STREAMS OF STONES. 255 



was subsequent to the land having been raised 

 above the waters of the sea. In a transverse sec- 

 tion within these valleys the bottom is neai'ly level, 

 or rises but very little towards either side. Hence 

 the fragments appear to have travelled from the 

 head of the valley ; but in reality it seems more 

 probable that they have been hurled down from 

 the ncai^est slopes, and that since, by a vibratory 

 movement of overwhelming force,* the fragments 

 have been levelled into one continuous sheet. If, 

 during the earthquaket which in 1835 overthrew 

 Concepciou, in Chile, it was thought wonderful 

 that small bodies should have been pitched a few 

 inches from the ground, what must we say to a 

 movement which has caused fragments many tons 

 in weight to move onwards like so much sand on 

 a vibrating board, and find their level 1 I have 

 seen, in the Cordillera of the Andes, the evident 

 marks where stupendous mountains have been 

 broken into pieces like so much thin crust, and the 

 strata thrown on their vertical edges ; but never 

 did any scene like these " streams of stones" so 

 forcibly convey to my mind the idea of a convul- 

 sion, of which in historical records we might in 

 vain seek for any counterpart : yet the progress 

 of knowledge will probably some day give a sim- 

 ple explanation of this phenomenon, as it already 

 has of the so long thought inexplicable transportal 

 of the erratic boulders which are strewed over the 

 plains of Europe. 



* " Nous n'avons pas ete moins saisis d'etonnenient k la vue de 

 I'innombrable qiiantite de pierres de toutes grandeurs, boulever- 

 sees les unes sur les autres, et cependant rangdes, comma si elles 

 avoient ete amoncelees negligemment pour remplir des ravins. 

 On ne se lassoit pas d'admirer les eft'ets prodigieux de la nature." 

 — Pernety, p. 52G. 



t An iiihabitant of Mendoza, and hence well capable of judging, 

 assured me that, during the several years he had resided on these 

 islands, he had never felt the shghtest shock o''"n earthquake. 



