118 NORTHERN CHILE. 



is the o})inion of the people of the country (althougn 

 they are much puzzled by the circumstance) that, 

 from the ajjpearance of the houses, the Indians 

 must have used them as places of residence. In 

 this valley, at Punta Gorda, the remains consisted 

 of seven or eight square little rooms, which were 

 of a similar form with those at Tambillos, but built 

 chiefly of mud, which the present inhabitants can- 

 not, either here, or, according to Ulloa, in Peru, im- 

 itate in durability. They were situated in the most 

 conspicuous and defenceless position, at the bottom 

 of the flat, broad valley. There was no water near- 

 er than three or four leagues, and that only in very 

 small quantity, and bad : the soil was absolutely 

 sterile ; I looked in vain even for a lichen adhering 

 to the rocks. At the present day, with the advan- 

 tage of beasts of burden, a mine, unless it were 

 very rich, could scarcely be worked here with 

 profit. Yet the Indians formerly chose it as a place 

 of residence ! If at the present time two or three 

 showers of rain were to fall annually, instead of 

 one, as now is the case, during as many years, a 

 small rill of water would probably be formed in 

 this great valley ; and then, by irrigation (which 

 was foiTnerly so well understood by the Indians), 

 the soil would easily be rendered sufficiently pro- 

 ductive to support a few families. 



I have convincing proofs that this part of the con- 

 tinent of South America has been elevated near 

 the coast at least from 400 to 500, and in some 

 parts from 1000 to 1300 feet, since the epoch of ex- 

 isting shells ; and further inland the rise possibly 

 may have been greater. As the peculiarly arid 

 character of the climate is evidently a consequence 

 of the height of the Cordillera, we may feel almost 

 sure that before the later elevations the atmosphere 

 could not have been so completely drained of its 



