windvane

A windvane, also spelled wind vane, is a device that shows the direction from which the wind is blowing. It consists of a lightweight, aerodynamically shaped vane mounted on a low-friction pivot, with a counterbalancing tail. When wind strikes the forward surface, torque rotates the vane so that it aligns with the wind, indicating the wind’s origin. A compass rose or cardinal-point indicator is usually attached to translate the vane’s orientation into a wind direction.

Construction and materials: Wind vanes are commonly made from metal such as copper or aluminum, or weather-resistant wood, and are mounted on a vertical mast. The pivot or bearings permit free rotation with minimal resistance.

Applications and variants: Wind vanes are widely used in meteorology, agriculture, and nautical settings to provide directional wind information. They are often paired with an anemometer to furnish both direction and speed. In architecture and decorative contexts, wind vanes may adopt various shapes, including birds, roosters, or arrows, without altering their function.

History: Wind vanes have been used since antiquity in many cultures. In Europe they became common on church steeples and rooftops during the Middle Ages and the early modern period. Modern wind vanes are mass-produced in a variety of designs, balancing functional accuracy with decorative appeal.

See also: Weather vane, Anemometer.