L. Page — Belativity and the Ether. 187 



the direction of acceleration, which cuts the electron into 

 two parts having equal charges. The apparent mass, at the 



TYl 



same instant, will be — H where j3 has the same meaning 



as above. 



In conclusion, it is to be noted that the above method of 

 finding the retarding force due to the electron's own field does 

 not explain, any more than Lorentz's original treatment of the 

 subject did, why the mutual repulsion of the parts of the 

 electron does not cause it to explode.* 



Summary. 



The electrodynamic equations have been shown to be the 

 kinematical consequences of three fundamental assumptions, 

 to wit : 



(a) An ether exists which transmits strains in accordance 

 with the postulate of the relativity of all systems moving with 

 constant velocities ; 



(b) A charged particle is the center of uniformly diverging 

 tubes of strain ; 



(c) The mechanical force on a charged particle is equal 

 to the product of the charge on the particle and the ether 

 strain in its immediate vicinity as measured in the charge's 

 system. Thus the number of assumptions underlying the 

 theory of electrodynamics has been reduced to half the number 

 contained in Lorentz's electrodynamic equations. 



The field due to an electron which is moving under the in- 

 fluence of a uniform external field has been investigated by a 

 new method, and an exact expression for the mass of such an 

 electron derived. 



Sloane Physical Laboratory of Yale University, 

 New Haven, Conn., June 17, 1914. 



*SeeH. T. Wolff, Ann. d. Physik, xxxvi, p. 1066, 1911, and G. A. Schott, 

 Electromagnetic Radiation, p. 262 et seq. 



