168 TEMPERATURE OF THE ATMOSPHERE. 



ploring the Himmalehs, suffered from this cause. Thys 

 Captain Gerard, in the account of one of his journeys, 

 says, "Our elevation was now upwards of 15,000 feet, 

 although we had but ascended in company with the river 

 against its current. Here only began our toils, and we 

 scaled the slope of the mountain slowly ; respiration was 

 laborioxis, and ice felt exhausted at cccry step. The crest 

 of the pass was not visible, and we saw no limit to 

 our exertions. The road inclined at an angle of 30°, 

 and passed under vast ledges of limestone. The projec- 

 tions frowned above us in new and horrid forms, and our 

 situation was different from any thing we had yet expe- 

 rienced. Long before we got up, ice were troubled with severe 

 headaches, and our respiration became so hurried and oppres- 

 sive, that ice were compelled to sit down every few yards, and 

 eccn then we could scarcely inhale a sufficient supply^ of q.ir. 

 The least motimi was accompanied with extreme debility and 

 a depression of spirits ; and thus we labourtd for tivo miles."* 

 Even the lower animals are observed to experience similar 

 inconvenience from attenuated air. Thus the yali and the 

 horse are mentioned by Moorcroft and others as suffering 

 considerably when driven into high mountainous situations. 



The effects of the attenuated air 'on sound is also a 

 curious subject for observation and experiment. Saussure 

 found sounds very feeble on the summit of Mount Blanc ; 

 Dr. Schultes experienced the same on the Glockner and 

 Stiria ; and other travellers notice the comparatively smal! 

 extent to which the voice can be heard at an altitude of 

 13,000 feet on Mount Rosa. Observations have never, 

 as far as we* know, been made on this point among the 

 Himmalehs, although such would prove interesting. They, 

 might be made by the explosions of a small detonating 

 pislol loaded with a constant charge, and the distances 

 should be measured ; for the voice loses much of its force 

 from the diminution of muscular energy in rarefied air, 

 and distances are much underrated by estimation in such 

 situations. 



4. Temperature of the Atmosphere. — The problem of the 

 distribution of heat' over the globe is a very complicated 



♦ For other details on this sutject, see that valuable periodical the 

 Asiatic Journal. 



