Friday, May 14, 2010

The Intimidating Compass


I have heard it said that if you want new-comers to the hobby of letterboxing to forego your boxes for easier targets, all you have to do is add a couple of compass readings to your clues. Well, I don't know if this is true or not, but I do know that a lot of folks are more than a little intimidated by reading a compass.

How 'bout a little tutorial?

Reading a Compass and Orienteering

How did the explorers of long ago find their way around? They used a compass and a map. Compasses are still used today to help people navigate across the landscape.

Getting to know a compass compass and its parts

This first step in becoming an explorer is to learn how to read and use a compass. There are many types of compasses. This will get you started with a compass that has a rectangular base, a rotating dial, and housing made of clear plastic.

  1. Find the directional signs, north, south, east and west. North is the most important direction to help orient yourself. Now find the orienting arrow, magnetic needle, and the direction of travel arrow on your compass.
  2. Notice that the magnetic needle points naturally towards the earth's magnetic north pole. Be careful to keep your compass away from metal, like a zipper, because it can affect the magnetic needle and lead you in the wrong direction.
  3. Hold the compass level in the palm of your hand near your chest, with the direction arrow facing away from body.
  4. Turn the housing so the N is lined up with the red end of the magnetic needle.
  5. Turn the housing so the E is lined up with the direction of travel arrow. Now you're ready to use the compass.

Using a compass

compass directions

Now that you've taken a closer look at your compass, go outside and give this fun activity a try.

Pick up four stones or twigs to use as markers. Put them in your pocket. You might find it helpful to have someone read the following directions to you.

  1. Place a marker where you are standing.
  2. Turn the housing on the compass so that N (north) lines up with the direction arrow.
  3. Hold the compass level in the palm of your hand, chest high, with the direction arrow facing away from your body.
  4. Turn your whole body, including your feet, until the red magnetic needle lines up with the orienting arrow on the dial.
  5. Look up. Choose a landmark, like a rock, tree or sign which is exactly ahead of you in the distance. Take six steps toward that spot without looking at the compass. Stop. Place a marker here.
  6. Turn the housing on the compass so that W (west) lines up with the direction arrow. Repeat steps 3, 4, and 5.
  7. Turn the housing on the compass so that S (south) lines up with the direction arrow. Repeat steps 3, 4, and 5.
  8. Turn the dial on the compass so that E (east) lines up with the direction arrow.
    Repeat steps 3, 4, and 5.
compass

Did you return to your first marker?

Go back and walk to each marker.

What shape did you make? You should have made a square.

Now repeat the activity using the following degrees: 360, 90, 180, 270. This should also make the same square.

Congratulations, you now know how to use a compass.

(--Adapted from the Wisconsin Explorer program, Wisconsin Dept. of Natural Resources.)


If you know how to read a compass, you can determine the bearing. A bearing is the direction from your position or degree reading to another object. You can measure the bearing on a map, or if you can see your objective, directly in the field.

Bearing in the field

Knowing how to take a bearing in the field can be useful, if, for instance, you are heading into a valley where the forest will hide your goal. Take a bearing on your objective while you can see it and then follow that bearing after you lose sight of your goal:

1. Hold the magnetic compass in your hand. Hold it quite flat, so that the needle can turn.

2. Point the direction of the travel line at your desired object.

bearing in field
3. Rotate the housing to align the pointed end of declination arrow with the red end (North) of the magnetic needle.

4. Read bearing at index line.

5. The direction of travel arrow now points precisely to your objective. Look up, sight on a landmark and walk to it. Repeat this procedure until you reach your objective. Using this pattern you will follow a relatively straight line.

Bearing on a map
How to read a compass

If you cannot see your objective in the field, you need to measure the bearing on your map:

1. Place the compass on your map with the edge along the desired line of travel. The direction of travel line points to the objective.

2. Rotate the housing to align meridian lines with north-south lines on your map, with "N" towards the top of the map.

3. Hold the compass level in front of you and turn your body until the red end of the needle is directly over the red part of the north arrow.

4. Read bearing at index line.

5. see 5) above

3 comments:

Ari C'rona said...

Love the carve, my friend! You know I've been intimidated by a compass... think some practice is in order! :o)

Anonymous said...

Or, just use the compass on your iPhone! :)
ElizabethB

Mama Cache said...

We were discussing this on our most recent letterboxing trip. Thanks for the timely tutorial.

Really like that carve, my friend.

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