LAKES. 
245 
1000 metres. The greatest depth of the lake is 
opposite Lausanne, where the thickness of the ice 
would be at its maximum. 
Moreover, the depth in proportion to its size is 
quite insignificant; Fig. 68 shows the height of the 
mountains, the thickness of the ice at the time of its 
greatest extension, while the dark line below gives 
the relative depth of the water, showing that after 
9 ZW 2 ?+ 71 + oso 
i ' • I 
978 060 800 
1 
si irr 
~n — ru inn ■ w in mi I’M! Illl li 11 Si 
Ice, 
The Lake 
Fig. 68.— Diagram Section along the Lake of Geneva. The dark line 
shows the relative depth of the water indicated by the figures above. 
all the 
Lake of Geneva is really but 
a film of 
water. 
There are, however, strong reasons against re- 
garding glaciers as the main agents in the formation of 
the great Swiss and Italian lakes. These have been 
pointed out with great force by Ball and Bonney, and 
Swiss geologists are not generally disposed to accept 
the action of glaciers as a sufficient explanation. They 
admit that glaciers grind and smoothe the rocks over 
