4 Proceedings of the Royal Society of Victoria. 



Of course his argument falls to the ground if, on the night of 

 23rd February, the bright bands were absent from the spectrum. 

 It seems to me that the presence of the bright edges of the fine 

 absorptions, recorded by Pickering, may be regarded as doubtful, 

 seeing that Vogel got no trace of them on plates taken under 

 better atmospheric conditions ; the latter observer, indeed, is of 

 opinion that a large part of the bright light of the continuous 

 spectrum of that night was due to very dense hydrogen. If 

 this be the case, these observations, taken alone, do not 

 furnish the experimentum crucis, which will have to be discussed 

 — if at all — on the basis of evidence furnished by the later 

 observations. 



4.— Second Stage of the Star's History. 



While the typical spectrum was predominant, a number of 

 photographs of the spectrum were taken at the Lick^ and by 

 Lockyer at South Kensington,- which demonstrate the important 

 fact that the wavelengths of the bright hydrogen lines increased 

 progressively in value for a time, while the wavelengths of 

 the dark lines — which were much shortened — remained nearly 

 stationary in magnitude. As Lockyer gives no measures, but 

 merely records the fact that a change did occur, I have put 

 together the scattered measures of the Lick observers in Tables 

 I. and 11. 



Table I. — Dark Bands. 



1 Ap. J., xiv., loc. cit. 



2 M. N., Ixi., App., pp. 15, 21, 37. 



