MOUNTAINS AND HILLS 
215 
manner, except that the bulge or uplift was 
more abrupt from being localized within a com- 
paratively small area. 
It is popularly supposed that the Alps, the 
Himalayas, the Rockies, are the oldest and the 
most permanent of the earth’s formations ; and 
the ‘‘steadfast mountains,” the ‘‘ everlasting 
hills,” the ‘‘ eternal Alps,” are the common fig- 
ures of speech used about them. But the 
lofty mountain would seem the youngest of the 
earth’s formations, and so far from being “ eter- 
nal” or “everlasting,” it is wearing away much 
faster than the lower heights. For the mountain 
is an exposed point of land—a high point—and 
is always suffering from the wear of the ele- 
ments. Of these elements, water is the most de- 
structive of all. The snow-cap of the peak is a 
condenser and a cloud-maker for the vapors of 
the plains. It rains or snows on the upper ridges 
night after night when never a drop or flake falls 
in the valley. The water collects in swift-run- 
ning streams, the more destructive for their ve- 
locity, that cut and rib the mountain-side. The 
soft portions of earth and rock are eaten out first, 
and the hard parts crumble from lack of sup- 
port. Then the sun-heat expands, the cold con- 
tracts and splits, the winds and rains erode, the 
The age of 
mountains. 
Agents of 
denudation, 
