Terremoti in relazione a fenomeni elettrici e magnetici (Milne, 1890). Traduzione commentata.

Abstract

This is a commented translation of the rare document cited by more than a century of bibliography as "Milne, 1890". The text was studied to verify the veracity of some recent claims that this report (presently difficult to find) had dealt with electromagnetic precursors for the first time. An attempt was made to investigate each episode and character, identifying the cryptic (and sometimes non-existent) bibliographic references, tracing almost all the texts, often expanding and commenting on the relative citations. My opinion is that no one, at the time of Milne, had consciously, but maybe not even accidentally, observed a precursor of electromagnetic origin. The phenomena described are studied from either a purely electrical or magnetic point of view. Electrical signals concern too high voltages and currents. Magnetic phenomena, already at the time, were contested as products of inertial effects, but in any case it is difficult to think that the magnetic field component of an EM signal can permanently deflect the needle of a compass. However this same research has brought to light some other potentially interesting cases that should be investigated further. One of them, could actually be the first documentable case of the observation of an electromagnetic seismic precursor.