248 PATAGONIAN EXPEDITIONS: GEOGRAPHY. 



Dr. Otto Nordenskjold has taken exception to this" theory of the origin 

 of these salt lakes, holding that they are not residual lakes, and that the 

 salt has not been derived directly from the sea, as I have maintained. 

 He holds that the salinity of these lakes is due to the fact that they have 

 no outlet, and that the salt has been derived, as in many other salt lakes 

 in other countries, from the surrounding rocks by the tributary waters. 

 To my mind there are two very conclusive arguments against this theory 

 and in favor of that of considering these as residual lakes. First: None 

 of these lakes are fed by perennial streams, their supply of water being 

 almost entirely limited to freshets, due to occasional heavy showers, and 

 to melting snow in the immediate vicinity, so that it is entirely made up 

 of surface water, which, necessarily, contains very little, if any, saline mate- 

 rial. Second: Those lakes found nearest the coast, and whose connection 

 with the sea has only just recently been completely closed, are found to 

 contain quite as important salt deposits as others situated many miles 

 inland, where the connection with the sea has long been severed ; thus 

 showing that the amount of salt in the latter' has not been appreciably 

 increased during the long period that has elapsed since their final iso- 

 lation. These facts, together with the observations made illustrating the 

 method of formation of these lakes about the heads of many of the inlets 

 of Patagonia, lead me, unhesitatingly, to pronounce them residual in ori- 

 gin, and as having derived the beds of salt found in and about them 

 almost entirely from the sea direct. 



Of the three systems of lakes described above, the first, or those of tec- 

 tonic origin, are, in point of size, of vastly more importance than either 

 of the other two. When Patagonia is finally opened up to civilization, 

 and its many natural resources are fully recognized and taken advantage 

 of, this superb series of magnificent mountain lakes will come to be more 

 generally understood and appreciated. They will then, no doubt, achieve 

 an importance and consideration commensurate with their exceptional size 

 and beauty. Hitherto, owing to their inaccessibility, few, indeed, are those 

 who have been enabled to see them ; but, buried deep in the recesses of 

 one of the most lofty and rugged mountain systems on the earth, by those 

 favored few they will ever be remembered as masterpieces of creative in- 

 genuity. Extending from the barren lava beds and bleak, cheerless plains 

 of the east through the forest-clad slopes of the foothills on into the re- 

 mote and silent recesses of the central range of the Andes, whose sum- 



