340 A. C. Ramsay on the Glacial origin of certain Lakes 
1st. That each of the great lakes lies in an area once covered 
“by a vast glacier. There is, therefore, a connexion betwee 
them which can scarcely be accidental. 
2nd. I think the theory of an area of special subsidence for each 
lake untenable, seeing no more proof for it in the case of the 
larger lakes than for the hundreds of tarns in perfect rock-basins 
common to all glacier-countries, present or past, and the con 
nexion of which with diminished or vanished glaciers I proved 
originally in The Old Glaciers of North Wales. In the Alps there 
is.a gradation in size between the small mountain-tarns and the 
larger lakes. 
8rd. None of them lie in lines of gaping fracture. If old 
fractures ran in the lines of the lakes or of other valleys, and 
ve a tendency to lines of drainage, they are nevertheless, 1 
the deep-seated strata, exposed to us as close fractures now, 
the valleys are valleys of erosion and true denudation. 
t ey are none of them in simple synclinal basins, formed 
by the mere disturbance of the strata after the close of the Mic 
cene epoch: nor, ; 
5th, Do they lie in hollows of common watery erosion; for 
running water and the still water of deep lakes can neither of 
them excavate profound basin-shaped hollows. So deeply 
Playfair, the exponent of the Huttonian theory, feel this truth, 
that he was fain to liken the Lake of Geneva to the pett 
on the New Red Marl of Cheshire, and to suppose that t hol- 
low of the lake had been formed by the dissolution and escap? 
of salts contained in the strata below. A 
th. But one other agency remains—that of ice, which, from 
the vast size of the glaciers, we are certain must have exe i 
a powerful erosive agency. It required a solid body, gm? 
teadily and fully in direct and heavy contact with an¢ 
steadily and powerfully in direct and heavy pang of 
rd 
gi ‘ 
7th. It thus follows that, valleys having exis — 
low country between the Alps and the Jura, these pivee ¥ . 
sisting in the excavation of the poe — pei gx ‘ 
In connexion with this point, it is worthy of remar. o 
i Ses é of the term, 
ciers, many of them very large in the modern sense Of 
on the south side of the Vallais (excepting those of Mont ; 
and the (3 shegcse on the south aia 
into the Lake of Geneva; those on the north of the last-na™ 
direction to the flow of the glaciers ere they protruded oD aa 
e of the Oberland, all dr: me : 
