Mad dogs and Englishmen go out in the mid-day sun. Have you noticed how dogs start chasing their tails in hot weather? And we humans can come over all funny too. You can end up with analemma syndrome if you’re not careful. There we are - a new word to describe staff meetings with no end and no purpose.

What analemma really means is a figure-of-eight shape, and it crops up regularly (and purposefully) in a curious book on the construction of playground sundials. Based on original work at Malltorees Junior School in Kilburn, London, the book provides the basis for an enjoyable and practical playground project for upper key stage 2 or 3 pupils this summer.

The book gives a clear rationale for the esoteric sundial business. There is a lovely introduction to sundial history going back as far as Egypt in 1, 500BC, calling in on King Ahaz of Judah in the 8th century BC. Another great word is gnomon. It’s the person or a vertical object that casts the shadow, such as the sundial stile. The more you read through the book, the more fascinating it becomes. There are detailed and precise measurements involved which raise some wonderful teaching issues about timelines - especially nice if you want an environmental link to the millennium.

The geometric, mathematical, artistic and social potential is gorgeous. Above all, you get a good piece of extended work to follow through until winter chills our chalk again. I can just see the hordes stretching out skewers and coloured wool, finding true north eventually and constructing dial ellipses for all they’re worth.

If you want the cheap and cheerful version, go for the Helix Weather Station. This kit goes together in 10 minutes and lasts for ages. I’ve had one in my back garden for yonks and the children love it. There’s a jolly blue and red chicken with a funnel for a beak at the top of a tall pole. That’s to catch the wind. And it’s got a wind speed indicator in mph and kph on one side. Underneath the chicken is a quartet of animals looking out in each compass direction. You can tell from the way they’re looking which way the wind blows. Further down, there’s a toothmug holder. You put the rain guage in this and pray on behalf of the water companies for something to measure.

And there’s the sundial. It is not as beautiful as the one you’re going to make with the children and parent helpers, but it does work. You can tell when it’s hometime anyway.

Included are weather station charts to record the planet’s bodily functions. You can have so much fun and still use this kit for a serious project in school. It a bargain. Parents and teachers reach for your wallets!

The instructions are simple, even though the review set included instructions in French, Italian, Dutch and German, but not English. Wait a minute. I don’t believe it. Guess what our French, Italian and German neighbours call a gnomon. Yes, a gnomon! The Dutch meanwhile seem more taken with wizjers. Oh well, happy wizjers everyone. Here’s to summer.

Helix, PO Box 15, Engine Lane, Lye, Stourbridge, West Midlands DY9 7AJ.

Tel: 01384 424441 Robert Hole, 58 Whitehall Park Road, Chiswick, London W4 3NB. Tel: 0181 995 3079