1835.] TORRENTS OF THE CORDILLERA. 303 



sea penetrated Chile, as it now does the more southern coasts. No 

 one fact in the geology of South America, interested me more than 

 these terraces of rudely-stratified shingle. They precisely resemble 

 in composition the matter which the torrents in each valley would 

 deposit, if they were checked in their course by any cause, such as 

 entering a lake or arm of the sea ; but the torrents, instead of de- 

 positing matter, are now steadily at work wearing away both the 

 solid rock and these alluvial deposits, along the whole line of every 

 main valley and side valley. It is impossible here to give the 

 reasons, but I am convinced that the shingle terraces were accu- 

 mulated, during the gradual elevation of the Cordillera, by the 

 torrents delivering, at successive levels, their detritus on the beach- 

 heads of long narrow arms of the sea, first high up the valleys, 

 then lower and lower down as the land slowly rose. If this be so, 

 and I cannot doubt it, the grand and broken chain of the Cordillera, 

 instead of having been suddenly thrown up, as was till lately the 

 universal, and still is the common opinion of geologists, has been 

 slowly upheaved in mass, in the same gradual manner as the 

 coasts of the Atlantic and Pacific have risen within the recent 

 period. A multitude of facts in the structure of the Cordillera, on 

 this view receive a simple explanation. 



The rivers which flow in these valleys ought rather to be called 

 mountain-torrents. Their inclination is very great, and their 

 water the colour of mud. The roar which the Maypu made, as 

 it rushed over the great rounded fragments, was like that of the 

 sea. Amidst the din of rushing waters, the noise from the stones, 

 as they rattled one over another, was most distinctly audible even 

 from a distance. This rattling noise, night and day, may be heard 

 along the whole course of the torrent. The sound spoke eloquently 

 to the geologist ; the thousands and thousands of stones, which, 

 striking against each other, made the one dull uniform sound, 

 were all hurrying in one direction. It was like thinking on time, 

 where the minute that now glides past is irrecoverable. So was it 

 with these stones ; the ocean is their eternity, and each note of that 

 wild music told of one more step towards their destiny. 



It is not possible for the mind to comprehend, except by a slow 

 process, any effect which is produced by a cause repeated so often, 

 that the multiplier itself conveys an idea, not more definite than 

 the savage implies when he points to the hairs of his head. As 

 often as I have seen beds of mud, sand, and shingle, accumulated 



