How Compasses Work

Creating Your Own Homemade Compass

If you don't have a compass, you can create your own in much the same way people did hundreds of years ago. To create your own compass, you will need the following materials:

  • A needle or some other wire-like piece of steel (a straightened paper clip, for example)
  • Something small that floats such as a piece of cork, the bottom of a Styrofoam coffee cup, a piece of plastic or the cap from a milk jug
  • A dish, preferably a pie plate, 9 to 12 inches (23 - 30 cm) in diameter, with about an inch (2.5 cm) of water in it

The first step is to turn the needle into a magnet. The easiest way to do this is with another magnet -- stroke the magnet along the needle 10 or 20 times as shown below.

If you are having trouble finding a magnet around the house, two possible sources include a can opener and an electromagnet that you make yourself (see How Electromagnets Work).

Place your float in the middle of your dish of water as shown below.

The "float on water" technique is an easy way to create a nearly frictionless bearing. Center your magnetic needle on the float. It very slowly will point toward north. You have created a compass!