214 RADIATING ELECTRON [APP. F. 



oscillations may be excited among the internal paired elec- 

 trons by shocks and collisions, or other perturbation. 



The most important aspect of the above calculation 

 is that it corresponds with the hypothesis that the whole 

 of the mass of an electron is electric, and none of it 

 material or unexplained ; for it shows that a pure electron 

 is able to revolve at distances of the molecular order 

 with luminous frequency.* The square of the wave length 

 emitted is proportional to the cube of the radius vector ; 

 provided the plane of the orbit contains the centre of 

 force, otherwise there may be constrained motion -of 

 smaller amplitude, analogous to that of a conical pendulum. 



APPENDIX G. 

 The Radiating Power of a Steadily Revolving Electron. 



Consider an electron revolving as above (Appendix F) 

 in an orbit of atomic dimensions b with luminous frequency 

 ^ = a>/27r; and calculate its radiating power. 



By considering separately the electric and magnetic 

 forces due to such a particle, at any point of space, and 

 then applying Poynting's theorem as to the convection 

 of energy wherever the two fields coexist, we get, as the 

 rate of transmission of energy past a point whose polar 

 coordinates, referred to centre and axis of orbit, are r, 0, 

 the mean value ^ 1 + cos s e ^ v 



V ' STT r L 



And integrating this all over the sphere of radius r we 

 get, as the total emission of energy per second 



*See Lodge in The Electrician for March 12th, 1897, vol. 38, p. 644. 



