166 



Mr. A. V. Harcourt. 



[June 15, 



XVIII. u On an Instrument for Correcting Gaseous Volume." 

 By A. Vernon Harcourt, M.A., F.E.S. Received June 13, 

 1882. 



This instrument has been devised in order to facilitate the correc- 

 tion of the observed volume of a mass of gas, measured at any common 

 temperature and pressure, to the volume the gas would occupy if 

 measured under standard conditions. A reading of the instrument 

 furnishes a number which serves for the making of this correction, and 

 stands instead of readings of the barometer and of the thermometer, 

 and a reference to a table of the tension of aqueous vapour at different 

 temperatures. 



NSIE 



: 95C 

 : 9*0 



: 950 

 : 35C 



The instrument consists of two small glass tubes standing side by 

 side ; the one is open above, having been drawn out and bent down- 



