Pendulum & Ball (conductor): Attach one or two pendulums to the Railing. You can click anywhere in the simulator to attach a pendulum ball. The ball is connected to the Railing by a long string that leaves the ball free to swing back and forth. With the Select button depressed, you can move the ball along the Railing. In the pendulum's Properties Box, you can set the ball's charge and either show or not show the Model View.

A pendulum ball can exchange charge with an electroscope or an insulator through direct contact. The ball can also exchange charge with an electroscope by touching the lead of a neon bulb attached to the conductor.