This is a fun way to interpret the natural world using household objects. Follow these directions to make a floating compass and a hanging compass for determining wind direction.
FLOATING COMPASS
Materials:
- 1 clear plastic cup
- 1 magnet
- needle or small nail
- pin
- cork or piece of foam about 1/4-inch thick an the size of a quarter
- pencil or pen
- penwater
- notebook
- (optional) webcam or camcorder
Procedure:
- 1. Rub one end of the magnet along the needle
- 2. Make sure you rub in the same direction, about 30 times
- 3. Test the needle’s magnetization by picking up the pin
- 4. Push the needle through the cork or foam piece
- 5. Fill the cup with water
- 6. Place the cork and needle so it is in the center of the cup
- 7. Wait for the needle to come to a rest
- 8. The thick end of the needle will point to North
HANGING COMPASS
Materials:
- 1 clear plastic cup
- 1 magnet
- thread – about six inches long
- needle or small nail
- pin
- pencil or pen
- notebook
- (optional) webcam, camcorder
Procedure:
- 1. Rub one end of the magnet along the needle
- 2. Make sure you rub in the same direction, about 30 times
- 3. Test the needle’s magnetization by picking up the pin
- 4. Tie one end of the thread around the middle of your pen or pencil
- 5. Tie the other end of the thread around the needle
- 6. Place the pencil across the rim of the cup
- 7. Make sure that the needle is not touching the bottom of the cup
- 8. Wait for the needle to come to a rest
- 5. The thick end of the needle will point north
If you have a commercially made compass, compare the results of your home made compass. Do the readings vary? Does one type of home made compass work better than the other? What happens when you move your compass to another location? How long will the needle hold magnetisation? How do you know when you need to re-magnetise the needle?
