NO. 10 SOLAR RADIATION AND WEATHER STUDIES ABBOT 55 



spectively, some interval between 272 and 276 months divided by the 

 following numbers : 



39, 34, 28, 2$, 20, 13, II, 8, 6, 5, 4, 3, and 2. 



d. The fourteenth period is the terrestrial period, 12 months, which 

 would certainly exist because no single expression of the march of 

 the monthly mean temperature or precipitation fits satisfactorily over 

 an interval of a century or more. 



e. The amplitudes of the 14 periodicities vary with respect to each 

 other and also from time to time. 



f . The phases of the 14 periodicities vary from time to time. 



g. In a majority of cases the periodicities retain approximately the 

 same phases, and to a less degree approximately the same amplitudes, 

 through either 23 or 46 years, and then abruptly alter. 



h. In a minority of cases abrupt changes in phase and amplitude 

 occur after a lapse of 11^ years. 



i. The 12-month periodicity is no exception to the general rules laid 

 down under g and h. 



j. Almost without exception, when phases remain unchanged 

 through 23 years, such a 23-year interval begins an integral number 

 of times 23 years after January 181 9. 



k. The amplitudes of the periodicities disclosed in the temperature 

 at Berlin range from o.°2 to i.°5 Centigrade. As stated in another 

 form under b, these 14 periodicities combined account for about one- 

 third of the whole range of 5-month smoothed departures from the 

 normal in the temperature of Berlin. The amplitudes of temperature 

 departure periodicities at other stations are of comparable magnitudes. 

 In precipitation the amplitudes range from 20 to 300 percent. Here 

 also the synthesis of the 14 periodicities found accounts for a sub- 

 stantial part of the entire departures from normal in the 5-month 

 smoothed values. These are by no means as striking results as were 

 found in respect to the periodic features in the solar variation reported 

 in caption 6. But it must be remembered that the terrestrial effects 

 are subject to various disturbing intermediate influences, besides the 

 original solar causes. 



1. Attempts to substitute some other set of periodicities, not related 

 to the 23-year interval, are conspicuously less successful either to 

 display continued periodic fluctuations or to bring to light any con- 

 spicuous regularities of behavior such as those stated under g and h 

 above. 



m. Other stations as widely separated from Berlin as Cape Town 

 and Adelaide show similar results in temperature and rainfall with 

 regard to numerous periodicities approximately integrally related to 

 23 years, and governed in phase and amplitude by the lapse of integral 



