368 



BAROMETRICAL MEASUREMENT OF HEIGHTS. DELCROS. 



TABLE II. CORRECTION FOR DIFFERENCE OF TEMPERATURE OF ATTACHED THERMOMETERS. 



Temperature of Barometers at Station 



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 



the same temperature by means of the following formula : H = h 1 -\- h' ( V 



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

 ence of temperature of the barometers. 

 D 28 



