Swiss luxury watch manufacture Jaeger-LeCoultre welcomes a new astronomy inspired complication watch to its prestigious Duomètre series of extra ordinary mechanical watches based on the innovative Dual-Wing® Concept.
Unveiled at SIHH 2015 luxury watch exhibition, the Duomètre Sphérotourbillon Moon 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.
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 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.
The Duomètre Sphérotourbillon watch’s 42-millimetre diameter platinum case with its 14.3-millimetre thickness ensures 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.
Each planet in the solar system 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. 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.
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. 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.
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 this particular flyback 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.
Model: Jaeger-LeCoultre Duomètre Sphérotourbillon Moon
Reference: Q608 65 20, limited series of 75 pieces
Mechanical manually-wound movement, Jaeger-LeCoultre Calibre 389, crafted, assembled and decorated by hand, nickel silver bridges and mainplate
45-hour power reserve
10.45 mm thick
33.70 mm in diameter
– 105 parts
– Tourbillon carriage: grade 5 titanium
– Total rotation speed: 30 seconds for a complete turn
– 2 combined movements. Carriage axis rotation speed: 15 seconds for a complete turn. Carriage rotation speed : 30 seconds for a complete turn
– Tilt of the carriage: 20°
– Diameter of the carriage: 11.50 mm
– Weight of the carriage: 0.518 grams
– 14-carat gold balance wheel with 14-carat gold eccentric inertia-blocks, inertia = 12.5 mg.cm2, 21,600 vibrations per hour
– Cylindrical balance-spring
Local hour, minute and small seconds with flyback function
2 Power reserves: one for the regulating organ and one for the functions
Moon-phase indication with one day of deviation every 3,887 years
24-hour reference time zone
Diameter: 42 mm
Thickness: 14.3 mm
Polished and satin-brushed finish
Lateral case opening revealing the Sphérotourbillon and satin-brushed finish
Cambered sapphire crystal
Water-resistance: 3 bar
Hours and minutes: “leaf”-type
Small seconds: baton-type with pear-shaped counterweight, blued steel
One crown to wind the watch, set the time and adjust the moon-phase display
One push-piece at 2 o’clock to activate the small seconds flyback function
Hand-sewn alligator leather with platinum High-End pin buckle