Cartier Tank Americaine Silver Dial Ladies Watch W2620031

Cartier presents two new watchmaking complications that push the frontiers of the mysterious yet further, continuing the founding tradition of the Maison. Inspired by the concept of transparency and hidden complexity, the watchmakers of the manufacture confronted the challenge of bringing enthusiasts two new creations with clean lines that seem to glorify time with incredible lightness. The first mysteriously displays the hour and minutes with two hands that seem to float magically in space. The second focuses the attention on a mysterious double tourbillon whose floating cage performs a delicate and spellbinding dance.

Breathtaking and ethereal, the Rotonde de Cartier Mystery watch hypnotises those who gaze on it with its hands that float in space. To bring a mystery wristwatch into being, the watchmakers of the Cartier Manufacture had to overcome all the constraints inherent in perfecting a display by hands whose connection to the movement is completely invisible. Thus, in order to limit friction between the sapphire crystal discs, it was decided that they should turn on fine pivots, like a wheel in a gear train, rather than in guide grooves, the traditional technique adopted for mysterious clocks.
This new concept, which is combined with the wheel of the hour hand, avoids friction and limits the power consumption of the movement. With friction reduced to a minimum, the next task was to reduce the inertia of these large discs of sapphire crystal, weighing just 0.56 g and fashioned using DRIE technology (Deep Reactive Ion Etching). Thanks to this cutting-edge method, the metal parts can be made by three-dimensionally building up material, thus obtaining a gear wheel of extremely high concentric precision in one piece with the sapphire crystal disc. The geometry of the assembly is exact to the nearest micron.
To facilitate the final assembly of the different components under optimum conditions, Cartier opted for a modular structure. Thus the movement is made up of two separate elements: the movement proper, which occupies a crescentshaped zone on the baseplate, and an independent display module occupying the circular space left vacant for the purpose. This sub-assembly, comprising four anti-reflective sapphire crystal discs with an antireflective finish, is assembled separately in a laminar-flow hood to prevent all possible presence of dust. When the timepiece is finally assembled, the hands begin to revolve in the void, as if by magic. By allocating 58% of the diameter of the movement to the sapphire crystal discs, Cartier has pushed back the limits of the mystery display and achieved record legibility.
 

Timepieces with a mystery display have always been considered more fragile than other traditional complications, due to the presence of the sapphire crystal discs. The innovative design of the calibre 9981 MC enabled it to pass all the certification tests, including the requirement that it should resist over 500 consecutive impacts, as well as being dropped on to a hard floor from a height of one metre. This movement with its spellbinding transparency, slimness and accuracy, with a balance oscillating at 4 Hz (28,000 beats per hour), has a power reserve of 48 hours.
Imagine a watch equipped with a tourbillon that seems to be suspended in space. That was the challenge taken up by Cartier with its new movement, the 9454 MC Double Mystery Tourbillon certified by the Geneva Seal. Slightly closer inspection will reveal the magic concealed in the mechanism. Indeed the flying tourbillon, which turns once on its own axis every 60 seconds, appears to be floating completely free in space, with no visible connection to any gear train. The illusion is complete when the same tourbillon cage starts to perform a second rotation at a rate of one turn every five minutes.
 

In its simple elegance, which masks unbelievable complexity, the Rotonde de Cartier watch highlights a totally original mechanical construction named «Double Mystery». The watchmakers of the manufacture have employed a disc of sapphire crystal with an anti-reflective finish containing an aperture the size of the tourbillon to give the best possible illusion of a cage in a state of levitation. To do this, they set the disc to support the cage in rotation. By doing this and positioning the minute wheel, which propels the oscillator, on the axis designed to limit the «resistance torque» inherent in the mechanism supporting the tourbillon, they succeeded in transmitting its force to the tourbillon, and thus causing the entire device to revolve in space once every 5 minutes. This results in the tourbillon making one full turn of the open, transparent space in 5 minutes, while the cage performs five complete revolutions in the same time... The ingenious way of achieving such a result is to place a rack around the edge of this sapphire crystal disc, transforming it into a large gear wheel that performs one revolution every five minutes.
Mystery clocks have their own special chapter in Cartier's history. «Mystery» because their diamond-and-platinum hands seem to float in the clock's transparent body, detached from its movement. These «clockmaking miracles», as La Gazette du Bon Ton called them in 1925, were born from Louis Cartier's collaboration with an exceptional clockmaker, Maurice Couet (1885- 1963). He was only 25, but already highly experienced when Cartier noticed his talent.
 

From 1911, he became Cartier's exclusive supplier. The first mystery clock, known as Model A, left the workshop in 1912. Maurice Couet took his inspiration from the clocks of the French illusionist and inventor of modern magic, Jean-Eugene Robert- Houdin (1805-1871). The principle that he borrowed and developed was based on a brilliant idea: the hands were not directly linked to the movement but were attached to two glass discs, each fitted into a metal border edged with gear teeth. The movement, which was generally housed in the clock base, turned the two discs - one at the speed of the minute hand and the other at the speed of the hour hand. To complete the illusion, the metal borders of the discs were hidden in the hour circle. In the past, Louis Cartier refused to give any explanation of how his mysterious clocks worked to those who sold them, so as not to divulge the secret.
These were extremely rare objects, some involving over a year of work and several ateliers. They appealed to many prestigious figures such as John Pierpont Morgan Jr., the Queen of Spain, Queen Mary, the wife of King George V, and the Maharaja of Patiala, some of whom owned more than one of these precious clocks. The production of these mystery clocks has never stopped and new models are developed on the principal themes that inspire the company today. For more than a century, Cartier has been mastering mystery.