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The term '''compass''' can refer to a navigational tool which points in a fixed direction, allowing travelers to find their way by inferring other directions and paths through the process of ''orienteering''.  When used alone the term usually refers to a magnetic compass. The plural ''compasses'' can also refer to a device used for drawing circles.

The term '''compass''' can refer to a navigational tool which points in a fixed direction, allowing travelers to find their way by inferring other directions and paths through the process of ''orienteering''.  When used alone the term usually refers to a magnetic compass. The plural ''compasses'' can also refer to a device used for drawing circles.

Magnetic compasses rely upon [[magnet|magnetized]] pieces of metal, typically floating in liquid to ensure low [[friction]]. These  align themselves with the Earth's magnetic field lines which point at the Earth's magnetic north pole. Magnetic field lines vary from true north (pointing to the geographic north pole) and thus must be adjusted according to information usually found on a map or chart. Maps and charts have a compass rose printed with the deviation from true north noted for the area of coverage of the map. Deviation often occurs due to large mineral deposits which occur in the area of interest.

Magnetic compasses rely upon [[magnet]]ized pieces of metal, typically floating in liquid to ensure low [[friction]]. These  align themselves with the Earth's magnetic field lines which point at the Earth's magnetic north pole. Magnetic field lines vary from true north (pointing to the geographic north pole) and thus must be adjusted according to information usually found on a map or chart. Maps and charts have a [[compass rose]] printed with the deviation from true north noted for the area of coverage of the map. Deviation often occurs due to large mineral deposits which occur in the area of interest.

Deviation from true north can also occur due to the presence of nearby large metal objects, such as ships at sea. At sea, this additional magnetic deviation is tracked, logged, and factored in to reading a magnetic compass in order to determine true north. In an aircraft the aircraft's movement can affect a compass, causing it to give inaccurate readings during turns and other maneuvers.

Deviation from true north can also occur due to the presence of nearby large metal objects, such as ships at sea. At sea, this additional magnetic deviation is tracked, logged, and factored in to reading a magnetic compass in order to determine true north. In an aircraft the aircraft's movement can affect a compass, causing it to give inaccurate readings during turns and other maneuvers.

Magnetic compasses were first invented as a device for [[divination]] as early as the [[Chinese]] [[Han Dynasty]] (since about 206 BC).<ref>{{cite book|last=Merrill|first=Ronald T.|title=The Earth's magnetic field: Its history, origin and planetary perspective|year=1983|publisher=Academic press|location=San Francisco|isbn=0-12-491242-7|page=1|edition=2nd printing|author2=McElhinny, Michael W.}}</ref> Magnetic compasses were in early use by [[Portugal|Portuguese]] explorers in the [[Age of Exploration]].

Magnetic compasses were first invented as a device for [[divination]] as early as the [[Chinese]] [[Han Dynasty]] (since about 206 BC).<ref>{{cite book|last=Merrill|first=Ronald T.|title=The Earth's magnetic field: Its history, origin and planetary perspective|year=1983|publisher=Academic press|location=San Francisco|isbn=0-12-491242-7|page=1|edition=2nd printing|author2=McElhinny, Michael W.}}</ref> Magnetic compasses were in early use by [[Portugal|Portuguese]] explorers in the [[Age of Exploration]].

Compasses are one of the two most essential pieces of navigation gear that one should carry, the other being a [[map]]. [[GPS]] devices and [[cell phone]]s with [[Google]] Maps may breakdown or run out of [[battery|batteries]] during an [[emergency]], [[disaster]] or a [[Post Apocalyptic World]] - [[SHTF]] - [[TEOTWAWKI]] event. Also the sun isn't always shining, and it takes a great deal of time and effort to learn to stellar navigation, however a map and compass will continue to work until your break or lose them.

Compasses are one of the two most essential pieces of navigation gear that one should carry, the other being a [[map]], though [[GPS]] devices are supplanting both.

Few things are more important than knowing where you are and where you're going and the compass helps you to do both. In selecting a compass there many types with many different features to consider, some of them are novelties while others are tremendous conveniences. There are several basic types of compass, and some compasses fall under more than one type.

In selecting a compass there many types with many different features to consider, some of them are novelties while others are tremendous conveniences. There are several basic types of compass, and some compasses fall under more than one type.

==Types of Compass==

==Types of Compass==

If you have to navigate at night, glow in the dark compass point will be extremely helpful.

If you have to navigate at night, glow in the dark compass point will be extremely helpful.

==See Also==

==See also==

* [[Map]] and Compass

* [[Map]]

* [[Orienteering]]

* [[Orienteering]]

* [[Geocaching]]

* [[Geocaching]]

* [[GPS]]

* [[GPS]]

==References==

==References==

{{Reflist|2}}

{{Reflist}}

==Bibliography==

==Bibliography==

* ''Geocaching For Dummies'' by Joel McNamara (ISBN 978-0-7645-7571-6)

* ''Geocaching For Dummies'' by Joel McNamara (ISBN 978-0-7645-7571-6)

==External Links==

==External links==

* [http://msi.nga.mil/MSISiteContent/StaticFiles/HoMCA.pdf]Handbook of Magnetic Compass Adjustment.

* [http://msi.nga.mil/MSISiteContent/StaticFiles/HoMCA.pdf Handbook of Magnetic Compass Adjustment]

* [http://www.magnet.fsu.edu/mediacenter/slideshows/compass/index.html How to Make a Compass] Audio slideshow from the National High Magnetic Field Laboratory

* [http://www.magnet.fsu.edu/mediacenter/slideshows/compass/index.html How to Make a Compass] Audio slideshow from the National High Magnetic Field Laboratory

* Paul J. Gans, [http://scholar.chem.nyu.edu/tekpages/compass.html The Medieval Technology Pages: Compass]

* Paul J. Gans, [http://scholar.chem.nyu.edu/tekpages/compass.html The Medieval Technology Pages: Compass]

* [http://www.orienteering.org/ International Orienteering Federation]

* [http://www.orienteering.org/ International Orienteering Federation]

* [http://www.geocaching.com/ www.geocaching.com]

* [http://www.geocaching.com/ www.geocaching.com]

* [http://www.youtube.com/watch?v=v58-RqssqUc YouTube.com:  Orienteering, USOF style]

* [https://www.youtube.com/watch?v=v58-RqssqUc YouTube.com:  Orienteering, USOF style]

* https://www.amazon.com/Suunto-Arrow-6-Orienteering-Compass/dp/B003JYVMJC

* https://www.amazon.com/Suunto-Arrow-6-Orienteering-Compass/dp/B003JYVMJC

[[Category:Navigation]]

[[Category:Navigation]]

[[Category:Geography]]

[[Category:Geography]]