On the relations between the variations in the earth currents, the electric currents from the atmosphere, and the magnetic perturbations

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The paper contains an historical sketch of the observations and researches made on the earth currents by Lamont, Airy, Wild, Blavier, and others. The author describes the method employed by him for measuring the electro‐motive force of the electric currents coming from the atmosphere, and gives the evidence of the fact that the variations or earth currents occur a short time (five minutes) before the magnetic perturbations, and that the former are more numerous than the latter. From the observations in Sodankyla it is, however, proved that all magnetic perturbations are not preceded by variations in the earth currents, but that these probably are caused by electrical currents from the atmosphere to the earth, or vice versa.The proofs of that conclusion are: (1) That the magnetic perturbations in polar regions have a contrary direction to those in more southern countries; (2) That at the times of auroras the electrical current from the atmosphere varies much, and must exert on magnetic instruments a marked influence depending on their position, relative to the space within which this current is moving. It follows from this that we can not find the causes of the magnetic variations, or, rather, perturbations, before we have investigated the earth currents and the electrical currents in the atmosphere.