CHAPTER V. 

 ELECTKIC DISTRIBUTION AND CONDENSATION. 



EQUIPOTENTIAL. A charge of electricity given to 

 any part of a good conducting surface is instantly dis- 

 tributed equally over every part, and such a surface is 

 called equipotential. For the momentary increase of 

 electric energy at any point creates electric movement 

 from higher to lower potential, which instantly results 

 in the establishment of equilibrium at every point. 



Separate points on such a surface are called equipo- 

 tential points, and a line of such points an equipotential 

 line. 



LINES OF FORCE. The direction along which elec- 

 tricity tends to move, from a point of higher to one of 

 lower potential, is called a line of force. Such lines 

 are perpendicular to the equipotential surfaces at the 

 points ; for, as the tendency is to move from one point 

 to the other, it would be from one such surface to the 

 other ; and if the line differed from a perpendicular, it 

 would imply, by the resolution of forces, that there 

 could be two lines of force at right angles to each 

 other, one of which would lie in an equipotential sur-. 

 face ; implying two points at different potentials in such 

 surface, which would be an impossibility. 



SURFACE CONDENSATION. Since the surface of a 

 solid sphere of any good conducting material is evi- 

 dently equipotential, we may regard its interior as 



