VUl 
CONTENTS. 
Variations of Magnetic Dip with the Moon's Declination, 
Remarks on the Variations of Ranges of Magnetic Dip,-- 
Diurnal Variations — 
Results from all the Observations for each Month, ■ 
Results from all the Observations, for Groups of Months, •••• 
Results from Undisturbed Observations, for Groups of Months, 
Effect of Disturbance on the Hourly Means, • 
Variations with reference to the Moon's Hour- Angle 
NO. 
126 
127 
128 
129 
130 
131 
132 
Ix 
Ixi 
Ixii 
Ixii 
Ixiv 
Ixiv 
Total Magnetic Force- 
Absolute Value, • • • • 
Secular Change, • • 
Effect of Disturbance on the Yearly Mean Value, 
Annual Period,- 
Effect of Disturbance on the Monthly Means, 
Annual Variation of Ranges of Monthly Mean Diurnal Variation,- 
Variations with Reference to the Moon's Age,- 
Variations with reference to the Moon's Declination, ■ 
Remark on the Variations of Ranges of Total Force, 
Diurnal Variations- 
Results from all the Observations, for each Month, 
Results from all the Observations, for Groups of Months, 
Results from Undisturbed ObservE,tions, for Groups of Months,- 
Effect of Disturbance on the Hourly Means, 
Variations with reference to the Moon's Hour-Angle, 
133 
134 
135 
136 
137 
138 
139 
140 
141 
142 
143 
144 
145 
146 
Ixv 
Ixv 
Ixv 
Ixv 
Ixv 
Ixv 
]xv 
Ixvi 
Ixvi 
Ixvii 
Ixvii 
Ixviii 
Ixix 
Ixx 
Combined Motions of the Magnetic Needle — 
Process of Projection and General Remarks 147 Ixx 
Annual Motions, 148 Ixx 
Monthly Motions, - 150 Ixxi 
Similarity of the Motions for the Positions of the Sun and Moon in De- 
clination 151 Ixxi 
Diurnal Motions, 153 Ixxi 
Foot-note on the Determination of the Epochs of Maximum and Minimum, Ixxii 
Perimeters of the Figures of the Diurnal Motions for each Mouth, 156 Ixsii 
Perimeters of the Figures for Disturbed and Undisturbed Observations, -.• 157 Ixxii 
Mean Angular Motions from Hour to Hour, 158 Ixxii 
Diurnal Variation of Velocity of Diurnal Motion and Relation to that of 
Disturbance, 159 l.xxiii 
Variations in the Velocity of Motion not related to ^'ariatious of Tem- 
perature of the Air, 161 Ixxiii 
Relation of Points of Greatest and Least Velocity to the Astronomical 
Meridian, 162 l.xxiii 
I 
