llfi 



Mr. Green's Obsercatioiis 



At the point of greatest altitude Mr. Green filled two bot- 

 tles, which had been previously prtparcd and filled with dis- 

 tilled water, with the atmospheric air; these have been since 

 examined at the laboratory of the Royal Institution by Mr. 

 R. H. Solly and Mr. Faraday ; the first was weighed and 

 opened under distilled water of the temperature of 60°, 660.5 

 grains of water entered, the whole quantity which the bottle 

 would hold being- 1,910 grains. The second bottle, when full, 

 held 1,916 grains of water; the quantity which entered when 

 opened was 636.7 grains. 



The average of these two experiments gives rather more than 

 one-third for the diminution of density of the atmosphere at the 

 height to which Mr. Green ascended. This agrees very nearly 

 with the results of the barometer. The analysis of the air con- 

 firmed the observation of M. Gay Lussac, that no diiference can 

 be detected in the atmospheric air taken from great altitudes 

 and at the surface of the earth ; the experiments were made by 

 explosion with hydrogen, and the comparison of the condensa- 

 tion made over mercury between the air of the bottles and that 

 of the laboratory ; the differences were perfectly immaterial, 

 sometimes on one side and sometimes on the other, evidently 

 arising from unavoidable errors in experimenting. 



