What machine for measuring wind speed did Leonardo da Vinci develop?

Leonardo da Vinci developed an anemometer, an instrument for measuring wind speed.

His design used a hinged plate that moved in response to the force of the wind. A graduated scale could indicate how far the plate was pushed, allowing the observer to estimate wind strength. Leonardo was interested in wind measurement because it could help assess conditions for flight and other mechanical experiments.

An anemometer measures wind speed, while a wind vane indicates wind direction. These instruments are often confused because both are common at weather stations, but they answer different questions. Leonardo’s device was an early mechanical approach rather than the cup, propeller, or electronic sensors used today.

The invention reflects Leonardo’s habit of turning natural forces into measurable quantities. His notebooks connected observations of air movement with studies of birds, flying machines, and atmospheric behavior, although his instrument was not a modern precision meteorological sensor.