[Houdini makes spirit hands] - Public domain book illustration, Library of Congress

In this sequence of photographs Houdini demonstrated how spirit hands that appeared at seances were made by less ethereal beings. In "A magician among the spirits" Houdini described the mediumistic fraud known as "finger-printing a spirit." A mold of a dead person's hand would be carefully prepared and, during a seance with the believed relatives, fingerprints of the deceased would appear on a lampblacked trumpet. In his book Houdini stated the following: "There are two cases on record where fortunes were at stake because of this sort of fraud. In one case five hundred thousand dollars changed hands upon the recognition of the finger prints of a man who had died two years before."

Harry Houdini was a Hungarian-American magician and escapologist, born in Budapest in 1874. He was one of the most famous and successful magicians of his time, known for his spectacular escape acts and death-defying stunts. Houdini's signature tricks included escaping from handcuffs, straitjackets, and locked boxes, as well as diving into and out of tanks of water while shackled.