170 



MR. GEORGE W. WALKER ON THE INITIAL ACCELERATED 



The superiority of THOMSON'S formula No. 1 in giving constant values for B and A 

 is at once apparent. ABRAHAM'S formula gives distinctly increasing values of B as k 

 increases, and thus does not give a large enough dependence of mass on speed, even 

 if the mass is assumed to be wholly electric. No. 2 gives the same disagreement in 

 the values of B and a negative value to the real mass, a result quite inadmissible. 



Selecting No. 1, we obtain 



e/C ,.-..,,.. 2-21 



and 



m + m' 



= I'62xl0 7 x 



-,= 1-62x10'. 



