Leonardo da Vinci designed an anemometer to indicate wind direction and strength.
An anemometer is an instrument for measuring or indicating wind speed. Leonardo’s design used a plate that moved in response to airflow, with a graduated scale showing the wind’s force. He also investigated wind direction, making the device part of a broader study of atmospheric motion.
Leonardo’s anemometer appeared in his notebooks during the late fifteenth century. It was not the same as the rotating-cup instruments widely used today. Instead, its operating principle depended on how far wind displaced a movable surface. That made it useful primarily as an indicator rather than a highly precise modern scientific meter.
The invention reflects Leonardo’s interest in applying mechanical measurement to natural phenomena. He studied air currents for several reasons, including flight, weather, and the movement of projectiles. An anemometer should not be confused with a barometer, which measures atmospheric pressure, or a thermometer, which measures temperature.