CONTENTS ix 



electric strain Intensity just outside the surface of a conductor Lines and 

 tubes of force Outward pull per unit area on a charged conducting surface 

 Note on the method of investigating the field in chapters III-V 



Pp. 61-71 



CHAPTER VI 



ELECTRICAL, LEVEL OR POTENTIAL. THE 

 ENERGY IN ELECTRIFIED SYSTEMS 



Electrical level Potential at a point Equipotential surfaces Intensity ex- 

 pressed in terms of rate of change of potential General nature of level 

 surfaces Energy of an electrified >ystem in terms of charges and potentials 

 Unit cells Number of unit cells in a system double the number of units 

 of energy Distribution of energy in a system Pp. 72-79 



CHAPTER VII 



POTENTIAL AND CAPACITY IN CERTAIN 



ELECTRIFIED SYSTEMS. SOME METHODS OF 



MEASURING POTENTIAL AND CAPACITY 



Definition of capacity Sphere in the middle of large room Two concentric 

 spheres Two parallel plane conducting plates Two long co-axial cylinders 

 Two long thin equal and parallel cylinders Long thin cylinder parallel to 

 a conducting plane Instruments to measure potential difference Quadrant 

 electrometer Attracted disc electrometer Practical methods of measuring 

 potential Reduction of the potential of a conductor to that of a given point 

 in the air Simple methods of measuring capacity Capacity of a Leyden 

 jar Capacity of a gold-leaf electroscope Pp. 80-98 



CHAPTER VIII 



THE DIELECTRIC. SPECIFIC INDUCTIVE 

 CAPACITY. RESIDUAL EFFECTS 



Specific inductive capacity Faraday's experiments Kffect of f-pecific inductive 



capacity on the relations between electric quantities Conditions to be 



tied where tubes of strain pass from one dielectric to another Law of 



refraction Capacity of a condenser with a plate of dielectric inserted 



The effect of placing a dielectric sphere in a previously uniform field 



inl charge and discharge Mechanical model 1'j.. H9-1 19 



