288 PATAGONIAN EXPEDITIONS: GEOGRAPHY. 



receding glaciers. Such ranges of hills have a trend parallel with the base 

 of the mountains, and are usually separated by broad stretches of meadow 

 land, with numerous small glacial lakes, either occupying slight depres- 

 sions in the meadows or, as more frequently seen, embraced by the low, 

 rounded hillocks of the terminal moraines. These conditions are espe- 

 cially characteristic in this region over the bottoms and slopes of the great 

 transverse valleys, but they extend also in many places out over the sur- 

 face of the higher pampas. 



The rolling surface of this western plains region, abounding in wide 

 pasture lands, dotted over with sparkling lakes of pure, sweet water, pre- 

 sents a pleasing contrast to the semi-arid region near the coast, and affords 

 a welcome relief to the traveller after a journey across the black, absolutely 

 barren lava beds of the central plains. Its modest, unobtrusive beauty 

 but emphasizes the grander scenery beyond, indications of which already 

 appear in the distant ranges of the Andes, whose summits, buried deep in 

 fields of snow and ice, are seen brilliantly white against the intensely black 

 background so often formed by the storm-clouds of the western skies. 



Entering the confines of the Andes, numerous rivers, deep rocky canons, 

 broad open lakes of beautiful clear water, fed by glaciers that descend from 

 the snow-fields at the summits, and all the other features characteristic of 

 an extremely rugged, mountainous region, thrust themselves upon the 

 attention and excite the wonder and admiration of the traveller. 



The country along and within the foothills of the Andes is in 

 many respects the most interesting region in Patagonia, whether con- 

 sidered geographically or geologically. Taking advantage of any of the 

 numerous valleys that extend westward from the western border of the 

 Patagonian plains and penetrate not only the secondary but also the main 

 range of the Andes, finally emptying into the Pacific, many facts may be 

 observed, not only bearing directly upon the structural and historical 

 geology of the Andes, but also throwing much light on the agencies which 

 have contributed to the peculiar topography and determined the unique 

 position of the continental watershed at present existing in southern South 

 America. 



I say unique, for I believe it has no parallel elsewhere. That its true 

 position was quite unknown and entirely unsuspected, even at the begin- 

 ning of the last decade, is clearly demonstrated by the unfortunate boun- 

 dary dispute between Argentina and Chili. This dispute, which recently 



