680 



REPORT— 1900* 



8. Duration of Totality of the Solar Fclijjse of May 28, 1900. 

 % C. T. Whitmell. 



The Paper included tlie following table : — 



9. Duration of Anntdarity in a Solar Eclipse. 

 By C. T. Whitmell, M.A., B.Sc. 



10. 



On the Connection hetu-een Latitude-variation and Terrestrial 

 Magnetism. By J. Halm. 



The following propositions were advanced : — 



I. The changes in the motion of the pole of rotation of the earth round the 

 pole of figure are in intimate connection with the variations of the earth-magnetic 

 forces. 



II. Inasmuch as the latter phenomena are in a close relation with the state of 

 solar activity, the motion of the pole is also indirectly dependent on the dynamical 

 changes taking place at the sun's surface. 



III. The distance between the instantaneous and mean poles decreases "with 

 increasing intensity of earth-magnetic disturbance. 



IV. The length of the period of latitude variation increases with increasing 

 intensity of earth-magnetic disturbance. 



V. In strict analogy with the phenomena of auroriB and of magnetic disturb- 

 ance, the influence of the eleven years' period of sun-spots, as well as of the 

 ' great ' period, is clearly exhibited in the phenomenon of latitude-variation ; and 

 the same deviations from the solar curve as are manifested by the aurorse are also 

 evident in the motion of the pole. 



yi. The half-yearly period of the earth-magnetic phenomena influences the 

 motion of the pole of rotation in such a way that its path, instead of being circular, 

 assumes the form of an ellipse, having the mean pole at its centre. 



"VII. The half-yearly period also explains the conspicuous fact of a rotation of 

 the axes of the ellipse in a direction opposite to that of the motion of the pole. 



