Chapman, Sydney, 1888-1970, Geomagnetism / by Sydney Chapman and Julius Bartels - Oxford : Clarendon Press, 1940 - 2 v. : ill., plates, charts (1 double) tables, diagrs. (1 fold.) ; 25 cm. Bibliography: v. 2, p. 938-1007. Subjects--Topical Terms: Geomagnetism