THE GHEAT CATARACTS. 253 



the great cataracts are not found near the sources of the 

 rivers. After a tranquil course of more than one hundred 

 and sixty leagues from the little Raudal of Guaharibos, east 

 of Esmeralda, as far as the mountains of Sipapu, the river, 

 augmented by the waters of the Jao, the Ventuari, the 

 Atabapo, and the Guaviare, suddenly changes its primitive 

 direction from east to west, and runs from south to north : 

 then, in crossing the land-strait* in the plains of Meta, 

 meets the advanced buttresses of the Cordillera of Parima. 

 This obstacle causes cataracts far more considerable, and 

 presents greater impediments to navigation, than all the 

 Pongos of the Upper Marafion, because they are propor- 

 tionally nearer to the mouth of the river. These geogra- 

 phical details serve to prove, in the instances of the two 

 greatest rivers of the New World, 1st, that it cannot be 

 ascertained in an absolute manner that, beyond a certain 

 number of toises, or a certain height above the level of the 

 sea, rivers are not navigable ; 2ndly, that the rapids are not 

 always occasioned, as several treatises of general topography 

 affirm, by the height of the first obstacles, by the first lines 

 of lidges which the waters have to surmount near their 

 sources. 



The most northern of the great cataracts of the Orinoco 

 is the only one bounded on each side by lofty mountains. 

 The left bank of the river is generally lower, but it makes 

 part of a plane which rises again west of Atures, towards the 

 Peak of Uniana, a pyramid nearly three thousand feet high, 

 and placed on a wall of rock with steep slopes. The situa- 

 tion of this solitary peak in the plain contributes to render 

 its aspect more imposing and majestic. Near the Mission, 

 in the country which surrounds the cataract, the aspect of 

 the landscape varies at every step. Within a small space 

 we find all that is most rude and gloomy in nature, united 

 with an open country and lovely pastoral scenery. In the 

 physical, as in the moral world, the contrast of effects, the 

 comparison of what is powerful and menacing with what ia 

 soft and peaceful, is a never-failing source of our pleasures 

 and our emotions. 



J shall here repeat some scattered features of a picture 



This strait, which I have several times mentioned, is formed by th 

 Cordilleras of ihe Andes of New Granada, and the Cordillera of Parima. 



