GLACIERS OF THE ANDES. 271 



side of Chimborazo, in a valley in which there is now no glacier at all, was 

 the only place in which I was certain of roches moidomvies, bnt this single 

 instance proved that glaciers on that mountain have formerly extended 

 lower down than they do now." 



The glaciers are largest on the eastern sides of these immense cones, as 

 might be expected, since the vapor-laden winds come from that dii'ection. 

 The frozen precipitation wraps the higher portions of the mountains in an 

 envelope, here of ice and there of snow, according as more or less rain falls 

 at those elevations, the high temperatures sometimes experienced at great 

 altitudes in the Ecuadorian Andes i-endering it certain that a part of the 

 precipitation must be in the form of rain even at the very summits of the 

 cones. Indeed, Mr. Whymper speaks of being "well-drenched in heavy rain- 

 storms" when encamped at heights of over lOjOOO feet. In camp on Cay- 

 ambe (14,760 feet), much rain and some snow fell during the night. Heavy 

 rain is mentioned also * between the Haciendas of Antisana and Antisanilla 

 (13,300 feet). 



Of the snow and ice conditions on the Peruvian Andes little is definitely 

 known. The examination of various excellent photographs of the higher 

 points of that portion of the country indicates the absence of anything like 

 well-formed glaciei-s. Usually the depressions and ravines around the very 

 summits are seen to be more or less filled with snow, but nowhere do 

 portions descend much below the general level of the lower edge of the 

 snow mass, as would be the case were there large glacier systems present. 

 Indeed, it is not to be expected that such would be formed around these 

 i-solated volcanic masses, for their conical form precludes the existence of large 

 gathering-grounds, in issuing from which the ice currents may be sufficiently 

 powerful and well-developed to make their way down to a level much lower 

 than that of the ordinary snow line. 



In the Andes of Northern Chili, in spite of their great elevation and their 

 higher latitude, there are, according to Pissis, no glaciers. The climatic 

 conditions seem to resemble in a marked de2;ree those of the Sierra Nevada 

 of California. The amount of pi'ecipitation is large ; but it is all in the 

 winter, and in the form of snow. In the summer the air is exceedingly dry, 

 and the melted snow is all evaporated from the sm-face and does not sink in 

 so as to form ice. Hence, as seen in the numerous excellent photographs of 



* On .\iitisana, for instance, during the two houi-s spent on the summit, the thermometer ranged between 

 44° and 60° (F.). 



