570 E. HUNTINGTON SOLAR HYPOTHESIS OP CLIMATIC CHANGES 



Av. Longitude ■; 

 , ■ 60°-65°W; 

 Max. 



Loui^tudo 

 110"- US" W 





1 ^ 



40 





— ^^ 







ll> 



W 



Min. 



Max. 



Lougitudt 

 120' -]•_•.■>• W. 



litiije 

 95- W 



SO'' N. 



Figure 19 — The douhle Storm Belt of the United States 



Av. = Average number of storm centers during the 30 j'ears from 1883 to 1912 

 Mn. := Average number of storm centers during 12 years of minimum spots 

 Mx. = Average number of storm centers during 9 years of maximum spots 

 6x = Average number of storm centers if the departure of Mx. from Av. were increased 



sixfold 

 B = Boreal storm belt 

 S ^= Subtropical storm belt 

 The figures on the left of each diagram indicate the scale on which the number of storm 

 tracks is plotted 



