CONTENTS xiii 



varies Calculation of induced magnetisation is only practicable when the 

 permeability is constant Diamagnetic bodies Magnetic induction in a body 

 when the surrounding medium has permeability differing from unity 



Pp. 229-252 



CHAPTER XX 



FORCES ON MAGNETISED BODIES. STRESSES 

 IN THE MEDIUM 



The forces on a body of constant permeability /* placed in a magnetic field in air 

 Illustrations The forces on a body of permeability /i. 2 placed in a field in 

 a medium of permeability /^ Forces on an elongated bar in a uniform field 

 in air when its permeability differs very slightly from 1 The magnetic 

 moment of a small paramagnetic or diamagnetic body placed in a magnetic 

 field Time of vibration of a small needle with /*-! very small suspended in 

 the centre of the field between the poles of a magnet Stresses in the medium 

 which will account for the forces on magnetic bodies The stresses on an 

 element of surface separating media of permeabilities /*j and ^ 



Pp. 2:>3-265 



( IIAl'TKR XXI 



THE MEASUREMENT OF PERMEABILITY AND 

 THE ALLIED QUALITIES IN FERRO- 

 MAGNETIC BODIES 



Magnetometer method Ballistic method Magnetisation in very weak fields 

 Magnetisation in very strong fields Kwing's isthmus method Nickel and 

 cobalt The hysteresis loop and the energy dissipated in a cycle Mechanical 

 model to illustrate hysteresis Pp. 266-281 



CHAPTER XXII 



MEASUREMENTS OF SUSCEPTIBILITY AND 



PERMEABILITY OF PARAMAGNETIC 



AND DIAMAGNETIC SUBSTANCES 



Faraday's experiments Rowland's experiment Experiments of v. Ettingshausen 

 Curie's experiments Curie's law Wills's experiment Townsend's experi- 

 ment Pascal's experiments The electron theoryThe rpagneton 



Pp. 282-300 



