GLACIAL FEATURES 275 



tion, the snowline in the northern hemisphere has been rising 

 since 1890 with an average increase of five hundred feet in sixteen 

 cases. To be sure, we must recognize that the observations upon 

 which these conclusions rest have unequal value, due both to per- 

 sonal factors and to differences in instrumental methods, but that 

 in spite of these tendencies toward inequality they should agree 

 in establishing a general rise of the snowline in the northern 

 hemisphere and an opposite effect in the southern is of the high- 

 est significance. 



It must also be realized that snowline observations are alto- 

 gether too meager and scattered in view of the abundant op- 

 portunities for making them, that they should be standardized, 

 and that they must extend over a much longer period before they 

 attain their full value in problems in climatic variations. Once 

 the possible significance of snowline changes is appreciated the 

 number and accuracy of observations on the elevation and local 

 climatic relations of the snowline should rapidly increase. 



In 1907 I made a number of observations on the height of the 

 snowline in the Bolivian and Chilean Andes between latitudes 17° 

 and 20° south, and in 1911 extended the work northward into the 

 Peruvian Andes along the seventy-third meridian. It is proposed 

 here to assemble these observations and, upon comparison with 

 published data, to make a few interpretations. 



From Central Lagunas, Chile, I went northeastward via Pica 

 and the Huasco Basin to Llica, Bolivia, crossing the Sillilica Pass 

 in May, 1907, at 15,750 feet (4,800 m.). Perpetual snow lay at an 

 estimated height of 2,000-2,500 feet above the pass or 18,000 feet 

 (5,490 m.) above the sea. Two weeks later the Huasco Basin, 

 14,050 feet (4,280 m.), was covered a half-foot deep with snow and 

 a continuous snow mantle extended down to 13,000 feet. Light 

 snows are reported from 12,000 feet, but they remain a few hours 

 only and are restricted to the height of exceptionally severe win- 

 ter seasons (June and early July). Three or four distant snow- 

 capped peaks were observed and estimates made of the elevation 

 of the snowline between the Cordillera Sillilica and Llica on the 

 eastern border of the Maritime Cordillera. All observations 



