186 



Sir Norman Lockyer and Mr. F. E. Baxandall. 



Eeference to the above table will show that the " arc " intensities of 

 the enhanced lines vary from 2 to 7 (maximum intensity adopted 

 is 8), and that nearly throughout Frost records corresponding ^eclipse 

 lines, the majority of the latter being quite prominent. 



The second list consists of the very strongest arc lines (intensity 

 7 and 8) which are not enhanced in the spark spectrum. Here again 

 the intensities of the corresponding eclipse lines, if any, are quoted. 



Strongest Arc Lines of Titanium, and their relation to Eclipse Lines. 



Titanium arc. 



Eclipse. 



(Hasselberg.) 



Frost. 



Kensing- 

 ton. 











Intensity. 



Max. 500. 



Int. 

 Max. 

 100. 



Frost's 



X. 



Int. 

 Max. 8. 



Adopted 

 wave-length. 



Prism spectra. 



origin. 





" Flash" II. 



Cusp II. 





4186 -27 

 4286-15 

 4287 '55 

 4289 -23 

 4295-91 

 4298 -82 

 4300 73 

 4301 -23 

 4306-07 

 4314-95 

 4318-83 



7 

 7 

 7 

 7 

 7 

 7 

 7 

 7 

 8 

 7 

 7 



4186-3 

 4286 -0 



4295 -98 

 4319 -02 



6 

 7 



20 



5 

 15 



12 



10 



Cr, Ti, Wi. 

 Ca, Mn ? 









Grating spectra. 













"Flash" I. 



"Flash" II. 







4427 -28 

 4457-59 

 4518-18 



4533 -42 



4534 -97 

 4544 -83 

 4548-93 

 4552 -62 

 4617 -41 



8 

 7 

 7 



I 



1 ? 



7 



4427-4 

 4457 -8 

 4518 -0 



12 



12 

 5 

 5 



30 

 10 



30 



Ti, Fe. 

 Ti,V,Zr,Mn. 



Here, it will be observed, there are only seven out of the twenty 

 strongest titanium arc lines which have possibly corresponding lines in 

 Frost's eclipse spectra. To three of these eclipse lines he assigns no 

 origin ; to the others he gives compound origins, three of ^ them 

 involving titanium. In no case is the corresponding eclipse line as 



