200 
SCENERY OF SWITZERLAND. 
a case the velocity will be uniform. The enlarge- 
ment of the bed of a river is not, however, in pro- 
portion to the increase of its waters as it approaches 
the sea. Other things being equal, a river which 
incieases in volume, increases in velocity; the 
“regimen” therefore would be destroyed, and the 
river would again commence to eat out its bed. 
Hence, if rivers enlarge, as for instance owing to any 
increase in territory, the slope diminishes. 
The above figure (Fig. 52) gives a sketch map, 
and Fig. 5 3 lepresents the profiles, of the principal 
rivers in the valley of the Garonne, and it will be 
seen that the larger the river the gentler is the 
slope. 
At present many of the smaller Swiss streams 
are eating into their cones and endeavouring to 
