652 Mr. J. L. Glasson on the Variation of Ionizing 



joining the origin to the centroids of each set of points. It 

 will be seen that the points fit the curves fairly well. 



Table I. 



I. 



11. 



III. 



IV. 



Pressure in 



Current in 



St*-- 



N 



mm. X9G0. 



solenoid (amps.)j 



1 J X9U0 



190 



6 



1-26 



•0066 





65 



109 



57 





7 



•97 



51 





7 - 5 



•86 



45 



175 



6 



1-17 



•0067 





()-5 



rui 



58 





7 



•90 



51 





7-5 



•80 



46 



140 



6 



•94 



•0067 





6-5 



•81 



b8 





7 



•72 



51 





7'5 



•64 



46 





8 



•58 



41 



105 



7 



•53 



•0050 



, 



7-5 



•48 



46 





8 



•44 



42 





- 8-5 



•40 



38 





9 



•35 



33 



90 



7 



•47 



•0052 





7-5 



•42 



47 





8 



•38 



42 





8-5 



•34 



38 





9 



•30 



33 



75 



8 



•32 



•0043 





8-5 



•28 



37 





9 



•25 



33 



In order to plot the variation of ionization with velocity 

 of the cathode rays, the values of N given in Table I. 

 column III. have been reduced to a standard pressure by 

 dividing the numbers in column III. by those in column I. 

 It will be seen that the numbers obtained for each of the 

 different velocities of rays agree to within about 4 per cent. 

 To get the most probable value the means have been taken, 

 and these are entered in Table II., column III. (p. 654) 

 against the corresponding velocity in column I. 



