You’ll need to line up your direction with the map ... To take your bearing, hold the compass flat and point your body and compass at the object or destination you want to navigate to.

Open a pair of compasses so the distance is slightly longer than the distance from P to the line. Place the compass at point P and draw two arcs, crossing the line either side of P Image caption ...

Earliest records show a spoon shaped compass made of lodestone ... it must indicate straight lines. It responds to the chhi by orientation, being central to the earth and deviating in various ...