Compasses

Compasses are navigational instruments that determine direction relative to Earth’s magnetic poles. Mechanical versions of these magnetically-sensitive devices usually contain a face with the cardinal points of north, south, east and west. A magnetized pointer on the north end is free to align itself with Earth’s magnetic field. The north end of the compass points towards the magnetic north pole (magnetic north) while the south end points towards the magnetic south pole (magnetic south). Most modern compasses are fluid-filled and may include a protractor. Additional features include map and roamer scales, luminous markings, and various sighting mechanism.