Leonardo da Vinci designed an anemometer to indicate the strength of the wind.
An anemometer is an instrument for measuring wind speed or force. Leonardo’s design used a lightweight plate that moved in response to airflow. A graduated scale could then show how strongly the wind was blowing. The device was connected with his broader study of flight, because understanding air movement was essential to evaluating wings and flying machines.
Leonardo’s instrument was not the modern cup anemometer familiar from weather stations. Later inventors developed rotating-cup and propeller types that provide more direct numerical measurements of wind speed.
The invention is sometimes confused with a wind vane. A wind vane indicates direction, while an anemometer measures the strength or speed of the moving air.