XVIII.] 



KESULT OF THE INQUIHY. 



257 



hottest regions of the sun, which spots and storms enable us to 

 study apart from the absorption going on at higher levels. 



It is not too much to say that the result of this inquiry was 

 most striking. What came out in the strongest manner was the 

 very remarkable fact that these common lines were always widened 

 in the spots. However feebly the brighter lines of a chemical 

 substance, taken as a whole, might be represented amongst the 

 spot lines, yet the common lines among these, which are often of 

 the second or third order of intensity and sometimes even of 

 the fourth, are never absent. The same fact held almost 

 equally true with regard to the storms. 



The comparison of Thalen's lines, recorded in two spectra, 

 with those seen by Young in solar spots and storms shows this 

 result : 



So far as my own knowledge of these matters goes, I can 

 imagine no severer test to apply to the hypothesis that 



s 



