symmetrical disposition of the climates is completed by the regular alternation of winds and rains in the zones of Mauritania and the Cape of Good Hope, both belonging to the region of sub-tropical ruins, which fall in the respective winters of each hemisphere. Africa is thus disposed from north to south in successive grey and more or less intensely green belts, presenting to the inhabitants of the other
Fig. 5.—Distribution of the Rainfall in Africa.
Scale 1 : 7,500,000.
planets an aspect perhaps analogous to that offered to our gaze by the parallel cloudy zones round about Jupiter.
These different zones of moisture, whose limits coincide in several places with the isothermal lines, are developed across the continent with sufficient regularity to enable M. Chavanne to map them out. Africa is more sharply distributed in distinct regions by its deserts than it could have been by broad arms of the sea,