Leonardo da Vinci designed an anemometer, an instrument for measuring wind speed, using a screw-shaped rotor.
Leonardo’s wind-measuring device was based on the movement of a rotating element exposed to airflow. By observing how the mechanism responded to the wind, an operator could estimate its strength. The design belongs to Leonardo’s broad interest in flight, weather, and the forces acting on moving bodies.
Anemometers became important in meteorology, aviation, engineering, and sailing. Modern instruments may use cups, vanes, heated wires, or ultrasonic pulses, but their purpose remains the same: determining how fast air is moving.
Leonardo’s instrument was not a modern calibrated weather station. Its importance lies in recognizing that wind could be measured mechanically rather than described only with words such as “strong” or “weak.” It is sometimes confused with a barometer, but a barometer measures air pressure, not wind speed.