Faiground attractions: 'Professor Vanessa's Wondershow' at the Roundhouse

Vanessa Toulmin grew up on a fairground in Lancashire in the 1970s. 'I saw the very last of the sideshows,' she remembers. 'They were the shows I loved - they're why showpeople are called showpeople.' Even as the form died out, Toulmin's interest grew: she spoke to more than a hundred veteran performers, completed a PhD and became director of the National Fairground Archive at the University of Sheffield. She also runs Blackpool's Showzam festival of circus, magic and variety. You can call her Professor Vanessa.

Sideshows retain their special charm for Toulmin. 'They're illusion shows,' she says. 'Many people think they're freak shows but that's the American tradition - that Coney Island side was never part of the British fairground. It wasn't someone who was deformed or disabled; it was literally a show on the side of the fair, a little playlet of six or eight minutes where you'd get told a story. It was the last of a popular theatrical tradition that went back hundreds of years. They always had sex, horror and comedy but you were never really shocked - it was titillation. There was a lot of irony too. There used to be a show called “The Fall of Greece” which was just a candle…'

For the past decade, Toulmin has been collaborating with John Marshall, a former magician and theatre producer who has restored original sideshows dating from the 1930s and 1950s: the Butterfly Girl; the Headless Lady; Electra, the 27,000 Volt Girl; Cleo, the Girl in the Goldfish Bowl. It's proved expensive and painstaking work, sometimes with little more than a story or booth illustrations to go on.

Now, for the first time, nearly all of this work can be seen in one place, in the form of 'Professor Vanessa's Wondershow', part of CircusFest at the Roundhouse. 'It's given us a chance to bring the elements together in a two-hour theatrical experience,' Toulmin explains. 'The Roundhouse's main space is transformed into a 1950s village green with the sideshows facing in like a wagon train. As the audience walks in, the sideshows are getting ready to open, barkers are wandering around. Miss Behave comes out as a show-woman and tells the story of how the Wondershow came to be, and how she won it in a card game.'

Then audience members will be taken in groups to see the sideshows while aerial work and parades by the delightfully creepy Insect Circus fill the main space. There will be six restored attractions plus two created for the show, including one turning the tables on the misogynistic slant of some traditional set-ups and another drawing on early cinema.

'The “Wondershow” is almost like the perfect scenario,' Toulmin says, offering 'what I'm just too young to have seen and is now mostly forgotten. The fairground we're presenting is no longer there but it's part of our history.' Audiences declined in the decades after the war and sideshows struggled to remain viable. 'They're too expensive,' Toulmin says. 'You need three people - the presenter, the performer and the technician - and on a modern fair you can have two people operating a ride for many more customers.'

But their appeal isn't entirely lost. Marisa Carnesky is perhaps the most prominent contemporary performer to work with fairground and sideshow elements and Marawa the Amazing performs in the 'Wondershow'. Once a training ground, the sideshow model still offers a visceral challenge to artists. 'The fairground was the place people never spoke about where they started their career,' Toulmin notes. 'It was called “illegitimate entertainment”. But when it's not legitimate, it's not institutionalised. All you have to do is appeal to the public.'

Today's audiences respond too. 'In this day of computer-generated imagery, to stand in a small, intimate space, see a trick in front of your eyes and not know how it's done… In Blackpool, children come back year after year and ask if the characters are coming back. A whole new generation has started believing.'