539 



destitute of recent traces of volcanic fire, and, 

 with the exception of the coast of Venezuela, 

 little exposed to the violence of earthquakes. 

 The mean height of the three systems diminishes 

 from north to south, from 750 to 400 toises * ; 

 those of the culminant points (maxima of the 

 height of each groupe), from 1350 to 1000 or 

 900 toises. It results from these observations, 

 that the loftiest chain, with the exception of the 

 small insulated system of the Sierra Nevada of 

 Santa Marta is the Cordillera of the shore of 

 Venezuela, which is itself but a continuation of 

 the Andes. In taking a view of the north, we 

 find in central America (lat. 12°— 30°), and north 

 America (lat. 30—70°), on the east of the Andes 

 of Guatimala, Mexico, and Upper Louisiana, 

 the same regular lowering which struck us 

 towards the south. In this vast extent of land 

 from the Cordillera of Venezuela to the polar 

 circle, eastern America presents two distinct 

 systems, the groupe of the mountains of the 

 West Indies, of which the eastern part is volca- 

 nic, and the chain of the Alleghanies. The 

 former of these systems, partly overwhelmed in 

 the floods, may be compared with respect to its 

 relative position and form, to the Sierra Pa- 

 rime ; the latter to the chains of Brazil, run- 



* See above, Vol. vi, p. 405. 

 f See above, Vol. vi, p. 481. 



