The Parisian House is causing a sensation this season with its Rotonde de Cartier Astrorégulateur watch which defies the laws of gravity while dispensing with the traditional tourbillon. Its original movement, Calibre 9800 MC for which four patents have been filed, offers an alternative solution to the tourbillon in compensating for watches’ rating errors in vertical positions. After five years of development, the master-watchmakers at Cartier had the clever idea of fixing the entire escapement, the oscillator and the pendular seconds onto the rotor, thereby stabilising the effects of gravity in a single position. Since the rotor can support five times more parts than a traditional tourbillon carriage, a platinum inertia block has been integrated into the microrotor to add weight so as to ensure it inevitably returns to the same position and thereby guarantees automatic winding . In keeping with the Cartier aesthetic, this horological feat is housed within a generously sized 50 mm case in a niobium and titanium alloy, and issued in a 50-piece limited edition.