A seance, c 1920.

ENGLAND - JUNE 14: A photograph of a group gathered at a seance, taken by William Hope (1863-1933). The information accompanying the spirit album states that the table is levitating - in reality the image of a ghostly arm has been superimposed over the table-stand through double exposure. Hope's spirit album photographs use multiple exposure techniques to render the appearance of ghostly apparitions. Hope founded the spiritualist society known as the Crewe Circle and his work was popular after World War One when many bereaved people were desperate to find evidence of loved ones living beyond the grave. Although his deception was publicly exposed by a private investigator in 1922, he continued to practice. (Photo by SSPL/Getty Images)