PLATE II. 



Fig. 1. — Full-sized reprodnction of a photograph of tho H and K lines in the 

 solar spet'truin, made with the curved tirst slit. The twt) curved slits regularly 

 einiilnycd with the s[)ectr(iheliograph to ciiiiiinate distortion of the solar image 

 have a radius of 522 mm., ecjual to that of the r-urved lines here shown. 



Flu. 2. — II and K lines on the solar disk and in the chromosphere (radial 

 slit). 



Fig. 2a. — ^hows llg and K3 (very faintly) in a prominence. 



147 



