CHAP. XIX. EVIDENCES OF DETERIORATION. 369 



for the instruction ; and they, imagining that the ascent of the 

 mountain was the first consideration, made a push for the summit 

 [p. 59]. They were away nearly twelve hours, and during this 

 time experienced reduction in pressure from 16*500 to about 

 15 "100 inches, while ascending from 16,664 to 19,300 feet. Upon 

 return, their condition closely approached complete exhaustion. 

 They staggered like men in an advanced state of intoxication, and 

 threw themselves down and went to sleep without either eating or 

 drinking [p. 59].' 



During the time they had been absent, my own condition had 

 materially improved ; and thus it appeared that although there 

 was a likelihood we should become habituated to a pressure of 

 16*500 inches, there was a probability that we should be further 

 affected at still lower pressures. This determined the position of 

 the Third Camp (16-000 inches; 17,285 feet). While transport 

 was being effected between the two posts, it seemed that we had 

 grown weaker, and we certainly were [p. 61] *^^ comparatively life- 

 less and feeble, and had a strong disposition to sit down." By 

 January 2, headaches had nearly departed, feverishness had dis- 

 appeared (my temperature had fallen to 97° '9 Faht.), and the 

 circulation had gone back to the normal rate ; but respiration 

 continued to be affected, and it was found that we could not 

 satisfy our wants for air, wliile in movement, except by breathing 

 through nostrils and mouths. 



Under the further fall in pressure which occurred when ascend- 

 ing on January 3 to the foot of the Southern Walls of Ohimborazo 

 (16*000 to 15*290 inches) it was remarked that the rate of travel- 

 ling was unusually slow ; and this was more distinctly seen on the 

 following day when mounting to the summit (pressure declining 

 from 16*000 to 14*100 inches). At a little above 19,000 feet, I 

 noticed that '^our paces got shorter and shorter, until at last the 



1 At the time of their return, no opinion could be formed as to their rate. If 

 two hours were occupied in halts, and ten hours in movement, the mean of their 

 ascending and descending rates would be only 526 feet per hour. 



3b 



