38 
PROCEEDINGS OF THE VICTORIA INSTITUTE. 
being made of the same size, the results obtained from the en- 
closed thermometers are directly comparable ; which is of the 
highest importance when recording temperatures. 
We often hear our friends say “ oh, it was 92 J downtown 
to-day — what was it at the Gardens?” — our reply is generally that 
it is much lower — “oh, but then St. Anne’s is cooler.”— “No, my 
friend, I don’t think St. Anne’s is cooler when we consider the 
general heat contained in the air, but St. Anne’s is certainly 
cooler when we consider the radiated heat of the many buildings 
which Port-of-Spain contains.” 
The temperature shown by a thermometer in a building greatly 
depends upon the position in which it is placed, and two similar 
thermometers which read when 'placed side by side exactly the 
same, will, when put into different buildings read different degrees 
of heat, simply owing to the fact that they are placed in positions 
not comparable, but when placed in a Stevenson’s screen, the 
real temperature, that is to say, the temperature of the air, mixed 
with the radiated heat of the earth’s surface, is more correctly 
ascertained. 
The temperature of the Stevenson’s screen being lower, shows 
that the system on which it is built gives a due amount of venti- 
lation, and we are thus shown that with a certain amount of 
ventilation given in a proper manner we can render our dwellings 
much more comfortable and conducive to health. 
Direct sunshine should never be allowed to enter any part 
of a house, except during the very early morning or evening, 
when the rays are not powerful enough to raise the temperature 
to any appreciable extent. 
Correct currents of air can be maintained through a house 
if the system followed by the Stevenson’s screen is adopted, 
without creating any discomfort to the inmates, and a cooler 
temperature can be maintained without aff actual or direct 
draught. Where the single jalousie creates a distinct draught or 
straight current, the double jalousie creates a circulating current 
