NO. 5 SOLAR VARIATION AND FORECASTING ABBOT 



19 



1918 



1919 



1920 



1921 



1922 



SEPT JAN. MAY SEPT JAN. MAY SEPT. JAN. MAY SEPT. JAN. MAY SEPT. 



NOV. JAN. MCH. MAY JULY SEPT. NOV. JAN. MCH. MAY JULY SEPT. 



1922 



1920 1921 



Fig. II. — Monthly mean solar-constant values and individual results of 1920- 

 1922 at Harqua Hala and Montezuma. The curve shows the great fall of solar 

 radiation beginning February, 1921. 



