98 SPENCER ON GLACIAL EEOSION 



the pans rise over all the low lying parts of the Islands grinding and polishing exposed 

 shores, and rasping those that are steep-to. The pans are shoved over the flat surfaces of 

 the Islands and remove with irresistible force every obstacle which opposes their thrust, 

 for the attacks are constantly renewed by the ceaseless ice stream from the north-west, 

 and this goes on uninterruptedly for a month or more." ' Similar results elsewhere have 

 been frequently recorded, as those of Prof. Milne in Newfoundland. " 



Whilst the power of glaciers, under favorable conditions, to abrade and scratch rock 

 surfaces, as " sand-paper " scratches " a cabinet," is not questioned ; yet these observations, 

 in Norway and elsewhere in high latitudes, all confirm the correctness of the verdict given 

 by many geologists — especially in Europe — who have had the opportunity of personally 

 studying living glaciers, that the potency of land-glaciers to act as great eroding agents, 

 capable of " planing down half a continent," or ploughing out great valleys, or lake- 

 basins, or even of greatly modifying them, is not only not proved, but most strongly 

 negatived. Even the power of glaciers to abrade is reduced in many cases almost to zero. 



' Notes on some Geological Features of the North-eastern coast of Labrador, Can. Nat., 1878. 

 ^ Ice and Ice action, Newfoundland, Geol. Mag., 1876. 



