NO. 3 



PROVISIONAL SOLAR-CONSTANT VALUES ABBOT 



31 



Table 2 contains certain coirections applicable to table 42, pages 

 149. 150. of Volume IV of the Annals of the Astrophysical Observa- 

 tory. These modifications result from computations made by the 

 " short method " with data received from Calama after Volume IV 

 went to press. 



Table 2. — Corrected Solar-Constant Values, 

 Calama, Chile, 1918 



[Vol. IV, Annals of the Astrophysical Observatory, 

 page 149] 



In table 3 we give the decade mean values corresponding to 

 column 8 of table i. We give these values as far back as the year 

 1918 when daily observations were begun. These results are plotted 

 in figure i (p. 34). To fix ideas, we have drawn a heavy line at 1.938 

 calories. This value is the mean of 78 monthly mean values published 

 in table 53 of Vol. IV of the Annals of the Astrophysical Observatory, 

 From the march of these data, the reader may perceive that a very 

 pronounced depression of solar-constant values has occuiTed since 

 March, 1922, but that we may be now returning towards a condition of 

 higher ones. This state of afifairs is not, indeed, surprising, because 

 we have recently passed through the minimum of sun-spots, and are 

 now to expect greater solar activity. See figure 2 (p. 38). 



In order to give a concrete impression of the closeness of cor- 

 respondence between the two stations, we have taken by months the 

 means of the daily differences between the weighted mean values for 

 Harqua Hala and Montezuma. These results appear in table 4. We 

 give also the differences of monthly mean values, with and without 

 regard to signs, for each individual month in table 5. At the end of 

 table 5, we add the means of the same for all years combined. The 

 reader will note that these general mean differences show but little 

 tendency to indicate a separation between the stations of yearly or half 



