Vibrations of Light with Electrical Currents. 293 



the equations (A) are transformed into the following differential 

 equations: — 



A 1 d% 7 /de 4 du\ 



. 1 d*v . (de , 4 dv\ 



A 1 d^w _ , /^e 4 e?wA 



with which is connected by (2) the equation 



du dv dw _ 1 de 

 dx dy dz 2 dt 



These equations are satisfied, for instance, by 



u —e~ hx cos p(cot—z), v=0, w = 0, ... (6) 

 where h } p, co are constants between which the relations prevail, 



h*a*=p*{a*—a>*) and hc 2 =l6>7rk<o (7) 



From this preliminary treatment of equations (A), it is clear 

 that periodical electrical currents are possible, that such ones 

 travel like a wave-motion with the velocity w, and, like light, 

 make vibrations which are at right angles to the direction of 

 propagation. If we assume thence that the vibrations of light 

 themselves are electrical currents, a> expresses the velocity of 

 light, while a is the velocity with which electrical action is pro- 

 pagated through space. It is manifest, further, from the latter 

 equation, that, when the electrical conductivity k of the body 

 is very small, the two velocities tend to become equal to one 

 another. 



The velocity with which in Weber's electrodynamical experi- 

 ments the electrical action at a distance has passed from one 

 conductor to another through the air, is according to this result 

 the same as the velocity of light in air. But now, according to 

 Weber's determination, c = 284736 miles, and therefore 



% =201360, 



V2 



a magnitude which remarkably agrees with the various determi- 

 nations of the velocity of light; for they lie both above and 

 below this value in such a manner that the present may be 

 regarded as a new determination of the velocity of light, and 

 not necessarily inferior in accuracy to any other. We have 



