| Description | Wilde refers to an earlier paper on magnetism (see AP/66/29), writing: 'it was shown that, by covering the ocean areas of the mapped globe with thin sheet iron, roughly contoured to the coast lines of the continental areas, a close agreement with the unsymmetrical lines of the declination, as determined by observation, was obtained. Although this method of producing a difference in the distribution of the magnetism of the globe was purely empirical, yet it at once became evident that the irregular configuration of the earth, as manifested by the distribution of land and water on its surface, was the primary causal condition of the unsymmetrical distribution of terrestrial magnetism.'
Includes a copy of a photograph of an electromagnetic globe (see AP/66/29/2 for same photo). See AP/67/12 for an alternate version of this paper.
Subject: Magnetism
Received 20 November 1890. Read 22 January 1891. Revised 31 July 1894. |