( 375 ) 



TABLE V. a = - C, formula in seriesform. 



The question whether or not Pearson's formula (1) leads to an 

 equally satisfactory result can be readily answered by supposing 

 formula (1) to be expanded according to formula (5). Then, of 

 course, the coefficients A x and A 3 will be the same whether calcul- 

 ated directly or with the help of a and b and, as the fourth term 

 plays an unimportant part, all depends upon the third term which 

 is determined by the mean of the third order ft,. 



If by means of (3) we calculate ft, from a and b, we find : 



by (3) 

 0.0631 0.0641 

 0.0859 0.0856 

 0.1683 0.1917 



From this we may conclude that, for the months of transition 

 formula (1) will lead to excellent results; for the West-Monsoon the 

 agreement will be satisfactory; but for the East-Monsoon rather 

 large discrepancies are to be expected. 



25 



Proceedings Royal Acad. Amsterdam. Vol. XI. 



