Mountain Journeys 111 



This elevation is higher than that at which travellers claim to 

 have begun to feel the effects of the rarefaction of the air in the 

 Alps and the Pyrenees. I did not feel them at all. Perhaps the breath- 

 lessness from which Saussure and his guides and all those who 

 followed his steps on Mont Blanc since then suffered was only the 

 result of a long and difficult march on exceedingly steep slopes. 

 Perhaps if one could be carried from Chamounix to the summit of 

 Mont Blanc, one would escape the illness which is generally attributed 

 to the rarefaction of the air at its crest. The Gerard brothers, who are 

 undeniably the foremost travellers in Alpine regions, constantly com- 

 plain of excessive fatigue and violent headaches on all the passes tney 

 crossed, between 4572 and 5791 meters; and this painful condition 

 continued as long as they remained at these heights, where they 

 camped several times. From that fact it would seem that this illness 

 was not merely the passing effect of fatigue caused by a long climb, 

 but really an effect of the atmospheric condition .... 



The elevation of Mont Blanc is 3780 meters above Chamounix, 

 which is only about 1036 meters above sea level. The ascent is made 

 in thirty hours. There is an enormous change in atmospheric pressure 

 in which one is immersed, and in a very short time. So sudden a 

 transition, independent of the fatigue involved in making it, can 

 definitely affect the respiratory organs. Here, on the contrary, for 

 more than three months, I have been living at an elevation on the 

 average 1829 meters above sea level, and for the last month, at 2743 

 meters, an altitude at which I feel none of the effects of the rarefaction 

 of the air. When I ascend to an absolute elevation of 4572 meters, I 

 pass through a vertical difference of only 1829 meters, half of that 

 which exists between Mont Blanc and Chamounix, and I have no 

 sensation which I can refer to a respiratory disturbance. Finally, the 

 proof that the annoying symptoms felt by travellers on the summit 

 of the Alps or on the passes of the Himalayas would vanish in time, 

 and that their lungs would find enough oxygen in an air which has 

 lost half its density, is the existence of the farm of Antisana in the 

 Andes, which M. von Humboldt told us about, at an elevation of about 

 4114 meters, where a family lives, plows, and works. There is no 

 doubt that the lake of Manasarowar exceeds this height by 305 to 457 22;> 

 meters, and yet there are dwellings on its banks, and pilgrims 

 go round it in a seven day journey. M. Gerard himself proves very 

 satisfactorily that a considerable portion of the high country, in 

 which the Kanaweri merchants travel in going from Shipki or 

 Skialkur to Garou (Gortope), is above 4877 meters in elevation, and 

 yet these merchants do not complain there of symptoms by which 

 we see them attacked when crossing passes often at a lower altitude; 

 whence I conclude that in the latter case it is from the fatigue of 

 the journey that they suffer, laden as they are, whereas in the lofty 

 plains of Chinese Tartary, they walk empty-handed on an almost 

 level road. 



I myself have felt at an elevation of 4000 meters some of the symp- 

 toms in question, that is, fatigue and headache. But I have hardly ever 

 mounted to this height without being exposed to a furious wind, and 

 whatever precaution I took against its cold, I was always chilled, and 



