( 319 ) 



the normal law leads to a iar less satisfaclory result for this place 

 than for Helder. The two values h and 1i! of the factor of steadiness 

 show considerable and systematic discrepancies, the calculated values 

 of Jt for May to August being collectively too great, and those for 

 the other months too small. Although the total mean, 3.235, does 

 not differ more than 3 7o ft'om the real value, these differences 

 amount to -f 15.7 7o in the five dry months and to — 6.5 7o 

 in the seven months of the wet season. 



Here, therefore, the secular variability cannot be regarded as a 

 purely accidental quantity unless another law, more complicated 

 than the normal one, applies and which is in some degree dependent 

 upon the monsoons. This might be the case if the atmospheric pressure 

 were dependent (and in a dilferent manner in different seasons) upon 

 another factor, for instance the temperature, the variability of which 

 might still be according to the law of accidental quantities. 



Similar systematic differences, varying with the season, between the 

 calculated and the real value of :it are not apparent in the results 

 of the calculations for the atmospheric temperature in France, and 

 the general average value of :;r does not differ from the real value more 

 than 0.13 V^. 



TABLE in. Monthly means of atmospheric temperature, France. 



