Leonardo da Vinci designed an anemometer to indicate changes in wind direction and strength.
An anemometer is an instrument for measuring wind speed or direction, depending on its design. Leonardo’s version used a light, movable indicator that could respond to airflow and provide information about changing wind conditions.
The instrument was connected to Leonardo’s investigations of flight and atmospheric motion. Understanding wind mattered to his studies of birds, gliders, and other flying-machine ideas, because air movement affects lift, balance, and travel.
Leonardo’s device should not be confused with a thermometer, which measures temperature, or a hygrometer, which measures humidity. Modern anemometers often use spinning cups, propellers, or ultrasonic sensors, while Leonardo’s concept was a much simpler mechanical indicator.