Leonardo da Vinci sketched an escapement mechanism to regulate the movement of a pendulum. His late-fifteenth-century clock studies show an interest in controlled, repeating motion and in improving timekeeping mechanisms.
An escapement allows a gear train to advance in measured steps rather than spinning freely. It also transfers small impulses to the timekeeping element, such as a pendulum or balance. Leonardo’s drawing is generally discussed as an early concept related to pendulum-clock escapements, not as a complete working clock of the type later developed by Christiaan Huygens.
The distinction matters because the pendulum clock itself was invented in the seventeenth century. Leonardo’s sketches predate that invention by more than a century, and the exact operation of his proposed mechanism remains subject to interpretation.