NO. 3 SOLAR VARIATION AND WEATHER — ABBOT I3 



Table 1. — Accuracy of solar obsen>ations 



Mean difference Number of 



Station Pair Calories -i- 10,000 comparisons 



Montezuma— Table 76.8 891 



Montezuma — Tyrone 79.6 283 



Montezuma — Mount St. Katherine 76.0 616 



Table— Tyrone 77.9 202 



In tabulations which we make of forms and amplitudes of harmonic 

 solar variations, these range from 4 to 91 months in periods. Results 

 on the solar-constant periods rest on mean values of tabulations of 

 between 10 and 100 months, their numbers increasing as their period 

 decreases. So the individual points on a periodic curve computed 

 from monthly values will have probable errors ranging from 

 1/20^ VTO down to 1/20-4- VTOO of 1 percent of the solar constant. 



Fig. 9. — Smithsonian pyranometer. 



