Wireless Telegraphy and Terrestrial Magnetism

Abstract

THE report in The Times of the discussion on wireless telegraphy at the British Association meeting in Dundee mentions the hypothesis—introduced apparently by Dr. Eccles—that several of the phenomena of the propagation of electric waves round the earth are largely influenced by the existence of an ionised layer in the atmosphere. The hypothesis seems analogous to, if not identical with, one made by several magneticians independently, with the object of explaining phenomena exhibited by the diurnal variation of the magnetic elements. This diurnal variation is now generally regarded as most probably due to electric currents in the upper atmosphere, and it has been suggested that the fact that the magnetic changes are normally larger by day than by night is due to an increased ionisation of the atmosphere due to sunshine.