Electricity from the Wehnelt Cathode. 



931 



photographic plate 26, the last plate exposed, are as 

 follows : — 



x in 

 mm. 



Curve. 





Expo 



sure a. 



i 





Exposure b. 





v from 

 curve 



v calc. 



xio 7 . 



1 



- xio*. 



m 



Elec. 

 ltoniie 



v from 

 curve 



v ealc.l 



xio 7 . 



- X 10 4 J 

 n 



Elec. 



atomic | 







xio T .' 







weight. 



xio 7 . 







weight.] 



140 



b 



- a 



5-3 



•91 



11 



5-6 



5-4 



•94 



1-00 ! 





a 



4 



3-8 



•47 



21 



4-0 



3-8 



•470 



2-1 1 





a \ 



2-2 



21 



•14 



71 



2-43 



2-3 



•17 



*5-8S , 





a. 2 



b 



1-8 

 51 



1-2 

 5-4 



•097 

 •90 



101 

 104 











1-74 













a 



36 



3-8 



•48 



2-OS 



3-89 



41 



•55 



1-81 





«i 



2-1 



23 



•17 



*rv$s 



2*2 



23 



183 



*5-4 



22 



a 2 



•84 



1-0 



•025 



400 











b 





















a 



3-3 



3-9 



•50 



20 



32 



3-8 



•48 



200 





a \ 



1-9 



22 



•16 



72 



1-9 



23 



■18 



*5-5 





a 2 

 b 



10 



1-2 



•046 



21-7 



•95 



10 



•043 



232 



265 





















a 



30 



3-9 



•51 



1-96 



3-1 



4-1 



•55 



, 1-81 





a x 



1-8 



23 



•18 



55 



1-8 



2-3 



•18 



! 5o 





'fl 2 



•89 



i. 



043 



23-2 



1 Vl 



1-35 



•059 



j 170 



Two successful exposures of 15 minutes each were made 



on this plate. I calculated the values of v and — for four 



m 



distances taken at random from the //-axis. The curve a Y 

 shows double at the distance x — 1*74 mm. in exposure a, 

 and distinctly double, except at the extreme end, in exposure 

 b. Note the calculated velocities given in the second column. 

 Near the y-axis these values are less than the velocities 

 Calculated from the curve. This indicates that the curves 

 are not parabolas as you approach the origin but degrade 

 into straight lines. The data for both exposures show this. 



Lastly I have collected in one table the electric atomic 

 weights calculated from the curves on the seven photographic 

 plates. Plates 21, 23, 24, and 26 have two exposures each. 

 The values calculated for a given curve are placed in the 

 same column even though they were in several instances 

 smaller or larger than the average for that column. In 

 plate 26 the values marked with an asterisk indicate single 

 settings on a double curve. If a redistribution of the values 

 in this table were made several would fall in adjacent 



