Just released at SIHH 2015 is the Jaeger-LeCoultre Duomètre Sphérotourbillon Moon. It is an amazing technically advanced feat which changes the way collectors look at the moonphase.
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 us or occasionally upset our plans. This penchant is shared by the additional rotation axis that gives the Sphérotourbillon its true magic.
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!
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 down 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.
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.
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. When it comes to precision, the Duomètre Sphérotourbillon Moon is firmly engaged on all fronts.
TECHNICAL CHARACTERISTICS
Movement
• Mechanical manually-wound movement, Jaeger-LeCoultre Calibre 389,
crafted, assembled and decorated by hand, nickel silver bridges and
mainplate
• 2 barrels
• 45-hour power reserve
• 476 parts
• 56 jewels
• 10.45 mm thick
• 33.70 mm in diameter
Sphérotourbillon
• 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
Functions
• 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
• Sphérotourbillon
Case
• Platinum
• 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
Dial
• Grained, silver-toned
• 4N appliques
Hands
• Hours and minutes: “leaf”-type
• Small seconds : baton-type with pear-shaped counterweight, blued steel
Crowns
• 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 functionStrap
• Hand-sewn alligator leather with platinum High-End pin buckle
Reference
• Q608 65 20, limited series of 75 pieces
