346 BEl.L SYSTEM TECTIMC.II. JOVRNAL 



phenomenon as due to a progressi\-e and reversible change of the 

 character of the filament with temperature, the initial emissions after 

 temperature changes from 10(i4 K, were used to determine the b 

 constant of Richardson's et|uation corresponding to the c(|uilil)rium 

 character of the filament at 1004° K, and similar measurements 

 were made for the b constant corresponding to the character of the 

 filament at 911° K. The two determinations lead, through the 

 relationship <t> = bk/e, to 1.79 volts and 1.60 volts for the correspond- 

 ing values of (t>. For 10(54° K, then, the two methods give values 

 for <t> in agreement. The measurements are, howe\-er, not sufficiently 

 accurate to give any indication whether or not an electron within 

 the metal possesses the thermal energy '3kT/2. The various cor- 

 rections made and possible errors are thoroughly discussed. It is 

 pointed out that if the transition from the ecjuilibrium state at one 

 temperature to that at another had occurred so rapidly as to avoid 

 observation, a disagreement of 2.5 per cent, between the values of 

 <t> gi\'en by the Iwf) methods wnuKi lia\c been obtained wliicli miiL;lii 

 have been misinterpreted. 



