Sophie Duncan sees which way the wind's blowing
The earliest record of a weather vane comes from Athens in 48 BC. They are simple structures, mounted on a rotating spindle. The weather vane lines up with the wind and points in the direction the wind is coming from.
By encouraging your students to make weather vanes you can explore how these instruments work, and reinforce teaching about compass directions.
The simplest weather vane is an arrow, but this design can be used with other shapes, such as animals.
Cut your arrow from strong cardboard. The arrow needs to have a large tail.
Fix your arrow to a short garden stick. This is the part of the weather vane that will line up with the wind.
To create a base for the weather vane, place some stones in the bottom of a plastic bottle. Attach a straw into the top. In particularly windy conditions you may need to secure the base of the plastic bottle using bricks to stop it toppling over.
Place the stick on the weather vane into the straw - ensuring that the weather vane can move freely inside the straw.
Find a safe place to try out your weather vane. They work when positioned on the ground, and work particularly well when raised from the ground, but if you place your vane at a height make sure it won't cause any damage if it falls over.
Using a compass mark the directions north, south, east and west on the bottle.
An even easier way of measuring the wind direction is to use a paper plate marked with the four compass directions. By attaching strips of tissue paper to each of the marks you can find out where the wind is going.
Hold the plate at the point you've marked south, horizontal with the ground, and with your arm outstretched. Using a compass to help you, point it towards the north. Watch how the tissue paper moves.
Sophie Duncan is project manager for science at the BBC www.bbc.co.uk