Leonardo da Vinci designed canal-lock mechanisms to raise or lower boats between different water levels.
A canal lock works by placing a vessel in a chamber bounded by gates. Water is admitted or released until the water inside the chamber matches the level of the next section of canal. The gates can then be opened, allowing the boat to continue its journey.
Leonardo worked on canal and water-management projects in northern Italy, where differences in elevation made navigation difficult. His designs included improved arrangements for gates and channels, especially in connection with Milan’s waterways.
A canal lock is not the same as a sluice gate. A sluice controls water flow, while a lock changes a boat’s elevation. Leonardo did not invent the basic principle of locks, but he helped develop and refine practical canal engineering during the Renaissance.