Computer Print-Out Lessons


You need a compass, clinometer and computer sun position program for these lessons. Read only the compass instructions about taking readings of (azimuths/directions/ bearings) in degrees, and measuring altitudes (height) above the horizon in degrees with the clinometer. Do not worry about compass declination adjustments yet. We will get to that later. If you bought a Suunto Clinometer or Tandum compass/clinometer ignore calculating the height of objects (right scale), only use the left altitude/height above the horizon in degrees of objects such as the sun. Ignore route finding by compass for now.

LESSON: Magnetic Compass Sun Locating (See Measuring Direction of Sun)

Print out a "magnetic north" sun position computer print-out for today. Go outside and find magnetic north with your compass. Find magnetic east (90 degrees), south (180 degrees) and west (270 degrees). Look on your print-out for the azimuth/direction of sunrise and sunset and find where the sun rose and will set with your compass.

Look at the print-out for where the sun will be or was at 9:00 am. Find that magnetic direction in degrees with your compass and notice a landmark in that direction. Now try this for different times of the day. If there seems to be a consistent error between your compass and the print out, you may have a strong local compass error. If so change your position and see if things improve.

LESSON: Measuring the Elevation of the Sun or Objects.


Look at your computer print-out for the altitude of the sun at 9:00 AM. With your clinometer find that altitude in the same 9:00 AM compass direction, (using the left scale on the Suunto Tandem). This is where the sun was or will be today at 9:00 am. Practice this for different times of the day.

DO NOT LOOK DIRECTLY AT A BRIGHT SUN! Without looking at the sun, point your clinometer at the sun and watch where the sun's shadow and/or reflection falls on your finger. For an obscured sun or other object look through the clinometer and line up the object with the horizontal line in the clinometer. Master this when the sun is low or behind some clouds and not dangerous to look at.

If you bought a sighting compass with a build-in clinometer, read the instructions with the compass for an obscured sun or other object. For a bright sun open the compass lid to full length with the mirror on your right. Point the compass at the sun and watch the shadow on your finger and read the clinometer dial. If the dial reads "0" when flat with the horizon you are set up correctly. Ignore the magnetic compass needle.
If you made your own clinometer from "Home Made Clinometer" read the instructions from there. An Angle Finder from a hardware store and a small mirror to read the dial will work too.

For other clinometers; Abney level, Alt-Track, Clinometer. Practice with low sun before you try with a bright sun.

LESSON: Finding the Time with a Clinometer

Measure the altitude of the sun with your clinometer and see if it agrees with your computer print-out. If it agrees with your watch you have a computer age sundial.

LESSON: Finding the Time with a Compass. Measure the azimuth of the sun. Check the computer print-out. If it agrees with your watch you are doing everything right.. Practice these methods until you can predict the time within 10 minutes.

LESSON: Magnetic and True Directions

Most new streets are laid out true north, south, east and west. Unless you live in a narrow line between Florida and Wisconsin, magnetic north and true north are not the same. Print out both a True and a Magnetic North print-out for the day and compare them. Compare them for the declination difference for your area. You will find this handy when we get to map reading.

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