Setting the Map
To set the map:
Line up the edge of the compass with the blue North/South grid lines on the map. Holding the compass firmly in this position with your thumb rotate yourself and the map around until the compass needle falls within the orienting needle on the base of the compass.
This process is illustrated in this interactive movie (right).
Click on the green arrows to rotate the map until the compass needle falls within the orienting needle on the base of the compass and the contours on the map match those on the ground. A tick appears when the map is set. If great precision is needed, you can make allowance for the magnetic variation by setting this on the orienting dial before you start.
If you are not sure which parts of the compass are which - select The Compass from the directory on the left.