What is the usual name for Leonardo da Vinci’s spring-powered self-moving cart?

Leonardo da Vinci’s spring-powered self-moving vehicle is usually called the self-propelled cart.

Leonardo drew the mechanism in the Codex Atlanticus, a major collection of his notes and drawings. The cart used coiled springs to store energy, while mechanisms connected to the wheels controlled its motion. The design may have been intended for theatrical performances, where a vehicle could move across a stage without a visible driver.

The cart is often called an early automobile, but that comparison needs qualification. It had no internal-combustion engine, battery or steering system comparable to those of a modern car. Its stored mechanical energy also would have limited its travel distance. The exact arrangement and purpose of some components have been debated because Leonardo’s drawings do not provide a complete modern-style construction manual.

Working replicas have been built from the surviving drawings. In 2006, researchers and museum builders in Florence created a functioning reconstruction, helping demonstrate how the spring mechanism could propel the cart. The invention illustrates Leonardo’s interest in automation, mechanics and stage technology.