Fig. 6. — Section from Basle across the Alps to Senago, north-west of Milan. B, Basle. .7, Jura. A, Aar, near Olten. 
Ap , Alps. S, Senago. Inclination from Basle to summit of Jura, i° 37'; from Basle to the summit of the Alps, i° 43'. 
SCENERY OF SWITZERLAND. 
64 
the cooling, and consequent contraction 
of the Earth, is a continuous process, it 
follows that mountain ranges are of very 
different ages; and, as the summits are 
continually crumbling down, and rain 
and rivers carry away the debris, the 
mountain ranges are continually losing 
height. Our Welsh hills, though com- 
paratively so small, are venerable from 
their immense antiquity, being far older, 
for instance, than the Vosges, which 
themselves, however, were in existence 
while the strata now forming the Alps 
were still being deposited at the bottom 
of the Ocean. But though the Alps are 
from this point of view so recent, it is 
probable that the amount which has 
been removed is almost as great as that 
which still remains. They will, however, 
if no fresh elevation takes place, be still 
further reduced, until nothing but the 
mere stumps remain. What an enormous 
amount of denudation has already taken 
place is shown for instance in Fig. 7, 
representing the mountain of Tremettaz 
near the valley of the Rhone, between 
ta 
