T0RREXT3 EXTINGUISHED. 261 



eaxtli, strewed along the surface of the great declivities of the 

 central ridge, and accumulated thickly between their solid but- 

 tresses. But it is on this crust that the mountaineer dwells. 

 Here are his forests, here his pastures, and the ravages of tlie 

 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 origiu to higher 

 causes. They are primitive fissures, ascribable to disruption in 

 upheaval or other geological convulsion, widened and scarped, and 

 often even poHshed, 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 aU 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 de- 

 rived, 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 earher geologi- 

 cal periods, we should find this theory often verified, and we can 

 not fail to see that the torrents go on at the present hour, depress- 

 ing still lower the ridges of the Alps and the Apennines, raising 

 still higher the plains of Lombardy and Provence, extending 

 the coast still farther into the Adriatic and the Mediterranean, re- 

 ducing the inclination of their own beds and the rapidity of their 

 flow, and thus tending to become river-hke in character. 



"We can not measure the share which human action has had in 

 augmenting the intensity of causes of mountain degradation, and 

 of the formation of plains and marshes below, but we know that 

 the clearing of the woods has in some cases produced, within 

 two or three generations, effects as blasting as those generally 

 ascribed to geological convulsions, and has laid waste the face of 

 the earth more hopelessly than if it had been buried by a current 

 of lava or a shower of volcanic sand. New torrents are forming 

 every year in the Alps. Tradition, written records and analogy 

 concur to establish the behef that the ruin of most of the now 



