Leonardo da Vinci improved the anemometer, an instrument used to measure wind speed.
Leonardo’s version used a vertical board or plate that moved with the wind. A graduated scale allowed an observer to estimate how far the plate was pushed, linking the movement to wind strength. His design was more systematic than simply watching flags, smoke, or tree branches, and it helped turn wind observation into a measurable activity.
An anemometer is not the same as a barometer, which measures air pressure, or a wind vane, which shows direction. Modern cup and propeller anemometers measure wind speed through rotation, while sonic instruments calculate it from sound pulses. Leonardo’s device worked through the force of moving air on a surface rather than through rotating cups.
The instrument reflects Leonardo’s interest in flight, weather, and fluid motion. His notebooks repeatedly connect practical engineering with observations of nature, although his anemometer was an early measuring device rather than a modern precision instrument.