ELECTRIC OSCILLLATIONS AND ELECTRIC WAVES. 259 



which tend to stand in a smooth row. If the gears are allowed 

 to slip at any point s, the gear / being held stationary and the 

 gear e being turned in the direction of the arrow, then the chain 

 of gears will be distorted into a zigzag row, as shown in Fig. 202. 

 Conversely, a chain of geared cells which by elastic action tend 

 to stand in a smooth row, will be relieved from such a zigzag 



Fig. 201. 



distortion as shown in Fig. 202 by permitting the gears to slip 

 at any point s, and the potential energy stored in the distorted 

 chain will be geared towards s from both sides. 



Fig. 202. 



Let A and B, Fig. 203, be two metal plates, and let the dotted 

 lines represent closed chains of geared ether cells, each chain 

 being like Fig. 201. Imagine the two plates A and B to be 

 connected by a wire,* and imagine an electric current to be 

 forced through this wire by means of a voltaic cell, thus causing 



* Strictly the wire in Fig. 203 must be thought of as a broad ribbon. All figures 

 in this discussion represent two dimensional distributions of electric and magnetic 

 fields. 



