Potentials due to Moving Electric Charges. 131 



If we put 



\ = fi ; 1/k = | x 1*40 = 1-05, 



2 2 



the correcting factor found from (20) will be 1*87 — ==- 



2 2 ^ ' 



77 o 



and from (21) will be 1*81—^. Thus we have again 



obtained very satisfactory results from the approximate 

 formula (17). 



§ 6. In this investigation of transverse vibrations we have 

 taken the expressions (3) for A and ot. By taking the 

 even fuuction of y for A and the uneven function for -sr, 

 we may obtain the solution of the problem of longitudinal 

 vibrations. 



Zagreb, 

 January 26, 1921. 



XI. On Scalar and Vector Potentials due to Moving 

 Electric Charges, By Prof. A. Anderson *. 



IN the Philosophical Magazine (March, 1921) Prof. A. 

 Lienard criticises my paper on " A method of finding 

 Scalar and Vector Potentials due to Motion of Electric 

 Charges" (Phil. Mag. August 1920). The criticism, though 

 just, touches only a slight error in notation ; the results of 

 the paper are not affected thereby. The last part of my 

 paper is very much condensed and perhaps, on that account, 

 unintelligible, and the object of the present communication 

 is to make the argument fuller, and, I hope, clearer. 



Fig. 1. 



V In fig. 1, Q is the position at time t of a moving charge e, 

 •and Q' is a point moving in the path of Q — the companion 



* Communicated bv the Author. 



K2~ 



