26 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. '/'] 



Solar Radiation below 1.911 (2^ below normal) 

 Pressure same day Summer half year 



Solar Radiation 1.9 21-30 (1% below normal) 

 Pressure same day Summer half year 



Solar Radiation 1.931-40 ( 0.5/^ below normal) 

 Pressure same day Summer half year 



-i i.,— J I L 



no 105 



Fig. i8. — Mean pressure deviations from normal following dif- 

 ferent intensities of solar radiation in steps below 1.941, summer 

 half-year. Units in hundredths of an inch. Same day. 



