NO. 9 PERIODICITY IN SOLAR VARIATION ABBOT AND BOND 



II 



curve B, and has a very different phase from corresponding curves at 

 Clanton and Washington. 



In order to fix our ideas of the relations between solar and terrestrial 

 periodicities which we have discovered, we give in Table i a summary 

 of them. We invite attention to the fact that a majority of the peri- 

 odicities in terrestrial temperatures which we have found are identical 

 in length with periodicities in solar variation. The sum of the maxi- 



Table I 



mum amplitudes of these periodicities which may be of solar causation 

 is much greater than the sum of those which appear to be of terrestrial 

 origin. In fact, if we make the hypothesis that a terrestrial tempera- 

 ture departure periodicity is of solar causation if it is of identical 

 period with a solar periodicity, then we shall come to the result that 

 nearly the whole magnitudes of the ranges of terrestrial temperature 

 departures from normal used in our analyses are due to variations of 

 solar radiation. 



