Also known as typtology, table tilting is the phenomenon that occurs when a spirit moves, shakes, or rattles a table as a sign of its presence. Also an early form of spirit communication, its first description is handed down to us by Ammianus Marcellinus in fourth-century Rome. Marcellinus describes a table cut from a large slab of stone, upon which were engraved the letters of the alphabet. Above the table, a cord was suspended, at the end of which hung a metal ring. Questions were posed to the spirits and the answer would be spelled out as the ring swung to the letters on the table.
Table tilting in its modern form sprang into use after the “Rochester knockings,” much the same as spirit rapping did. Part of its popularity rested on the fact that anyone with a table could do it without the need for a professional and sometimes expensive medium. People would gather in the parlor and seat themselves around a small table. After the lights had been dimmed to make the room more inviting for spirits, the sitters would place the palms of their hands lightly on the table’s surface. A question would be asked of the spirits, who would rattle the table in response. Sometimes the answers would come as mere tremors in the table, while at other times it would bang about violently or even levitate off the floor.
Table tilting became so popular in its heyday that doctors and scientists thought the craze dangerous to the public's mental health. In reaction, a committee was formed to study the fad, which it reported on in the Medical Times and Gazette on June 11, 1853. After heated debate, the committee's findings concluded that table tilting was due to the unconscious muscular activity of the sitters and not to any real spiritual presence. Scientist Michael Faraday tested sitters by placing their hands atop a flat surface, which rested on metal rollers. Any unconscious movements by the muscles in the palms of the hands could then be detected by the table’s movement and measured. Not to be outdone by the scientific community, the church also rallied against table tilting, claiming it to be the work of Satan.
From Ghosts, Apparitions and Poltergeists, by Brian Righi