at Low Pressures. 

 Table III. 



255 



Pressure 0"98 mm. 

 Mag. Field 45 -1 



Pressure 1*85 mm. 

 Mag. Field 45-1 



Hall Effect (Volts) 



Current 



Hall Effect (Volts) 



Current 



0-806 

 0-791 

 0-828 

 0-814 

 Mean 0-810 



6-65 x 10- 4 



8-54 „ 

 13-20 „ 

 20-60 „ 



0-38 

 0-36 

 0-40 

 0-36 

 0-40 



2-16 xlO- 3 

 2-79 „ 

 4-41 „ 

 5-31 „ 

 7-11 „ 



Mean 0-38 









Table IV. gives the results obtained for the Hall effect at 

 different pressures from 290 to 0;266 mms. 



These results show that the Hall effect varies inversely as the 

 pressure. If Z is the transverse fall of potential or Hall effect, 

 p the pressure in millims. of mercury, and H the magnetic field, 

 then 



Z = 00248 — . 

 V 



Table IV. 



Pressure 

 (P) 



Hall Effect 

 (Volts per cm.) 



Mag. Field 



Zp 

 H 



2-91 



0-356 



45-2 



2-29 x 10- 2 



2-23 



0-475 



45-8 



2-32 , 





1-85 



0-597 



46-3 



2-38 , 





l-22> 



0-915 



44-7 



2-49 , 





0-983 



1-20 



46-3 



2-54 , 





0-650 



1-85 



46-8 



2-56 , 





0-508 



2-42 



46-3 



2-76 , 





0-333 



3-24 



46-8 



2-31 , 





0-266 



4-60 



46-4 



2-64 , 





Mean 2-48 , 







