TOTAL RAINFALL IN M.M. IN THE MONTHS JULY, AUGUST, AND SEPTEMBER 
Wet East monsoons Dry East monsoons 
Batavia | Ternate | Koepang Batavia | Ternate | Koepang 
1880 363 599 0 1881 121 268 0 
82 144 485 36 83 30 254 0 
89 148 4715 4 85 22 61 0 
90 290 452 18 88 34 42 1 
92 248 353 I 91 102 321 0 
95 262 470 44 6 | 51 393 0 
98 162 402 10 E902, es 16 | 38 0 
1900 146 LN OE: 05 119 261 22 
04 340 145 16 11 155 133, | 0 
06 364 434 3 
09 215 697 àl 
10 258 305 5 
Average 245 432 Ta 72 197 3 
Archipelago as far as Australia. They are regular and can with 
great approximation be represented by a series of waves with periods 
of 3 to 5 years; the other periods are quite subordinate. As a 
typical example we mention the amospheric pressure at Port-Darwin 
where not only the amplitude is maximal, but also the variations 
are characterised by an extraordinary regularity '). For this reason 
in what follows the rainfall in various parts of the Archipelago has 
been referred to the indications of the barometer at this station. 
The stations whose observations are regularly published by the 
Batavia Observatory under the title ‘Rainfall observations in the 
Dutch East Indies” were arranged in groups, containing places of 
approximately similar situation. These contain from 1 to 5 stations 
and are: 
1 North Sumatra, 2 North East Sumatra, 3 East Middle Sumatra, 
4 Padang Highlands, 5 West Middle Sumatra, 6 South East Sumatra, 
7 South West Sumatra, 8 West Borneo, 9 South Borneo, 10 North 
coast of West Java, 11 the Preanger district, 12 North coast of 
1) Cf. Meteorologische Zeitschrift, Heft 1, 1912, p. 1, 
