In the year 1600, the Englishman William Gilbert published "De Magnete", one of the first true scientific treatises. He had studied, with a compass needle, the dip and pattern of the magnetic field around a sphere of lodestone magnetite (the mineral Fe304). Further, he deduced that the Earth had a similar field, and was therefore like a giant magnet.
Iowa Science Teachers Journal
© Copyright 1980 by the Iowa Academy of Science
Carmichael, Robert S.
"The Earth's Magnetic Field,"
Iowa Science Teachers Journal: Vol. 17
, Article 4.
Available at: https://scholarworks.uni.edu/istj/vol17/iss1/4