438 Proceedings of the Royal Physical Society. 
grave,” which is given to this part of Africa, is well deserved. 
The conditions which are so inimical to the white races in 
this region are continuous heat, excessive moisture, and 
sudden changes of weather, but much may be done to 
render the climate more salubrious by sanitary precautions. 
On the whole coast probably the Cameroon mountain system 
is the only place of sufficient altitude to form a really 
valuable health resort, but the Portuguese coast is not so 
unhealthy as that farther north. 
A rapid summary of the climatological conditions which 
obtain in the various regions along the west coast must now 
follow. 
First, with regard to the coast of Senegambia. The mean 
annual temperature is 75° F.; the mean diurnal range 9° F. 
The average rainfall is about 18 inches; the average humidity 
73. The hottest months are June to November. In the 
interior of the country the mean annual temperature is 
about 83° F., the hottest months being April to June. 
There is considerably more variation in the temperature in 
this inland region, it having an average for the year of 18° F. 
At Bathurst, which is situated on St Mary’s Island, the 
chief rains fall from July to September, about 39 inches 
falling in 80 days. At Sierra Leone the mean annual 
temperature is 82° F.; the rainfall 100 inches in August 
and September. On the Gold Coast at Accra the mean 
annual temperature is 80° F.; the mean range about 7° F 
Humidity is very high, averaging about 75 per cent. The 
rainfall varies considerably, some years being as low as 23 
inches, in others nearly 40. The rainy season begins at the 
end of March and continues to June. The dry season is 
from November to March. 
We may take the climate of Lagos, still farther to the 
east, as another example of the meteorology of Western 
Africa. The dry season obtains from the beginning of 
December to the middle of March; then follow the hea 
rains until the middle of July; fo then till September 
‘there is a moderate amount of rain until the end of 
November. There is however some rainfall during each 
month, but only about 1 inch from December to March. 
