GEOLOGY. 247 
buted the similar phenomena presented by the mountains 
and rocks in Finland to which reference has been made. 
With ice as with water, notwithstanding its hardness 
and its tenacity, it seeks the lowest level to which it can 
attain, and the glacier is ever in astate of flux from the 
land towards the lower level of the sea, and on its 
advance grinding away, smoothing, and striating the 
surface of the rocks, past which, or over which, it flows. 
The pressure, and consequent abrading power of a glacier 
must be tremendous. The vis a tergo being such that it 
treats as mere peebles in its path ridges, and even hills of 
considerable elevation, and seems to pass as easily over 
them as a deep river flows over the stones that may be in 
its channel. 
And thus may be accounted for the numerous lakes 
existing in the land, giving to its character and poetic 
designation, and the existence of the lakes so abounding 
in Norway and in Sweden. 
In the Quarterly Journal of the Geological Society, vol. 
xviii, p. 185, in a paper by Professor (now Sir Andrew) 
Ramsay, entitled ‘The Physical Geology and Geography of 
Great Britain,’ may be found the first suggestion, and illus- 
tration, and proof of this fact. There ‘he has shown that 
the innumerable rock-enclosed basins of the Northern 
hemisphere do not lie in gaping fissures, produced by 
underground disturbance, nor in areas of special subsid- 
ence, nor in synclinal folds of the strata, but that they are 
true hollows of erosion.’ 
I cite the statement of Professor Geikie, in his ‘Scenery 
of Scotland, viewed in connection with its Physical Geo- 
graphy ;’ and to this work I am indebted for the following 
illustrations :— 
‘Lakes, at least those which mottle the surface of Scot- 
land, may be grouped into three classes: Ist, those which 
lie in original hollows of the superficial drifts; 2d, those 
which have been formed by a bar of drift across a valley 
or depression ; 3d, those which lie in a basin-shaped cavity 
of solid rock.’ 
