Part I. gives 



OF TWO PLACES BY MEANS OF THE BAROMETER 



for H = 30.046 inches 



J89 



for h = 23.66 inches 



Difference 

 T' = 7°.2, 



Part II. gives for T 



Approximate altitude a, 

 ^ (« 4- ^' _ 64) = 6.918 X 83.8, 



Second approximate altitude A, 

 Part III. gives for A = 6806, and L = 21% 

 Part IV. gives for 6806, 



Height above the sea, 



27649.7 

 21406.9 



6242.8 

 —16.9 



62259 

 4-579.7 



6805.6 

 + 13.3 

 + 19.3 



6838.2 feet. 



Example 2. 



M. Gay Lussac in his celebrated balloon ascent in 1805, found his barometer to 

 indicate 12.945 English inches, the temperature being 14°. 9 Fahrenheit. The ba- 

 rometer at Paris at the same time indicated 30.145 English inches with a tempera- 

 ture of 87°.44 Fahrenheit. Required the elevation of the balloon above Paris. 



Part I. gives 



for H = 30.145 inches, 

 for h' = 12.945 inches. 



27735.6 

 5650.4 



Height of balloon above Paris, 



22922.8 feet. 



D 



49 



