Table 157. 



169 



DETERMINATION OF HEIGHTS BY THE BAROMETER. 



Formula of Babinet : Z : 



■ — r -^0 — ^ 

 B„+B 



C (in feet) = 52494 fi + ^0 + ^ — 64 "! English measures. 

 L goo -J 



C (in meters) = 16000 \i + ^ ^ " *" ' metric measures. 

 L 1000 -J 



In which Z =r difference of height of two stations in feet or meters. 



Bq, 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 only approximate. Not good for great altitudes. A more accurate formula with 

 corresponding tables may be found in Smithsonian Meteorological Tables, 3 revised ed. 1906- 



Smithsonian Tables. 



