Precision is paramount and even more so when combining complications with timekeeping. Jaeger-LeCoultre optimises the marriage via its patented Duometre, which gave rise to a collection of sophisticated models in 2007.
A new generation of watches starring the Duometre Heliotourbillon Perpetual, along with a campaign, reinforce the maison's standing as "The Precision Pioneer".
Achieving accuracy fundamentally requires a smooth power supply from the movement's barrel to the escapement. Incorporating a complication becomes a problem as its power consumption interrupts the steady flow and jeopardises the precision.
Jaeger-LeCoultre tackled the conundrum by separating the power supply via two streams -- one barrel and gear train for timekeeping and another pair of them to drive the complications. Both are linked to a single escapement in the calibre.
The resulting Duometre mechanism ingeniously enables adding complications without compromising the "heartbeat" for accurate timekeeping.
A view of the innovative tourbillon from the side of the case.
Its development was inspired by a two-barrel movement of a pocket watch that dates back to 1881. In that year, Antoine LeCoultre passed away, leaving his legacy as a precision pioneer.
He established his atelier in 1833 in the village of Le Sentier, located in Switzerland's Vallée de Joux. In 1903, third-generation Jacques-David LeCoultre partnered with Parisian watchmaker Edmond Jaeger for a new era of the company's haute horlogerie.
Over the years, Jaeger-LeCoultre has taken on various titles such as La Grande Maison and The Watchmaker of Watchmakers.
Its expertise in complications includes the tourbillon, which neutralises effects of gravity for the precision of mechanical timepieces.
Patented by Abraham-Louis Breguet in 1801, the tourbillon with a single axis was originally devised for pocket watches. This invention, however, did not compensate for the effects of gravity in all positions, and an additional axis of rotation would enhance the accuracy of wristwatches.
Jaeger-LeCoultre's engineers developed the dual-axis Gyrotourbillon and worked on various configurations, each fitted with differently-shaped hairsprings.
They took this to the next level by employing a cylindrical hairspring and constructing the Heliotourbillon with a trio of titanium cages rotating on three axes and at different speeds, resulting in a playful kinematic effect.
The Heliotourbillon is a new spin on multiple axes.
Resembling a spinning top, this captivating performance debuts in the Duometre Heliotourbillon Perpetual equipped with the manually-wound Calibre 388.
The innovative tourbillon with 163 components is set above a background of lacquer in deep blue. As it spins, red triangles on the third cage indicate 20-second intervals marked on a sapphire crystal arc that floats above the starry blue scene.
A sapphire crystal window in the side of the case and the open-worked left side of the dial flaunt the Heliotourbillon in action.
On the right, an opaline silver dial features a time display, flanked by two power reserves, 46 hours for each barrel. Thanks to the Duometre, the power supply also fuels the perpetual calendar.
Jaeger-LeCoultre has also mastered this challenging complication, comparable to a miniature computer that automatically adjusts for months of different lengths and for leap years.
A Grande Date is positioned at 3 o'clock on the time display while the moon phase-days and months-years indicators oppose each other on the refined dial with a gold bridge separating it from the open-worked side.
The moon-phase indication is accurate to 122 years, and the perpetual calendar requires manual correction of the day and date indications only in 2100 and in subsequent centenary years that are not leap years. The year indication shows the last digit of a leap year in red -- a Jaeger-LeCoultre patent.
Calibre 388 with the Duometre mechanism featuring two barrels and two gear trains.
Backwards setting of the hours and minutes can normally damage the calendar mechanism, but the newly-developed Calibre 388 safely allows backwards or forwards time setting.
Moreover, the Duometre collection has been updated with an entirely new case, which is a contemporary interpretation of those housing savonette pocket watches produced by the Swiss brand in the 19th century.
The French word savonette refers to a small disc of soap with rounded contours that can be cradled in the palm of a hand. With its convex crystal and gracefully rounded bezel, the new Duometre case expresses this literal definition.
Limited to 20 pieces, the Duometre Heliotourbillon Perpetual shines in a 44mm pink gold case. Slightly smaller cases house the new Duometre Chronograph Moon in platinum or pink gold and the steel version of the Duometre Quantieme Lunaire that further illustrate the maison's relentless pursuit of precision.
