Table 30. 



DETERMINATION OF HEIGHTS BY THE BAROMETER. 



Formula of Babinet. 

 .Br. — B 



Z=C 



Bo + B 



t — 

 900 



2(/'o + /)- 



C(in feet) = 52494 fi + ^2_+^ — ^4l _ English Measures. 



t2 U "T n~\ 

 I + j°QQ — — Metric Measures. 



In which Z = Difference of height of two stations in feet or metres. 



Bq, B = Barometric readings at the lower and upper stations respectively, corrected for 

 all sources of instrumental error. 

 /q, /■ = Air temperatures at the lower and upper stations respectively. 



Values of C. 



ENGLISH MEASURES. 



METRIC MEASURES. 



Smithsonian Tables. 



160 



