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The first Chronomètre à Résonance from F.P. Journe debuted twenty years ago this year in a limited series of 22 watches, and since then, it has been seen in a number of different variations, all of which were based on essentially the same movement. The family was discontinued last year, and while covering this last model, HODINKEE's Stephen Pulvirent wondered what might come next.
Now we know. This year, for the 20th anniversary of the Chronomètre à Résonance, F.P. Journe has released a new version which adds considerably to the technical complexity of the watch, while at the same time refining even further the already very aristocratic approach it takes to chronometry. The new version is equipped with a new movement, the caliber 1520 in rose gold. (Rose gold is a signature feature of F.P. Journe movements; generally Swiss movements from the most proletarian to the most aristocratic use rhodium-plated brass, or less commonly, German silver). In addition to the signature double balance design, in which two balances oscillate in resonance with each other, the movement now features a single, rather than a double, mainspring barrel, as well as a differential which directs the power flow to each of the separate going trains, and another signature Journe complication – a one-second remontoir d’egalité, one for each of the two trains.
The Search For Resonance
Making a resonance watch is an extremely difficult undertaking and, through most of the history of watchmaking, they were largely experiments. Breguet, who was among the first to examine the effect in which two oscillators in close physical proximity to each other, and with the same natural frequency, begin to beat in synchrony, found it hard to believe that resonance could be observed in a watch with two balances and not just in a double pendulum clock. However, after many tests and experiments, he wrote, "This appears to be absurd, but experiment proves it a thousand times over."
Movement, Breguet dual-train resonance pocket watch. Originally sold to a Mr. Garcias of London for 5,000 francs in August of 1814; auctioned at Christie's in 2012 for CHF 4,339,000.
The phenomenon of resonance was first observed by Christiaan Huygens, to whom we owe the development of the first practical pendulum clocks, as well as the application of a spiral balance spring to a watch (in 1657; he shares the credit for this development with the Englishman Robert Hooke). The famous French horologist Antide Janvier (1751-1835) also created resonance clocks. The theoretical basis for resonance timepieces is relatively straightforward. If the two oscillators are in resonance, each will tend to correct any deviations in rate which occur with the other, thanks to the exchange of rhythmical energy between the two of them. The only caveat to this is that it is necessary to have the oscillators adjusted to keep a very close frequency, each with the other, in order for the effect to occur at all. Breguet noted that in his pocket watches, each balance had to be adjusted to no more than a 20 second-per-day deviation from the other, otherwise resonance would not occur and the balances would not lock to each others' frequency.
Double pendulum clock by Antide Janvier, Patek Philippe Museum, Geneva.
This is all rather heady stuff and represents some of the most exactingly difficult watch and clockmaking in the history of the art of horology. The question of how to wring the very last drop of accuracy out of a purely mechanical system occupied some of horology's greatest minds for centuries, until chronometry began to become a matter for the physicist and digital engineer rather than mechanical horologists with the advent of quartz timekeepers. The difficulty in making resonance timepieces of any kind, and especially wristwatches, has meant that after Breguet, very few horologists even made the attempt, and to this day, F.P. Journe remains the only watchmaker who makes resonance timepieces relying on the same principle which Breguet exploited in his watches.
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The F.P. Journe Chronomètre à Résonance
The first version of the Journe resonance watch debuted in 2000, and since then, there have been a number of variations. The 2000 series was a subscription series, and the first actual collection was released in 2001. Major releases since then include a platinum-cased model with a ruthenium dial and a movement in 18k rose gold, a 2010 release with a digital 24-hour dial, and in 2019, a model with a 12 as well as a 24-hour dial.
The 2010 F.P. Journe Chronomètre à Résonance with digital 24-hour dial. Note the position of the winding and setting crown at 12:00, with the crown at 4:00 for re-setting the seconds hands.
While F.P. Journe released his first resonance watches in the early 2000s, his interest in the phenomenon is long-standing, and he was experimenting with making a resonance watch based on the Breguet principle as early as 1983.
Prototype movement plate for two train resonance watch, by F.P. Journe, 1983.
The basic configuration of the movement of the resonance watches has not varied in any major technical respect since 2000, and with good reason – creating a movement which can reliably produce a resonance effect is extremely challenging, and moreover, there is the additional labor required to get the two balances adjusted closely enough in rate that the resonance effect can occur at all. While there have been other resonance watches produced since the 2000s, these generally rely on a direct mechanical linkage between the two balance springs, rather than the transmission of what F.P. Journe terms "acoustical" energy.
The F.P. Journe caliber 1499.3.
The original configuration can be seen in its essentials in the F.P. Journe caliber 1499.3. At the top of the movement, next to the winding stem, is the crown wheel, which winds the two mainspring barrels; the jewels for the barrels can be seen on either side of the crown wheel. At this point, the movement divides into two entirely separate going trains, each of which terminates at the escape wheel, lever, and balance of each of the trains. One notable element is the rack system on the balance co*ck on the right, which allows the distance between the two balances to be adjusted with high precision.As with Breguet's pocket watches, the two balances must be adjusted so that their rate is very close in order for the resonance effect to occur. While a 20 second difference was the minimum for Breguet's timepieces, the smaller balances in the Chronomètre à Résonance must be running to within no more than a 5 second per day difference in rate.
Though making a resonance watch is very difficult, the basic principle is straightforward, and it would seem that there is nothing left to improve on in the implementation of the Breguet resonance principle in a wristwatch as developed by F.P. Journe. However, F.P. Journe has not been content to leave well enough alone, and the 2020 version of the Chronomètre à Résonance introduces not only greater complexity, but greater refinement in the search for precision as well.
The 2020 Chronomètre à Résonance, With Remontoire And Differential
At first glance, it would be easy to mistake the 2020 version for its predecessors – we have the same basic dial configuration which has characterized all previous Chronomètre à Résonance watches. However, there is an unusual-looking mechanism which is now visible between the two time-telling dials, and as well, the position of the crowns is slightly different. The crown at 2:00 is used to wind and set the time – pulling it out lets you set each of the two dials, turning counter-clockwise to set the time on the left, and clockwise to set the time on the right. Pulling out the lower crown simultaneously re-sets the two seconds hands. Previous versions of the Chronomètre à Résonance had the winding and setting crown at 12:00 so the new version represents improved ergonomics as well.
The mechanical device located at the center of the dial, however, is something that has never been used in a Chronomètre à Résonance before, and comparing the original movement to the new 2020 movement clarifies some of the changes that have been made.
The Chronomètre à Résonance, 2020 version, with caliber 1520.
First, you'll see that the position of the crown wheel has changed; it is now at 10:00, approximately, rather than being in line with the two balances. This reflects the fact that there is now a single mainspring barrel, with a power reserve of 42 hours and, most notably, an "efficiency" of 28 hours, about which more shortly. The position of the mainspring barrel is indicated by its single, very large jewel at 12:00. As with the predecessor caliber 1499.3, there are still two separate trains, so the energy from the single mainspring barrel is divided by a differential, which is the enigmatic device you can see on the dial side at the center of the dial. Energy from the single barrel, once directed to each of the separate going trains, is then controlled by a remontoir d'égalite
F.P. Journe's Tourbillon no. 1, 1991. Remontoir d'égalite visible at 6:00, from our Reference Points on F.P. Journe tourbillons.
As with the resonance effect, the remontoir d'égalite is something that's fascinated F.P. Journe for many decades. Long before the company that bears his name existed, he'd already incorporated it, in 1991, into a tourbillon. The device has a very distinguished history – the gravity remontoire, for clocks, was invented by the Swiss clockmaker Jost Burgi around 1595 (he also did pioneering work on what we call logarithms today), and the spring-powered remontoire was invented by none other than John Harrison, of marine chronometer fame, who invented it for his H2 sea-clock and refined it further for H4, which of course was the first successful marine chronometer.
Differential, visible from the dial side.
The purpose of the remontoir d'égalite is to address the fact that as a mainspring unwinds, it gradually transmits less and less energy to the balance, and as balance amplitude drops, rate stability begins to suffer. This is not especially a practical problem, nowadays, in modern wristwatches which benefit from the much flatter torque curve you can obtain from modern mainspring alloys. And, of course, an automatic winding mechanism in a watch worn every day will tend to be a sort of expedient remontoir d'égalite in itself, as the mainspring will never unwind far enough for amplitude to especially suffer. However, the complication continues to fascinate connoisseurs, and it actually does have a practical benefit in the new Chronométre á Rèsonance.
The two going trains.
One of the basic issues with a resonance watch is that one wants to keep balance amplitude as constant as possible, in order to reduce the chance of the two balances becoming de-synchronized. Each going train has its own one-second remontoir d'égalite, which can be seen above at 3:00 and 9:00 respectively. A remontoir d'égalite is essentially a second, subsidiary mainspring, which is wound up at regular intervals by the mainspring. As long as the mainspring has enough energy to rewind the remontoire spring, torque delivered to the balance should remain constant, rather than dropping as the mainspring winds down. Depending on the watch, the remontoire can rewind at intervals ranging from minutes to seconds; F.P. Journe often uses a one-second remontoire, two of which are found in the 2020 Chronomètre à Résonance.
We've said that delivery of energy will be constant for as long as the mainspring has enough energy to power the remontoire, and because the remontoire is in the power flow to the balance, it is possible for a watch equipped with one to continue running even when the remontoire spring can no longer be rewound. This is the reason that while the total running time for the Chronomètre à Résonance is 48 hours, "efficient running time" is 28 ± 2 hours; after about 28 hours, the mainspring no longer has enough torque to rewind the remontoire spring. This, however, should not prove to be a practical problem in a watch worn daily, and wound daily at the same time.
Despite the considerable complexity of the 2020 Chronomètre à Résonance, it remains a remarkably compact watch. Journe enthusiasts will remember that it has generally been F.P. Journe's goal to make watches which, regardless of their complexity, are elegantly proportioned and wearable at the same time. When the original Chronomètre a Résonance line was discontinued, the watch was available in a 40mm case and was just 9mm thick. The 2020 Chronomètre à Résonance is hardly larger – you can have it in platinum or red gold, with a diameter of either 40mm or 42mm; the total thickness is just 11mm.
When the first Journe resonance watches came out, I was very much a skeptic – the idea that almost homeopathically minute amounts of energy could be transmitted by the oscillation of a watch balance seemed absurd, and I happily expressed that view quite often in online discussion forums in the early 2000s. Several friends came to own them, and I'd see them at watch enthusiast events and, indeed, they seemed to have balances beating happily away in synchrony, but I remained stubbornly convinced that the effect could not be real. Then, in 2014, I happened to read the section on Breguet's resonance watches in George Daniels' The Art Of Breguet and realized, with my face reddening, that F.P. Journe had indeed followed in Breguet's footsteps and obtained the same result – which led to my publishing a retraction of my previous position in Revolution magazine, for which I was then functioning as US editor-in-chief.
I have continued to find the Chronomètre à Résonance watches irresistibly fascinating ever since. As a dyed-in-the-wool chronometry nerd, I'm well aware that modern materials science and high precision manufacturing have achieved accuracy of which the great makers of previous decades and centuries could only dream. But there is something enduringly wonderful about pursuing chronometry armed, not with silicon and LIGA-fabricated escapement components, but rather the materials which are most traditional to watchmaking. As with high-end hand-finishing of movements, watchmaking on the level of the new Chronomètre à Résonance maintains a connection to some of the most exalted past efforts in watchmaking history and shows that, rather than being the exercise of rote techniques and solutions, it can represent a fresh field for invention and endeavor – for those very few watchmakers with the inclination and skill.
The F.P. Journe Chronomètre à Résonance, 2020, with caliber 1520: case, platinum or 18k 6N rose gold, available in 40mm or 42mm; thickness, 11mm. Movement, F.P. Journe in-house caliber 1520; 34.20mm x 7.97mm. Thickness, 7.97mm. Double independent going trains, each with one-second remontoir d'égalite; single mainspring barrel with differential. 12 and 24-hour displays of the time, with power reserve. Power reserve, 42 hours with approximately 28 hours running time from full wind with the remontoires operating. Hand-wound, with one crown for setting the time and one for re-setting the seconds; frequency, 21,600 vph, running in 62 jewels. Price, $106,800 in 18k rose gold; $110,600 in platinum. Limited production but not a limited edition; expected in F.P. Journe boutiques mid-2020. Find out more about the 2020 Chronomètre à Résonance with the new caliber 1520 at FPJourne.com.
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Remontoire
Resonance
New-watches-2020
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Differential
