I 
THE CLIMATE AND PHYSICAL ASPECTS OF THE EQUATORIAL 
ZONE 
The three Climatal Zones of the Earth—Temperature of the Equatorial 
Zone—Causes of the Uniform High Temperature near the Equator— 
Influence of the Heat of the Soil—Influence of the Aqueous Vapour 
of the Atmosphere—Influence of Winds on the Temperature of the 
Equator—Heat due to the Condensation of Atmospheric Vapour— 
General features of the Equatorial Climate—Uniformity of the Equa- 
torial Climate in all parts of the Globe—Effects of Vegetation on 
Climate—Short Twilight of the Equatorial Zone—The aspect of the 
Equatorial Heavens—Intensity of Meteorological Phenomena at the 
Equator—Concluding Remarks. 
Ir is difficult for an inhabitant of our temperate land to 
realise either the sudden and violent contrasts of the arctic 
seasons or the wonderful uniformity of the equatorial climate. 
The lengthening or the shortening days, the ever-changing 
tints of spring, summer, and autumn, succeeded by the leafless 
boughs of winter, are constantly recurring phenomena which 
represent to us the established course of nature. At the 
equator none of these changes occur; there is a perpetual 
equinox and a perpetual summer, and were it not for variations 
in the quantity of rain, in the direction and strength of the 
winds, and in the amount of sunshine, accompanied by corre- 
sponding slight changes in the development of vegetable and 
animal life, the monotony of nature would be extreme. 
In the present chapter it is proposed to describe the chief 
peculiarities which distinguish the equatorial from the tem- 
perate climate, and to explain the causes of the difference 
between them,—causes which are by no means of so simple a 
nature as are usually imagined, 
