Like all good ghost stories, the one set in the gardens of the Petit Trianon has passed down through the generations. I first heard about the two Oxford women who visited Versailles in 1901 and saw the ghost of Marie Antoi­nette from my mother. She in turn had heard it from her mother. Not long ago, I mentioned it to a friend who said she had heard it from her mother. A lot of people vaguely knew the story but no one could remember the details.

Two respectable female academics who got lost in the gardens of the Petit Trianon, encounters with people in powdered wigs, a queen, a caped figure, a "running man", apparently bearing bad news. The story of Charlotte Moberly and Eleanor Jourdain and their claim to have been transported two centuries to the 18th-century French court had a long echo. The two women were products of the mid-19th century in which science and faith collided, often awkwardly, and where old certainties had been unbalanced by specula­tion into the strange and inexplicable. They were born into the time of Robert Browning's "Mr Sludge, 'the Medium'", and died in the era of Aleister Crowley, the occultist. Their account, An Adventure, reflects the intellec­tual preoccupations, hopes, fears, longings and anxieties of its time and beyond.