NO. 10 SOLAR-CONSTANT VALUES ABBOT 9 



The average deviation between observed and synthetic curves, taken 

 without regard to sign, from the middle of 1923 to the end of 1945, 

 is 0.00177 calorie, or 0.081 percent of the solar constant.^ This very 

 surprisingly satisfactory fit between the observed and the synthetic 

 curves seems to me to support my action with respect to the 91 -month 

 periodicity, as described above. For this period repeats three times. 

 If the increasing importance of the unremoved part of the 6-1/16- 

 month period toward the latter part of the 91 -month periodicity was 

 spurious, and caused by some large irregularity in a few years, then 

 it would not be expected that to include these large ups and downs in 

 the 9 1 -month periodicity would so precisely satisfy the original ob- 

 servations, right through the entire interval 1923 to 1945. Following 

 the prophetic curve back from 1923 to 1920, the great depression of 

 the observed curve in 1922 is not found in the prophetic curve. But 

 the principal features observed in 1920 and 1921 are well indicated in 

 the prophetic curve. It will be of great interest to compare the obser- 

 vations, when they become available, with the prophetic curve from 

 1946 to 1951. 



It is impossible at present to be certain whether the failure to follow 

 the observations in 1922 is caused by defective observations, as already 

 suggested, or by a deviation of the sun's output of radiation, at that 

 time, from its normal course, which may represent a feature of a 

 longer periodicity, such as 45^ or 91 years. 



The system of long-range solar periodicities that I now prefer is 

 given in the Hues marked "1945" of table 2. Like the curve of the sun- 

 spot cycle of 113- years, the curves of these periodicities in the solar 

 constant are not regular sine curves, but their forms are given by the 

 tabulations, as in figure i and table 3. I see no advantage in forcing 

 them to conform to Fourier's series procedures. 



2 It will be noted that the curves of figure 2 come too close together at the 

 end of 1945. As this paper was in press, work on the 1946 observations reached 

 a stage which showed something wrong at Table Mountain. If Montezuma 

 results Oct.-Dec, 1946, are used alone, the anomaly disappears. 



