INDEX OF SUBJECTS. 777 



PART III. MAGNETIC MEASUREMENTS. 

 CHAPTER I. MAGNETIC FIELD. 



PAGE 



Oscillations of a Magnetic Needle 568 



Methods of Torsion 570 



Methods of Deflection 573 



Use of Galvanometers . 576 



Induced Currents 577 



Field of a Magnet 578 



Reciprocal Couples of Two Magnets 580 



Experiments of Gauss 585 



Terrestrial Field. Declination 586 



Inclination 591 



Indirect Method 597 



Induction Method 598 



Intensity 600 



Poisson's Method 602 



Gauss's Method 603 



Correction for Magnetisation induced by the Earth 607 



Comparative Deflectors 609 



Variation Apparatus 6ll 



CHAPTER II. CONSTANT OF MAGNETISATION. 



Magnetic Moments. Oscillation and Deflection 617 



Methods of Torsion 618 



Method of Induction 621 



Intensity of Magnetisation 623 



Method of Detachment 624 



Method of Induction 625 



Induced Magnetisation 626 



Properties of Iron 629 



Variation of Magnetisation with Magnetising Force 631 



Nickel and Cobalt 637 



Influence of Temperature 637 



Steel and Cast Iron 639 



Mechanical Actions 643 



Distribution of Magnetism in Magnets 645 



Determination of the Fictive Layer 646 



