nature 

 as many astronomers even at that time thought pro- 

 bable we might be able to see their spectral lines 

 even when the sun is not eclipsed. He directed the 

 attention of the Koyal Society to this method of obser- 



