A possible cause of the earth's magnetism and a theory of its variations

A possible cause of the Earth's magnetism is the rotation of an electrostatic field within the Earth, as Rowland's experiments have proved (Phil. Mag. [5] xxvii) that a moving charge of electricity produces a magnetic field analogous to that of a current. If the Earth carries round an electrostatic field in its rotation, then it will have the axis of its magnetic field identical with the axis of rotation which is the chief approximate fact of the Earth's magnetism. The actual obliquity of the magnetic to the rotational axis is traced to unsymmetrical magnetic permeability of the Earth, which also causes the induction of Earth currents, the secular variation of whose tracks is the cause of magnetic secular variation. The theory advanced to account for daily variation is that under the action of the Sun's rays the oxygen and ozone of the atmosphere become the active substance of a large secondary battery or accumulator whose alternate charge and discharge are the cause of the daily variations.