V-] 



STELLAR ATMOSPHERES. 



Now the chromosphere by a well-known physical law must be 

 hotter than anything outside it, but we know that the reversing layer 



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T5 



O 



I 

 I 



I 



a 



i 

 2.2 



lies outside it, therefore the reversing layer of a Cygni must be hotter 

 than the reversing layer of the sun. 



In the chromosphere of 1898, the enhanced lines are all of greater 

 intensity than the corresponding Fraunhofer lines, and they are also 



