Orientation

If we're navigating into unfamiliar terrritory, we need three things.

• The best map we can find,

• The best compass we can lay our hands on,

• And to know where we're starting from.

Each of these three things carries it's own challenges.

The map of course is a reduction, done by somebody at a different point in time. It will tell you where things are in relation to each other, show geographical features, and help you understand differences. It will not show you what the weather's going to be like, or the animals you might come across, or who else might be there. The map is not the territory.

The compass has it's own idiosyncracies. Compasses point to magnetic north, not true north, and magnetic north moves around - known as variation. They are also subject to deviation, which is determined by the surroundings of the compass - the materials in a boat for instance. To find true north, you have to correct for both variation and deviation.

Neither compass nor map however are a great deal of use unles…