I have a Compass, the sort you use for Land Trekking. As you know a compass works on a Magnetic North basis, whereas say an Ordnance Survey map shows True North.
My Compass has two black lines on it; one is longer than the other and they are 17mm apart at the outside edge, although they both aim at the centre but without touching, as segments.
Now when the compass is placed on the map and has settled it will be aiming at MAGNETIC NORTH. One of the lines marked on the compass glass has to be lined up with it so that I will know what other parts of the compass (North, East, South, West) will be in the correct positions.
I need to know therefore which line to use to achieve this.
One of you must be a dab hand with a compass, so can you help me, please.
2007-03-27
23:06:03
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4 answers
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asked by
greatbrickhill
3
in
Geography