174 



winds; they rise where the breeze cannot come; 

 and if the mountains of the Upper Oroonoko^ 

 the tops of which are generally crowned with 

 trees, were more elevated, they would produce 

 the same impetuous movements in the atmos- 

 phere, as we observe in the Cordilleras of Peru, 

 of Abyssinia, and of Thibet. The intimate con- 

 nection that exists between the direction of 

 rivers, the height and disposition of the adjacent 

 mountains, the movements of the atmosphere, 

 and the salubrity of the climate, is a subject 

 well worthy attention. The study of the sur- 

 face and the inequalities of the soil would in- 

 deed be irksome and steril, were it not con- 

 nected with more general considerations. 



At the distance of six miles from the island of 

 Piedra Raton we passed first, on the east, the 

 mouth of the Rio Sipapo, called Tipapu* by 

 the Indians ; and then, on the west, the mouth 

 of the Rio Vichada. Near the latter are some 

 rocks covered by the water, that form a small 

 cascade, or raudallto. The Rio Sipapo, which 



* The sources of the Rio Tipapu, it is said,, are north of 

 the parallel of Atures, on the eastern side of those granitic 

 mountains, from which the Rio Cataniapo rises. In the 

 upper part of it's course it bears the name of Uapu or Tuapu. 

 One of it's tributary streams, the Auvana, which Surville has 

 transformed into Abana, and Caulin into Amanaveni (water 

 or river, veni, of Amana), is remarkable for the fine cascade 

 of Arucuru, above the Raudal of Quiamicuana, 



