Ronnie Irvine/Elaine Simpson 2017
MUWC
Where is North?  Not as simple as it seems, as there are three different North directions.  What we call True North is the direction to the North Pole-we can ignore this in hill-walking. Use the Pole Star to find this. Grid North is the direction to which the grid lines on a map point. (ie) north according to the map.   Magnetic North is the direction in which the compass needle points. The difference between magnetic north      and grid north varies from place to place and is slowly changing with time.       At present (December, 2013) magnetic north is 3°49’ west of grid north.  Details of magnetic variation, annual rate of      change and date of calculation are printed on maps.  Remember-the difference between grid and magnetic north      must be considered when converting between bearings on a map and bearings on the ground.               
Setting a map.   Setting a map is orientation of the map so that the North of the map is in the same direction as north on the ground.  When using a map you should always try to keep it set. There are two usual ways to do this. Use a compass to align the grid lines to the north.  Use known features to orientate the map so that the direction of these features on the map are the same direction as on the ground
The map section is set (as near as can be managed ) using the view of the Mournes immediately above.