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Devoted to Fine Watches


In recent Issues, QP has devoted plenty of space to the resurgence of ambition on British watchmaking and QP58 is no exception as we recount the debut of M [...]


QP Magazine Current Issue #58
Double-Time: Jaeger-LeCoultre

Double-Time: Jaeger-LeCoultre

By James Gurney

Tourbillons are routinely referred to as the pinnacle of watchmaking and they certainly add a cachet to any catalogue, but with the latest watch in the Duomètre line, Jaeger-LeCoultre has put the emphasis on timekeeping back to the fore. QP is arrested by the striking design of the Sphérotourbillon.


Watchmaking in its more extreme forms can veer, all too easily, into the esoteric; a watch is presented that answers questions of horology so abstruse as to make it all but impossible to know whether the watch presented is a fair answer to a fair question. Add to this the sure and certain knowledge that everything you thought you knew about a particular watch or complication is almost entirely wrong, as any helpful watchmaker will be only too happy to demonstrate at the first opportunity. All this makes the task of reviewing, even merely describing, a watch as purely haute horlogerie as Jaeger- LeCoultre's Duomètre Sphérotourbillon both daunting and somewhat thankless. It's notable that very little written about the watch makes much of an attempt at describing it, let alone attempting to say whether it has value beyond its obviously high standard of finish and complication.

 closeupThe platinum version of the Duometre à Spherotourbillon will be available in a limited edition of 75. 


Confessions of stage-fright aside, there is much to be said on value of the Sphérotourbillon, particularly as it is part of a process as much as a single discrete piece of horology. Jaeger-LeCoultre's history of high complication wristwatches may not have the depth of some of the other Grandes Maisons, but what it lacks in numbers it certainly makes up in impact, as the roll-call of recent watches makes clear. From the Reverso Triptyque and the Extreme Lab to the unfortunately named Hybris Mechanica (luckily the gods seem to have been in a forgiving mood), Jaeger-LeCoultre's high-complication watches embody some seriously creative and, if it does not stretch the definition too far, useful thinking. There's a better sounding gong and an easier to regulate striking mechanism for the Sonnerie watches; more durable, lightweight and robust materials for the escapement and, of course, the dual-train architecture that allows chronographs or calendar functions to run without affecting the precise running of the watch's timekeeping.



The unifying strand in Jaeger's high-end watchmaking is a utilitarian ethic that gives their watches a notably separate character from the watches made by their neighbours in La Vallée de Joux and their competitors beyond. There's always a point to Jaeger-LeCoultre's watchmaking that can be understood of itself and without recourse to the rhetoric of some haute horlogerie, there is never a solution that doesn't come across as having a purpose and a discernible logic. Where most companies are content to assert that this idea or that is the best possible and the highest expression of the watchmaker's art, Jaeger-LeCoultre makes decent attempts at explaining what it is trying to do. Don't worry though, there's still a legion of watchmakers ready and willing to explain just how you've misunderstood and how it will never work.


jamesjlcAn atelier of watchmaker's assembling the Sphérotourbillon at the Le Sentier manufacture.


However, Jaeger-LeCoultre has independent evidence that its approach actually works. After chronometer competitions were abandoned in the early 1970s as both quartz and the Japanese threatened Swiss ascendancy, the Musée d'Horlogerie in Le Locle initiated a revival of the competitions a couple of years ago and in tests conducted by a clutch of prestigious Swiss institutions, Jaeger- LeCoultre took the two first places with the Master Tourbillon and the Reverso Gyrotourbillon 2. These tests naturally have flaws in the process and should be taken with a small pinch of salt, but taking the first two places is all that can be asked of a company, and if nothing else demonstrates Jaeger-LeCoultre's intentions.


High power

While the high-complication watches should be viewed with appropriate awe, the most attractive watches from Le Sentier have undoubtedly been the Duomètre watches. The thinking behind the line is two-fold: firstly, having separate power trains for the timekeeping and the display functions (which have included a beautiful foudroyante chronograph and a moonphase calendar) protects the timekeeping from the variable power demands of other functions - the effect of chronograph modules on the precision of a watch in particular is much debated. Whether the problem is as serious as to need such a radical approach is hard to say, but the dual-train architecture has history at Jaeger-LeCoultre and an undoubted elegance in execution. The second inspiration behind the Duomètre is to recall, or rather re-imagine, the style and refinement of the large format pocket watches of the early-20th century, an ambition that is possible now given the acceptance of much larger wristwatch sizes than was the case even 15 years ago - the Duomètre actually comes in at a relatively modest 42mm.


double]The Duometre à Spherotourbillon in rose gold. 


The Sphérotourbillon takes the Duomètre principle to its logical conclusion, marrying the idea of separated power sources and a tourbillon escapement. As the chronometry competition showed, tourbillons are not necessarily complicated ornaments, they really can live up to theory (though you might question the return for such formidable investment of time and effort). And what works in one axis, works better in two. The Sphérotourbillon having a dual-axis, dual-cage tourbillon, set on a 20° incline.


The Sphérotourbillon rotates on twin axes, thereby counteracting error in any three-dimensional position, at 30 and 15 second periods, providing the, arguably, primary function of compelling viewing - the massive cylindrical spring at the heart of the escapement is quite a sight, as is the outer cage's passage around its base - and stability of rate in almost any position or state. Doubtless it will be a contender for the next set of competitions. The technical details of the tourbillon are impressive - the carriage, which is machined from titanium, weighs a mere 0.518g, meaning more energy is available to drive the 14ct. gold balance wheel. However, in visual terms, it is the balance spring that completely dominates as it rotates around its inclined plane, its expansion and contraction far more vivid in effect than any flat balance.


The test of time

For obvious reasons, helical springs are very rare in wristwatches and are only practical in a watch that already has a certain depth (the Calibre 382 is 10.45mm deep, more than substantial in horological terms). They do, however, confer some very desirable advantages in terms of rate stability. Attempting to understand the behaviours of springs has consumed years of thinking from some very gifted minds (horology's only Nobel Prize being that awarded to Charles Édouard Guillaume for his work on alloys with "low or zero thermal coefficient of the modulus of elasticity") and geometry makes a significant difference.


movementThe Calibre 382 has nickel-silver bridges and plates that will acquire a patina over time, allowing a beautiful contrast with the other components. 


In theory, any tourbillon should perform well in tests and, more importantly, well in real life. There is a problem, however, in finding out how they perform in practice. With a good-quality, conventional watch, you simply wait until the second hand hits zero, pull out the crown and the movement stops, instantly re-starting when you have set hands and pushed in the crown, so allowing you to synchronise exactly with a reference time. This usually involves a lever that touches the edge of the balance, so braking it. This simple option is not available for a tourbillon, as the cage is in the way and the balance is in motion, meaning that if you want to check your tourbillon's performance, you need to read the time it gives against a reference, record and re-check in the same way the next time. Now, it has to be said that vanishingly few tourbillon owners will ever bother, but that isn't stopping Jaeger-LeCoultre.


The Duomètre architecture separates out the time indication from the timekeeping, this means that synchronising with a reference time is simple - press the button at two o'clock and the second jumps back to zero (without even the tiny error caused by a balance-spring regaining its amplitude). No need for a hacking feature at all. Very neat and very Jaeger-LeCoultre, as is the finish and design - the Duomètre collection is acquiring a very pleasing look that recalls vintage pocketwatches without being a facsimile. Lastly this is Jaeger-LeCoultre and, for the most part, the company stays away from unique pieces as if to prove the point that these are watches designed to work well, rather than persuaded to by the wiles of a masterwatchmaker. There won't be a flood of these watches, but they are in regular production.


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