What instrument for estimating wind speed did Leonardo da Vinci design?

Leonardo da Vinci designed an anemometer for estimating wind speed.

His design used a light, movable element that responded to airflow. The amount of movement could be compared with a scale, giving an indication of how strong the wind was. This made the instrument useful for studying weather and for assessing conditions relevant to flight.

Leonardo’s anemometer was not the same as the modern cup anemometer commonly seen on weather stations. Modern instruments use calibrated rotating cups, propellers, or electronic sensors, while Leonardo’s proposal relied on a simpler mechanical indicator.

Leonardo’s interest in wind measurement was connected to his investigations of birds, flight, and atmospheric motion. The related hygrometer measured moisture, not wind, and the barometer measures atmospheric pressure.