March, 1835. mountain torrents. 385 



mule always appears to me a most surprising animal. That 

 , a hybrid should possess more reason, memory, obstinacy, 

 social affection, and powers of muscular endurance, than 

 either of its parents, seems to indicate that art has here out- 

 mastered nature. Of our ten animals, six were intended 

 for riding and four for carrying cargoes, each taking turn 

 about. We carried a good deal of food, in case we should 

 be snowed up, as the season was rather late for passing the 

 Portillo. 



March 19th. — We rode during this day to the last, and 

 therefore most elevated house in the valley. The number of 

 inhabitants became scanty; but wherever water could be 

 brought on the land, it was very fertile. All the valleys in 

 the Cordillera agree in the same kind of structure. An 

 irregularly-stratified mass of well-rounded shingle, together 

 with a Uttle mud and sand, fills up the bottom to the depth 

 of some hundred feet. This deposit follows the course of 

 the valley, sloping upwards with a most gradual and gentle 

 inchnation. The rivers have removed a large part in the 

 centre; thus leaving a terrace of equal height, but varying 

 width, on each side. This narrow space between the cliffs 

 bordering the bed of the river, and the foot of the moun- 

 tains, is the only part fit for cultivation, and on it likewise 

 the road is carried. 



The rivers, such as the Maypo, which flow in these 

 valleys, should rather be called mountain torrents. Their 

 inchnation is very great, and their water the colour of mud. 

 The roar which the Maypo 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 

 at 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 thou- 

 sands of stones, which, striking against each other, make 

 the one dull uniform sound, are all hurrying in one direc- 

 tion. It is like thinking of time, where the minute that 



VOL. III. 2 c 



