What kind of machine did Leonardo da Vinci sketch to measure wind speed?

Leonardo da Vinci sketched an anemometer to measure wind speed.

Leonardo’s design used a vertical board or plate that could move in response to wind. A graduated scale allowed an observer to estimate the wind’s force or speed from the board’s position. He created the instrument while studying flight and atmospheric conditions, because understanding wind was essential to his investigations of birds and proposed flying machines.

Leonardo’s device was not necessarily a direct ancestor of every modern anemometer. Modern instruments commonly use rotating cups, propellers, or ultrasonic pulses, while his design relied on the movement of a plate. The historical attribution also concerns a sketch and concept, not a documented standardized instrument used across scientific observatories.

The anemometer illustrates how Leonardo connected natural observation with practical measurement. Rather than merely describing wind qualitatively, he sought a repeatable mechanical method for comparing its strength. That interest helped support his wider studies of flight, water, weather, and forces acting on moving bodies.