In 2012, the Grande Maison in the Vallée de Joux propelled watchmaking firmly into the third millennium. The Duomètre Sphérotourbillon, a truly original model uniting peerless technical performance, elegance and a spectacular complication, thereby met the expectations of the most demanding connoisseurs and collectors.
Whether it comes to the effects of gravity on the earth, the discrepancy that creeps into the moon-phase indication, or the impact on a watch’s precision when a complication is activated, the new Duomètre Sphérotourbillon Moon of Jaeger-LeCoultre invented its own solutions.
The Duomètre Sphérotourbillon Moon, revealed at this year’s SIHH, expresses its strength of character through the realm of calendar-type horological complications. Equipped with a moon-phase display endowed with a reliability stemming from lengthy research, it embodies the age-old wisdom of traditional astronomy as well as the inventive power of Jaeger-LeCoultre.
An awe-inspiring moon phase
A classic moon phase shows a one-day discrepancy every two and a half years. For a Jaeger-LeCoultre Perpetual Calendar, that difference amounts to just one day every 122 years. The new Duomètre Sphérotourbillon Moon is from a whole different galaxy, since when its moon phase is properly adjusted, it is designed to remain accurate for a full 3,887 years! From this sense of verging on eternity stems the depth and beauty of Fine Watchmaking.
For the Grande Maison, pushing boundaries and daring to dream bigger is backed by the conviction that the fundamental nature of a watch should not be impaired by horological culture nor by technical feats. The Duomètre Sphérotourbillon Moon is thus intended to be worn with pleasure. Its 42-millimetre diameter and its 14.3-millimetre thickness ensure a definite sense of comfort, while hinting at the wealth of talent lavished on accommodating such a masterfully accurate mechanism within such a modest space.
Analogous axes: an invitation to share a passion for astronomy
Astronomy lovers are passionate about the earth’s axis. Each planet spins around an axis that is never perpendicular to the orbital plane. The angle formed by the earth’s axis is around 23°. This natural tilt explains the successive seasons and it is to this posture that we owe the alternating weather patterns that delight or occasionally upset our plans.
This penchant is shared by the additional rotation axis that gives the Sphérotourbillon its true magic. As well as performing a full turn around the axis of its titanium carriage, the Sphérotourbillon also spins around a second axis inclined at a 20° angle – a nod to the inclination of the earth that follows an imaginary line stretching to Ursae Minoris, the polestar.
Powerful aesthetic codes… and exceptions to the rule
One of the Duomètre collection’s most captivating aspects lies in the fact that technical performance does not override aesthetic appeal. While undeniably eloquent in horological terms, it is endowed with an elegance revealing considerable creative force.
Part of the strength of the design characterising the Duomètre Sphérotourbillon Moon, reworked to ensure even greater readability, lies in the symmetrically choreographed dance of the functions displayed on the finely grained dial. A shrewd observer will doubtless note that the moon phase appears at 3 o’clock, whereas Jaeger-LeCoultre generally places it at 6 o’clock.
A tribute to astronomy, this disc is made of lapis lazuli, a rock that looks as if it has landed there from the sky chart. It features a dusting of stars echoing the moon, hands and hour markers, creating a two-tone ambiance also differing from the traditional identity codes of the Grande Maison.
A theatrical stairway, in non-treated nickel silver with a satin finish, forms an ideal stage for the rotating movements of the Sphérotourbillon while an opening in the side of the case offers another more intimate vision. Like a spectator with a ringside seat for this mechanical show, the wearer of the watch thus establishes a special relationship with its very own Duomètre Sphérotourbillon Moon.
A precisely adjustable tourbillon
Through the use of the Dual-Wing® concept, the 2 o’clock push-piece serves to reset the small seconds at 6 o’clock to zero, based on the Flyback principle. The distinctive feature of the dualwing function is that it does not halt the operation of the regulating organ. In a classic configuration, pulling out the crown freezes the small seconds hand and the balance-spring, whereas the Duomètre Sphérotourbillon mechanism allows the small seconds hand to return to zero and restart instantly, without the balance wheel missing a beat.
No time is wasted between the stopping operation and the resumption of the regulation organ’s steady to-and-fro motion. The watch thus remains accurate even when adjusting the time to the nearest second. When it comes to precision, the Duomètre Sphérotourbillon Moon is firmly engaged on all fronts.