42 



midst of the principal chain of the Andes, whose 

 height appears to me not inferior to that of the cele- 

 brated Chimboraso of Quito, various shells, evi- 

 dently the production of the sea, oysters, conchs, 

 periwinkles. Sec. are found in a calcined or petrified 

 state, that were doubtless deposited there by the wa- 

 ters of the deluge. 



The summit of this mountain, whose form ap- 

 pears to be owing to some volcanic eruption, is flat, 

 and exhibits a plain of more than six miles square ; 

 in the middle is a very deep lake, which, from every 

 appearance, was formerly the crater of a volcano. 



The principal chain of the Andes is situated be- 

 tween two of less height that are parallel to it. These 

 lateral chains are about twenty five or thirty miles 

 distant from the principal, but are connected with it 

 by transverse ramifications, apparently of the same 

 age and organization, although their bases are more 

 extensive and variegated. From the lateral ridges 

 many other branches extend outwardly, composed 

 of small mountains, occasionally running in differ- 

 ent directions. 



These external mountains, as well as the middle 

 and maritime, are of a secondary formation, and an 

 order essentially different. Their summits are gene- 

 rally more rounded, and they consist of horizontal 

 strata of various substances and unequal thick- 

 ness, which abound with marine productions, and 

 often exhibit the impressions of animals and vege- 

 tables. I have observed both in excavations formed 

 by the water, and those made by the inhabitants, 

 that the inferior stratum of these mountains is gene- 



