Annular Eclipse of May 8–9

Abstract

BAD weather conditions went far to spoil the project of the National Geographic Society to link up the triangulations of Asia and of the United States and Canada by exact timing of contacts at the recent eclipse (Nature, March 13, p. 389). Only two expeditions—those to Rebun Jima, a little fisher-folk island off the north-western tip of Japan and to Bangkok in Siam—were favoured by clear enough conditions to get satisfactory results. Dr. C. H. Smiley, head of the last-named party, reported thin cirrus clouds, while Dr. John A. O‘Keefe of the other party had ideal conditions due to a last-moment clearing. These two observations may link up the Indian geodetic triangulation with those of Japan and possibly Korea. A link-up with the American triangulation may also be possible owing to the successful photographs secured from two B29 Superfortress planes working from an air base on Shemya Island in the Aleutians. Short-range navigation methods were used, radar signals being sent out from the aeroplanes and received by ground stations the exact locations of which were known. Obviously fresh problems are involved in the use of data from moving aeroplanes, and it will be interesting to see the final reports when the material obtained has been examined. It is to be hoped that Great Britain, from which the suggestion first originated that eclipse observations might be used for geodetic studies, may before long take a part in securing some valuable results along these lines.