330 AVERAGE BKEADTJI OF THE CHAIK. 



issud from those mountains, those of Las Trincheras (90'4) 

 on its southern slope, and those of Onoto and Mariara on 

 its southern slope. The former issue from a granite with 

 large grains, very regularly stratified ; the latter from a rock 

 of gneiss. What especially characterizes the northern chain, 

 is a summit which is not only the loftiest of the system of 

 the mountains of Venezuela, but of all South America, on 

 the east of the Andes. The eastern summit of the Silla of 

 Caracas, according to my barometric measurement made in 

 1800, is 1350 toises high,* and notwithstanding the commo- 

 tion which took place on the Silla during the great earth- 

 quake of Caracas, that mountain did not sink 50 or 60 toises, 

 as some North American journals asserted. Four or five 

 leagues south of the northern chain (that of Mariara, la Silla, 

 and Cape Codera,) the mountains of Gruiripa, Ocumare, and 

 Panaquire, form the southern chain of the coast, which 

 stretches in a parallel direction from Gruigue to the mouth of 

 the Bio Tuy, by the Gruesta of Tusma, and the Guacimo. 

 The latitudes of the Villa de Cura and San Juan, so erro- 

 neously marked on our maps, enabled me to ascertain the 

 mean breadth of the whole Cordillera of Venezuela. Ten 

 or twelve leagues may be reckoned as the distance from the 

 descent of the northern chain \vhich bounds the Caribbean 

 Sea, to the descent of the southern chain bounding the im- 

 mense basin of the Llanos. This latter chain, which also 

 bears the name of the Inland Mountains, is much lower 

 than the northern chain ; and I can hardly believe that the 

 Sierra de Guayraima attains the height of 1200 toises. 

 The two partial chains, that of the interior, and that 



only 44'5, and the bubbles of air which are disengaged at intervals, are 

 at Onoto, as well as in the thermal waters of Mariara, pure nitrogen. 

 The waters of Mariara (244 toises) have a faint smell of sulphuretted 

 hydrogen; they leave, by evaporation, a slight residuum, that yields carbonic 

 acid, sulphuric acid, soda, magnesia, and lime. The quantities are so 

 small that the water is altogether without taste. In the course of my 

 journey, I found only the springs of Cumangillas hotter than the thermal 

 waters of Las Trincheras : they are situated on the south of Porto 

 Cabello. The waters of Comangillas are at the height of 1040 toises, 

 and are alike remarkable for their purity, and their temperature of 96*3 

 cent. 



* The Silla of Caracas is only 80 toises lower than the Caniou in the 

 Pyrenees. 



