Pampa de Moses is on the north of the province of Moxos, between the rivers Beni and Marmor6; and between the junction of this latter and the Guapore, another source of the Madeira, are other pampas of considerable extent.
Pampa del Saeramento.—This pampa is situated on the north-west of Cuzco. It differs from the other pampas in having a more tropical vegetation, and in its soil not being saline. It occupies a surface of from 54,000 to 63,000 square miles.
Such are the principal pampas of South America; and, if we include a part of Patagonia as being of the same nature with the pampas, we shall have, without reckoning the pampas of Moxos and Sacramento, and a number of spots of similar character but less extent, an almost uninterrupted band, extending from the Campos Paresis, in latitude 15° S., tothe bay of St. George in 45', or about 2800 geographical miles long and 300 wide, or a surface of 840,000 square miles of plain, partly sand, and partly marshy and saline, and producing hardly anything but pasture and a few stunted trees. Humboldt estimates the whole of the pampas of Rio de la Plata and Patagonia at 135,200 square leagues of 20 to the degree.
The Selma, or forest-covered plain of the 31arafion.—Independent of the vast forests which cover great part of the plains of North America, particularly on the east of the Mississippi, there is the immense plain of the 31arailon in South America, extending over a surface of 2,340,000 square miles,of which about 719,000 are covered with primeval forests, the rest of the space being occupied by the waters, and by open patches of a character similar to the llanos and savannas, though little known.
We merely mention this region here as one of the most extensive con tinuous plains in the world.
If the great plains wo have described owe their peculiar character to climate and situation, a very little reflection will suffice to show the immense influence which they in their turn must exercise over the climate of the regions contiguous to them, and the great modifications they most effect on mere solar temperature. Indeed the curves of the isothermal lines sufficiently prove that the several climates of the earth depend on the joint action of solar radiation, and tho magni tude, distribution, conformation, soil, and productions of the solid parts of the globe, and the extent and relative position of the great bodies of water by which they are surrounded. Nor have the vast plains of Asia and America performed a less important part in the moral history of mankind, whether as having favoured or opposed the emigrations of nations and the progress of civilisation.