Electron necessarily Radiate Energy ? 



407 



in the position of the corresponding line of fig. 2 at t — ; 

 it then moves outwards, passing the position of fig. 1 again 



at t= + -. The magnetic force is directed along the parallel 



Fig-.l. 



B' Y B 



Fig. 2. 



of latitude, and, passing through zero value, is reversed in 

 sign at the moment when the electric lines change their 

 direction of motion. The dotted circles, ->|r= const., ortho- 

 gonal to the lines of force, are the lines of the Poynting 

 energy-flux. 



° y 2 E 2 



