3G2 Hi SIN OF THE A.MAZOW. 



Vertentes and the Bio de Tres Barras (tributary streams of 

 the Araguay and the Topayos), several ridges of the Monta 

 Parecis run northward. On the right bank of the Topayos, 

 a series of little hills advance as far as the parallel of 5 

 south latitude, to the fall (cachoeira) of Maracana; while 

 further west, in the Bio Madeira, the course of which is 

 nearly parallel with that of the Topayos, the rapids and 

 cataracts indicate no rocky ridges beyond the parallel of 8. 

 The principal depression of the basin of which we have just 

 examined the outline, is not near one of its banks, as in the 

 basin of the Lower Orinoco, but at the centre, where the 

 great recipient of the Amazon forms a longitudinal furrow 

 inclining from west to east, under an angle of at least 25* 

 The barometric measurements which I made at Javita on 

 the banks of the Tuamini, at Vasivia on the banks of the 

 Cassiquiare, and at the cataract of Eentema, in the Upper 

 Maraiion, seem to prove that the rising of the Llanos of 

 the Amazon northward (at the foot of the Sierra Parime), is 

 150 toises, and westward (at the foot of the Cordillera of 

 the Andes of Loxa), 190 toises above the sea-level. 



(jb.) Part of the basin of the Amazon stretching from south 

 to north. This is the zone or land-strait by which, between 

 12 and 20 of south latitude, the plains of the Amazon com- 

 municate with the Pampas of Buenos Ay res. The western 

 bank of this zone is formed by the Andes, between the knot 

 of Porco and Potosi, and that of Huanuco and Pasco. Part 

 of the spurs of the Eio Beni, which is but a widening of the 

 Cordilleras of Apolobamba and Cuzco and the whole promon- 

 tory of Cochabamba, advance eastward into the plains of 

 the Amazon. The prolongation of this promontory has given 

 rise to the idea that the Andes are linked with a series of 

 hills which the Serras dos Parecis, the Serra Melgueira, and 

 the supposed Cordillera of San Fernando, throw out towards 

 the west. This almost unknown part of the frontiers of 

 Brazil and Upper Peru merits the attention of travellers. It 

 is understood that the ancient mission of San Jose de Chi- 

 quitos (nearly lat. 17; long. 67 10', supposing Santa Cruz 

 de la Sierra, in lat. 17 25' ; long. 66 47'), is situated in the 

 plains, and that the mountains of the spur of Cochabamba 

 teminate between the Gruapaix (Eio de Mizque) and the 



