RESPIRATION 375 



have hitherto been able to go is due entirely to the physiological 

 effects of the reduced oxygen pressure and the quite evident im- 

 perfections of the apparatus used for overcoming these effects. 



Hot-air balloons were devised by the brothers Montgolfier, and 

 first used at Paris in 1783. Shortly afterwards the well-known 

 French physicist Charles invented the hydrogen balloon and made 

 the first ascent in 1785, reaching a height of 13,000 feet. Higher 

 ascents were soon after made, and in 1804 another Frenchman, 

 Robertson, reached about 26,000 feet and was greatly affected. 

 In the same year Gay-Lussac went to about 23,000 feet, but only 

 noticed slight effects. It seemed pretty evident that the limit of 

 safety was about 25,000 feet, but until 1875 no balloonist seems to 

 have been actually killed by asphyxiation due to the rarefied air. 



In 1862 the well-known meteorologist Glaisher and the bal- 

 loonist Coxwell made a famous very high ascent from Wolver- 

 hampton; and Glaisher's account of the symptoms observed was 

 very full and valuable. 14 In 48 minutes they had reached a height 

 at which the barometer stood at 10.8 inches (274 mm.). Glaisher 

 found that after this he could no longer read his thermometer or 

 even his watch. His last reading of the barometer was 9.75 inches 

 (248 mm.), which he estimated as corresponding to 29,000 feet. 15 

 He then found that his arms and legs were paralyzed, and then 

 his neck also, so that he could not hold up his head. He could still 

 vaguely see Coxwell, who had climbed up to free the rope of the 

 valve, this having got tangled, owing to rotation of the balloon. 

 He tried to speak, but could not, and then suddenly he became 

 blind. He says, "I was still completely conscious, and my brain 

 was as active as in writing these lines." Then suddenly he lost all 

 consciousness and appears to have been unconscious for about 

 seven minutes, during which Coxwell had fortunately succeeded in 

 stopping the ascent of the balloon and bringing it down again for 

 a considerable distance. During Glaisher's return to consciousness 

 he first heard the words "temperature" and "observation," but 

 without seeing anything. Then he began to see his instruments 

 vaguely, and then other objects, and finally was able to take up 

 his pencil and continue his observations. The barometer was then 

 ii T /2 inches (292 mm.). Coxwell had never lost consciousness. 

 He climbed down with great difficulty. Seeing Glaisher's condition 

 he tried to pull the valve rope, but found that his own arms were 

 now paralyzed. He then, with great presence of mind, got hold 



14 Glaisher, Travels in the Air, London, 1871. 



15 It is somewhat doubtful whether the aneroid barometer was correct. 



