What is a metronome?
A metronome is a device that produces an audible count, a click or other sound, at regular intervals that the user can set in beats per minute. Musicians use the device to practice with a normal pulse. In 1696, French musician Etienne Loulie made the first recorded attempt to apply the pendulum to a metronome, although the first working metronome did not emerge until 1814.
History metronome
The pages of history with attempts at the invention and construction of metronomes, such as those for automatic page turners, are filled with failure and impractical ideas, but they do give a few successes. Why such a small field should attract so many inventors is a mystery.