TABLE OF CONTENTS. 



Page 



A. Introduction 1 



B. Declination 10 



The Needles 



The Double Declination Needle 10 



The Small Needle 14 



The Mark 15 



The Azimuth 15 



The Observations 17 



Observations of Declination 20 



C. Horizontal Intensity 62 



The Making of the Observations 



Observations of Deflection 64 



Observations of Vibration 67 



Determination of the Constants 



Direct Determinations 69 



Employment of the Observations for the Verification of the Constants . . 71 



The Final Values of the Temperature-Coefficient 73 



The Final Values of the Constants fi and C 75 



The Observations and their Reduction 



Observations of Deflection 77 



Observations of Vibration 98 



Summary of the Results ' 118 



D. Inclination 127 



Determination of the Index-Error 128 



The Observations 136 



Observations of Inclination 137 



E. Total Intensity 166 



Observations of Deflection 169 



F. General Results 181 



Arrangement of the Results in Groups 189 



Plates I -XVII. Variations of Declination. 



