SIR NORMAN LOCKYER 367 



gradually been dragged out from the region of the unknown, and many 

 are now recognized as enhanced lines, to which I have already called 

 attention as appearing in the spectra of metals at a very high tempera- 

 ture. 



But useful as the method of observing the chromosphere without 

 an eclipse, which enables us 



". . . to feel from world to world," 



as Tennyson has put it, has proved, we want an eclipse to see it face 

 to face. 



A tremendous flood of light has been thrown upon it by the use of 

 large instruments constructed on a plan devised by Respighi and my- 

 self in 1871. These give us an image of the chromosphere painted 

 in each one of its radiations, so that the exact locus of each chemical 

 layer is revealed. One of the instruments employed during the Indian 

 eclipse of this year is that used in photographing the spectra of stars, 

 so that it is now easy to place photographs of the spectra of the 

 chromosphere obtained during a total eclipse and of the various 

 stars side by side. 



I have already pointed out that the chemical classification indicated 

 that the stars next above the sun in temperature are represented by 

 y Cygni and Procyon, one on the ascending, the other on the descend- 

 ing branch of the temperature curve. 



Studying the spectra photographed during the eclipse of this year 

 we see that practically the lower part of the sun's atmosphere, if 

 present by itself, would give us the lines which specialize the spectra 

 of y Cygni or Procyon. 



I recognize in this result a veritable Rosetta stone, which will 

 enable us to read the celestial hieroglyphics presented to us in stellar 

 spectra, and help us to study the spectra and to get at results much 

 more distinctly and certainly than ever before. 



One of the most important conclusions we draw from the Indian 

 eclipse is that, for some reason or other, the lowest, hottest part of 

 the sun's atmosphere does not write its record among the lines which 

 build up the general spectrum so effectively as does a higher one. 



There was another point especially important on which we hoped 

 for information, and that was this : Up to the employment of the 

 prismatic camera insufficient attention had been directed to the fact 



