RT Journal Article SR Electronic T1 The present annual effect of the secular change of the magnetic declination in the eastern part of the United States, accompanied by a chart JF American Journal of Science JO Am J Sci FD American Journal of Science SP 149 OP 150 DO 10.2475/ajs.s2-41.122.149 VO s2-41 IS 122 A1 Charles A. Schott YR 1866 UL http://www.ajsonline.org/content/s2-41/122/149.abstract AB