Leonardo da Vinci improved an anemometer, an instrument for measuring wind speed, in the late fifteenth century.
His design used a plate that moved in response to wind. The position of the plate could be read against a graduated scale, allowing the observer to estimate the wind’s strength. This was an important change from simply describing wind by direction or by visible effects on trees, flags, and waves.
The word anemometer comes from the Greek god Aeolus, associated with the winds. Leonardo’s instrument was not the modern cup anemometer, which uses rotating cups, but it helped establish a mechanical approach to quantifying airflow. Later instruments became more accurate and easier to calibrate, supporting meteorology, navigation, engineering, and aviation.