32 
Introduction: Seasons and Winds. 
As a general conclusion it may be stated that Borneo south of the equator 
has its fine season during the months of our summer and its wet one in those 
of our winter. A little north of the equator the conditions are much the same, 
the differences being that the rainfall is more copious, and that the wet and 
fine seasons commence a little earlier in the year. August, when the S.W. Mon- 
soon of Asia is in full force, appears to be a very wet month here, as it is 
also at Labuan, Mempakol, Gaya on the N.W. coast of the island, and at 
Banguay Island off the north point of Borneo. On the N.W. coast the figures 
from four stations show a strongly marked minimum rainfall in February; the 
fine period appears to last for about three months only, January — April. On the 
North and N.E. coast the true wet season takes place in the N.E, Monsoon and 
the true dry season about the period of the shifting of the winds, February — May. 
Sumatra. — Dr. van der St ok shows that very varying conditions prevail 
upon the different coasts of this great island. 
In the Malacca Straits land- and sea-breezes are general, neutralizing the 
effect of the Monsoons. The wettest months along this part of the coast of 
Sumatra are from October to December, the rains being apparently brought up 
by the N.E. Monsoon out of the China Sea and the Straits. The dry months 
are February and March, and also June and July, there being here, as in North 
Borneo, a second rainy and fine period. 
At the northern end of Sumatra the S.W. Monsoon/ is much more marked, 
being felt from May till October, and bringing the rains with it from the 
Indian Ocean. February and March, when the E. Monsoon is blowing, are the 
finest months. 
Along the N.W. coast down to the equator it is hard to speak of any 
rainy — or one might better say of any fine — season. South of the equator 
down to the Straits of Sunda the wettest months are from September to De- 
cember, and the driest May to August, with a reduced rainfall in February. 
In South and S.E. Sumatra the Monsoons are well marked, the dry season 
being produced by the S.E. Monsoon from April or May till September, the 
wet accompanying the northerly and westerly winds which prevail from November 
to March. 
The Bintang.) Lingga, Karimon., Timhidan., Aiiamhas^ Natuna, and Serasan 
Islands: groups of small islands in the South China Sea between Malacca and 
Bangka and Borneo. — These islands receive the rains of both Monsoons and 
are very wet almost the whole year, the greatest number of fine days occurring 
in January, February and March. The climate is not considered unhealthy. 
Banka., Billiton and the Straits of Karimata and Gaspar. — Here the climatic 
conditions are very changeable, varying on the land at different altitudes. The 
greatest amount of wet is brought up by the N.W. Monsoon in November, 
December and January; there is a minimum of rainfall in February, but the 
driest months are July, August and September. In Banka the temperature on 
the coast is given as 2D — 24“ C. (17“ — 19“ R, 70“ — 75“ F.) during the night 
