THE GLACIERS 21 



world, we must bear in mind while trying to ac 

 count for the changes going on that the same sun 

 shine that wastes them builds them. Every glacier 

 records the expenditure of an enormous amount of 

 sun-heat in lifting the vapor for the snow of which 

 it is made from the ocean to the mountains, as 

 Tyndall strikingly shows. 



The number of glaciers in the Alps, according to 

 the Schlagintweit brothers, is 1100, of which 100 may 

 be regarded as primary, and the total area of ice, 

 snow, and neve is estimated at 1177 square miles, 

 or an average for each glacier of little more than 

 one square mile. On the same authority, the average 

 height above sea-level at which they melt is about 

 7414 feet. The Grindelwald glacier descends below 

 4000 feet, and one of the Mont Blanc glaciers reaches 

 nearly as low a point. One of the largest of the 

 Himalaya glaciers on the head waters of the Ganges 

 does not, according to Captain Hodgson, descend 

 below 12,914 feet. The largest of the Sierra glaciers 

 on Mount Shasta descends to within 9500 feet of 

 the level of the sea, which, as far as I have observed, 

 is the lowest point reached by any glacier within 

 the bounds of California, the average height of all 

 being not far from 11,000 feet. 



The changes that have taken place in the glacial 

 conditions of the Sierra from the time of greatest 

 extension is well illustrated by the series of glaciers 

 of every size and form extending along the moun 

 tains of the coast to Alaska. A general explora 

 tion of this instructive region shows that to the 

 north of California, through Oregon and Washing 

 ton, groups of active glaciers still exist on all the 



