212 ELEMENTS OF ELECTRICITY AND MAGNETISM. 



solid cannot affect B in any way, and conversely stress and dis- 

 tortion of B cannot affect the surrounding solid because the 



empty space is incapable of transmit- 

 ting stress. This empty space in its 

 behavior towards mechanical stress is 

 analogous to a conducting substance 

 in its behavior towards electrical 

 stresses (electrical field). 



118. A charged conductor shares its 

 charge with another conductor which 

 is brought into contact with it. Fig- 

 ure 142 shows the lines of force in the neighborhood of a charged 

 conductor A. When another conductor B is brought into con- 

 tact with A, the lines of force arrange themselves as shown in 

 Fig. 143. The charge which was originally on A spreads over 

 A and B, as indicated by the ending of the lines of force. 



Fig. 141. 



Fig. 142. 



Fig. 143. 



119. Faraday's experiment. A charged body B, Fig. 

 is lowered into a metal vessel and the opening of the vessel is 

 closed with a metal lid. As the body is lowered into the vessel, 

 each line of force that emanates from B is cut in two, as it were, 

 by the wall of the vessel so that, when B is entirely enclosed 

 by the vessel, as many lines of force emanate from the external 

 surface of the vessel as from the body B, and all the lines of 



