Wind Vanes (or weather vanes)
Which way is the wind blowing? Notice that one end of each arrow is larger than the other end so that arrow will point in the wind's direction when air blows over it.
Simple yet elegant vane
A simple vane consists of the four cardinal directions (N, W, S and E) and an arrow on a rotating axis. But most wind vanes are fancier.
I am linking to Jenny Matlock at Alphabe-Thursday HERE