CHADDS FORD, PENN. — Weathervanes have a long history of adorning buildings around the world and offering guidance on wind direction. They get their name from the Old English “fane,” which means flag or banner. Weathervanes are among the oldest forms of weather prediction, with mentions in ancient writings from Mesopotamia more than 3,500 years ago. The Chinese talk about strings or flags used to read wind directions in Second Century BC writings. Today, weathervanes are increasingly prized collectibles.
Weathervanes have simple designs, but in order to function, they must be perfectly balanced on their rotating axis and need an unequal area on each side against which the wind can blow. As the weathervane spins to reduce the force of wind on its surface, the end with the least surface area turns into the wind, thus indicating the wind direction. Vanes also must be located on the highest point of a structure, away from other buildings that could affect wind direction... Read more