Abstract
The authors of the present paper investigated statistically the phase difference between the corresponding pulsation of terrestrial magnetism and earth current recorded at Toyohara Magnetic Observatory. The results were compared with the values theoretically derived assuming the earth surface being a plane. The main results are as follows:-
(1) The forced oscillation of the magnet of magnetometer and the moving coil of galvanometer were carefully examined, and the phase difference between the variation of the external force and the forced oscillation was calculated. The observed phase difference was corrected by this results.
(2) The results are illustrated in fig. 1. The phase difference is less than that observed at Kakioka by the amount of the instrumental phase difference.
(3) If we assume that the distribution of the amplitude of the variation of the magnetic and electric force takes a form of probability curve, the phase difference theoretically derived nearly coincides with the observed one.
(4) In this case we notice the difference of the phase difference according to the distance from the disturbing source. Or apparently the pulsation propagates with a considerable velocity (say 1000km per second).
