are generally low, the latter Province, however,
containing a snuvll area of hills in the west.
Hydrography. Aside from_ a few inclosed basins in the interior, the entire area is drained by easterly flowing rivers into the Atlantic. The great river system of the Plata, formed by the confluence of the Uruguay and the Parana, belongs only partly to Argentina, as both its branches rise in the interior of Brazil, and for a large part of their course flow along the frontiers of Brazil, Paraguay, and Uruguay. The Parana is of great importance to Argentina as a commsrcial highway. With the Paraguay, it drains the Gran Chaeo, tliroigh the cliannels of the Pilcomayo, Bermejo, and Salado, and also the northern pampas, where in past times there were several important tributaries that are now represented by smaller streams with intermittent flow. The Parana is navigable by steamers for a distance of about 1200 miles, and by light-draught boats for nearly its whole length. From the confluence of the Paraguay to the sea, the fall amounts only to about 225 feet, so that a slight depression would separate the Plata system into three independent branches — the Parana, the Paraguay, and the Uruguay. In the central Provinces of Argentina, between the Kio Salado on the north and the Rio Colo- rado on the south, there is an area of inclosed drainage, with extensive saline marshes, which deposit alkaline salts during the dry season. South Argentina is drained by the Colorado and Negro, both rising on the slopes of the Andes. The drainage basin of the Colorado formerly covered a much larger territory, as the prov- inces of San Juan, San Luis, and Mendoza were drained by a northern tributary that now ends in a swampy reservoir. Patagonia has several large streams, including the Chubut, Deseado, Salado, and Chico, which receive their water sup- plies from the slo))es of the Andes, where there are numerous glacial lakes. See the articles on Plata, Rio de la; ParanA, etc.
Climate. The northern part of Argentina projects well within the equatorial hot belt, while the central and southern parts extend throvigli the south temperate zone. The peculiar location of Argentina, with oceanic conditions on the east and higli mountains on the west, make its climatic details very dependent on the direction of the winds. The northern sec- tion lies within the region of prevailing east winds, which convey inland the warm, moist air from the Atlantic Ocean, and cause a very uni- form temperature, with lieavy precipitation on the coast, but decreasing in amount with prog- ress inland. South of the Plata the west and northwest winds of middle latitudes prevail, and these cr>nvey across the narrow territory the air from the Pacific Ocean, which has been deprived of most of its moisture on the wind- ward slopes of the Chilean Andes. Thus the air becomes drier, and the precipitation de- creases with apiJroach toward tlu> Atlantic coast. The monsoon-effects considerably modify these general conditions, so that for the northern and more imiiortaut half of Argentina, in winter, northerly winds are very common.
The temperature decreases with increase of latitude, and varies in the annual average from 70° F. at the north to less than 45° V. at the south. In tlio nortli the temperatures range from a maximum of lO.'i" 1. to a mininuim of ° F.; the hottest month averages about 80° F., and the coldest month about 55° F. Toward the middle of Argentina the hottest month averages only 75° F. and the coldest a little less than 50° V., and at the extreme south the hottest month averages less than 50° F., and the coldest month has a temperature near that of freezing water. There is in general a great difference between the day and night tempera- tures; but the intense cold waves of the middle latitudes of the continents of the Northern Hemisphere are entirely lacking. In general, the rainy season is in sununer, with a winter season that is dry, even to the utter lack of rain in the interior. Three rain belts lying nearly parallel to the Andes are noticeable; in the extreme northeast the raiifall is moderately heavy, from 50 to 70 inches. To the west of this there is a zone of moderately light rainfall, extending as far south as the mouth of the Plata, ^llere the annual average is about 30 inches. Still farther west there is a rapid de- crease to the Andean slopes. On the pampas the weather is variable, changes from the cool, dry south winds to the moist, hot north winds frequently occurring with great suddenness. The foi'iner winds, which sometimes blow with stormy violence, are called "Pamperos." They come with little warning, and are sometimes of day-long continuance. The moist, hot wind from the north, called "Zonda" (somewhat similar to the sirocco), causes intense discomfort to the inhabitants. The dry Zonda of the east side of the Andes region is of Fiihn character.
Flora. In the north and northeast are found tropical woodlands, to the south and west of which are scattered forests containing most of the species usual in the warm temperate zone. The slopes of the Andes are well wooded, especially with thorny and shrubby plants, as are the banks of the Parana and the rivers flowing from the west into the Paraguay; although the trees do not attain great size. Palms are a distinctive feature of the base of the Sierra de Cordoba and of the northwestern foothills. The pampas, in the wet season, are covered with clover and thistles, or with tall grass and flowers, gay verbenas, geraniums, etc.; but here, as well as on the Gran Cliaco, there is little to form thickets, except mimosas and cacti. The algaroba, a shrub resembling a honey locust, is widely distributed; it is used for fence posts; from the pulp of the pod are made a kind of flour, and, by fermentation, an intoxicating liquor called Chica. Patagonia has herbs, shrubs, cacti, some tufty grass, brambles, and copse; but is almost treeless, except in the south, and even there but four species of trees are found, two of them being beeches. Among the indigenous trees and plants are the quince, aloe, coca, cinchona, mate (or Paraguay tea), manioc, the prickly pear, with edible fruit; the Cactus foliosns, on which the cochineal insect feeds, and a shrub harboring an insect yielding a handsome green dye. The apple-tree, introduced from Chile by the Indians, flourishes in the soulhwestern Provinces; the grape is extensively grown in thewestcrn Provineesof Rioja,San,Iuan, and Mendoza; the Province of Salta is famed for its bananas and coffee; and the peach, flg, orange, and walnut are grown in many parts. The scarcity of wood in some Provinces compels the
