WATCH REVIEW Jaeger-LeCoultre Duomètre à Quantième Lunaire

About the Jaeger-LeCoultre Duomètre

“La Grande Maison” continues to expand its Duomètre family which is in the process of becoming its own product line in the Jaeger-LeCoultre manufacture catalogue.

Thus, after the Duomètre à Chronographe and the Hybris Mechanica à Grande Sonnerie – with a movement made up of 27 complications and with a total of 1,300 components, the brand has unveiled the Duomètre à Quantième Lunaire to the public during the 2012 Salon International de la Haute Horlogerie (SIHH).

A name that is both mysterious and poetic to say the least!
The term quantième lunaire is the easiest of the two to grasp since this terminology in the watchmaking world refers to a watch that displays both the date – quantième – as well as the moon phases – lunaire.

As for the Duomètre designation, invented by Jaeger-LeCoultre, it refers to a movement made of two barrels and gear trains that are independent of each other, but regulated by the same balance.
To put it another way, this watch possesses two hearts, but only one brain.

The goal is to optimize accuracy by delinking the measurement of time from its display. This principle, at the root of the Dual Wing concept unique to the Duomètre, uses a first gear train solely dedicated to the accuracy of the watch, and a second one dedicated to the hours, minutes, seconds, the calendar, and the display of the moon phases.

A Jumping Seconds hand that measures 1/6^th of a second

The Duomètre collection truly emphacizes the search for accuracy, with one of its distinctive characteristics being the presence of a jumping seconds hand situated at 6 o’clock.
The jumping seconds hand measures 1/6^th of a second and thus travels an entire revolution every second. It actually goes around so fast that it’s barely visible – thus its name.

But since having an accurate watch is useless without the ability to synchronize it to a temporal point of reference, the 381 Caliber that drives this Jaeger-LeCoultre is also equipped with a device called stop seconde sautant: each of the two seconds hands – jumping and main one – is no only stopped but also reset to zero when the crown is pulled.
Very useful for a perfect synchronization when setting the time!

The Jaeger-LeCoultre 381 factory caliber, 7.25mm thick with 40 jewels, beats at the rate of 21,600 vibrations per hour and offers a 50-hour power reserve for each of its two barrels.

Even though the two barrels are independent of each other, they both have to be wound up in order for the watch to work.

The Côtes de Genève sunray finish typical for Jaeger-LeCoultre is very pleasant to the eyes. Furthermore, the movement’s visible depth and complexity gives us the ability to spend hours admiring all of its nooks and crannies.
The purists might however be disappointed that the bevelling is not more elaborate…

A dial with a magnificent texture

On the heads side, Jaeger-LeCoultre gives its Duomètre à Quantième Lunaire a design worthy of its mechanical prowess.

The version tested today is the model that was unveiled during the 2012 SIHH, one without the opening in the dial where the power reserves are.
This version of the watch is thus a little more sober, but it also gains in elegance and readability.

The silver dial gives a visual richness that will delight the enthusiasts of that style, thanks in part to the multiple levels on which the indicators are divided, but also thanks to its very unusual and beautiful parchment texture.

Indeed, contrary to what we are accustomed to see, the dial is neither smooth nor engine-turned.
It has a very granular texture similar to that of paper which allows for some lighting effects and gives it a nice depth.
The quality of the finish is abolutely impeccable.

The pink gold case is also perfectly finished, even if it remains very classic in its concept.

The Duomètre à Quantième Lunaire in daily life

It’s with its settings that this Jaeger-LeCoultre is clearly aimed at the fanatics.
It requires a very careful reading of its instruction manual in order to get set-up!

You start by winding up both barrels, which is done by turning the crown in one direction to wind up the first barrel, then in the other direction to wind up the second one…rather surprising!

The time setting is done in the classical manner by pulling on the crown.
You’ll then have to set up the moon phases using a corrector located between the lugs at 12 o’clock – the watch comes with the required tool to do this – and then set the date using the push button situated at 10 o’clock.

The main ergonomic criticism that can be raised with this piece which is otherwise impressive is the very fact that you have to use a push button to set the date. Indeed it is easy to accidentally press this button and thus change the date…
A corrector system identical to the one provided for the setting of the moon phases would have been more reassuring and would have allowed for the elimination of this button on the side of the case.

The time readability is good. On the other hand you’ll need relatively good eyes to read the date and the moon phase.

Conceptually-speaking, there exists a certain contradiction between the display of lunar phases, poetic and slow in nature, and the presence of a jumping seconds hand with a tendency to catch one’s eye with its frenetic pulsations.
This point might seduce some and turn off others. Each will have to form his own opinion!

Finally, the comfort of this Duomètre à Quantième Lunaire is excellent despite the watch’s rather generous size.

Jaeger-LeCoultre Duomètre à Quantième Lunaire
What to remember

The Duomètre à Quantième Lunaire is truly a piece dedicated to the enthusiasts of beautiful mechanical watches. While it’s totally possible to get perfect accuracy without decoupling the measuse of time from its display, this system offers a novel and rather attractive solution.

This Jaeger-LeCoultre watch is full of poetry, which is not that common when it comes to watches.

It therefore takes a rightful place in the landscape of contemporary watchmaking for a price that is ultimately reasonable given its benefits.