Introduction: Seasons and Winds. 
21 
equator, and the lands, which had their dry season before, now get their wet 
one, and those, which then had their rainy season, now have their fine one. 
Though easy to be understood, this alternation of the seasons is often not a 
little striking. See Map iV. 
Professor van der Stok of Batavia recognises 4 different types of Monsoons 
in the East India Archipelago, about which he has most obligingly sent us (in 
lit.) the following particulars. 
“There are various types of Monsoons in the Indian Archipelago: 
“First, the perfectly regular, the S. E. Trade-wind, or the S. E. Monsoon 
blowing out of Australia, which prevails in the southern parts of the Archipelago 
from April till October, characterized by dry weather (instances: Java, Bima in 
the Lesser Sunda Islands, Macassar, S. Celebes, and Banjermassin, S. Borneo); 
while from October to April the heavily saturated West Monsoon is in force. 
“A second type is found, as your map^) also shows accurately, in South and 
Middle Sumatra, especially on the west coast, and in the middle portion of 
Borneo, where all through the year a tolerably equal quantity of rain descends 
(instances: Padang, Siboga, Sintang, Singapore). For these conditions also your 
map is suitable. 
“It is otherwise with the third type, of which examples in North Sumatra 
and North Borneo are recorded. Here it is not possible to divide the year into 
two halves in such a manner that the one contains the dry, the other the wet 
season. (See below p. 29 under Borneo.) 
“Finally a fourth type is found in the eastern parts of the Archipelago 
where, as in Amboina, Saparua, etc., the Monsoon-periods — at least on the 
south side of the Island — are exactly reversed [as compared with the first 
type], as your map also shows. As a whole Celebes also lies under the southern 
Monsoon-division, for in North Celebes there is still to be found only a trace 
of the February minimum whereby North Sumatra and North Borneo are 
characterized”. 
Change of climate at different altitudes. It is probably always the case that 
the highlands of tropical islands have a very different climate from the coasts 
and plains. In April, 187J , when the fine season had begun at Manado, 
Meyer could not start for the mountains of the Minahassa, as the rainy season 
was still going on there. The following table shows this: 
Average 
April 
May 
June 
July 
of years 
mm 
mm 
mm 
mm 
Masarang (highlands) 
15 
256 
249 
228 
135 
Manado (coast) .... 
17 
205 
167 
179 
125 
In Java where meteorology has been much more thoroughly studied than 
elsewhere in the Archipelago, Dr. J. J. de Hollander (Handl. Land- en 
1) An original MS. map, since revised and modified. 
