Leonardo da Vinci designed water-wheel machinery to turn falling water into rotary motion.
His notebooks contain detailed studies of water flow, wheels, pumps, and mills. In water-wheel designs, moving water strikes or passes beneath blades, causing the wheel to rotate. That rotation can drive machinery such as millstones, hammers, or pumps. Leonardo’s interest was practical as well as theoretical: he examined how channels, buckets, and wheel shapes affected the useful transfer of energy.
Leonardo did not invent the water wheel. Water-powered wheels had been used in the ancient world and were widespread in medieval Europe before his lifetime. His importance lies in his systematic analysis and refinement of hydraulic machines. The designs should also not be called modern turbines without qualification. A turbine extracts energy from moving fluid through a rotor, but many of Leonardo’s sketches describe traditional wheels, undershot wheels, or overshot arrangements. His notebooks nevertheless show an advanced understanding of how water could replace human or animal labor.