BAROMETRICAL MEASUREMENT OF HEIGHTS. DELCROS. 



TABLE II. Correction for Difference of Temperature of Attached Thermometers. 



{Uoper = T' 

 Lower = T 



This Table supposes the scale to be of brass from the top to the cistern. If it 

 were of glass or of wood, the argument T' — T ought to be diminished at the ratio 

 of 54 to 62. 



In computing by the formula of Laplace, we begin by reducing the barometers to 



/T' — T\ 

 tlie same temperature by means of the following formula ; 11 = li' -j- W I p-Vp- )• 



Table II. saves this trouble, and gives, in metres, the correction due to the differ- 

 ence of temperature of the barometers. 

 D 30 



