Note 489 — Chapter II
Reading edition
Wolf, Mitth., No. xv., p. 107, etc. Olmsted, following Hansteen, had already, in 1856, sought to establish an auroral period of sixty-five years. Smithsonian Contributions, vol. viii., p. 37.
Reading edition
Wolf, Mitth., No. xv., p. 107, etc. Olmsted, following Hansteen, had already, in 1856, sought to establish an auroral period of sixty-five years. Smithsonian Contributions, vol. viii., p. 37.