From Cartier comes the Rotonde de Cartier Astromystérieux. Incorporating the astonishing movement, Calibre 9462 MC, it utilises a completely novel concept where the escapement, balance wheel, gear train, and barrel are all held together by a set of plates and bridges. This collective unit effectively functions as the minute indicator because it completes one full turn every hour; the minutes hand is affixed to the movement thusly. Because of this rotation about a central axis, the entire construct is practically a flying tourbillon, although not in the most conventional sense.
A system of four sapphire discs holds the secret to the Astromystérieux. In lieu of a traditional carriage, the entire movement revolves, not just the balance and escapement, as its lower bridge is one of the four sapphire discs. Two upper bridges (one for the balance wheel and another for the escapement, gear train, and barrel) complete the construct that forms the tourbillon carriage. The hours are indicated by way of a second sapphire disc, which is linked to the tourbillon lower disc.
Solving the mystery of how the Astromystérieux gets its power is a disc-based winding system that brings the third sapphire disc into play. This patented system connects the barrel with the crown using a floating pinion between the winding shaft and winding disc, allowing the movement to be wound only when the crown is in the correct position. A disconnectable system has also been developed so that the crown’s winding shaft and the barrel cannot be broken in the event of excessive winding.
Finally, the fourth sapphire disc is used to set the time. Situated at the base of the movement, it provides the motion required to turn the tourbillon carriage, but when the crown is pulled, it engages the time-setting system. All this is made possible because of a revolutionary lever that blocks the sapphire disc during the normal running of the watch. When the crown is pulled, it frees the lower sapphire disc, thus also freeing the tourbillon carriage (linked to the minutes wheel) and allowing time to be adjusted.
Although the negative space around the movement communicates a feeling of simplicity and emptiness, the Astromystérieux is anything but. This juxtaposition between the complex and the pure is perhaps the single most alluring thing about this awe-inspiring watch.
Available to order each edition will cost £160,000.