The Simultaneity of Certain Abruptly-beginning Magnetic Disturbances

Abstract

IN the first volume of my work “The Norwegian Aurora Polaris Expedition, 1902–3”, I stated (p. 63), after studying the magnetograms from seventeen stations in all quarters of the earth, that the characteristic sudden similar magnetic changes occurring often during positive equatorial perturbations “appear simultaneously, or rather, the differences in time are less than the amount that can be detected by these registerings”. “The above question on simultaneity, which is of great importance, cannot be definitely decided until we are in possession of rapid registerings.”