246 
SCENERY OF SWITZERLAND. 
which they pass, but deny that they effectively ex- 
cavate. 
The Lake of Geneva, 375 metres above the sea, 
is over 309 metres deep, and if we allow for the ac- 
cumulation of sediment, its real bottom is probably 
below the sea level. The Italian Lakes are even 
more remarkable. The Lake of Como, 199 metres 
above the Sea, is 414 metres deep. Lago Maggiore, 
194 metres above the Sea, is no less than 655 metres 
deep, so that the bottom is 46 1 metres below the sea 
level. 
The difficulty thus arising, moreover, is not so 
much the absolute depth, as the absence of relative 
height above the Sea, so that there would be no suf- 
ficient fall to carry off the water. 
Even if we suppose that the Sea came up to 
Lyons, still the distance from Lausanne being 
180 km., the Lake must have been raised 300 
metres to give even a minimum fall of 2 per cent.* 
In the valley of the Rhone the upper level of the 
ice had a slight but regular slope. At Schneestock 
the upper limit was at a height of 3550 metres 
above the sea, at Leuk 2100, at Morcles near 
St. Maurice 1650 metres. But at Chasseron on the 
Jura the height is now 1410 metres, at Chasseral 
* Forel, Le Leman. 
