Whether you call them weathervanes or wind vanes, these devices have been used for centuries. Since the time of the ancient Greeks, the weather vane has served a dual purpose. Since the advent of the weathervane, their use has been both decorative and functional. The source of the wind may not have been fully understood, but the ancient Greeks and others certainly understood how important the wind is.
The wind is very often the predictor of weather. The sun is out, the temperature is warm and suddenly things changes. The wind speed rises, the temperature drops, and the weather takes a drastic turn. The direction of the wind can be as important as the speed. A southerly wind can mean fair skies and warm weather. A northerly wind can foreshadow cold stormy night.
Surely, the ancients knew that changes in wind speed and direction came with certain degree pf predictability. So it should come as no surprise that the simple weathervane became more practical than ornamental. Some historians believe the one of the first weathervanes was part of the Tower of Winds in ancient Greece. The tower was believed to have been constructed around forty B.C. by the astronomer Andronicus. The weather or wind vanes used on the tower were said to pay homage to various Greek gods including the god Triton, a son the god Poseidon.
The ancient Romans had a similar theme to many of their early weathervanes, with Roman gods playing a central role. The rich and famous were fond of placing weathervanes on their homes, both as a sign opulence and practicality. Prior to the advent of recorded scientific observation, there was a great deal of superstition around the weather. Through good weather or bad, the gods were often given credit for the prevailing winds.
Ancient seafarers used a simple type of weathervane while out to sea. The small piece of cloth would be fastened to the rigging. This makeshift wind vane came to be known as a telltale and is still used today by sailors. The telltale was not the only use for a simple piece of cloth to indicate the strength and relative direction of the wind. Anyone who has seen a period movie about ancient Rome or medieval times will certainly remember the presence of long banners or streamers. Amid the pomp and ceremony this streamers are said to have served an important function. The streamers, or telltales, could very well have been used by archers to determine the wind direction and speed.
The weather vane has been discovered to be part of almost every ancient culture. Aside from depictions of various gods, animal themes common for wind vanes, even today. The use of animal characters usually had a connection to religious beliefs. Artisans have adopted the weathervane as a medium for their craft adding to the decorative qualities of these simple weather tools.
The key to a properly functioning weathervane is balance. The typical weather vane must be able to turn in reaction to the slightest breeze. The center of the weathervane must rest on a center axis and be equally balanced on both sides. A basic design includes a center post with the body of the weathervane resting over it. The center post may come to a sharply tapered point. The body of the weathervane would fit on the post in a way were the weight would be concentrated directly on the point. If the body of the weathervane is not allowed to move freely, its reaction to changes in wind direction and speed will be too slow.
The shape of the weather vane can vary from a simple arrow, to more ornate and decorative figures. Even a large weathervane can be designed in way that optimizes its reaction to the wind. The shape is probably more important than the size. The body of the weathervane must designed in a way that is somewhat aerodynamic. An airplane wing creates lift by generating a positive pressure under the wing surface and a negative pressure on the top. Think of a weathervane as a wing surface turned perpendicular to the ground. The reaction to both positive and negative pressure causes the weather vane to turn.
Before the wide spread availability of electricity, farmers and ranchers relied on the wind to operate water pumps. Anyone who has traveled the American heartland may remember seeing these simple windmills turning. A key to an operating windmill is its ability to rotate with changes in wind direction. These windmills have a tail stock that acts in the same way a weathervane does, helping to point the blades of the windmill in the optimal direction. Large windmills used to generate electricity use precisely the same principle. A tailpiece helps the windmill to turn with the prevailing winds.
Another common form of weathervane can be seen at small, general aviation airfields. Used for years, the windsock operates on the same principle as the telltale, providing pilots with an approximation of wind direction and speed.
For most of us, the need for a windmill has little to do with whether we have a weathervane. In these days of modern meteorology, weather predictions are readily available, often in great detail. These advancements in modern technology have rendered the humble weather vane to a decorative addition to our homes. Like many pieces of Americana, antique weathervanes have become quite collectible. Many diverse themes have been used for the wind vane from the artistic to the humorous.
Decorative weathervanes for your home are as close as your favorite fine web store. There is an almost unlimited variety of creatures, critters, shapes, and themes appropriate for any exterior home decor. With a rich history and functionality, the humble windmill can add a touch of whimsy and lore to your home.