HemsalecS. 



Phil. Mag, Ser. 6, Vol. 40, PL VIIl 



Red Bands of Calcium in Fringe and Luminous Vapour. 



Q> co 



C^ Ol 

 CO CD 



\/ 



Upper 

 Red Fringe. 



Edge 

 of Plate. 



Lower 



Red Fringe 



Lower 



Luminous 



Vapour. 



^1 



til 



^ 



<o\ 



col 



\ 



«Oi 



Ni 



o> 



r M 



(*) 



SJ- 



co| 



col 



CO 



Mode of 

 £~x-r/tation. 



> thermo - chemical 



the r mo- electrical- 



thermal. 

 J thermo -electrical. 

 > thermo -chemical 



Plate temperature : about 3000' C. Drop of Potential along plate : about 8 -^— ~ 



