Robert Norman

Illustration of magnetic dip from Norman's book, The Newe Attractive

Robert Norman was a 16th-century-English mariner, compass builder, and hydrographer who discovered magnetic inclination, the deviation of the Earth's magnetic field from the vertical.

Work

Robert Norman is noted for The Newe Attractive, a pamphlet published in 1581^[1] describing the lodestone (magnet) and practical aspects of navigation. More importantly, it included Norman's discovery of magnetic dip, the incline at an angle from the horizon by a compass needle. This effect is caused by the Earth's magnetic field not running parallel to the planet's surface. Norman demonstrated magnetic dip by creating a compass needle that pivoted on a horizontal axis. The needle tilted at a steep angle relative to the horizon line.

Magnetic inclination and local variations were known before Robert Norman, but his pamphlet had a greater influence than the earlier work.

The crater Norman on the Moon is named in his honour.

Writings

• Norman, Robert (1721) [First published in 1581]. The newe attractive: shewing the nature, propertie, and manifold vertues of the loadstone : with the declination of the needle, touched therewith under the plaine of the horizon (Reprint ed.).

See also

• William Gilbert, founder of magnetic science
• History of geomagnetism
• List of geophysicists
• Shen Kuo, discoverer of magnetic declination

References

1. Published in London by Ballard. See Harré, R. (1981). Great Scientific Experiments. Phaidon (Oxford). pp. 49 – 56. ISBN 0-7148-2096-2.