THE 



JOURNAL OF GEOLOGY 



APRIL-MAY, ign 



CERTAIN PHASES OF GLACIAL EROSION 



THOMAS C. CHAMBERLIN and ROLLIN T. CHAMBERLIN 



The University of Chicago 



Oscillation, more or less rhythmic, seems to be a phenomenon 

 of the intellectual, as well as of the physical world. The doctrine 

 of glacial erosion has its ups and downs in quite typical undulatory 

 fashion. It seems that even individuals at times ride on the 

 crest of the wave of advocacy and at other times sink into the 

 hollows of doubt. These moods are apt so to distribute them- 

 selves that while some workers are on the crest others are in the 

 trough. The crest-riders have recently been much the most in 

 view, but just now voices from the hollows of doubt are heard. 

 The president of the British Association for the Advancement of 

 Science, speaking from official vantage ground, voices a cautious 

 skepticism as to the glacial parentage of certain kinds of configura- 

 tions that are held by others to be the erosive offspring of glaciers. 1 

 Professor Garwood goes beyond the measured skepticism of Dr. 

 Bonney and gives a critical analysis of his grounds of doubt and 

 laudably matches his destructive criticism with constructive 

 interpretations. In these interpretations, he marshals topographic 

 phenomena in support of the view that protection 1 is the character- 

 istic effect of glaciers rather than erosion. 



1 T. G. Bonney, Presidential Address before B.A.A.S. (Sheffield, iqio), Science, 

 XXXII (iqio), 321-36, 353-63. 



2 E. J. Garwood, "Features of Alpine Scenery Due to Glacial Protection," Geog. 

 Jour. (September, iqio), pp. 310-39. 



Vol. XIX, No. 3 193 



