Edison Effect in Glow Lamps. 



57 



suddenly from one value to another. This effect renders it 

 difficult to obtain the stable values of the plate and positive 

 electrode potential-difference. Corresponding to any definite 

 steady voltage on this lamp, the current may have one or 

 other of two values, but not always permanently preserving 



Table No. 1. — Curve No. 1. 



32 34 36 38 40 42 44 46 48 

 Working Volts of Lamp, 



either ; a galvanometer deflexion indicating say 10 volts 

 between the plate and positive electrode of the lamp will 

 often slowly increase until after a few minutes it is 12 or 

 14 volts, yet all the time the working volts on the lamp are 



