Abstract
Hitherto in the dynamo-theory of the diurnal variation of the ter estrial magnetic field, we have entirely fixed our attention to the atmospheric tides, but our attention must be also extended to oceanic tides.
The author calculates the fields produced by the oceanic tides and finds it comparable with the observed lunar diurnal variation when the earth is covered with the sea-water 2km. deep (its conductivity 4×10-11 e. m. u.) above-mentioned idea.
At any rate in future we must expect to pay a careful attention to the oceanic tides in discussion of the lunar diurnal variation of the carth's magnetic field.
