THE WORK OF SNOW AND ICE. 



299 



same as that favoring erosion, but the two processes are not favored 

 at the same point. Erosion is greatest on the " stoss " side of an obstruc- 

 tion (the side against which the ice advances), and deposition on the lee 

 side. The ice is hkely to be overloaded (1) just beyond a place where 

 conditions have favored the gathering of a heavy load, and (2) where 

 the ice is rapidly thinning. On the whole, however, the deposition of 



Fig. 275. — Glacier building an embankment. Southeast side of McCormick Ba}*, 

 L North Greenland. 



material beneath the main body of a glacier is much more than balanced 

 by erosion in the same position. 



2. At ends and edges of glaciers. — At and near the end of a glacier the 

 conditions of deposition are somewhat different. Here deposition 

 beneath the ice goes on faster than elsewhere, chiefly because of the 

 more rapid melting and the more rapid thinning and weakening of 

 the ice. If the end of the glacier be stationary in position, drift is 

 being continually brought to it and left there, for though the end is 

 stationary, the ice continues to move. If the glacier moves forward 

 500 feet per year, and if its end is melted at the same rate, all the debris 

 in the 500 feet of ice which has been mehed has been deposited, and all 

 except tha^ which has been washed away has been deposited at and 



