The front dial of the Nonantième exudes refinement and elegance. The pink gold case with its signature gadroons frames a silvered, sunray-brushed dial with applied golden indexes and Dauphine hands. In the lower half of the dial, a moonphase display is set within the circle formed by the small seconds counter. Beneath 12 o’clock is a large date display, framed by an applied filet of pink gold that echoes the rectangular shape of the dial and case. The classically elegant aesthetic of the front dial gives no hint of the surprise concealed on the reverse side of the watch. Flipping the case over reveals an entirely new visual expression of some of watchmaking’s most familiar complications. Dramatic and captivating, it is unlike anything seen on a Reverso before.
The solid pink-gold caseback is dominated by two round apertures of different sizes, arranged like a figure-eight and encircled by gadroons that echo the rectilinear gadroons on the upper and lower edges of the case. The small upper aperture displays a semi-jumping digital hour indication. Seen for the first time in a Reverso, this complication recalls digital displays developed by the Manufacture for wristwatches in the 1930s. In the large aperture below the hour, minutes are displayed on a rotating disc that is partially concealed by a three-quarter plate lacquered in vivid blue – in the Atelier des Métiers Rares® – and sprinkled with tiny golden stars to depict the night sky. Within a small circle at the centre, an applied golden sun and moon, pass above a horizon, to indicate night and day. In the semi-circle below the horizon, a JL logo is set on a sunray-pattern background.
As is the case for all complicated Reverso models, Jaeger-LeCoultre’s engineers developed an entirely new, manually wound movement for the Nonantième, Calibre 826. Comprising 230 components and showing the same time on both faces of the watch, it offers a power reserve of 42 hours.