Abstract: A base supports a vertical pivot arm, one end of which supports a pivotal rotation means for a rotation support housing with a plurality of radial connector sockets. One of several pendulum arms can be fitted into each of the radial connector sockets, the pendulum arms supporting a pendulous mass on each pendulum arm. One such pendulum arm is articulated into two portions, each portion with a plurality of additional pendulum arms attached thereto. The apparatus consequently demonstrates the physical principles of not just a simple pendulum, but those of a variety of compound pendulum configurations.