Leonardo da Vinci designed an anemometer to indicate wind strength by the movement of a hinged plate.
His design used a vertical board or plate that could swing in the wind. A graduated scale allowed the observer to estimate how strongly the air was blowing. It was an early attempt to turn wind pressure into a readable measurement.
Leonardo’s anemometer was not the same as the modern cup anemometer, which measures wind speed through rotating cups. His design primarily indicated wind force rather than producing a precise numerical speed in the modern sense.
Leonardo studied wind because it mattered to flight, weather observation, sailing, and the behavior of water. His notebooks contain several investigations into air movement, including ideas connected with flying machines and atmospheric motion.