630 Solar Vortices and Magnetic Fields. [May 14, 



account such rapid decrease in strength at higher levels as is actually 

 observed, would be altogether incompetent to account for terrestrial 

 magnetic storms. 



In concluding, I wish to express my appreciation of the assist- 

 ance I have received from my colleagues at Mount Wilson. I am 

 particularly indebted to Messrs. Adams, Ellerman, King, Nichols 

 and St. John for aid in connection with the present investigation. 



[G. E. H.] 



