﻿Properties of Thin Metal Films 

 Table I. 



545 



Measurement of the velocities of the electrons produced 

 by incident and emergent lights. 



Eelative 



Emergent Light. 



Incident Light. 













thickness 



Maximum 



Correspond- 



Maximum 



Correspond- 



C 



of film. 



Potential 



ing velocity, 



Potential 



ing velocity 



ir 





attained by 



xlO'^. 



attained by 



1A7 cra. 

 XlO' . 







film. 



sec. 



film. 



sec. 







A. 



C. 



B. 



D. 





5 minutes... 



086 volt 



2-76 



064 volt 



237 



116 



8 „ ... 



0-80 



266 



0-65 



2-40 



in 



18 „ ... 



0-84 



273 



080 



266 



102 



40 ,. ... 



1-56 



371 



1-57 



373 



0-99 ) 





1-20 



3-26 



1-36 



347 



0-94 I Mean 





1-75 



394 



1-95 



4-15 



95 f =0-96 





1-68 



3-86 



1-85 



4-05 



0-95 J 



45 „ ... 



1-99 



420 



2-32 



4-53 



093 



50 „ ... 



2-19 



4-40 



2-77 



4 95 



0-89 ! ,. 

 0-91 fe 

 0-93 1 ~ U yi 





133 

 1-53 



3-43 



3-68 



1-62 

 1-75 



3-77 

 394 



55 „ 



1-91 



4-11 



216 



4-37 



094 



Fig. 2 shows graphically the relation between — and the thickness of the film. 



Fiff. 2. 



30 40 



////C/f/VSSS OF flLM. 



found that the actual velocities 

 incident and emergent lioht. 



On standing 



some time the velocities increased ., 



the same values as before letting in air. It will be noticed 



that the ratio of the emergent to incident velocities has not 



had diminished both for 

 in a vacuum for 

 igain, but not to exactly 



varied much, although the actual velocities varied 

 Phil Mag. S. 6. Vol. 23. No. 136. April 1912. 



2 O 



