Leonardo da Vinci designed an early anemometer to indicate changes in wind movement.
An anemometer is an instrument used to measure wind speed or, in some designs, to show relative changes in airflow. Leonardo’s version was created in connection with his investigations of flight and atmospheric conditions. It used a lightweight plate or surface that moved with the wind, allowing the observer to compare the force of air movement.
The device was not a modern cup or electronic anemometer. Instead, it provided a practical way to study the wind while Leonardo was examining how birds and proposed flying machines might remain aloft. His engineering notebooks frequently connect instruments with observations of nature.
An anemometer should not be confused with a hygrometer, which concerns moisture in the air, or a barometer, which measures atmospheric pressure. Leonardo is associated with designs for all three kinds of investigation, but they measure different properties.