24 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ']'] 



Another relation has been found by Mr. Clayton. He speaks of 

 it in his paper. When faculae are conspicuous, high solar-constant 

 values may be predicted. Mr. Clayton has gone further. He has 

 made visual solar observations daily with a telescope in Canton, 

 Mass., on every available day for nearly a year, and has sent me a 

 letter the same afternoon in which he has predicted what the solar 

 constant would be 5 days after. After these predictions had been 

 maintained for 7 months, I compared them with our observations. 



.004 



VERific/^T/o/v. Claytons 5- D-4vSoL/\R-Co/vsr/\(vr Forecasts 

 May to Nove-MBLr /9<£4 



iNus26 Da 's Thedict Bdujw -/)0J 



Fig. 17. — Verification of Clayton's solar-constant forecasts. The 

 mean march of solar variation from three days before to three 

 days after Clayton's forecasts is compared for those dates on 

 which he predicted .005 calorie above with those on which he 

 predicted .005 calorie below normal. 



I found a strong correlation which reached its maximimi exactly on 

 the day he predicted for, as shown in figure 17. Mr. Clayton has 

 discovered other relations between solar changes and faculae ob- 

 served on the solar disk. 



Hence, we may claim that the visible appearances of sun spots, 

 faculae, and flocculi on the sun are clearly associated with the short- 

 period variations of the solar constant. 



Thesis (d). — Solar changes are localized to short wave lengths. 



