Those little metallic devices that you see on top of houses and show you which direction the wind is blowing are called weather vanes, and they will usually consist of north and south indicators, as well as an arrow. The lower half of the device usually is still, with the arrow in the upper half and rotating depending on where the wind is blowing.Get a weather vane and put it together the way that the instructions in the packaging describe. You should have a top half, which contains the letters and the arrow and a bottom half that will consist of a spire and a circular, metallic ball.Get a ladder and prop it up against the house. Climb on the roof with the weather vane in hand. Ideally, you would bring another person up with you to hold the weather vane while you work up on the roof and ha