Page:Whymper - Scrambles amongst the Alps.djvu/371

 by these distinguished geologists, he published two papers in the Philosophical Magazine; and, in endeavouring to present my reader with a resume of the Professor's views, I shall draw from these papers as freely as from his original memoir, for they afford amplification and elucidation of his argument,

Professor Ramsay said, in opening his case, "There is no point in physical geography more difficult to account for than the origin of most lakes. When thought about at all, it is easy to see that lakes are the result of the formation of hollows, a great proportion of which are true rock-basins, that is to say, in hollows entirely surrounded by solid rocks, the waters not being retained by loose detritus." It is in reference to such ones alone that his theory is propounded. He then went on to state, in especial reference to lakes of this class in the Alps—

§ 1. "That the theory of an area of special subsidence for each lake is untenable.

§ 2. That none of them lie in lines of gaping fracture (rents and fissures).

§ 3. That none of them occupy simple synclinal basins formed by the mere disturbance of the strata after the close of the Miocene epoch."

And he therefore argued that they must have been produced by erosion; but

§ 4. They do not lie in hollows of common watery erosion, nor can they be effects of marine denudation.

He consequently concluded, "If we have disposed of these hypotheses for the formation of such hollows, what is left?

§ 5. The only remaining agent is the denuding power of ice." He then proved that, in the Alps and elsewhere,