( 561 ) 
Table IV exhibits the values of the constants 4 and A 
calculated by means of these formulae. 
Hither formula gives a good image of the characteristic differences 
of the curve in the course of the year, viz. the sudden transition 
in April, the congruity between the curves for April and August 
and the single and double annual variations in the phenomenon. 
If we define as normal the curve obtained by putting p= 1 in 
Pwarson’s formula and A, =O in the series-formula, both formulae 
assume the form: 
as 
3 
u= Ae—th x 
and we see from Tables [IL and IV that in the East-monsoon the 
curve approaches the normal form; in April, May, August and 
September its shape is almost fully normal, but in June and July 
the curve clearly shows considerable deviations from this simple type. 
Peculiarities of this kind are not perceptible in the rainfall during 
these months at Batavia, but in some other places, more directly 
exposed to the influence of the South-Kast-monsoon as Tjilatjap, a 
rather large increase of rainfall obtains after April, thus giving rise 
to a secondary maximum. In the West-monsoon the deviations from 
the normal type are greatest. 
4. Owing to the rather large irreguiarities in the data, the 
monthly frequencies as given in Table II are not very suitable to 
serve as material for putting frequency-formulae to the test of a 
comparison between observed and calculated aggregate values; for 
this purpose, therefore, all frequencies for the period April to 
November have been taken together and reduced to a total of 1000. 
(Table V). 
In the last column of this Table frequencies are given between 
the limits « and 0, which frequencies are to be compared to the 
corresponding values calculated from the formula: 
HH 
B= f ude 
0 
For the constants of the formulae we find: 
== 0 STAT U — 0.5366 
A, = 0.6429 m = 0.5576 
p = 0.2222 
The integration of the series-formulae between the limits 2 and 
38 
Proceedings Royal Acad. Amsterdam. Vol. XI. 
