Leonardo da Vinci is credited with popularizing the miter lock, a canal lock with two gates meeting at an angle.
A miter lock uses a pair of gates whose closed edges meet in a V shape pointing toward the higher water level. Water pressure then pushes the gates together, helping them seal. When the water levels are equalized, the gates can be opened to let boats pass between canal sections at different elevations.
Leonardo studied canal engineering in northern Italy and designed improvements for waterways around Milan. His work included lock gates that could be opened and closed more effectively than earlier arrangements. The famous “Leonardo lock” is therefore associated with Renaissance canal engineering, although the broader history of lock gates includes earlier developments by other engineers.
This mechanism should not be confused with a simple sluice gate, which controls water flow but does not create a navigable chamber between two water levels. The miter principle remains common in canal and navigation locks today.