How to Make a Compass from a Needle and Magnet

Learn how to create a working compass using simple household items like a needle, magnet, and water bowl.

1. Gather Your Materials. You'll need a sewing needle, a strong magnet (refrigerator magnets work well), a small bowl of water, a small piece of cork or foam (about the size of a coin), and scissors if you need to cut the cork. Make sure the bowl is large enough that the cork can float freely without touching the sides.
2. Magnetize the Needle. Hold the needle by its eye and stroke it with the magnet in one direction only, from the eye to the point. Do this 30-50 times, always moving the magnet in the same direction and lifting it away from the needle before starting the next stroke. This process aligns the metal particles in the needle, turning it into a weak magnet.
3. Prepare the Float. Cut a small piece of cork or foam, about the size of a quarter. Carefully lay the magnetized needle on top of the cork. The needle should lie flat and be balanced so the cork doesn't tip over when it floats.
4. Test Your Compass. Gently place the cork with the needle on the surface of the water. The cork should float freely. Within a few moments, the needle will start to rotate and eventually point toward magnetic north. Turn the bowl gently and watch as the needle moves back to point north again.
5. Understanding How It Works. Your needle became magnetized when you stroked it with the magnet. Like all magnets, it now has a north and south pole. Earth acts like a giant magnet with magnetic poles, so your needle aligns itself with Earth's magnetic field, just like a real compass.