Twenty five small compasses are arranged into neat rows and columns on the exhibit table. The exhibit user observes how all of their pointers line up to the earth magnetic north pole. When a bar magnet is place just above the compasses, its stronger magnetic field causes these pointer to spin then align themselves to its magnetic field. Looking at all the pointers will show that they create a pattern that follows the shape of the magnetic field of the bar magnet.

Lines of Force is available in the "I AM a Scientist" travelling exhibit package.