46 Mr. J. N. Lockyer. On the Classification [Apr. 12, 



Table of Brighb Lines in 7 Cassiopeia?. 



Secclii. 



Vogel. 



Huggins. 



G-othard. 



Konkoiy. 



Sherman. 



Probable origin. 



C. 

 B,. 



F. 



D 3 . 

 F. 



C. 



r> 3 . 



F. 



C. 



Da- 



F. 



C. 

 Pa- 



F. 



a. 



C. 



635-6 

 616 



r> 3 - 1 



584? J 

 555 75 

 542-2 

 530-98 



OlO / O 



499 

 F. 



462-3 



a. 



418 

 h. 



H. 



(?) Limerick Met, 

 Fe. 

 Mn. 



Mn. 



Mn. 



(?) Coronal line. 



Q 



Mg. 

 H. 



H. 



H. 









Dark Lines. 













633 

 589 



517 (b) 



666-2—656 

 659-0—624 

 589 



516 (b) 

 431 



628 



576 



502 

 492 

 467-35 

 3993 



D. 



b. 



vol.6 of the O'Gyalla Observations, records the same in 7 Cassiopeia?. 

 When we consider the great variations in brightness of D 3 in these 

 stars and the great changes in the conditions of the radiating 

 meteorites and their atmospheres, indicated by these changes of 

 brightness, these apparently discordant results are not so difficult to 

 understand. An increase in the number of meteorites containing Mn 

 would cut out all the D absorption and brighten D 3 ; an increase of 

 sodium and a decrease of Mn would cause the D dark lines to assert 

 themselves, while the condition of bright D 3 and dark D is obtained 

 by increased quantities of Mn and 2Ja vapours produced by collisions.* 



Sherman does not record dark b lines, although Konkoiy observed 

 them several times. Sherman, however, saw the bright carbon at 

 517, which would completely mask the b lines. It seems possible 

 Konkoiy saw this bright carbon, and by contrast with the surrounding 

 spectrum, imagined he saw the dark " b " lines — at any rate no other 

 observer has recorded dark b.' 



Sherman saw the magnesium 500, while neither Konkoiy nor 



* Konkoly's D 3 extends quite up to D dark and seems more like a fluting than a 

 bright line. 



