303 



Ayres, which are also Llanos covered with fine 

 grass, destitute of trees, and filled with oxen 

 and horses become wild. They suppose, ac- 

 cording to the greater part of our maps of Ame- 

 rica, that this continent has only one chain of 

 mountains, that of the Andes, which stretches 

 from South to North ; and they form a vague 

 . idea of the contiguity of all the plains from the 

 Oroonoko and the Apure to the Rio de la Plata 

 and the Straits of Magellan. 



I shall not stop here to give a mineralogical 

 description of the transverse chains, which divide 

 America from East to West, and which I made 

 known in the year 1800 in my Sketch of a Geo- 

 logical View % It will be sufficient to notice 

 in the most clear and concise manner the gene- 

 ral structure of a continent, the extremities of 

 which, though placed in climates little analo- 

 gous, yet afford several features of resemblance. 

 In order to have an exact idea of the plains, 

 their configuration, and their limits, we must 

 know the chains of mountains, that form their 



* Esquisse d'un Tableau Geologique, Journal de Physique, 

 vol. liii, p. 30. This paper had been written and sent to 

 Europe immediately after my return from the iDroonoko, 

 when I had scarcely had time to calculate the astronomical 

 observations, by which I determined the configuration of the 

 chain of La Parime. I have since rectified those first notions 

 of the extent of the plains, by the help of ideas which I acquired 

 during- my stay in Peru, and by my Connections with Brazil, 



