NO. 3 



EFFECT OF SOLAR RADIATION CLAYTON 



3 



the annual period, because changes due to the north and south move- 

 ment of the sun are different from changes which may arise from the 

 variabiHty of the sun's heat. In order to eliminate the annual change 

 of temperature and other changes of long period, monthly means 

 were obtained, and from these means daily values were obtained by 

 interpolation made arithmetically or by curves drawn through these 

 values. If the mean of the daily maxima of temperature in September 

 is 28.1° C. and that of October is 19.1° C. the mean daily change for 

 the seasonal effect is 0.3° C, and successive daily values were obtained 

 by subtracting 0.3° C. each day. Thus 28.1° would be the value for 

 September 15; 27.8° for September 16; 27.5° for September 17; etc. 

 Subtracting these values from the observed values a series of plus 

 and minus values were obtained showing the short period oscillations 

 of temperature. These deviations from the mean were arranged in 

 tables in the following manner : 



Table i 



In this table the values under 3; in column (o) show the departures 

 of the temperatures at Pilar on the same date as the solar measure- 

 ments. Those in column (i) departures on the day following the 

 solar measurements, etc., up to four days after the solar measure- 

 ments. The values under y^ show the values of y squared (yy), and 

 the values under xy show the product of the radiation deviations x 

 and the temperature deviations y. From a table like table i the data 

 were obtained for use in formula i. 



The values of the correlation coefficient for Pilar obtained in this 

 way for 1913 and 1914 were as follows : 



