sa 
Ore 
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Geology. 277 
there are certain planes in the ice along which melting takes place 
more readily than others will perhaps favor the descent of the gla- 
ciers, 
We have in this theory a satisfactory explanation of the origin 
of “crevasses” in glaciers, Take, for example, the transverse 
crevasses formed at the point where an increase in the inclination 
of the glacier takes place. Suppose a change of inclination from, 
say, 4° to 8° in the bed of the glacier. The molecules on the slope 
where the change of inclination occurs. the slope of 
8° will tend to pull after it the mass of th er moving 
slowly on the slope above. e pull being continued, the glacier 
will snap asunder the moment that the cohesion of the ice is over- 
he greater the change of inclination is, the more readily 
lace. E i 
Of course, a 
as rapidly in the latter case as in the former; for in fact, as Canon 
Moseley has shown, it would not in the latter case descend at all; 
ases to be same, the conclusion I have stated would follow. 
Consequently whatever denuding effects may have been attributed 
to the glacier, according to the ordinary theory, must be equally 
attributable to it according to the present theory. _ ; 
is theory, however, explains, what has always hitherto excited 
astonishment, viz: why a glacier can descend a slope almost ho 
zontal, or why the ice can move off the face of a continent per- 
fectly level. oe pees 
_ Canon Moseley suggests that heat passing into the ice might by 
its mechanical energy, together with the weight of the glacier, be 
Sufficient to account for the motion. But the mechanical energ: 
of heat is not required to push the glacier forward; gravitation 
