PROCEEDINGS OF THE POLTTECHNIC ASSOCIATION. 559 



this space, saj's Mr. Glaisher, " Mr. Cuxwell, my companion and myself' 

 both put on additional clothing, feeling certain that we should experience 

 a temperature below zero before we reached an altitude of five miles; but 

 to my surprise, at the height of 14,500 feet, the temperature, as shown by 

 all the sensitive instruments, was 31 degrees, and to each successive read- 

 ing up to 19,500 feet the temperature increased and was 43 degrees When 

 we had risen somewhat, the temperature again began to decrease, and with 

 extraordinary rapidity, and was 16 or 27 degrees less than it was twenty- 

 six minutes before. At this time, about 11 A. M., we were at a height of five 

 miles. In an ascent on the 20th of August, the balloon hovered for a long 

 time over London, the hum of which was very audible, and when the city 

 was lighted at night, it presented the appearance of an enormous confla- 

 gration. 



The most important ascent however was made on the 5th of September, 

 in which a greater elevation was obtained than had ever before been reach- 

 ed by human beings,, rising upwards of 30,000 feet above the level of the 

 sea, being about six miles, or 2,000 feet above the highest peak of the 

 Himalaya mountains. 



The ascension commenced at 1 P. M. They reached two miles in height 

 at 1.21, three rniles at 1.28, and four miles at 1.40; in ten minutes more 

 they reached the fifth mile, and the temperature had passed below zero, and 

 then read minus two degrees. Up to this time Mr. Glaisher had taken ob- 

 servations with comfort; soon, however, both observers breathed with diffi- 

 culty, and began to feel unpleasant — their sight became dim, and their 

 hands almost useless, so as to be unable to write. Mr. Glaisher became 

 entirely insensible, and Mr. Coxwell felt that insensibility was coming over 

 himself. Becoming anxious to open the valve he found his hands failed 

 him, and he instantly seized the line between his teeth and pulled the valve 

 open two or three times, until the balloon began to descend. In the course 

 of a few minutes Mr. Glaisher revived, and by the time that he reached the 

 earth the effects of the faintness had entirely disappeared. 



Compared with this serial voyage, all other balloon ascensions sink into 

 insignificance. Guy Lussac attained an elevation of about four miles; Mr. 

 Glaisher, on two occasions, rose considerably above this elevation, and on 

 the last ascent, as already stated, probably attained a height of six miles. 

 Had it not been, moreover, for the presence of Mr. Coxwell, the voyagers 

 would have shot up into an atmosphere so thin that respiration could not 

 have been sustained, and in the end the expansion of gas would probably 

 have burst the balloon, or if the safety valve had been sufficiently large to 

 allow for that expansion, they might have been carried so high into space, 

 as to be numbered among the victims on the altar of science. 



Temperature at Different Altitudes. 



From a mean of all his observations, Mr, Glaisher presented to the Bri- 

 tish .': ssociation the following table, showing the mean temperature of the 

 air at every five thousand feet of elevation above the level of the sea in 

 each hiffh ascent : 



