THE PHENOMENA OF ELECTROSTATICS. 



from a positively charged metal ball. If the ball is sufficiently 

 charged the electric field near its surface reaches the breaking 

 point of the dielectric, and the rupture starts as described in Art. 



Fig. 153. 



122, but in this case the rupture very soon extends into a region 

 where the field was originally very much less intense than at the 

 surface of the ball, and such lines of force as have moved side- 



F\g. 154. 



wise into the rupture and have partially (that is, through a portion 

 of their length) broken down, now form in a widely divergent 

 bundle from the end of the rupture as shown in Fig. 1 54 (com- 



