MO UK TAIN TRAVEL* 
153 
Tlie effect of rarefied air at great heights in reducing the powers of the 
human frame is a subject on which precise knowledge is still wanting* 
Probably no one has yet closely approached the limit at which the 
exertion of walking nphill becomes impossible to a person in normal 
health and accustomed to great elevations. It lies, therefore, considerably 
above 23,000 feet. On the other hand, mountaineers agree that their 
powers diminish perceptibly as they ascend above 12,000 feet. In De 
Saussure’s generation both he and his guides were, at 15,000 feet, on 
Mont Blanc, unable to do more than advance a few yards at a time, 
while men of science now spend three days and nights on the summit 
of Mont Blanc, and modern climbers feel little or no inconvenience 2000 
feet higher on the difficult peaks of the Caucasus, and can still climb and 
observe between 22,000 and 23,000 feet in the Karakoram or the Andes. 
Probably up to 18,000 feet the body acclimatizes itself to the upper 
air; and “ training ” is therefore one of the best preventives of mountain- 
sickness. The inhalation of oxygen has been advised as a palliative, but 
the remedy, if such it be, is not practically possible on the mountain side. 
The inconveniences felt on high ascents arise in some part from indiges¬ 
tion, and light but frequent meals ( e.g . soup at starting, peptonised meat 
sandwiches and chocolate and cold tea during the climb) will be found 
very efficacious in avoiding bodily discomfort. A scientific investigation 
of the process by which the human frame adapts itself to high altitudes 
has recently been made by M. Yallot. (See Levasseur’s ‘Les Alpes/ 
Paris, 1889 ; Geographical Journal, January, 1893; Sir Martin Conway’s 
work on the Karakoram, and Mr. "Whymper’s on the Andes.) Professor 
Mosso, in his f Life of Man on the High Alps 5 (English translation, 
Eisher Unwin, 1898), gives the results of an elaborate investigation into 
the subject, but many of his views have been seriously questioned. The 
subject is complex, involving both local and personal conditions, and 
demands further experiment and research; all dogmatic statements must 
at present be received with reserve. 
Next to the rarity of the air frostbite is the most formidable enemy 
of the climber who attempts great altitudes. Satisfactory foot-gear has 
not yet been devised. Some modification of Arctic expedients suitable 
for rock-climbing is wanted. The feet must not be compressed and the 
circulation impeded. Generally foreign mountaineers pay more attention 
than Englishmen to climbing-shoes and crampons. The ordinary hob- 
