PROGRESSION OF GLACIERS. 
281 
also in one important point, that of the accelerar 
tion of speed with the steepness of the slope. 
The motion of the glacier bears no such direct 
relation to the inclination of its bed. And though 
in a glacier, as in a river, the axis of swiftest 
motion is thrown alternately on one or the other 
side of the valley, according to its shape and 
slope, the very nature of ice makes it impossible 
that eddies should be formed in the glacier, and 
the impressive feature of whirlpools is altogether 
wanting in them. What have been called gla- 
cier-cascades bear only a remote resemblance to 
river-cascades, as in the former the surface only 
is thrown into confusion by breaking, without 
affecting the primitive structure ; * and I re- 
iterate my formerly expressed opinion, that even 
the stratification of the upper regions is still 
recognizable at the lower end of the glacier of 
the Rhone. 
The internal structure of the glacier has al- 
ready led me beyond the limits I had proposed 
to myself in the present article. But I trust 
my readers will not be discouraged by this dry 
discussion of various theories concerning it, and 
will meet me again on the glacier, when we will 
examine together some of its more picturesque 
* For the evidence of this statement I must, however, refer 
to my work on Glaciers, already so often quoted in this article, 
where it may be found with all the necessary details. 
