PARTICULARS OF VOLCANOS AND EARTHQUAKES. 245 



air brought from the loftieft point we vlfited, gave on Air 0.218 of 

 being anal)' fed 0.218 of oxigen gas, and 0.008 of carbonic °'"^^"* 

 acid. 



We vifited Cotopoxi, but could not reach the mouth of Cotopoxi not 

 the crater. The affertion, that this mountain was diminifhed e^rthquake^of 

 in height by the earthquake of 1797, is a miftake. J797' 



In June we proceeded to meafure Chimboraco and Tungu- 

 ragua, and take a plan of all the country affedled by the 

 grand cataftrophe of 1797. We approached within about 500 

 yards of the fummit of Chimboraco, our afcent being faci- 

 litated by a line of volcanic rocks bare of fnow. The height Air at 6465 



we reached was 64-65 yards ; and we were prevented from y"'*^* contained 

 •^ ' 0.20 of oxigea. 



afcending farther by a chafra too deep to crofs. We felt the 



fame inconveniences as on Antifana ; and were unwell for 



two or three days after. The air at this height contained 



0.20 of oxigen. The trigonometrical meafurement I took 



of the mountain at two different times, and I can place fome Chimborsco 



confidence in my operations, gave me for its height 6970 ^97° yards 



yards, a hundred niore than Condamine afligns it. The 



whole of this huge mafs, as of all the high mountains of the Confifts of por- 



Andes, is not granite, but porphyry, from the foot to theP^^yy* 



fummit, and there the porphyry is 4050 yard*; thick. 



Chimboraco is probably a volcanic mountain, for the track Chimboraco a 

 by which we afcended, confifts of a burnt and fcoritied rock ^'^ '^^"°* 

 mixed with pumice-ftone, refembling all the ftreams of lava 

 in this country, and ran higher up the mountain than we 

 could climb. The fummit therefore is in ali likelihood the 

 crater of an extind volcano. 



The mountain of Tunguragua has diminiflied in height fince Tunguragua 

 the earthquake of 1797. Bouguer affigiis it 5589 yards, I j,'™Sf '^ '"? 

 found it but 5399, fo that it muft have loft 190 yards; and ijow 5399 

 indeed the people in the vicinity fay, that they have feen its yards. 

 fummit crumble away before their eyes. 



During our ftay at Riobancha, we accidentally made a 



very curious difcovery. The ftate of the province of Quito, 



previous to its conqueft by the Inca Tupaynpangi, in 1470, is 



wholly unknown: but the king of the Indians, Leandro indJanmanu- 



Zapla. who refides at Lican, and has a mind extraordinarily '^^''P" °^^^^ 

 _,_. r • (-11 ictn century. 



cultivated for an Indian, poflefles manulcripts compofed by 



one of his anceftors, in the fixteenth century, which contains 



the hiftory of that period, They are written in the Parugay 



tongue, 



