42 MOUNTAIN OBSERVATOEIES IN AMERICA AND EUROPE. 



times Mr. Whymper went to a height of 18,528 feet Mountain-sick- 

 ness had been experienced by all at a height of 16,600 feet ; but '^ in 

 course of time the more acute symptoms disappeared," though onlv a 

 slight decrease of })ressure could be sustained without bringing it on 

 once more. 



The volcano Cotopaxi (19,613 feet) was next attacked, and a camp 

 was established at 15,139 feet altitude. Twenty-six hours were passed 

 at or near the summit, and during this time there was no recurrence of 

 the mountain-sickness which had been so marked on Chimborazo. Mr. 

 Whymper remarks especially that there was no work to tax tlniir 

 strength, and says "it is by no means certain, if larger demands had 

 been made upon it, that our condition would have remained equally 

 sound." 



After ascending various peaks, Antisana (19,335 feet), Cayaml)e 

 (19,186 feet) among them, Chimborazo (20,498 feet) was ascended a 

 second time without experiencing the acute symptoms of mountain- 

 sickness. Something like seven months had been spent at high alti- 

 tudes, and the party had become habituated to low barometric pressures. 



Mr. Whymper devotes some twenty pages of his book to a discus- 

 sion of his observations upon mountain-sickness. A small part of 

 these observations has been summarized in what has gone before. 



The important question is, can one become accustomed to low [)ix's- 

 sures, so that work can be accomplished at high altitudes with about 

 the same facility as at lower ones ? 



Mr. Whymper's conclusion from all his experiments is that '' we 

 became somewhat habituated to low pressures," but he at once limits 

 this statement. A crucial experiment showed that he himself, a 

 skilled mountaineer, was "materially affected by and weakened x\\ a 

 pressure of twenty-one inches (9850 feet)." 



Certain efi'ects — increased circulation, fever, and general illness — 

 were transitory, and disappeared after the explorers had become accus- 

 tomed to great heights. These are the acute symptoms of mountain- 

 sickness, and Mr. Whymper supposes them to arise from the difference 

 of pressure between the external air and the internal gases of the body. 

 In time an equilibrium is brought about, and the acute symptoms dis- 

 appear. 



Other efi'ects are permanent so long as the person remains at a low 

 pressure. These are chiefly due to a great increase in the rate of 

 respiration. At rest, it was not too difficult to maintain life by in- 

 creasing the volume of air inspired. The least exertion, however, 

 made it extremely difficult to inhale sufficient air. Mr. Whymper 

 examines the proposal of M. Paul Bert to inhale oxygen, and shows 

 that however useful this may be for persons who pass rapidly from 



