58 THE OASES OF THE NORTH-WEST 



however, not made any notable change in the pastoral 

 industry. Pastoral life in the scrub has very uniform 

 characters. It is chiefly dominated by the question 

 of water-supply. Natural open water is scarce, and 

 the cattle can drink only where man's industry makes 

 it possible. The problem of taming the beasts, which 

 the breeders on the prairies have not always been 

 able to solve, is simplified by the scarcity of water. 

 There is no need to hunt the cattle, no periodical rodeos, 

 when the herd is drawn in every night by thirst to the 

 water-supply. Advance in colonization means the 

 provision of wells and reservoirs {baldes and represas), 

 without which the breeders cannot occupy the plain 

 permanently, but have to fall back during the dry 

 season upon the few streams that cross it. The word 

 balderia means districts where the presence of a sheet 

 of water not far underground has enabled them to 

 form a system of wells. The best known is the Balderia 

 Puntana, in the northern part of the province of 

 San Luis. 



Of the regions apart from the Andes which still depend 

 on the Chilean market it will be enough to mention 

 two, which may be regarded as typical. The first is 

 the Chaco Salteiio, on the eastern slope of the Sierra 

 de la Lumbrera. The Lumbrera is a lofty anticlinal 

 range of limestones and red sandstones, which pass to 

 the west underneath the clay of the Chaco plain, and 

 separate it from the great longitudinal sub-Andean 

 corridor, which was followed by the old road, and is 

 now followed by the railway from Tucuman to Jujuy. 

 Colonization began beyond the Lumbrera in the 

 eighteenth century by passing round it, from south to 

 north, by the valleys of the Juramento and the San 

 Francisco (which joins the Bermejo). The ranches, 

 which employed the Indians — the occupation of the 

 Chaco at this point being pacific — bordered the Ber- 

 mejo and the Rio del Valle, which flows from 

 the Lumbrera range toward the former bed of the 



