Electricity from the Wehnelt Cathode. 



929 



especial^ if low potential differences are used in accelerating 

 the carriers. The data relative to the two most prominent 

 lines on plate 18 are as follows : — 



yl 



Va. 



X. 



Square 

 of ratio. 



X 



X 



1-5(5 



X 



X 



X 10 7 . 



Va 



XlO 7 . 



\'"Jb 

 XlO". 



n 



XlO". 



605 



4-00 



2-56 



2-28 



2-65 



147 



6-2 



3-9G 



2-62 



•86 



•38 



4-80 



3-15 



201 



231 



2-38 



1-56 



11-4 



4-4 



4-0 



2-62 



•63 



•30 



3-03 



241 



loo 



2-34 



2-3G 



1*55 



8-7 



Q.-r 



39 



26 



•32 



•23 



2-61 



1-71 



•98 



2-34 



2-61) 



1-74 



6-9 



2-9 



4-4 



2-9 



•42 



•18 



In this photograph the accelerating and electric fields 

 were 1158 and 153 volts respectively. The following data 

 taken from plate 20 represent a set of curves that approach 

 the second type. The corresponding accelerating and electric 

 fields were 1548 and 171 volts. 



Vb. 



Va. 





497 





4-49 



5-52 



3-S9 



4-80 



3-48 



square 

 of ratio. 



265 

 2-20 

 174 

 1-40 







1-87 







20 



201 



3-17 



2°4 



1-90 



34 



25 



17-5 



16-3 



X 



v b 

 XlO 7 . 



Va 



xio 7 . 



\mlb 

 XlO". 



\»U a 



XlO'. 



9-32 





3-0 





•51 



916 





33 





•50 



8-79 



5-1 



3-6 



•96 



•48 



8-65 



5-6 



40 



•91 



•47 



From an inspection of the table for plate 18 we see that 



the velocity of the carriers remains constant as x and — in- 

 J m 



crease ; however, in plate 26 the velocity falls off as x 



increases while — remains (nearly) constant. To get curves 



m " ° 



of type 2 it is necessary to use a stronger accelerating 

 field. The stronger this field the nearer the heads of the 

 parabolas are pushed towards the origin. At this writing 

 I have not been able to use fields above 1518 volts because 

 of logging due to internal sparking. 



