In the summer of 1853, with table-turning the rage of London, Michael Faraday sat with table-turners he trusted and gave them a table with a secret. Under their hands lay four or five sheets of smooth card, held one on another by little pellets of soft cement — wax and turpentine — that kept them in place but let them creep under a steady push. The lowest was fixed to sandpaper on the table, the top one was larger to hide the rest, and a pencil line was drawn across their edges. When the table had turned, the line told which had moved first: the top card had gone furthest, the ones below less, the table least. The hands had led, and the table had been dragged after them.
Then he made the push visible: a lever of foolscap paper on an upright pin, its short arm, a quarter of an inch, fixed to a slipping card under the hands, and its long arm, eleven and a half inches, a pointer — so that a push showed forty-six times larger — with a coin to mark where it should rest. Hidden from the sitters, it moved before the table did. In their sight, the push stopped, and so did the table.
The top card 0.0 mm off the table’s mark · the table 0.0 cm from where it stood. Faraday wrote it up for The Times (printed on 30 June 1853) and the Athenaeum (2 July), and put the movement down to “a quasi involuntary muscular action”.