Find True North - the scout's way
  A compass will only give you an approximate reading for north since the magnetic field of the earth is not perfectly aligned with the planet’s poles. The magnetic field also changes with time. The magnetic declination for Pretoria is approximately -17°. (That means "True North" will be 17° east of magnetic north. **)

You can quickly find "True North" using an analog watch and a tooth pick or small straight twig.
 

In the Southern hemisphere:

  • Place the watch on a level piece of ground.
  • Point the figure 12 towards the sun. For more accuracy, align the shadow cast by the twig with the 12 o'clock line.
  • The North-South line is the line dividing the angle between the hour hand and the 12 o'clock line in half.

In the northern hemisphere point the hour hand in the direction of the sun. The North-South line is again the line dividing the angle between the hour hand and the 12 o'clock line in half.

Note:
This method does not work if your watch is set to summer time. It is also not very accurate if you are close to the equator or if you are in a very wide time zone, that is, a time zone were the local (solar) time differs significantly from Universal Time (UTC) also called Greenwich Mean Time (GMT).

** The magnetic declination for Cape Town is -24°

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"True North" - shadow method  
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© Helga Nordhoff (2001-2003)