254 Mr Wilson, On the Hall Effect in Gases 



Table I. 





Pressure 0-30 mm. Current 1*56 x 



10~ 4 ampere 





Angle 



P.D. 



P.D. -r- Sine 



Angle 



P.D. 



P. D.-^ Sine 



90° 



122 



122 



40° 



75 



117 



80° 



120 



122 



30° 



59 



118 



70° 



114 



121 



20° 



39-5 



116 



60° 



103 



119 



10° 



21 



121 



50° 



90 



118 



0° 



3 



— 



Table II. shows the variation of the Hall effect (that is the 

 electrometer deflection) with the magnetic field. When measuring 

 the Hall effect the field was always reversed and the sum of the 

 two deflections obtained taken as the Hall effect due to double 

 the field employed. 



The results in Table II. show that the Hall effect is pro- 

 portional to the magnetic field. Similar results were obtained at 

 other pressures. 



Table II. 



Pressure 1*56 mm. Current 5-4 x 10~ s ampere 



Hall Effect 

 (Electrometer deflection) 



Magnetic Field 



Eatio 



79 

 48 

 24 

 14 



113 

 69 

 35 

 21 



1-43 

 1-44 

 1-46 

 1-50 



The results in Table III. show that the Hall effect is very 

 nearly independent of the current producing the discharge. At 

 pressures below one millimetre the range of current which could 

 be employed at any one pressure was too small to allow this 

 independence to be satisfactorily verified for each pressure 

 separately, but the results on the variation of the Hall effect with 

 the pressure make it extremely probable that the Hall effect is 

 nearly independent of the current at pressures down to 0'26 mm. 



