xii CONTENTS 



CHAPTER XVI 



GENERAL ACCOUNT OP MAGNETIC QUALITIES 



OF SUBSTANCES OTHER THAN IRON 



AND STEEL 



Faraday's classification of all bodies as either paramagnetics or diamagnetics 

 General law Explanation of the action of the medium by an extension of 

 Archimedes' principle Ferromagnetics, pararaagnetics, and diamagnetics 



Pp. 203-207 



CHAPTER XVII 

 THE INVERSE SQUARE LAW 



Variation of the force due to a pole as the distance from the pole is varied The 

 inverse square law Magnetic measurements founded on the law Coulomb's 

 experiments Unit magnetic pole Strength of pole ;// Magnetic intensity 

 Geometrical construction for the direction of the intensity in the field of 

 a bar magnet Gauss's proof of the inverse square law Deflection method 

 of verification Moment of a magnet Comparison of moments Some conse- 

 quences of the inverse square law Application of Gauss's theorem Flux of 

 force Unit tubes A pole m sends out 4iw unit tubes Potential 



Pp. 208-218 



CHAPTER XVIII 

 SOME MAGNETIC FIELDS 



Small magnets Magnetic shells Uniform sphere Pp. 219-228 



CHAPTER XIX 

 INDUCED MAGNETISATION 



Magnetic induction Induction and intensity in air Lines and tubes of induction 

 in air Induction within a magnetised body Hydraulic illustration Equa- 

 tions expressing continuity of potential and continuity of induction tubes 

 Representation of induced magnetisation by an imaginary distribution of 

 magnetic poles acting according to t he inverse square law Magnetic suscepti- 

 bilityImagined investigation of B and H within iron Permeability and 

 the molecular theory Induction in a sphere of uniform permeability /u placed 

 in a field in air uniform before its introduction Long straight wire placed 

 in a field in air uniform before its introduction Circular iron wire in a 

 circular field Energy per cubic centimetre in a magnetised body with con- 

 stant permeability The energy supplied during a cycle when the permeability 



