An outline of a theory of magnetic storms

摘要: 1. This paper briefly outlines some results of a study magnetic storms, the object which was to ascertain their broad general features, leaving aside individual details and cases. The account is limited in several respects, mathematical developments, particular, being omitted; this because intended be followed by more complete discussion, when conditions permit. In future memoir I hope deal adequately with many points here lightly passed over, especially disturbance phenomena polar regions, where are scarcely ever quiet, divergence between geographical axes earth introduces most complication. Part I.— Magnetic Data . 2. Apparently all great world-wide storms commence simultaneously within few seconds, over whole earth, although small local fluctuations may sometimes mask commencement at particular stations. It therefore possible, we not concerned very time intervals, speak “storm time,” measured from beginning storm, without reference any locality. contradistinction storm time, same for stations, shall reckon midnight.