Introducing the "Coffret Observatoire" A unique set of 5 watches

The Coffret Observatoire is a bespoke Atelier Cabinotier set of 5 tourbillon pocket watches each with a different escapement



Introducing the Introducing the



Tourbillon with Detent Escapement

A very rare combination having both a tourbillon and a detent escapement! The difference between the detent escapement and the standard anchor escapement is that the detent escapement, being unidirectional, has no recoil during its action whereas for each motion of the standard anchor escapement there is a very slight backward motion or recoil because the two pallets of the anchor are alternately engaged on both the forward and backward swing of the balance. The elimination of the recoil in the detent chronometer provided by its unidirectional action and almost detached balance makes it much more precise and capable of extreme accuracy.

A watch with detent  escapement can be visually recognized by looking at the action of the small seconds hand which moves in a noticeably precise way in half-second “jumps” as opposed to the typical “sweeping” action of a watch with anchor escapement. The detent escapement works by the controlled locking and unlocking of the ruby pallets that provide the impulse to the escape wheel, a long thin straight spring or “detent” momentarily locking the escape wheel by its teeth until it is released again on each forward swing of the balance, the ruby pallet mounted on its staff unlocking the escape wheel as it passes and allowing it to advance by one tooth at a time. The balance wheel of the detent escapement swings almost free and undisturbed by the escapement resulting in very little friction between the components, again contributing to the overall accuracy of the watch.

Introducing the Introducing the



Tourbillon with Constant Force Escapement

The constant force escapement has a very sophisticated additional mechanism attached to the escape wheel of the watch’s movement which as the name implies, supplies a constant, equal and unchanging power charge to the lever escapement throughout the entire running period of the watch. Whilst the escapement itself is driven and powered by the mainspring via the tourbillon in the usual manner, the integral constant force mechanism discharges the power at precise intervals so that the timekeeping of the watch is unaffected by the changes in the force of the mainspring as it runs down. This means that this mechanism allows the watch to run at a constant unfluctuating rate regardless of whether the watch is fully wound or running down. The constant force mechanism of this tourbillon comprises a spiral spring mounted directly above the escape wheel on its arbor which is wound and released at very short intervals by two further toothed wheels mounted below with which a jeweled lever locks and releases the spring above. Therefore each time the spiral spring is wound and released a small “charge” of power acts upon the escape wheel so that it is always powered at exactly the same moment and with an unchanging amount of energy at all times and as such can never be affected by any fluctuation during the mainspring’s running cycle. 

Introducing the


Introducing the



Tourbillon with Remontoire d'Egalité

For a watch to run accurately it could be said to have two separate but integral “halves”; one half to provide the power to run the watch (the mainspring and wheels) and the other the escapement which releases that power at exact and precisely calculated intervals. The mechanism known as “remontoir d’égalité” can be thought of as a bridge between these two halves because it regularizes the supply of power and at the same time directly controls the running of the escapement. The “remontoir d’égalité” is essentially a very high-precision power transmission control mechanism to combat even the most minor negative effects on accuracy caused when the mainspring is winding down so that the accuracy of the watch is maintained and unaffected by the fluctuations in power during the entire period of running.

The “remontoir d’égalité” also corrects any possible variation in accuracy that could be caused by the mechanical action of the wheels themselves in the train between the mainspring and tourbillon. In short, the “remontoir d’égalité” compensates for any small potential error caused simply by the normal running and unwinding of a mechanical watch in the parts of the watch up to, but not including, the escapement which has its own compensatory devices. The “remontoir” achieves this by loading and releasing stored power from an extra spring on the tourbillion that is released in exactly controlled amounts, in this watch, at 10 second intervals, therefore equalizing exactly and constantly the power from the mainspring to the tourbillion. In this watch, the “remontoir d’égalité” is used in combination with the tourbillion – to combat errors due to the change in the watch’s position and a balance wheel and spring that have been made to correct fluctuations in temperature. As such, this watch has compensation devices to combat errors in power transmission, position and temperature so as a result is capable of extreme accuracy. The “remontoir d’égalité” is almost never seen in a portable watch because of the high level of skill required to make it. Only the very best watchmakers are capable of constructing a watch with this complication because if a watch has a “remontoir d’égalité” it means that the entire watch has been specially designed and made specifically to allow for its inclusion meaning that the entire layout of the wheels of this watch is different to that of other tourbillion watches and can therefore only ever be hand-made as an individual piece. Introducing the Introducing the     Tourbillon with Marine Chronometer Balance Change in temperature has one of the greatest negative effects on the accuracy of a watch by causing the metal to expand or contract. When the hairspring and balance expand and contract it naturally causes slight changes in the diameter and elasticity of the components and this in turn makes the watch go faster or slower. Technically speaking, it is in fact the balance spring or hairspring which is affected and during extreme changes in temperature this can cause a watch to lose or gain as much as four seconds per day. To counteract this problem, the balance wheel of the watch is specially made to compensate for these expansions and contractions. The unique balance wheel of this watch is made to allow fine adjustment to compensate for the errors in timekeeping that can be caused by fluctuations in temperature. The design is taken from the principle of the marine chronometer balance, the marine chronometer being an instrument of high-precision for navigational purposes. The visibly distinctive and very special feature of this balance is the four large gold weights mounted on the rim of the balance in addition to twelve screws for extra-fine adjustment. The balance wheel itself is bimetallic, made of two strips of metal with different rates of expansion and open free ends to allow movement during temperature fluctuation, the four large gold weights are then placed on the rim of the balance during adjustment and testing of the watch by the watchmaker until they are situated in the optimum position to counteract the contractions and expansions of the balance rim. Put simply, the bimetallic balance and special compensation weights mean that the oscillation of the balance remains the same in any normal range of temperatures and therefore the accuracy of the watch is almost unaffected.  Introducing the Introducing the Introducing the


03/17/2015 - 12:05
03/23/2015 - 13:18
03/24/2015 - 13:41
03/26/2015 - 03:16
I stay speechless. Congratulations VC and the owner has great taste
03/17/2015 - 10:53

Thanks for this post and nice read.


An AMAZING tribute to the technical excellence and history of precision, mechanical, time-keeping!
03/17/2015 - 11:30

Observatory trials, marine navigation, historic escapement designs,...surprise.  Wow, Wow, Wow!

It would be an honor if the opportunity ever arises to meet this collector, your concept and ideas for creating this collection are inspiring.

Having the skill to make this collection is a credit to VC that should last for generations.

03/17/2015 - 12:05

Also, beautifully understated.

Thanks very much for posting these beauties, Alex.

Best regards,

Tony C.

Alex, I saw this on a fellow WIS page on FB a few days ago. I believe this
03/17/2015 - 13:20

is a request from Taiwan.

I am sure a lot of work went into this, and must have cost millions. But more importantly, the guy has a big heart to share this openly. A huge thank-you to him.

I made a list of all the five terms to read up on later; but now thanks to you; they have been answered exceptionally well. This is education.

A couple of questions:

- Will VC be allowed to use the different escapements in future regular models; or are they unique to the client? 

- Also, please convince VC to introduce a time-only watch with this exact dial, with automatic movement and officer-case-back hinge-cover. I would be first in line for that.

A huge thanks to you for this post. 


An article in the Liberty Times of Taiwan
03/23/2015 - 00:43

had some interesting tidbits.  If someone can translate their unofficial price tag of 1億3千595萬元 , it would be appreciated!  Dom Bernaz, who entertained us one year at SIHH with some amazing stories of the deliveries he's made around the world, has another to add to his repertoire.  He informed the writer that a team of two watchmakers spent 8 years to complete the set.  They also published these official pictures of the pieces in their case.

An article in the Liberty Times of Taiwan

An article in the Liberty Times of Taiwan

Re: An article in the Liberty Times of Taiwan
03/23/2015 - 10:20

135,950,000.  I am guessing it is in Taiwan Dollars since the article is from a Taiwan newspaper.  That would make it approximately US$4.32 million.

Thanks Dan, not unreasonable
03/23/2015 - 15:17

considering the time and resouces involved and, most importantly, the results yes.  I think their value and importance is best maintained as a set and hope that a hundred years from now we still see them all nestled together in that lovely box like eggs in the nest.

One more point I want to make. I believe this is VC at its Best. This is what
03/17/2015 - 13:22

separates VC from the rest. Very few can come close to this.


Re: Introducing the "Coffret Observatoire" A uniquie set of 5 watches
03/17/2015 - 14:51

A really outstanding accomplishment from VC!

The pocket watch is definitely not dead!

Congratulations to VC and to the owner of this set.


A truly visionary watch collector.
03/17/2015 - 18:29
What a marvelous idea to have all these different escapement in identical watchcases. A true treat for fellow collectors to have a chance for seeing these incredible timepieces. Thanks and congratulations to the owner.  I have two questions Alex: 1: The movement numbers are quite low and these numbers would normally indicate that they were made a long time ago. Is there any reasons for this? 2: Would it be possible to upload the photos of the movements so that we could examine them closer. When enlarging the photos they are only a little bit bigger. Could you upload them so that we could zoom in and relish in all the gorgeous details. Cheers Kent
Good eye Kent:-) the movements were ébauches from
03/18/2015 - 06:50

The 1930s thus the low numbers but fully reworked, the escapements are all new though

Here is a V&C Pellaton tourbillon ebauche from 1929
03/23/2015 - 15:51

serial nr. 413628

Here is a V&C Pellaton ebauche from 1929

James Cesar Pellaton made these distinctive and remarkable movements until 1939 and many represented the best Swiss brands at Observatory Trials, including Vacheron & Constantin and Patek, Philippe.  In his day, Pellaton also manufactured these tourbillons with spring detent and constant force escapements.  As mentioned in my SIHH post here:, the design lives on with the appropriately named brand James C. Pellaton.  I neglected to provide pictures then, so here are a few:

Here is a V&C Pellaton tourbillon ebauche from 1929Here is a V&C Pellaton tourbillon ebauche from 1929Here is a V&C Pellaton tourbillon ebauche from 1929

Thanks Alex! Fantastic watches...
03/17/2015 - 22:16

Yesterday I was speechless trying Siderale Scafusia.

Now with reading about this set. Congrats to VC...

Is it possible to get an understanding about the special markings?
03/17/2015 - 23:40

I'm referring to the ones on the small seconds dial at the 20 and 30 second positions. angel

Dan please reas SJX's review on this on I am not sure
03/18/2015 - 01:50

if I am allowed to promote another blog here, but he does a superb job of explaining these five pieces plus answering the question you just asked.

The triangle at the 30s is in fact used for precise
03/18/2015 - 08:46

Indication of the full minute. When the seconds hand fills the gap between the 2 markers a full minute has passed. This was found a better solution as the eye is naturally drawn to the 6 o'clock position vs noon.

in the Observatory trial movements these triangles were either drawn on the the test dials with a pencil or using tape!!

Thanks Alex
03/18/2015 - 11:10

Do you know if there is any signficance to the same markers at the 20s position?  I can imagine:

1. It is an alternate position, if one wishes to use the one at 20s instead of at 30s?

2. There is meaning to the 10 second interval between the two sets of markers?


Re: Thanks Alex
03/18/2015 - 16:03

Hi Dan,

It may just be a count-down indicator since a "10 seconds to go" is a frequently used interval.

As Alex stated, the eye is better drawn to the 6 position than the 12; so this would be an appropriate place to put a 10 second interval marker... just a thought.

Thanks JB, Alex's post below confirms your thought! (nt)
03/19/2015 - 02:01
The marker at 20s is a type of "warning" to get
03/18/2015 - 22:35

ready for 30s

Thanks Alex, I like asking specific, detailed, and sometimes
03/19/2015 - 02:03

stupid questions, but it's one of the most effective ways for me to learn things.  Greatly appreciated!

As unexpected as amazing... or the contrary
03/19/2015 - 11:12

A beautiful idea, the customer has a true love for chronometric device.

The pocket watch is the right shape for tourbillon and this escapement make more sense in such watches imho. Kudos to VC and the customer for such a result, even in such a bespoke piece it's more a partner than a customer. Brilliant


Just one very important question...
03/22/2015 - 23:23

Will he (or she) adopt me?  OMG, what a superb result of concept and execution heart.  A most thrilling post for our return from a week's R&R in the mountains, thanks Alex.


unfortunately no, as the
03/23/2015 - 09:48

adoption procedure to adopt me has already started cheeky

Observatory Tested?
03/23/2015 - 15:08

OK, now for a more serious question angel.  Alex, perhaps you know if the pieces received an actual observatory rating?  While the absence of this in no way compromises the brilliance of the project, it would surely be a wonderful footnote.

no they did not undergo observatory trials. In fact to the best of my knowledge observatory
03/25/2015 - 16:52

testing is no longer available for watches in Switzerland and only Besançon in France offers this possibility

There were two testing procedures available
03/25/2015 - 21:17

You introduced Timelab's Observatoire Chronometrique program to us back in April of last year,  This process may have suited our esteemed collector as the finished watches could have been examined in VC's ateliers.

The deadline for entry into the 2015 Concours International de Chronmetrie ( passed at the end of January and results will be announced this October.  IMHO, this is most in the spirit of Observatory Trials and it would really have knocked their socks off to have some or all of these watches participate.

A bit of a tangent, can you advise if the possibility of Geneva Seal for these watches was discussed?




the base movements were originaly intended for observatory trials and as you know
03/26/2015 - 09:54

these type of movements were never intended to have amazing finish but rather all the focus was on the escapement and accuracy. The client therefore asked not to have the Geneva seal and keep in the origins of the watch.

The decision of not having them undego Observatory test  was also the client's as this would mean the watches would have been tinkered with and the client did not want them to be touched by anyone other than VC

very understandable :-)
03/26/2015 - 16:24


A little late to comment...
03/23/2015 - 13:18

But seriously, this is truly amazing.  What a great concept to essentially create a set of the same piece executed in different ways.  You could consider it a time machine making stops along the way of escape development.  Alternatively, since each escapement has its pros and cons viz. accuracy, dureability, shock-hardiness, etc.  Just truly remarkable and, quite honestly, a validation, in my opinion, of the value of the Ateliers Cabinotiers in general.  What is the likelihood of anything approaching this type of series being produced otherwise?  Zero.  Thank you and the owner for sharing.

HOLY %$#&@!$%$%#%
03/24/2015 - 13:41

If I had $4.5m this is exactly how I would spend it....... the family can dig for food from the forest!!!

I love that The watches are seemingly so ordinary but behind it are incredible complications.  The dichotomy of simplicity vs complications...... why I love watches.

+10! :-) (nt)
03/26/2015 - 03:16