256 Sir J. K Lockyer and Mr. Baxandall. Enhanced [July 13, 



were then compared with Rowland's solar wave-lengths, and in cases of 

 close agreement with solar lines it was deemed probable that the two 

 lines were really identical. In this connection, however, the relative 

 intensities of the solar and enhanced lines were, to a great extent, 

 taken into account in judging whether a solar line could be accepted 

 as the analogue of a metallic line. 



The three elements investigated are dealt with separately. The 

 tables show the wave-lengths of the enhanced lines as reduced from 

 the most recent and best photographs, their intensities in spark and 

 arc spectra, the wave-lengths of Rowland's solar lines to which they 

 probably correspond, and the origins, if any, to which Rowland has 

 attributed such solar lines. 



The wave-lengths of some of the enhanced lines differ in the second 

 decimal place from those published* previously for the same lines. 

 More weight can be given to the present wave-lengths, as in the 

 photographs from which they have been reduced the lines are more 

 sharply defined than in the earlier photographs employed. In the 

 case of chromium a much more extended list of enhanced lines than 

 the previous one has been obtained. 



The numbers in the last column refer to the notes at the end of each 

 table. 



Titanium. 



* ' Koy. Soc. Proc.,' vol. 65, p. 451. 



