4/24 One substantial fact has been established, owing to our having crossed over ten degrees of latitude in the centre of the continent, or from 5 deg. north latitude, which is this: There exists a regular gradation of fertility, surprisingly rich on the equator, but decreasing systematically from it; and the reason why this great fertile zone is confined to the equatorial regions, is the same as that which has constituted it the great focus of water or lake supply, whence issue the principal rivers of Africa. On the equator lie the rainbearing influences of the Mountains of the Moon. The equatorial line is, in fact, the centre of atmospheric motion. |