Smithsonian Report, 1904.— Hale and Ellerman. 



Plate II. 



(a) 



(b) 



(c) 



Fig. 1.— Curvature of 

 Lines in the Spectro- 

 heliograph. 



Fig. 2.— H and K Lines on the Disk, in the 

 Chromosphere, and in a Prominence (a). 



