272 CLIMATIC CONDITIONS OF THE GLACIAL EPOCH. 



those mountains, the snow lies in masses which vary greatly in size fiom 

 year to year, according to the variability of the seasons or of a succession of 

 seasons, just as is the case in the Californian range.* 



Pissis remarks,! that in going south along the Andes the first glaciers are 

 seen in the province of Colchagua, and that the most remarkable of these is 

 that from which issues the Rio de los Cipreses. The ice here descends to a 

 point 5,8r50 feet above the sea-level. 



Proceeding southward from Colchagua, we pass into a region in which the 

 climatic conditions are very dift'erent from those prevailing in the country 

 farther north. The ranges border the sea very closely, the amomit of pre- 

 cipitation increasing and becoming more generally distributed tln-oughout 

 the year. The temperature, at the same time, diminishes, and all the con- 

 ditions favorable to the formation of glaciers are found to prevail. In con- 

 sequence of this there is an extensive display of snow and ice along the 

 southern coast of Chili, and especially at the very extremity of the continent. 

 According to the measurements of the officers of the Beagle, the culminating 

 peaks between latitudes 41° and 43° 30' are from 5,G00 to 7,500 feet in height. 

 On these the snow in February (answering to our August) descended to 

 4,480 feet above the sea-level, "presenting to a distant beholder a perfectly 

 horizontal line." In Chiloe (lat. 41°-43°) the elevation of the snow line is 

 given by Darwin at 0,000 feet; in Tierra del Fuego (lat. 54°), at 3,500 to 

 4,000 feet. He remarks as follows in regard to the glaciers of that region : 

 " In Tierra del Fuego the snow-line descends very low, and the mountain 

 sides are abrupt ; therefore we might expect to find glaciers extending far 

 down their flanks. Nevertheless, when on first beholding, in the middle of 

 summer, many of the creeks on the northern side of the Beagle channel 

 terminated by bold precipices of ice overhanging the salt water, I felt greatly 

 astonished. For the mountains from which they descended, were far from 



* Mr. Dnnviii, in his "Journal and Remarks" forming a part of tlie Voyage of the Beagle (pp. 277 - 278), 

 makes the following statement, wliieh is of interest as connected with what has been mentioned ahove in regard to 

 the varying amonnt of snow in tlie l.'hilian .Andes : "I have reason to snspeet that the snow -line in Chile is subject 

 to extreme variation. I wa-s told that during one remarkably dry and long .summer, all the snow disappeared from 



Aconcagua It must be remembered that even in ordinary summers the sky is generally cloudless for six or 



seven months, that no fresh snow falls, ami that the atmosphere is excessively dry. It may be askeil whether vast 

 quantities of snow would not, under this condition of circumstances, be evaporated ? so that it might be possible 

 that all the snow shonlil disapjiear from a mountain without the temperature having risen aliove the freezing point. 

 Mr. Miers (Voh I. p. 3S4) says he passed the Cordillera by the Cumbre Pass on Jlay .30th, 1819, 'when not the 

 smallest vestige of snow w.'is observable in any part of the Andes.' Yet Aconcagua is in i'all view of the approach 

 to this pass. Mr. Miers, in another part (p. 38-3), makes a general assertion to the same effect." 



t Descripcion topografica i jeolojica de Colchagua, in .4nales de la Universidad de Chile, XVIl. 703. 



