CATARACTS OF THE ORINOCO. 211 



upon which the sailors again swim, though not with- 

 out difficulty, through the whirlpools to the nearest 

 island. When the bars are very high the vessels 

 are taken ashore, and drawn upon rollers, made of the 

 branches of trees, to a place where the river again 

 becomes navigable. During the flood, however, this 

 operation is seldom necessary. 



Although the rapids of the Orinoco form a long 

 series of falls, the noise of which is heard at the dis- 

 tance of more than three miles, yet the rocks were 

 found by Humboldt not to have a greater height than 

 thirty feet perpendicular. He thinks it probable that 

 a considerable part of the water is lost by passing 

 into subterranean cavities, independently of that 

 which disappears by being dispersed in the atmo- 

 sphere. Numberless holes and sinuosities are formed 

 in the crevices by the friction of the sand and quartz 

 pebbles ; but he does not consider that any great 

 change is effected in the general form of the cata- 

 racts by the action of the water, the granite being 

 too hard to be worn away to a great extent. The 

 Indians assert that the stony barriers preserve the 

 same aspect ; but that the partial torrents into which 

 the river divides itself are changed in their direc- 

 tion, and carry sometimes more, sometimes less 

 water towards one or other bank. 



When the rush of the cataracts is heard in the 

 plain that surrounds the mission of Atures, one ima- 

 gines he is near a coast skirted by reefs and break- 

 ers. The noise is thrice as loud by night as by day. 

 This circumstance had struck the padre and the In- 

 dians, and Humboldt attributes it to the cessation 

 of the sun's action, which is productive of number- 

 less currents and undulations of the air, impeding 

 the progress of sound by presenting spaces of differ- 

 ent density. 



The jaguars, which abound everywhere on the 

 Orinoco, are so numerous here that they come into 

 the village, and devour the pigs of the poor Indians. 



