432 



SOUTH AMERICA— THE ANDES REGIONS. 



The Chilian Lakes. 



The lakes of North Chili, dried by the process of evaporation, have all been 

 reduced to the condition of mere saltpans or morasses. Nevertheless, ihe old 

 contour-lines may still be traced, while the Ittkes themselves are often conjured 

 back by the mirage. Ascotan, Atacama and the other neighbouring lacustrine 

 depressions have all been filled in by vast quantities of alluvial matter washed 

 down from the cordillera. Shafts have been sunk in Salar del Carmen, east of 

 Antofagasta, to a depth of 290 feet without reaching its rocky bed. 



True lakes of pure water and abysmal depths are met only in South Chili at 

 the foot of the glaciers, whose crystalline masses probably at one time filled these 

 lacustrine basins. The Laguna Negra, near the sources of the R.io Maipo, has a 

 depth of no less than 890 feet. Southwards the flooded depressions increase 

 gradually in size and number as far as Lake Llanquihue and E,eloncavi Bay, which 

 itself appears to be also of lacustrine origin. All these sheets of water are 

 extremely deep, and in Llanquihue the soundings have revealed depths of 360 feet 

 near the shore. Rubanco, to which the name of its larger neighbour is often 

 given, is partly fed by thermal springs. The low ridges of gravel Avhich separate 

 the Araucanian lakes, and through which the streams easily excavate a channel, 

 appear to be composed of ancient moraines.* 



IV. 



Climate of Chili. 



The long strip of Chilian territory presents every degree of transition between 

 heat and cold, moisture and aridity. As a rule the isothermal line of temperature 

 diminishes by about 1° Fahr. for every parallel of latitude in the direction from 



* Table of the Chilian rivers according to the Aniiario hydrogrdfico and other documents :- 



