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How to Make a Simple Floating Cork Compass

Compasses have helped navigators for thousands of years. Although modern compasses have come a long way in sophistication, the first compasses were merely a needle floating in a bowl of water. The needle always points in the same direction, regardless of how the bowl is moved or rotated. Similar compasses can be made easily with household materials. Homemade compasses provide a quick and engaging way to demonstrate magnetism to young learners.

Things You'll Need

Wine cork (non-plastic)
Sharp knife
Sewing needle, 1 to 2 inches long
Bar magnet
Round cup or bowl
Permanent marker
Standard compass

Instructions

- 1
  Cut a slice off the wine cork about one-fourth inch thick to provide a float for the compass needle.
- 2
  Rub a permanent magnet along the sewing needle 30 to 50 times. Always rub in the same direction and with the same pole of the magnet. This turns the needle into a weak magnet attracted to the earth's natural magnetic field.
- 3
  Poke the needle through the cork disc. You want the needle to go through the long axis of the cork rather than through the flat faces.
- 4
  Fill a round cup or bowl with enough water that the cork can float freely. Let the water stand until it is still.
- 5
  Balance the cork and needle in the water. The needle should rotate until it comes to rest pointing along the north-south axis. Compare the homemade version to a regular compass to determine which tip of the needle points north; mark this point with a permanent marker.

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