to produce Discharges in Gases at Low Pressures. 485 



the different diameters oi the inner cylinder, have also been 

 plotted (curve c). The sparking potential with the inner 



electrode positive (curve a) is below the parallel plate value, 

 for the largest diameter, but becomes relatively higher as 

 the diameter decreases ; with the inner electrode negative 

 (curve 6), the sparking potential tor the largest diameter is 

 lower than with cither parallel plates or positive inner 

 cylinder, and becomes relatively lower yet tor the smaller 



