NO. 



SOLAR RADIATION AND THE WEATHER CLAYTON 



Example. — Where 11=12 (it might be 12 observations at intervals 

 of two hours, or 12 observations at intervals of one month, or 12 

 observations at intervals of one year), 



A, = j\I>',Zl'lr, (11) ^i = -J-2o7,cos<^,, (12) B, = ^X^' I, sin cf>,, (13). 



In which Ir is equal to successive values of / from to « — i and (/>,- 

 successive values of (f> from to n— i. 



By assigning- various values to r, periods of any length may be 

 computed. ^ 



90 



Fig. 7. 



Before applying these formulas to a search for hidden periods 

 several tests on known periods were first made. Taking some known 

 period like that of the daily change of temperature, the values of 

 and of a were calculated for successive individual periods, say for 

 22 hours, 23 hours, 24 hours, and 25 hours. 



When the computed values of 6 and a were then plotted on a dia- 

 gram like figure 8, it was seen that when the trial period was longer 

 than the true period, the successive values of fell along a line 

 diverging from the horizontal line and beneath it as AC. When the 

 trial period was of the correct length the dots fell along a horizontal 

 line showing no change in 6 ; but when the trial period was shorter 



