For the young scientist who wants to outsmart the science teacher, here’s an excellent science fair project that duplicates the work of American physicist Henry Rowland.

Your teacher undoubtedly knows that a an electrical current generates a magnetic field. But what your teacher probably doesn’t know is that a moving charge of static electricity also generates a magnetic field. This can be demonstrated from this experiment in the July 1940 issue of Popular Science.

To do the experiment, you set up an electric motor as shown here. You attach a disk of hard rubber, which you electrify by rubbing it with a woolen cloth. (Instead of the rubber disk, you can use an old phonograph record. If you don’t know what that is, you can ask your grandparents, or read some of our posts about the history of the phonograph).

Once the disk is charged up, you turn on the motor. As soon as it starts spinning, a compass placed nearby will deflect, showing the presence of the magnetic field.