Smithsonian Report, 1930.— St. John 



PLATE 1 



^,^ 



1 Drawing by Kircher and Scheiner. 1635. from the Copy of Kircher's 

 ■MuNDus Subterraneous" (Amsterdam. 1678) in the Library of Mount 

 Wilson observatory 



2. Disk of Sun and Prominences from Combinrd 

 Spectroheliograms in the K light of Calcium. 

 1916 



