Inside, the story of a British orphan who discovers that he is a wizard with magical powers is identical. Adults can now read about Harry Potter's adventures and nobody need know. Each has an appropriate look , challenging the myth that you can judge a book by its cover.

 

Just a year ago, Rowling was struggling to make ends meet as a single mother in Edinburgh. After graduating from Exeter University, she worked as a teacher but always wanted to write. Nigel Newton, the chief executive of Bloomsbury, described how, when she was short of money, she would go to her local cafe, buy one cup of coffee and stay there all day writing with her baby at her side. she could not afford to photocopy her manuscript and retyped the whole thing to send it to an agent.

 

But yesterday, at the Frankfurt Book Fair, news came through of a Hollywood deal: Warner Brothers had paid "a heavy seven-figure" sum to acquire the two books for at least on major film, describing the stories as " family adventure ... that can be appreciated by all ages."

 

At the fair, where the books are being promoted, Mr Newtonsaid that the story of Potter's adventures had become universal. But, appreciating that reading a children's book in public could distort an adult's image, he pointed out how the alternative cover "looks like a good adult book". The children's jacket has an animated cartoon of the various characters; the adult one is an enigmatic image of a train at a station.

 

The author's agent, Christopher Little, said that several adults had confessed to concealing the books behind thier newspapers on trains. One seven- year- old boy wrote a note to the author, saying: "Mum loved it so much she would not let Dad read any of it to me because she did not want to miss any of it as it was so exciting"

 

The Times Literary Supplement's review said that the Harry Potter stories "Will join the small group of children's books which are read and reread into adulthood."

 

The books, which began with Harry Potter anthe Chamber of Secrets, have  proved an astonishing success . Within thier first month they were outselling all adult hardbacks in Britain, including John Grisham  and Jeffrey Archer. Topping the adults bestsellers has, it is thought , been achieved by only three children's authores: Roald Dahl, J.R.R. Tolkien and C.S Lewis. Rowling has also been showered with children's book prizes.

 

Mr Little said that he did not usually  cover children's books, but he had to make an exception with this one. " I read it and thought, 'Where does the imagination come from?' " Asked whether Rowling's style could be compared to anyone, he added:"If I had to liken her to anyone, it would be Dahl."

 

Andrew Low, Vice-president of Golden Books, one of the world's largest specialist children's publishing houses, whose most successful sales are Disney and Sesame Street characters, was impressed by Bloomsbury's move: " When it comes out, I might buy it. It's an interesting idea," he said.

 

As a Father, he explained, he has thoroughly enjoyed reading children's books: "They have lots of drama and pathos. It doesn't surprise me that adults would enjoy a children's book. It recaptures childhood memories. Children are also very sophisticated these days. They are growing up much quicker."

 

Harry Potter is not the first children's character to be approved by grown-ups: Winnie- the- Pooh. James and his Giant Peach and Alice in Wonderland also achieved a wider audience. On the other hand, these things can work both ways: children have claimed Gulliver's Travels - written by Swift for adults - as one of theirs,