Houdini's Margery sitting

On 23 July 1924, Harry Houdini and a Scientific American party attended a séance with the medium known as Margery at 10 Lime Street, Boston.

On 23 July 1924, in the middle of a Boston heat wave, Harry Houdini went up to the séance room on the fourth floor of 10 Lime Street. Mental Floss reports that he came with Scientific American's editor, O.D. Munn, and a group of scientists, all there to watch the medium Mina Crandon, called "Margery", who was 36 years old. Wikipedia says J. Malcolm Bird, a Scientific American employee outside the prize committee, had told Houdini that Margery might win the magazine's prize.

The New England Historical Society describes the setup: Margery's husband sat on her right, and the sitters at the wooden table joined hands. Houdini said afterwards that Margery had slipped her control and stretched her foot out to ring a bell. He told the committee she was a fraud and showed them how it could be done, according to Wikipedia. Bird then wrote in Scientific American in praise of her abilities, and newspapers backed him. Dr. Crandon, her husband, kept notes on this sitting. A blog on Houdini says this sitting alone took place at the Lime Street house, since the later ones were held at the Charlesgate Hotel, and that it produced the most spirit phenomena.

Wikipedia counts two Boston séances for Houdini and the committee, on 23 and 24 July 1924.