52 



Mr. J. N. Lockyer. On the Classification [Apr. 12 y 



The Radiation Flutings. 



We will first deal with, the radiation flirtings — those of carbon. 

 The brightest less refrangible edge of the chief one is at wave-length 

 517, where it sharply cuts off the tail end of the absorption of the 

 magnesium Anting the darkest edge of which begins at 520, as the 

 carbon light from the interspace pales the absorption. The same 

 thing happens at the more refrangible edge of the other absorption of 

 Mg at 500, as Duner's figures show. 



Less refrangible More refrangible sharp 

 edge. edge. 



p502 496 in a Herculis. 



Band 8 (absorption J £01 496 in p Persei. 



of Mg) 1 503 496 in R Leonis Min. 



Uo5 496 in £ Pegasi. 



If this explanation of the rigidity of the less refrangible edge may 

 be accepted, it is suggested that the rigidity of the end of band 8 at 

 496, near the nebula line 495, seems to indicate that we may have 

 that line as the bright, less refrangible, boundary of another radiation 

 fluting. 



The fluting at 517 is the chief radiation fluting of carbon. The 

 next more refrangible one, which would be most easily seen, as the 

 continuous spectrum would be less bright in the blue, has its less 

 refrangible and brightest edge at 474. 



This in all probability has been seen by Diiner, though, as before 

 stated, there is here a discrepancy between his maps and his text. 

 It lies between his dark bands 9 and 10, the measurements of which 

 are as follow : — 



Less refrangible 



edge. More refrangible edge. 



Band 9 482 476 in a Orionis. 



484 477 in Pegasi. 



Band 10 472 460 in a Orionis. 



474 462 in a Herculis. 



It is not necessary for me to point out the extreme and special 

 difficulty of observations and determinations of wave-lengths in this- 

 part of the spectrum. Taking this into consideration, and bearing in 

 mind that my observations of the chemical elements have shown me 

 no other bands or flirtings in this region, I feel justified in looking 

 upon the narrow bright space between bands 9 and 10 as an indica- 

 tion of another carbon fluting — the one we should expect to find 

 associated with the one at 517, with its bright edge at 473 instead of 

 476, where Duner's measurements place it. There is a bright fluting 

 in this position in Nova Orionis. 



