A number of causes, many of them still but little understood[18], diminish the dryness and heat of the New World. Among these are: the narrowness of this extensively indented continent in the northern part of the tropics, where the fluid basis on which the atmosphere rests, occasions the ascent of a less warm current of air; its wide extension towards both the icy poles; a broad ocean swept by cool tropical winds; the flatness of the eastern shores; currents of cold sea-water from the antarctic region, which, at first following a direction from south-west to north-east, strike the coast of Chili below the parallel of 35° south lat., and advance as far north on the coasts of Peru as Cape Pariña, where they suddenly diverge towards the west; the numerous mountains abounding in springs, whose snow-crowned summits soar above the strata of clouds, and cause the descent of currents of air down their declivities; the abundance of rivers of enormous breadth, which after many windings invariably seek the most distant coast; Steppes, devoid of sand, and therefore less readily acquiring heat; impenetrable forests, which, protecting the earth from the sun’s rays, or radiating heat from the surface of their leaves, cover the richly-watered plains of the Equator, and exhale into the interior of the country, most remote from mountains and the Ocean, prodigious quantities of moisture, partly absorbed and partly generated—all these causes produce in the flat portions of America a climate which presents a most striking contrast in point of humidity and coolness with that of Africa. On these alone depend the luxuriant and exuberant vegetation and that richness of foliage which are so peculiarly characteristic of the New Continent. If, therefore, the atmosphere on one side of our planet be more humid than on the other, a consideration of the actual condition of things will be sufficient to solve the problem of this inequality. The natural philosopher need not shroud the explanation of such phenomena in the garb of geological myths. It is not necessary to assume that the destructive conflict of the elements raged at different epochs in the eastern and western hemispheres, during the early condition of our planet; or that America emerged subsequently to the other quarters of the world from the chaotic covering of waters, as a swampy island, the abode of crocodiles and serpents[19].