NO. 9 PERIODICITY IN SOLAR VARIATION ABBOT AND BOND 



named, it becomes of interest to see it these same periodicities are 

 traceable in temperature departures of the weather. We have inves- 

 tigated this question for three widely separated United States stations, 



Fig. 4.— Temperature departures, Clanton, Ala., and their periodicities. A, 

 original data; C, 8-month; D, gi-month; E, i8-month; F, 2i-month; G, 

 25-month; H, 34-month; I, 39-month; J, 45-month; K, 68-month; B, residual 

 after removing periodicities, shows iii-year periodicity. 



viz. : Clanton, Ala. ; Washington, D. C, and Williston, N. Dak. We 

 have taken our data from the climatological summaries of the United 

 States Weather Bureau, 1918 to 1930. In order to eliminate the 

 yearly march of temperature, we have computed for each station the 



