Make a Mariner's Compass
You will need: A needle, cork, knife, small bowl,
Peter Peregrinus was the
first man to use a compass. This was in 1269, but even he failed to realize why
the compass needle always pointed in one direction. It was left to William
Gilbert (1544-1603) to become the first man to realize that the earth itself
acted as a huge magnet.
Starting with a magnet, it
is possible for you to make a simple form of mariner's compass from ordinary
First, cut a section from the end of a cork. This disk of cork should be about to of an inch thick.
Make a narrow groove in the top of the disk, big enough for a needle to rest firmly in the groove. Use a sharp knife, but be careful not to cut your fingers.
Now comes the task of magnetizing the needle for your compass. Holding the needle at one end between finger and thumb, stroke it 20 times in one direction on one leg of the magnet. As the needle leaves the magnet at the end of each stroke raise it in a small semicircle above the magnet before commencing the next stroke.