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WIND VANES Several kinds of instruments can be made to indicate wind direction. a. Cut a notch about 1 inch deep in each end of a piece of wood one foot long. Cut a small arrowhead and a large tail piece from an aluminum pie pan. Insert the arrow- head and the tail piece into the notches, and nail them in place. Find the point along the stick where the stick is balanced, then drill a hole at that spot just large enough for a small test tube or medicine dropper tubing to fit through. The medicine dropper tubing can be prepared by holding the dropper by the rubber bulb, placing the tip of the dropper in a flame, and rotating it slowly until the opening is completely closed and rounded. When the glass is cool, remove the rubber, and insert the tubing through the wood. You might need to use some friction tape to keep the wood from slipping off the tubing. Now bend a coat hanger to form a bracket, and mount the wind vane on a post of fence where winds blowing from many directions will strike it. Be sure to note that the arrow points in the direction from which the wind comes. b. The wind sock is another instrument that is used at airports as a wind direction indicator. A wind sock can be made by bending a section of light wire into a circle and attaching some thin cloth to it. It can then be attached to a stick with strings and placed outdoors where the wind will blow freely into it. (Wind socks are quite popular for ourdoor patio hangings, and they can be purchased in stores where they sell stuff for barbecues.) Winds are named for the direction from which they come (e.g., a north wind comes from the north, and the arrow will point north). Use a compass to determine from which direction the winds come. ---oOo--- The lower part of a moving air mass is usually obstructed and influenced by trees, houses, and other objects; thus, wind vanes, which are usually near the ground, do not always indicate the true direction of the wind. To observe movement higher in the atmosphere, glue a round mirror to a piece of cardboard, and mark the points of the compass around the mirror. Paste a small paper circle about the size of a dime in the center of the mirror. Set the cardboard on a level spot outdoors with the N on the cardboard pointing north -- a compass can be used to orient the mirror. Look down into the mirror. When you see a cloud passing over the dime-sized circle, follow it with your eyes until it reaches the edge of the mirror. At that point you will see a wind direction indicated on the cardboard. This is the direction toward which the wind is blowing. Use a commercial or homemade wind vane or nephoscope, and record the wind direction at the same times twice a day for a five-day period. Note whether there seems to be any connec- tion between the direction of the wind and the kind of weather that follows. Why is wind direction important? Do winds from different directions bring different kinds of weather? Why else is wind direction important? Why would it make any difference to an airplane pilot? Why would it matter to a farmer? Why would a pirate care?  Any problems with this page? Send URL to
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