150 TRAVELS AMONGST THE GREAT ANDES, chap. vii. 



but it was steadily maintained. At one point, when between 

 18,000 and 19,000 feet above the level of the sea, they went 

 up 360 steps without stopping. I noticed nothing unusual 

 during the ascent, nor upon the summit, except the overpower- 

 ing desire to sit down, which always mastered us when we were 

 at great elevations (low pressures), and the disposition to breathe 

 through open mouths. The collapse on Chimborazo had, how- 

 ever, occurred very suddenly. We were all right in one hour 

 and all wrong in the next. It came upon us, so it seemed, 

 without premonition. All at once, we found ourselves with 

 intense headaches (not having had any before), gasping for air, 

 and half asphyxiated. Hour after hour went by on the summit 

 of Cotopaxi without anything of the kind happening again. 

 Jean-Antoine refused to admit that he had any ailments ; Louis 

 acknowledged that he had a rather sharp headache, and I had 

 a slight one. That was all, beyond the feeling of lassitude 

 which, I repeat, always came over us at the greatest heights. 

 On Chimborazo we had all been feverish. Even when recover- 

 ing, my blood temperature was as high as 100° '4 with the air 

 at 49°. On Cotopaxi it remained at 98° "2 both with higher and 

 lower air temperatures. In short, during the twenty-six hours 

 which we passed on the summit of Cotopaxi, from mid-day 

 February 18, to 2 p.m. on the 19th, there was no recurrence of 

 the more acute symptoms, and no perceptible effects were pro- 

 duced (beyond those which have been mentioned) by the low 

 atmospheric pressure that we experienced.^ 



When night fairly set in we went up to view the interior 

 of the crater. The atmosphere was cold and tranquil. We could 

 hear the deadened roar of the steam-blasts as they escaped from 

 time to time. Our long rope had been fixed both to guide in 

 the darkness, and to lessen the chance of disturbing the equi- 

 librium of the slope of ash. Grasping it, I made my way 



1 At 6.20 a.m., on Feb. 19, on the rim of the crater (above the tent), the 

 mercurial barometer stood at 14 '748 inches, with the air temperature at 21° Faht. 



