WRIGHT] VARIATIONS IN THE CONDUCTIVITY OF AIR 



93 



present investigation, a number of preliiniuary sets of observations was 

 made throughout diiferent days in a room in the Physics Building on 

 tlie conductivity of the air confined in a lead receiver, in order to obtain 

 evidence of the daily variation, and also, if such existed, to obtain an 

 estimate of its magnitude. 



Two sets of continuous readings taken in this way with the air 

 m a lead cylinder in the steady state mentioned above, are given in 

 Table VI, and from the values quoted it will be seen that there is no 

 evidence of any appreciable regular variation in the conductivity. It 

 is to be noted, too, that the extreme values obtained did not differ from 

 the mean conductivity by more than 3 per cent of the latter. 



TABLE VI. 



Lead Cylinder 1, in steady state. 

 Cylinder— 83. 



Voltage on 



