236 
SCENERY OF SWITZERLAND. 
The Lakes of Neuchatel and of Bienne only 
differ by 1 metre as regards the water level, but 
the Neuchatel basin is 60 metres deeper than that 
of Bienne. 
The great Italian lakes, as shown in the fore- 
going table, descend below, sometimes much below, 
the sea level. 
The lakes, moreover, are in some cases true rock 
basins. In the case of Geneva, for instance, though 
the actual outlet is over superficial debris the solid 
rock appears in the river bed at Vernier only 10 metres 
below the surface of the lake, or 300 metres above 
the deepest part. 
The materials brought down by the rivers have 
not only raised the bottoms of the lakes, but have 
diminished their area by filling them up in part, 
especially at the upper ends. It is evident that they 
were at one time much larger than they are now. 
The Lake of Geneva extended at least to Bex and 
perhaps to Brieg, that of Brienz to Meiringen, of 
Lucerne to Erstfeld, the Walensee to Chur, the Lake 
of Constance at least to Feldkirch, the Lago Maggiore 
to Bellinzona, that of Como to Chiavenna, 
Moreover, the lakes of Brienz and Thun formed 
one sheet of water, as also did the Walensee and the 
Lake of Zurich. 
