Ch. III. SOUTH AMERICA. 237 



XXIV. Signal on the desert of Yasuay. 



Our observations at the signal of Yasuay were not 

 finished till the i6th of July; there being a necessity, 

 before we could conclude them, to pitch on the most 

 convenient placefor measuring a second base,in order 

 to prove the accuracy of all the preceding geome- 

 trical operations ; and, after fixing on a proper spot, 

 to determine vvhere the signals between Yasuay and 

 the base could be most properly placed. In order to 

 this, we went to Cuenqa, and from thence proceeded 

 to the plains of Talqui and los Bannos. At last it 

 was determined that the base should be measured in 

 the former, by which the result of the triangles was to 

 be verified by my company, and that of the other in 

 the plain of los Bannos. The requisite signals also 

 were erected ; and we returned to the desert of Yasuay, 

 . where we continued our observations, which employed 

 us from the yth to the i6th of July. Though this 

 mountain is one of the highest in the whole territory 

 of Cuenqa, and the ascent so steep that there is no 

 going up but on foot, nor even by that method with- 

 out great labour, yet the cold is far from being so 

 intolerable as on Sinasaguan and the deserts north of 

 that mountain. So that we cheerfully supported the 

 inconvcniencies of this station. 



XXV. Signal on the mountain of Borma. 



This mountain is but low, as are all the others in 

 the neighbourhood of Cuenqa, so that here we were 

 not impeded by any cloudy summits. It was also our 

 good fortune that Yasuay, contrary to our apprehen- 

 sions, was clear and visible the whole 19th of July ; 

 so that we finished our observations in two days agree- 

 ably. 



XXVL 



