294 



Prof. Richardson and Lieut. Bazzoni on the 



The minimum velocity with which an electron can enter the 

 cup is given from the calculations for the innermost radius 

 of the slits — the maximum velocity from the calculations for 

 the outermost radius — slightly corrected to allow for the 



Fig. 4. 





X 



Dotted I 

 = 



ines 

 400 



800 



1200 



1600 



2000 



2400 



2800 



3200 



-8 

 *!0 cm. 



J? 



I* 

 •8 

 10 

 1-2 

 1-4 

 1-6 

 1-8 

 2-0 

 2-2 

 2-4 







1 









































1 









































1 































































































































































































































































































































| 































i 







1 













I 















1 



1 





















1 













i 





! 



1 









H 

 4* 



8 



12 



16 



20 



24 

 28 

 32 

 36 

 40 

 44 

 48 



V=0 I 2 3 4 5 6 7 8 3 10 II 12 13 14 15 16 17 18 .13 20 *10 

 Solid lines 



fact that electrons can enter on radii somewhat larger than 

 this outside radius. This correction does not affect the 

 further calculations or deductions used in this paper since 

 we are, as pointed out above, particularly concerned only 

 with the inside radius. With the slit widths used we have 

 (neglecting the correction referred to) 



v min ='±20 x 1-77 x 10 7 x H= '743 xHx 10 7 , 



v =-580 x 1-77 x 10 7 x H = 1-026 x H x 10 7 . 



max. 



The impinging frequency corresponding to any particular 

 velocity is determined from the relation 



±mv 2 = eV = li(v — Vq) , 



whence 



15 



v = v + 



2/i 



or, putting m = 'S9S X lO" 27 and 7i = 6'55xlO- 



