June 1906 Issue [Article] Terrestrial magnetism Download PDF Adjust Share by Cyrus C. (Cyrus Cornelius) Adams, Subscribe or log in to continue reading. Tags Discoveries in science Geomagnetism Geophysics History Magnetic declination Observations Secular variations More from Cyrus C. (Cyrus Cornelius) Adams Maps and map-making The Sargasso Sea Unexplored regions of the earth Adjust Share