Making a Chinese Hanging Compass
Equipment: needle, cotton, pencil, bar magnet, large beaker (or a other clear glass or plastic drinking glass)
Method: take care with the sharp needle.
•Gently stroke the pointed end of the needle in one direction with one end of the bar magnet.
•You need stroke the needle 40 – 50 times. Make sure you always stroke in the same direction, using the same end of the magnet each time.
•Tie one end of the string around the middle of the needle. Tie the other end around the middle of the pencil.
•Place the pencil across the top of your beaker and carefully adjust the needle so that it hangs straight (horizontally) and can move freely
•Your needle will now move so that the point faces in the direction of magnetic north.
You could do this instead:
Cut a circular slice from a cork (the slice should be around 4mm thick).
Push the magnetised needle through the cork from one side of the circle to the other.
Float the cork in a wide glass of water so that it can turn freely.
How could you find north without a compass?
How does a compass know which way is North?