112 STUDIES, SCIENTIFIC AND SOCIAL . ohaP. 



that sufficiently rapid and extensive earth-movements 

 actually did occur in the subalpine valleys of these countries 

 at the epoch required we must decline to accept such a 

 hypothetical and unsatisfactory explanation. 



Nothing is more easy, and nothing seems at first sight 

 more plausible, than to allege these " earth-movements " 

 to account for any one lake whose origin may be under 

 discussion. But it ceases to be either easy or plausible 

 when we consider the great number of the lakes to be 

 accounted for, their remarkable positions and groupings, 

 and their great depths. We must postulate these move- 

 ments, all about the same time, in every part of the High- 

 lands of Scotland, everywhere in the Lake district, and on 

 both sides of the Alps. Then, again, the movements must 

 have been of greater extent just where we can prove the 

 glaciation to have been most severe. It produced lakes 

 from 100 feet to 270 feet deep in Cumberland and 

 Westmoreland ; in Scotland, where the ice was much 

 thicker, the lakes are from over 300 to over 1,000 feet 

 deep ; while in the Alps of Switzerland and North Italy, 

 with its vast glaciers and ice-sheets, many are over 1,000 

 feet, and one reaches the enormous depth of over 2,500 

 feet. It may be said that the depth is in proportion to 

 the height of the mountains ; but in equally high mountains 

 that have not been glaciated there are no lakes, so this 

 cannot be the true explanation. One more remarkable 

 coincidence must, however, be pointed out. The two 

 largest Swiss lakes — those of Geneva and Constance — are 

 situated just where the two greatest West European 

 rivers, the Rhone and the Rhine, get beyond the mountain 

 ranges ; while on the south, one of the largest and by far 

 the deepest of the lakes — Lago Maggiore — collected into 

 its basin the glacier streams from a hundred miles of the 

 high Alps, extending from Monte Rosa on the west to the 

 peaks above San Bernardino on the east. Throughout this 

 great curve of snowy peaks the streams converge, with 

 an average length of only 30 miles, to unite in a valley only 

 646 feet above the sea level. No such remarkable con- 

 centration of valleys is to be found anywhere else in the 

 Alps, and no other lake reaches to nearly so great a depth. 



