156 Mr Glazebrook, On some equations connected with [Nov. 28, 



Fitzgerald. Some of the results are expressed in form capable of 

 direct experimental verification. 



We shall suppose that the dielectric medium remains at rest 

 and that the coefficient of magnetic induction /j, is the same in 

 all directions. This assumption is made by Maxwell, Electricity 

 and Magnetism, Vol. II. § 794. 



Let (F, G, H), (a, b/c), (P, Q, R), be the components parallel to 

 the axes of the vector-potential of electric induction, of magnetic 

 induction, and of electromotive force in a medium whose coefficient 

 of magnetic induction is \i, and whose specific inductive capacities 

 parallel to the same three axes are K v K 2 , and K 3 (the axes being 

 principal axes). 



Then Maxwell, Vol. II. § 598, we have the equations 

 p = _dF_df 

 dt dx ' 



and two similar ones, also 



= dH _dG 

 dy dz ' 

 etc. 



Again if /, g, h are the displacements 



f=^ p W. 



s = ^Q (2), 



^t R < 3) ' 



and 



dx dy dz 



The term ^ may be supposed to contain the E. M. F. due to 

 the polarization of the dielectric. 



Differentiate (1) with respect to y, (2) with respect to x. 

 Divide by KJkir, KJ^ir, respectively, and subtract 



\K X dy K 2 dx 



_dP_dQ 



dy dx 



dc 



dt 



.(4). 



