The story of Cartier’s famous “mystery clocks” has been envisioned in a number of limited-edition wristwatches with modern complications.

There’s a certain allure to being enchanted by the same magic trick, over and over again — the whimsical presentation of a man prancing on stage in a dramatic cloak, brandishing swords and waving handkerchiefs only to set them ablaze, and summoning white doves in midair. The illusionist’s job is to enthrall his audience even when performing tricks that we’ve all seen before. We’ve probably noticed the quick flick of his wrists, the secret trapdoor, and other diversions and distractions. Yet we leave with the satisfaction of having enjoyed a good show while feeling comforted in the fact that we’ve had it all figured out all along.

A 13 rue de la Paix window featuring a Chimera mystery Clock in 1927. Cartier Archives © Cartier
A 13 rue de la Paix window featuring a Chimera mystery Clock in 1927. Cartier Archives © Cartier

In fact, Cartier was once on such a stage. But instead of slicing people in half and turning cards into confetti, it displayed a time-mechanic illusion of separating the Sun from the stars. Born from the genius of Louis Cartier and master clockmaker Maurice Coüet, Cartier created exclusive table clocks called “planet” or “comet clocks” with unique day/night indicators. The incorporation of illusion into Coüet’s clocks wasn’t an epiphany pulled from midair. In fact, the watchmaker had decided to “hide” the components of the clocks after being inspired by the works of French illusionist Jean Eugène Robert-Houdin.

Louis Cartier (© Wladimir Rehbinder, Vogue Studio/Collection)
Louis Cartier (© Wladimir Rehbinder, Vogue Studio/Collection)

Maurice Coüet came from a lineage of clockmakers, his grandfather was a regulator for Breguet’s table clocks in the 19th century. The young Coüet trained as an apprentice in his father’s workshop and, thereafter, worked in the workshop of Prèvost, a firm that supplied movements for Cartier. Coüet then set up shop in Paris in 1911 and became Cartier’s exclusive clockmaker. By then, science and mathematics had had a strong influence on the arts, which steered Coüet’s designs to the same tune. Astronomy-inspired designs took over Cartier’s jewellery line and horological division, thus leading to the production of the first day-and-night clock.

The first of these planet clocks were made in 1912, constituting round or angular cases with two superimposed dials. The lower dials would usually be crafted from light or dark blue enamel and constantly rotate to represent a day or night sky. Sometimes, a crescent moon in diamonds served as an indicator to the hours at night. The other model that year featured a central disc with a comet that rotated within the dial, while the minutes were read off a pointer that circled along a concentric ring.

1920 Day and Night Comet Clock made by Coüet (Nils Herrmann, Cartier Collection © Cartier)
1920 Day and Night Comet Clock made by Coüet (Nils Herrmann, Cartier Collection © Cartier)

Although Coüet’s main supply were these table clocks, many of them were either unique pieces or produced in very limited quantities. A 1915 day-and-night comet clock went under the hammer for CHF133,000 during a Christie’s auction in 2008, surpassing its estimate by more than two times. It was powered by an eight-day movement in a round crystal with silver-plated edges surrounding gold-decorated elements on white enamel. A rotating disc with sunburst pattern was set with platinum and diamond Sun and Moon motifs, indicating day or night-time hours along the top half of the circle.

The day-and-night clocks had enigmatic appeal but even more fascinating were the mystery clocks that Cartier created with Coüet. The first and most famous of these clocks was the Model A from 1912. It was a large rock-crystal block with finely machined edges, and a white enamel Roman chapter ring in the centre. Fully adorned with platinum and gold accents, as well as rose-cut diamonds, the base was a slab of white agate which housed the movement. Incorporating the use of transparent crystal discs, the rotating hands were affixed to hidden gears within the gold columns. It was an ingenious interpretation of clockmaking — minimalistic yet strongly Art Deco-esque all at once.

1914 “Model A” Mystery Clock. (Nick Welsh, Collection Cartier © Cartier)
1914 “Model A” Mystery Clock. (Nick Welsh, Collection Cartier © Cartier)

An Open Secret

Unveiled as a prelude to SIHH 2018, the Rotonde de Cartier Mysterious Day & Night wristwatch was the first time Cartier combined the mystery movement and the day/night indication. Bringing attention to the centre, a semi-circular insert contains a rotating crystal disc sandwiching two stylised hour indicators — the Sun motif for day and the Moon motif for night. These point out the hours along the Roman numeral chapter ring overhead, while retrograde minutes fill in the bottom half of the dial. The heart of the dial is where Cartier sets the stage. Each time the blued steel hand travels back to its start position, the motif indicator creeps closer to the opposite edge. When the Sun sets at the six-hour mark, a glimpse of the Moon peers out from the other side, accompanied by its gold stars. The crystal discs rotate in this whimsical manner every 12 hours, popping in and out of the dial’s horizon.

Rotonde de Cartier Mysterious Day & Night in 18k pink gold with moon and sun indicator
Rotonde de Cartier Mysterious Day & Night in 18k pink gold with moon and sun indicator

The preservation of history from the early mystery clocks is evident at a single glance. With elevated details such as a brushed chapter ring, a fluted inner bezel and a sapphire cabochon crown, the Rotonde de Cartier Mysterious Day & Night is undeniably a beautiful timepiece. Two versions are made, in 18K pink or white gold, housing the calibre 9982 MC in a 40mm case.

Rotonde de Cartier Mysterious Day & Night in 18k pink gold with moon and sun indicator (back)
Rotonde de Cartier Mysterious Day & Night in 18k pink gold with moon and sun indicator (back)

The same collection also offered another mysterious movement — this time, a skeletonised double tourbillon. Created in a limited quantity of 30 pieces, the Rotonde de Cartier Skeleton Mysterious Double Tourbillon enthralls with the floating visual of the tourbillon framed by skeletonised bridges, which are also designed to form Roman numerals. It’s been a mere six years since Cartier debuted the mysterious complication in a wristwatch in 2013, but the brand has already gone beyond simple time-telling by developing versions with high complications such as the Rotonde de Cartier Astromystérieux (2016) and Rotonde de Cartier Minute Repeater Mysterious Double Tourbillon (2017). Within the crystal discs, the double tourbillon completes a single 60-second rotation while the cage makes a second revolution every five minutes. Holding up the display within the 45mm case is the manual-winding 9465 MC movement with the provision of a 52-hour power reserve. The blued steel hands create a vivid contrast against the platinum case, with a separate version available in a diamond-encrusted bezel.

Rotonde de Cartier Skeleton Mysterious Double Tourbillon in platinum
Rotonde de Cartier Skeleton Mysterious Double Tourbillon in platinum
Rotonde de Cartier Astromystérieux (2016)
Rotonde de Cartier Astromystérieux (2016)
Rotonde de Cartier Minute Repeater Mysterious Double Tourbillon (2017)
Rotonde de Cartier Minute Repeater Mysterious Double Tourbillon (2017)

During the peak of production of Cartier’s mystery clocks, it was recorded that Louis Cartier wanted the mechanism to remain just as it was named — a mystery. His sales staff had no luck in prying information out from the craftsmen and the plan was to keep the mechanism within a secret to never be revealed. Fortunately or unfortunately, today, we are armed with the knowledge of Cartier’s mysterious inner workings. But that doesn’t stop us from feeling enthralled by the mysterious display, over and over again.