63 



friction of the sand, and the movement of quartz 

 pebbles. We have seen some of these pebbles, 

 that were whirled perpetually by the current at 

 the bottom of the funnels, and contributed to aug- 

 ment them in every direction. The pongos of the 

 river Amazon are very destructible, because the 

 rocky dikes are not granite, but a conglomerate, 

 a red sandstone with large fragments. A part of 

 the pongo of Rentema was broken down eighty 

 years ago, and, the course of the waters being 

 interrupted by a new bar, the bed of the river re- 

 mained dry for some hours, to the great aston- 

 ishment of the inhabitants of the village of 

 Payaya, seven leagues below the pongo. The 

 Indians of Atures assert (and in this their testi- 

 mony is contrary to the opinion of Caulin*) ? 

 that the rocks of the raudal preserve the same 

 aspect ; but that the partial torrents, into which 

 the great river divides itself as it passes through 



* Historia corographica, p. 72. This author seems to think, 

 that the raudales have become easier to pass since the time of 

 father Gumilla, because in 1743 the expedition of the bound- 

 aries, under the orders of Don Jose Solano, succeeded in 

 making nine large boats (champanes) go up the raudales j 

 while father Gumilla asserts, that no hai otro arbitrio en el 

 raudal de Atures que llevar las embarcationes por tierra. The 

 jesuit certainly could not mean, that the boats are transport- 

 ed by land the whole length of the rapids. I was assured on 

 the spot, that the Indian pilots conveyed the champanes of the 

 royal expedition up the cataracts, in the same manner as they 

 have always done the small boats of travellers. 



