Burchfield Park, August 17, 2004

Measurement Exercise

1. Start at the north side of the bridge over the toboggan run on the west side of the warming house near the ice rink.

2. Walk down the hill on the east side of this bridge to the eastern track of the toboggan run, to a point east of a tree.

3. Set your compass for the northerly direction of this track.

4. Set your compass for 90 degrees west of the direction you set in step 3.

5. Walk to a point on the track where your compass is pointing to the tree in the direction you set in step 4. Mark this "starting point" with some object.

6. You are now going to use your compass to measure the distance from your "starting point" to the tree.

7. Set your compass for 45 degrees south of the direction which you set in step 4.

8. Walk along the track in its northerly direction to a point at which your compass is pointing to the tree in the direction which you set in step 7. Mark this "ending point" with some object.

9. Pace off the distance from your ending point to your starting point. This should be the distance from your starting point to the tree.

10. Pace off the distance from your starting point to the tree. This count should be approximately the same as your count in step 8, confirming the accuracy of your compass measurement.

Question: Why does this method work? Why is it not more precise?

Last Revised 8/17/04

John D. McCarthy