268 TORRENTS EXTINGUISHED. 
into the very heart of the mountains, the streams, though 
rapid, have often lost the true torrential character, if, indeed, 
they ever possessed it. Their beds have become approximate- 
ly constant, and their walls no longer crumble and fall into the 
waters that wash their bases. The torrent-worn ravines, of 
which I have spoken, are of later date, and belong more prop- 
erly to what may be called the crust of the Alps, consisting of 
loose rocks, of gravel, and of earth, strewed along the surface 
of the great declivities of the central ridge, and accumulated 
thickly between their solid buttresses. But it is on this crust 
that the mountaineer dwells. Here are his forests, here his 
pastures, and the ravages of the torrent both destroy his world, 
and convert it into a source of overwhelming desolation to the 
plains below. 
I do not mean to assert that all the rocky valleys of the Alps 
have been produced by the action of torrents resulting from 
the destruction of the forests. The greater, and many of the 
smaller channels, by which that chain is drained, owe their 
origin to higher causes. They are primitive fissures, ascribable 
to disruption in upheaval or other geological convulsion, 
widened and scarped, and often even polished, so to speak, by 
the action of glaciers during the ice period, and but little 
changed in form by running water in later eras. 
It has been contended that all rivers which take their rise in 
mountains originated in torrents. These, it is said, have 
lowered the summits by gradual erosion, and, with the material 
thus derived, have formed shoals in the sea which once beat 
against the cliffs ; then, by successive deposits, gradually raised 
them above the surface, and finally expanded them into broad 
plains traversed by gently flowing streams. If we could go 
back to earlier geological periods, we should find this theory 
often verified, and we cannot fail to see that the torrents go on 
at the present hour, depressing still lower the ridges of the 
Alps and the Apennines, raising still higher the plains of Lom- 
bardy and Provence, extending the coast still farther into the 
Adriatic and the Mediterranean, reducing the inclination of 
