BAROMETRICAL MEASUREMENT OF HEIGHTS. 



Example of Calculation by the complete Formula of Laplace 



Height of the Balloon of Gay-Lussac. 

 The observation gave : 



ly the Tables 



mm. 



Balloon h' = 328.80 

 Paris h =765.68 



T 7 = 9.5 

 T = + 30.8 



t' = 9.5 

 t = + 30.8 



T T' = + 40.3 (* + *') = + 21.3 et 2 (t + t') = 42.6 

 With these data the formula of Laplace gives the following calculation : 

 Log. h'. = 328.80 = 2.5169318 



Log. (T T') = + 40.3 = 1.6053050 



Log. dilat. coefficient = 0.0001614 = 6.2079035 



Milli. 



Corr. a = + 2.14 log. = 0.3301403 



A' = 328.80 



H = 330.94 log. = 2.5197480 



log. h = 765.68 = 2.8840473 



(Log. h Log. H) = Difference of Log. 



Log. of (Log. h log. H) = 

 Log. general coefficient = 18336 = 



= 0.3642993 



9.5614583 

 4.2633046 



Log. ( (4) 18336 ) = (A + a) = 3.8247629 



Corresponding number = 6679.79 = (A -|- a) 



Log. cos. 2 L = 97 40' = 9.1251872 



Log. constant = 0.0028371 = + 7.4528746 



Log. (A + a) = 6679.79. = + 3.8247629 



Log. ( (0.0028371. Cos. 2 L) X (A + a) ) = 0.4028247 



Milli. 



Corresponding number = 2.53 

 6679.79 



(A + a + ft) = 6677.26 



Vorr. temp, air = v = 284.45 



= 6961.71 

 15926 



22887.71 

 6366200 

 = 6961.71 



25.03 



^986.74 

 Altitude barom. Paris = \ 48.70 



Metres. 



= (6.677 X 42.6) 



Log. . . . = 4.3596022 

 Log. . . . =3.1961197 

 Log. . . . = 3.8427153 



Log. = + 1.3984372 



Altitude of balloon = 7035.44 by the formula of Laplace. 

 D 13 



