Which Leonardo da Vinci device measured wind speed and direction?

Leonardo da Vinci designed an anemometer to measure wind speed and indicate wind direction.

His design used a flat, hinged plate that moved upward when wind pushed against it. A graduated scale beside the plate allowed the observer to estimate the wind’s strength. The arrangement was simpler than modern cup or propeller anemometers, but it applied the same basic principle: stronger airflow creates greater movement.

Leonardo’s interest in wind measurement was closely connected with his studies of flight, clouds, weather, and the movement of air around wings. His notebooks contain several investigations of atmospheric motion, not just isolated machine sketches.

The device is often described as an early anemometer rather than the first modern wind meter. It did not provide the digital precision of contemporary instruments, and it should not be confused with a barometer, which measures air pressure.