The Llanos of Venezuela occupy a superficial area, estimated, according to Humboldt, at 153,000 square miles, between the deltas of the Orinoco and the river Coqueta. They are as flat as the surface of the sea, and covered with long rank grass. You might travel over the dreary level for 1100 miles from the delta of the Orinoco to the foot of the Andes of Pasto, and frequently not encounter an eminence a foot high in 270 square miles. Their length is twice that of their breadth; and as the wind blows constantly from the east, the climate is the more ardent the further west. "These Steppes, for the most part," says Mrs. Somerville,[92] "are destitute of trees or bushes, yet in some places they are dotted with the mauritia and other palms." Flat as they are, two kinds of inequalities will sometimes occur: one consists of banks or shoals of grit or compact limestone, five or six feet high, perfectly level for several leagues, and imperceptible except on their edges; the other inequality can only be detected by the barometer or levelling instruments; it is called a _Mesa_, and is a gentle knoll swelling very gradually to an elevation of a few fathoms. Yet slight as is this altitude, a Mesa forms the watershed from south-west to north-east, between the affluents of the Orinoco and the streams flowing to the northern coast of Terra Firma. In the wet season, from April to the end of October, the tropical rains pour down in torrents, and hundreds of square miles of the Llanos are inundated by the overflow of the rivers. In the hollows the water is sometimes twelve feet deep, and such numbers of horses and other animals perish, that the ground smells strongly of musk, an odour peculiar to many quadrupeds. "From the flatness of the country, too, the waters of some affluents of the Orinoco are driven backwards by the floods of that river, especially when aided by the wind, and form temporary lakes. When the waters subside, these Steppes, manured by the sediment, are mantled with verdure, and produce ananas, while occasional groups of fan palm-trees and mimosas skirt the rivers. When the dry weather returns, the grass is burnt to powder; the air is filled with dust raised by currents occasioned by difference of temperature, even when there is no wind. If by any accident a spark of fire falls on the scorched plains, a conflagration spreads from river to river, destroying every animal, and leaves the clayey soil sterile for years, till vicissitudes of weather crumble the brick-like surface into earth."