Comparison of Magnetic Disturbances Recorded by the Self-Registering Magnetometers at the Royal Observatory, Greenwich, with Magnetic Disturbances Deduced from the Corresponding Terrestrial Galvanic Currents Recorded by the Self-Registering Galvanometers of the Royal Observatory
George Biddell Airy. "Comparison of Magnetic Disturbances Recorded by the Self-Registering Magnetometers at the Royal Observatory, Greenwich, with Magnetic Disturbances Deduced from the Corresponding Terrestrial Galvanic Currents Recorded by the Self-Registering Galvanometers of the Royal Observatory." Philosophical Transactions of the Royal Society of London (1868) 465-472