The Pampas of Buenos Ayres are bordered on the west by the forests which lie along the base of the Andes of Chile ; on the east by the Atlantic • on the south by the Rio Negro and Patagonia, the interior of which, though little known, seems to be of the same nature with the pampa itself ; and on the north-east by the Rio de la Plata. In the direction due north the pampa narrows between the Parana and a ridge corning from the Andes, called the Sierra. de Cordova.
This region, reckoning to the foot of the mountains on the west, occupies a surface of about 315,000 square miles. This plain has no general slope, or rather it slopes so gently towards the east, that the slightest inequalities, together with the absorbing nature of the soil and the great evaporation, are sufficient to arrest the course of the waters ; so that, with the exception of the rivers Colorado and Negro, which come from the Cordilleras, and which traverse the southern part of the pampas, and the Salado, a small stream which flows into the Rio de la PLata at its mouth, the pampas have no running waters, hut, instead of them, a great many shallow pools, of which the water is often brackish. There is one at about 450 miles from Buenos Ayres, in the direction west-south-west, always filled with salt, from which the city of Buenos Ayres was yearly supplied before the port was thrown open to foreigners. The southern part of the pampas is sandy, with patches of saline plants and stunted trees • the northern parts are covered with grass, supplying food to large herds of cattle and wild horses, the descendants of those first introduced by the Spaniards. It has been said that several million head of cattle and about half as many horses feed on the pampas of Buenos Ayres. There are also wild bea=ts.
This plain is traversed by a road which leads from Buenos Ayres to Chile, along which the traveller meets with huts, which form stations, distant from each other about seven or eight leagues. The journey may be made on horseback or in a carriage, hut it is sometimes dangerous, on account of the Indians.
The pampa of Cordova extends from the right bank of the lower Parana to the Sierra do Cordova at the west. On the north it joins the sandy plains or traresia of Santiago del Estero.
This pampa resembles that already described in all things, excepting being traversed by a greater number of streams. All these streams, however, with the exception of the Rio Salado, which falls into the Parana, lose themselves in the sands, or end in marshes and lakes without issue, and which in the country are called Laguna:. Such is
particularly the case with the Rio Dulee, which, rising in a fertile valley on the eastern slope of one of the lateral chains of the Andes, passes by S. Miguel de Tucuman and Santiago, and finally empties itself into the Lagunas de las Porongos; the same is also the ease with the Rio Primero, ou which is situated Cordova, the best of all the towns of Tucuman, and where the Jesuits had formerly a celebrated university.
Throughout the whole of the country between the Parana and the mountains to the west, from Chaco on the north to the extreme southern extremity of the Pampa of Buenos Ayres, there is neither river, lake, nor well that is not brackish, saline, or alkaline. Even the Pilcomayo and the Vermejo partake of this saltness ; and Azara assures us that he has seen in laguua.s, dried up by the heat, a layer of Epsom salts above three inches in thickness. Nitron, sulphate of soda, and glauberite also occur in the lagunas.
The inhabitants of the fertile valleys lying to the west and north of the plains of Tucuman, similar in some respects to Little Bueharia, rich in their flocks, without ambition, and without care, close the day in rural amusements worthy of being sung by Theoeritus and Virgil. It is nevertheless true that there are spaces of many square leagues in extent condemned to absolute sterility. The traveller may pass for days together over sands and stones, between which there spring up here and there some saline plants, without meeting with any other objects than a few isolated huts on the borders of some brackish stream; these barren districts are generally designated by the term traresia.
Pampa of Lraanacos.—Leaving the pampa of Cordova on the south, and travelling through forests swarming with bees, which extend beyond the Rio Duke and the Salado, we enter on the territory of the Abipones, a race of very warlike Indians ; after which, crossing the Rio Vermejo, we gain the plains of the Gran Chaco, occupied by more or less savage indigenous tribes. This region is traversed by the Rio Pilcomayo, which, passing near the mines of Potosi, falls into the Paraguay below the city of Assumption. To the north lies the Pampa de Huanacos, adjoining the province of Chiquitos, bounded on the east by the great Laguna of Xarayes, through which passes the frontier of Brazil; on the west by the heights of Santa Cruz de Sierra, and on the north by the forests of the province of Ilexes and the sandy plateau called Campos Paresis.