^3 



3 

 O 



Protective or Circuit Breaking Device. 

 Fig. 8. 



281 



27-55 



20 40 60 80 100 120 140 



Milliamperes in heater for curves I, II, III. 



29-55 31-55 33-55 settings 



between the arm and the tube. This also explains why 

 the reflector showed no effect in time for small deflec- 

 tions as it was moved over the arm. The glass absorbed 

 most of the radiation from the arm and hence the reflec- 

 tor had no appreciable function to perform. The ap- 

 paratus was very sensitive aud yet differential. Touching 



