AskDefine | Define loadstone

Dictionary Definition

loadstone n : a permanent magnet consisting of magnetite that possess polarity and has the power to attract as well as to be attracted magnetically [syn: lodestone]

User Contributed Dictionary

English

Etymology

First attested from 1515, from Middle English lode guide + stone, was used as a guide tool by mariners. See also: lodestar.

Noun

  1. In the context of "archaic": A magnet, iron oxide in the form of magnetite.

Synonyms

Translations

a magnet

Extensive Definition

Lodestone or loadstone refers to either:
  • A piece of intensely magnetic magnetite that was used as an early form of magnetic compass.
Iron, steel and ordinary magnetite are attracted to a magnetic field, including the Earth's magnetic field. Only magnetite with a particular crystalline structure, lodestone, can act as a natural magnet and attract and magnetize iron. The name "magnet" comes from lodestones found in a place called Magnesia.
In China, the earliest literary reference to magnetism lies in a 4th century BC book called Book of the Devil Valley Master (鬼谷子): "The lodestone makes iron come or it attracts it." The earliest mention of the attraction of a needle appears in a work composed between 20 and 100 AD (Louen-heng): "A lodestone attracts a needle." By the 12th century the Chinese were known to use the lodestone compass for navigation.

References

External links

Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1