the Anode in Vacuum- Tubes. 201 



when the distance between the electrodes was so small that 

 the nearness of the cool anode kept the cathode temperature 

 low. With the anode the energy given up increased con- 

 tinuously with the length of the positive column. 

 The results are shown in the following Table : — 



Table VII. 



Lead Cathode in Oxygen. 



i=-0030 amp. 

 jp?* = 2 , 8 mm. Hg. 

 L = distance between electrodes (cm.). 

 = rise in temperature per minute (0° C). 



L. 



Q. 



L. 



0. 



03 



6-15 



8-10 



7-15 



0-3 



6-20 



107 



7-00 



0-65 



6-50 



13-8 



710 



0-65 



6-85 



17-5 



6-90 



070 



6-80 



22*2 



7-05 



0-70 



6-50 



25-8 



7-10 



1-80 



6-90 



29-8 



7-02 



1-80 



7-05 







Table VIII. 

 Lead Anode in Oxygen. 



^=•0050 amp. 

 pr = 3'6 mm. Hg. 



L. 



0. 



241 



142 



20-1 



14-1 



16-5 



140 



5-9 



126 



40 



11-8 



2-5 



10-8 



1-3 



11-8 



6 here represents the equilibrium temperature of the anode 

 under the above conditions, i. e. the temperature the anode 

 rises to after a long interval of time. This method is more 

 sensitive, for the rise in temperature per minute is only 



