NO. 



SOLAR RADIATION AND THE WEATHER— CLAYTON 



43 



from the average from about lo months while the upper was derived 

 from the broken averages of several years. 



Examining part II of table XV, it is seen that the maxima, although 

 considerably scattered, tend to group themselves about certain 

 periods, as for example 26-J and 34 days and their submultiples, while 

 there is also some evidence of grouping around 29 days and 40 to 

 42 days. The largest values are near the submultiples of 34 days, 



Table XV. — Amplitudes of Periods in Solar Radiation 



(Fourier Series of 23 to 44 days) 



Part I. — Mean Radiation Values at Sun-Spot Maxima following 



VALUES OF 2.00 



Part II. — Mean of all values, July, iqiS-May. 1919 



Unit equals o.ooi gram calory per sq. cm. per minute. 



as if these were the strongest periods in solar radiation and the range 

 of oscillation (twice the amplitude) is about 0.016 calory, or nearly 

 I per cent of the total mean radiation value. 



That the maxima do not come exactly at subdivisions of certain 

 periods is perhaps due to the fact that the period of time used is short 

 and the observations much interrupted, or it may be due to the fact 

 that the lengths of the periods are not exact, but oscillate around cer- 

 tain mean values. The proper interpretation can only be determined 

 by a longer series of observations, although the evidence at present 

 seems in favor of the latter. 



