362 



A STUDY OF COKUELATIONS AMONtJ TERKESTKIAL TEMPERATURES. 



The South American products being formed in the same way, the results of their 

 summation are : 



-Lvv' = + 4 



It will be seen that, while there seems to be a general tendency toward a positive 

 correlation, the largest part of A arises from the two combinations India-Batavia and 

 Batavia-Australia. These pairs being in comparative geographic proximity, we may 

 well throw them out. The remaining pairs give : 



Hence, 



Whole number of products, 2924 

 Sum of all these products + 96 



Mean vv' = mean t^- = -f 0.033 



Mean t„ = ± 0°.18 C. = ± 0°.32 Fahr. 



It therefore seems that the monthly departures of temperature indicate fluctua- 

 tions in the general world temperature of which the general amount is about ± 0°.18 C. 

 on each side of the normal mean value This is scarcely greater than the degree of 

 correlation which we should expect to be shown from our omission to correct the nor- 

 mal tables for the sun-spot inequality, and from the systematic deviations of the 

 annual temperature brought out in §9. The evidence is therefore rather weak in 

 favor of very minute fluctuations in the sun's radiation for periods greater than one 

 month and less than several years. If they exist, they are too small to produce any 

 noticeable meteorological effect. 



