Memoirs of the Kakioka Magnetic Observatory Vol.07 No.02， p.49, March, 1956
Secular Variation of the Magnetic Declination in Japan
Imamiti, S.
Abstract
Data used for the 17th. and the beginning of the 18th century are mostly observed on boat. Accuracy of compasses in this period is discussed, and the observed values were reduced to that of Kakioka, which is situated in the middle of Japan.
Assuming the rate of changes for secular variation is linear with respect to time, period and amplitude of it are estimated and compared them with those of Europian stations.
