Leonardo da Vinci improved the miter lock, a canal-control structure with hinged gates.
Leonardo worked on hydraulic engineering in northern Italy and studied canal navigation, water levels, and gate mechanisms. The miter lock uses two gates that meet at an angle pointing upstream. Water pressure pushes the gates together, helping them seal when the chamber holds a higher water level.
Leonardo is often credited with refining canal-lock designs, especially for the Naviglio di San Marco in Milan. The basic idea of locks existed before him, so describing him as the inventor of the canal lock would be inaccurate. His importance lies in practical engineering improvements and detailed analysis of water-control systems.
A lock lets boats pass between waterways at different elevations. Gates close around a chamber, and water is added or released to raise or lower the vessel. Leonardo’s hydraulic studies also covered canals, irrigation, bridges, and mechanisms for regulating flow.