Principal facts of the earth's magnetism and methods of determining the true meridian and the magnetic declination. Reprinted from the United States magnetic declination tables and isogonic charts for 1902 (1909)
U.S. Coast and Geodetic Survey · Washington Govt. Print. Off · leaf 36
he globular lodestone. In fact, Gilbert in no way improves on Normans idea but adopts it bodily. Some writers have extravagantly asserted that Gilbert anticipated Faradays conception of the field of force surrounding a magnet. Norman also proves experimentally that the attraction exerted on the… … Fig. 7. In experiments with the terrella the needle is attracted obliquely or directly toward the globewith a very perceptible force. This is because the length of the needle is so considerable in propor-tion to the diameter of the globe that the magnetic forces on the two ends are not equal and…
Magnetism, Terrestrial
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Examen dv livre des Recreations mathematiqves, & de ses problemes en geometrie mechanique, optique & catoptrique [du J. Leurechon] Où sont aussi discutées & restabiles plusieurs experiences physiques y proposées (1639)](https://img.insideoutlibrary.com/img/200/ia-examendvlivredes00mydo-102-21.webp)
