Leonardo da Vinci improved the canal-gate system known as the miter lock.
A miter lock uses two gates that meet at an angle pointing upstream. Water pressure pushes the gates together, helping them seal the opening. Leonardo studied and improved this principle while working on canal engineering in northern Italy.
The system made it possible for boats to move between water levels by filling or emptying a chamber. Leonardo’s canal work included designs for gates, channels, and mechanisms intended to control water more efficiently.
Leonardo did not originate every part of the navigation lock. Earlier forms of locks existed before him, but his drawings show detailed attention to gate construction and hydraulic operation. The miter-gate principle remains common in canal locks today.