Basically, longitude is calculated by measuring time and observing astronomical phenomena. Galileo tried to solve this problem by observing the motion of Jupiter's satellites and applying a pendulum to a mechanical clock.

He determined the motion of the satellites using an instrument of his own invention, called the Jovilabe. A touch screen lets visitors use this instrument virtually.

The operation of the pendulum clock is illustrated by an enlarged reproduction of the timekeeper designed by Galileo and by a mechanical model that compares Galileo's circular pendulum with the cycloidal pendulum.

Very large models of escapements, which can be directly actuated, show how mechanical clocks operate.