NO. 7 



THE ATMOSPHERE AND THE SUN CLAYTON 



15 



1 2-month period. The 6-month period and the annual period in pres- 

 sure were computed in this way for stations all over the northern 

 hemisphere from the data in " World Weather Records " for the 



Fig. 9. — Departure from normal pressure by months with high solar 



activity. 



months when solar activity was high and for the months when solar 

 activity was low as given in table 2. The results for the 6-month 

 period when solar activity was high at the epochs April and October 

 are shown in figure 10 plotted on a map of the northern hemisphere. 



