20 
Introduction: Seasons and Winds. 
China Sea, brings the season of most rain to Borneo north of the equator, 
though the climate of that country is moist at all times of the year. The Sooloo 
Islands and the southern and western parts of the Philippines have now their 
rainy season. See Map III. 
During the other half-year, October to April, the N.E. Monsoon is operative 
and reverses the work of the S.W. Monsoon. Laden with moisture taken up 
in the Pacific it deposits much of it on the northern and eastern parts of the 
Philippines, and, on arriving in Borneo north of the equator, does not bring 
with it so much rain as the S.W. Monsoon. In the Siamese Peninsula, Annam, 
facing the wind, now has plentiful rains, but on the opposite side Siam and 
Cambodia have their finest time of year: ‘‘at this time the sky is frequently 
unclouded for a week together”, but the wind again becomes saturated in pass- 
ing over the Gulf of Siam, and on the opposite coast along the eastern shore 
of the Malay Peninsula “the weather is wet and stormy”. 
The Rains: south of the equator. — In the parts of the Archipelago lying 
south of the equator the S.E. Trade-wind — here called the S.E. Monsoon — 
is the prevailing wind from April till October. Blowing from out of the arid 
deserts of Australia, it leaves the north coast of that country hot and dry, and 
has not time to take up much vapour before it reaches Timor and the chain 
of islands stretching between there and Java. Consequently these islands have 
now their dry season, and the vegetation of Timor — which country is probably 
the driest of all — is said by Wallace to have an aspect strikingly similar to 
the Australian. Before reaching the west end of Java the S.E. Monsoon, having 
passed over a wide stretch of ocean, has gathered moisture, and this part of the 
island now receives ample quantities of rain, though not in such abundance as 
is the case there during the returning N.W. Monsoon, which is the bad season, 
and the vegetation here is consequently most luxuriant. The same holds good 
even in a still greater degree for the west coast of Sumatra south of the 
equator, where there is still less difi"erence between the two seasons. During 
this Monsoon it is also the fine season in South Borneo and in almost the whole 
of Celebes; but further east this is now no longer the case. The winds that 
reach the shores of the Gulf of Tomaiki in East Celebes, the southern coasts 
of Bum and Ceram, the Islands of Kei and Am, the S. W. Coast of New 
Guinea, etc., pass from the South Pacific Ocean either through the Torres 
Straits or over the Cape York Peninsula across the Gulf of Carpentaria; thus, 
there are no broad lands in the way to receive their moisture until they reach 
the above-mentioned territories, which now have their rainy season. The high 
mountain-chains of New Guinea and the ranges which intersect the islands of 
Ceram and Bum serve to retain the clouds brought up by this Monsoon, and 
here again occurs the phenomenon of the rainy season on the south side of an 
island and the fine season on the north. 
These conditions are reversed during the counter Monsoon, the N.W . Monsoon, 
which predominates from October to April in the Archipelago south of the 
