Leonardo da Vinci improved the canal-control structure known as a miter lock by using hinged gates that meet at an angle.
A navigation lock raises or lowers boats between water levels. Leonardo studied canal engineering in northern Italy and developed ideas for gates that could resist water pressure more effectively. In a miter-gate arrangement, the two gates meet in a V shape pointing toward the higher water, allowing pressure to help hold them shut.
The system became important in canals around Milan, where water transport and irrigation depended on reliable control of changing water levels. Leonardo’s work built on existing hydraulic knowledge rather than creating every part of the lock from nothing.
A lock is not the same as a dam or a simple sluice. Its defining feature is a chamber with gates at both ends, allowing a vessel to move between different elevations.