450 
OX THE MEDICAL TOPOGRAPHY OF SINGAPORE. 
sun, giving us perpetual summer and continuous verdure: Pinang 
and Singapore being islands, and Malacca with an extensive sea 
frontage, always possess a gentle breeze blowing from one quarter or 
another, and being protected by Sumatra on the one hand, and the 
Malay Peninsula on the other, never experience furious gales or 
strong monsoons. But if more than ordinary heat has accumulated 
moisture and electricity, a squall generally sets in attended with a 
smart breeze of wind, and followed by a heavy shower of rain : ve¬ 
ry seldom is the wind unaccompanied by rain, and still more seldom 
is it accompanied by thunder and lightning. These squalls have 
but a short duration, seldom exceeding one or two hours. According 
to the monsoon which blows you will have them rising in that direc¬ 
tion, as seen by the tables of observations taken at the Singapore ob¬ 
servatory in January 1841. During the N.E. monsoon the squalls 
were four in number having their general direction northerly. In 
February the same direction was noticed, while there were six. In 
March there were four, but variable as to direction, for in that month 
the monsoon may be said to be changing. In April, two only were 
observed and they were from the west. In May, there were six in 
the direction of S.W. and N., and lastly in June, their direction was 
S.W, and their number four. Unfortunately this table stops at this 
month and gives but a faint idea of what more commonly occurs, for 
Instead of 4 or 6 a month, it is much more common to have in certain 
months 15 to 20. During the last six weeks (26th April 1848), we 
have had 35 squalls ; but in estimating the average number of squalls, 
this number is as disproportionally great, as the tables of the obser¬ 
vatory are disproportionally under-rated. In the north-east monsoon 
a heavy dark cloud may be seen rising from the sea to theE. or N.E. 
this nimbus has generally an outer border of a lighter color, but 
the cloud itself is to the sight nearly black, and convex in its free 
border. The air that was heavy, hot, and close, now feels cool ; a 
dark ripple is seen on the water, a rushing noise is heard, then is 
felt the breeze, quick in its progress, powerful in its effects, and 
short in its duration; to be followed by a heavy shower of rain. 
These squalls are very periodical in their appearance. If to-day one 
