A scientific manuscript, which had been lying in a drawer for more than 20 years, is expected to raise up to £5,000 for a village school.

The document contains the blueprint for a revolutionary form of motor which could hold the key to future space travel.

It was donated to Lewknor Primary School in 1979 by scientist Prof Eric Laithwaite, and is now being auctioned off to raise cash for the school.

The manuscript contains hundreds of closely written pages, and charts the development of Prof Laithwaite's linear motor -- a concept that could allow trains to travel as fast as aeroplanes, and propel space craft into orbit.

The 1979 appeal brought in Russ Conway's alarm clock, a tie donated by Douglas Bader and a list of autographs -- as well as prompting a phone call from Prof Laithwaite's secretary. She said the professor had little of value to send, but offered the original manuscript of his invention.

Instead of being sold, the document was stored at the home of a former headteacher, until being returned to the school six months ago.

The manuscript will go under the hammer at Swindon's Dominic Winter Book Auctions on November 6.

School governor Shirley Moore said: "It is amazing. Prof Laithwaite didn't think it was worth much and no-one had bothered to do anything with it for years.

"Maybe it's worthwhile we left it so long, as he is now recognised as a brilliant scientist. It's just a shame he isn't still alive."

Richard Westwood-Brookes, a valuer for the auctioneers, said: "This is one of the most important manuscripts of the latter half of the 20th century.

"It never ceases to amaze me how great men continued to think their manuscripts and works are of no value.

"It is akin to receiving a letter from Leonardo da Vinci saying, 'I would love to support your charity, I have nothing of any value, but would you like this painting of the Mona Lisa!'"

Prof Laithwaite, who died in 1997, was one of the best-known British scientists of his generation. He was a close friend of Prince Charles and frequently appeared on television, including The Great Egg Race.

Before his death he was working on a project with the US space agency Nasa, which wanted him to develop his linear motor into a device to power space craft.