It didn't take long for Britain's potting-shed boffins to begin beating a path to the door of the Tomorrow's World studio, hoping to find a springboard for the questionable innovations that had not yet progressed beyond the Patent Office's in-tray.

Theirs was mostly harmless stuff - no doubt the aspiring Doctor Mengeles were weeded out at an early stage - and of course there were a number of genuinely good ideas that subsequently flourished, having been given a platform on the programme.

With the advantage of 20:20 hindsight, we can easily spot the Great Misguided who once found their way on to TW. Clever people, with excellent brains and fine minds - but if only they'd known then what we know now.

In 1975, the Hon Brenda Carter had her fifteen minutes. With the appearance of Jackie Onassis and the air of Nancy Mitford, she was an unlikely candidate for Scientist of the Year. Stylish, aloof, composed... Brenda would have worn a starched, white lab coat as if it were a Courreges blouson.

Like Brenda, her invention was an intriguing blend of beau monde glamour and no-nonsense practicality - the solar-powered sentry box. This wooden- slatted contraption would not have looked out of place standing at the gates of Buckingham Palace - much like Brenda herself - but it was designed to open out into a huge, solar-panelled suntrap.

Harnessing the sun's energy was Brenda Carter's life pursuit, and her doctrine was clearly born out of a personal fondness for sun-worship. Whereas roof-mounted solar panels could be used to supplement - if not replace - conventional household heating systems, the sole purpose of the solar wall was to maximise tanning potential. Demonstrating her prototype in the garden of an impressive rural pile, Brenda briskly opened out the walls of the aluminium-lined sentry box and seated herself in front of it, basking in the watery English sunlight. Curiously, at the time she was wearing thick, navy blue trousers, a long-sleeved shirt, a headscarf and huge dark glasses. Perhaps even then she harboured suspicions that too much undiluted sunlight might have a detrimental effect on her porcelain complexion, leaving her with a face to match her Gucci handbag.

However, the canny aristocrat showed no such compunction in using her own staff as guinea pigs for her innovation. Indeed, she even set up a smaller version of the solar wall where the gardener/ stable-boy/ gravel raker et al could sit and enjoy their afternoon break, little leathery faces beaming gratefully over their mugs of Lipton's tea. How generous of 'er Ladyship to warm up this patch of garden for her 'umble retainers. (I wonder how many of them subsequently developed life-threatening melanomas.)

Tomorrow's World pronounced the portable suntrap as being "very successful". Really? It seems to me that British sunseekers of the late 1970s were more inclined to take cheap package tours to Benidorm.

And please don't ask what happened to the Honourable Brenda who tried to tame the sun, for that, gentle reader, is a cautionary tale. Her house burned down.