306 THE POKOROCCA. 



rising across the whole width of the stream, to the height of 

 twelve or fifteen feet sweeps up the stream. Advancing noise- 

 lessly over the deeper portions of the river-bed, it rises into 

 an angry billow, with a fearful roar when passing over a shal- 

 low, or meeting any impediment in its course. A French 

 traveller describes an island where he and his companions 

 had rested on their voyage down the stream. They had hap- 

 pily gone over to the mainland on the previous evening, 

 when, as they stood on the shore, the pororocca was heard 

 approaching. Onward it came till the island was reached, 

 when, with an angry roar, it burst into masses of foam, and 

 swept over the devoted spot, carrying in its fierce embrace 

 not only the whole mass of vegetation, but overturning the 

 foundations of the island itself, so that in a few seconds not a 

 vestige remained. Sometimes, too, the higher banks of the 

 Upper Amazon, crowned by lofty trees, are worn away by 

 the rapid current, increased during the rainy season, continu- 

 ally passing beneath them, till the upper portions, deprived of 

 their support, fall over with a terrific roar into the stream, 

 dragging with them their neighbours. The earth trembles 

 with the concussion, the waters hiss and foam and rush furi- 

 ously over the impediments in their course. Sometimes miles 

 of the bank thus give way, the sound being heard far up and 

 down the stream. Occasionally a canoe and its crew- -who, 

 to avoid the current, have been toiling close along the bank 

 have been thus overwhelmed ; while others, descending, un- 

 aware of the obstruction, have been dragged by the furious 

 whirlpool thus formed amid the tangled branches, and de- 

 stroyed. 



