needle compass

 
You can make a compass that points north. It is a basic demonstration of the fundamental force of magnetism. Perhaps having it will bring to you appreciation and wonder for something so much a part of the universe yet so much not understood.
 
The compass works well but it is not portable. Fold a 1 by 2 inch piece of paper lengthwise along the middle. Magnetize two needles by sliding them across one pole of a strong magnet. Hold the two needles together eye to eye and point to point. Use end first passes in one direction. Corresponding needle ends will become either both north poles or both south poles. Push the needles through the folded paper as shown in the diagram on the following screen. Again ends are placed eye alongside eye and point alongside point.
 
Push a pin through the center of a heavy piece of cardboard. Place this point up and balance the paper on this stand. Your compass should point north and south.
 
Placing the compass in a clear jar will protect it from air currents and accidents. Thin aluminum sheet metal such as that commonly found in bakery pie pans can be used instead of paper. It can be cut with a scissors and if worked carefully it gives a pleasing appearance.
 
An easier to make version is to cut knotches at two opposite points on the rim of a plastic soda cap. Put a magnetized needle in the knotches and float the cap on water in a tumbler filled so that the water bulges slightly above the tumbler's rim.