Abstract
Point-discharge in the electric field of the earth is an important factor for the maintenance of the earth's negative charge. The observation of point-discharge at the Kakioka Magnetic Observatory has been begun from June, 1937 and the results of these observations are reported in this paper during a year, from June, 1937 to May, 1938. Point-discharge-currents have been continuously recorded with a galvanometer and photographical recording apparatus.
For a year, the quantity of discharge q1, positive electricity flows into the earth through the point, is 530 millicoulombs and the quantity of discharge q2, positive electricity flows out of the earth through the point, is 108.89 millicoulombs.
Thus the difference (q2-q1) and the ratio q2/q1 is 55.80 millicoulombs and 2.1 respectively for a year.
The number of discharge in which q1<q2 is markedly numerous than that in which q1q2. It is shown, by these results, that the earth is charged negatively as a whole by point-discharge now concerned. The greatest discharge occurs in July in the annual variation and in the period 16h_??_18h in the diurnal variation.
