NO. 7 ASTROPHYSICAL OBSERVATORY, I9O4-I953 — ABBOT 



13 



necessarily as super-riders, the existence of nearly all of the 27 periods, 

 harmonics of 273 months, which we use in forecasting weather. 

 Similar clearing gives similar sine-curve results for long periods at all 

 54 stations so far forecasted. 

 Referring now to figure 21 of Pub. 4545,^ it shows the actual plus 



Fig. 3.— Kiev, U.S.S.R., Precipitation. 34i Month Period Cleared. 



and minus quantities which resulted from tabulations I made for 

 St. Louis, working on them alone without electronic assistance. These 

 23 columns of figures, being added, gave a 20-year back-cast from 

 the mean date 1897 of the precipitation at St. Louis, 1875-1879. It is 

 nearly identical with the actual precipitation observed. As stated in 

 Pub. 4211,^° all that work was done on 5-month consecutive means 



1° 60-year weather forecasts, by C. G. Abbot. Smithsonian Miscellaneous 

 Collections, vol. 128, No. 3. 1955. 



