Mystery Clocks

You might think that the clock labelled « a » doesn’t have a mechanism. You can see it has a base, and a transparent decorative column, but it seems impossible that it could work. And yet it tells the time as well as any other clock.

Puzzling clocks like this one are called “mystery clocks”. Jean-Eugène Robert-Houdin specialised in making them, and not surprising : this clockmaker was also the most famous French magician of the 19th century. He had studied clockmaking, electricity and the construction of automata before he made his fortune with an illusionist theatre in Paris.

Now this “mystery clock” is Robert-Houdin’s challenge to your intelligence. What is the trick?

Here’s the answer in four steps :

One, there is a clock movement in the base

Two, the column between the base and the dial does not move, but it contains a second column which revolves on its own axis.

Three, don’t be fooled by the griffin ornaments: they are used to transmit the energy from the internal column to a toothed wheel.

Four, the toothed wheel turns a glass disc which covers the whole of the back of the dial. The hand is on this disc, and it is the disc which turns, creating the impression that only the hand is moving.

Next to Robert-Houdin’s clock is another « mystery clock » on a square black base. You have a statue holding a pendulum, and the difficulty is to guess how this pendulum can be moving, since there doesn’t appear to be anything to set it in motion.

The answer is simple: it’s the whole statue which moves. It turns imperceptibly, by one or two tenths of a millimetre, on its base. And obviously the clock has to follow its movement.