TABLE 17', 



DETERMINATION OF HEIGHTS BY THE BAROMETER. 



Formula of Babinet : Z = C -~ 



B +B 



C (in feet) = 52494 ft -\- f Q~T~ *~ &4 | English measures. 

 l_ 900 -I 



C (in metres) = 16000 \ i + 2 ^ " ~*~ ' I metric measures. 

 L 1000 J 



In which Z rr difference of height of two stations in feet or metres. 

 S , B barometric readings at the lower and upper stations respectively, corrected for all 



sources of instrumental error. 

 /, t := air temperatures at the lower and upper stations respectively. 



Values of C. 



SMITHSONIAN TABLES. 



169 



