﻿Mr. A. Bramley on Radiation, 121 



But the amount of energy radiated is 



-c[E.H]; 

 .*. the force acting on unit energy density 



according to the third law. 



In this calculation we have taken account of the con- 

 densation of the energy. 



The force per unit of mass 



j|{log[B.H]}. 



Xow 





jg£^rf s# ^= c |log[B.H]. 



But this mass is similar to that due to a charged particle, 

 so that the force of attraction is not the ordinary Newtonian 

 force of gravitation but rather the electrostatic force, there- 

 fore multiplying by 10 40 t-4'1 



we have ±7ry pa da = j^q . s.log [E '. H] . ac, 



where p is the density and da the thickness of the shelL 



But M = 4Lira 2 pda= -j- 



where E is the total energy condensed. 



c* £1 u a? 



7 '10 40 V4 



-w-, u * j. u a- 



But if we examine the equation for the intensities, we see 

 that the frequency 2irv = co, 



A = 6'57 x 10" 27 app., 



taking the radius of the electron =1*5 x 10 -13 [Lorentz's 

 value] , 



