This web site intends to reach a large public having a passion for watches and eager to understand how a genuine and high quality mechanical watch works - a unique object, the result of repeated exploits by master watchmakers over more than 300 years.

With the support of prestigious houses, zVisuel developed 12 animations of the watch mechanicals with the help of Cult3D interactive technology. Complementary information was provided by specialists and historians, throwing light on the course of the development of the watch making art.

Each animation will be complete with information provided by specialists and historians who will throw light on the course of the development of the watch making art.

montres passion

zVisuel SA

This animation is offered by:
zVisuel
and
Montres-Passion

Energy is necessary to turn the hands of a clock. The clocks in medieval towers were driven by a weight system, thus using the force of gravity.

The watch spring was invented in the 15th century: a long metallic strip coiled around itself and placed in a cylinder equipped with a cog-wheel, the toothed barrel. Clocks had become transportable, even portable.

Pocket watches, then wrist-watches were equipped with such a mechanism. Many remarkable improvements have been made to it over the years.

Considerable progress has been made in steels; alloys were developed to first limit, then almost eliminate the risk of breakage of the watch-spring, which is subjected to strong mechanical forces.

For a long time, external winders were used to wind up the barrel. These had to be inserted perpendicularly into the watch-face after opening the watch-cover. To adjust the hands it was also necessary to open the watch-case.

An innovative way to rewind a watch consisted of a revolving bezel - a metal ring that holds the glass - was quite popular during a certain period of time.

In 1838, the watchmakers Louis Audemars proposed the first watch equipped with a crown winder. An Englishman, Thomas Prest, paved the way from 1820 on; Patek and Czapek further developed the concept. Finally Adrien Philippe and Charles Antoine LeCoultre perfected it at the end of the 1840's.

The first filed a patent for a mechanism integrated into the watch that provided the means to adjust the hands; the second added the possibility to wind up the barrel using the same mechanism.

Nowadays placed at the 3 o'clock position, the crown winder of a wrist-watch is generally used to wind up the main spring, to adjust the time and to set the date.

Using your mouse, move the pointer in the 3D animation area. Whenever it turns into a little hand, click and watch! For example:
Click on the crown winder several times to wind up the watch. Fully wound up, a simple mechanical watch can run between 36 to 40 hours. The necessary energy is accumulated in the tension of the steel spring, the true engine of a mechanical watch.
Click on the centre-wheel to let this mechanical energy out.

This animation contains audio.



it is offered by:
F.P. Journe
Invenit et Fecit

The energy released by the watch engine, the barrel, must be mastered, controlled and distributed parsimoniously at a rate corresponding to the real flow of time, to its exact measure. This precise dosage is given by the regulating part, the oscillator - pendulum or balance. In order to function in a regular and continuous manner, the oscillator needs energy; this is gradually provided by a specific mechanism: the escapement.

From the barrel to the escapement, the engine energy is transmitted through a succession of wheels and pinions, each one rotating faster than its predecessor. This de-multiplication breaks the force up into smaller and smaller units.

At the last set of wheels, the so-called "Swiss lever escapement", the most widely used in today's wristwatches, is composed of a pallets wheel and an anchor shaped part with two ruby pallet-stones and its upper extension terminated by a fork.

The escapement wheel is blocked in turns by each pallet-stone and freed at each oscillation of the regulator through the fork and balance. Concurrently the pallets keep the oscillator running.

The true heart of the watch, the oscillator, is nowadays composed by the balance and spring pair, actually a wheel coupled to a spring which brings it to its balanced position. At each step, the balance allows one tooth of the escapement to go by, through the fork and pallets.

Tic-toc, tic-toc. The usual number of steps is 21600, 28800 or even 36000 per hour.

Made of a special alloy, the balance spring is fabricated exclusively by Nivarox (Swatch Group). Its complex set-up requires craftsmen dedicated to this task only.

All sorts of escapement systems have been imagined and built by watchmakers since the invention at the XV th century of the shock-wheel or rod escapement.

Mechanical clocks were equipped with pirouette escapement, pallets with backward movement, then without backward movement. In 1695, the famous English master Thomas Tampion invented the cylinder escapement, while his colleague George Graham developed the pause escapement (1720). In 1750, Thomas Mudge proposed the first free pallets escapement. Georges A. Leschot conceived in 1830 the Swiss lever escapement that his pupil Antoine Léchaud later fabricated in industrial quantities.

The peg escapement designed by L. Perron de Besançon in 1798 was then adapted by Frédéric Roskopf to his invention of "The Proletarian", the first affordable watch in the world. One can also mention the electrical escapement proposed by the Neuchâtel resident Mathias Hipp as early as 1878. In their quest for precision and reliability, watchmakers continue to work on this mechanical watchmaking key theme and put forward new solutions.

The latest significant contributions include the coaxial escapement by Georges Daniels, the constant-force remontoir by François-Paul Journe and the dual-impulsion escapement by Ludwig Oechslin.

Just apply the 3D navigation instructions appearing below the window and watch how the very small half-moon ruby pin knocks the pallets fork. This produces the famous tic-toc of the watch, which you can hear if your PC has loudspeakers.
Click on the + and - signs. You will know how your watchmaker can fine tune your watch. This adjustment is very sensitive; it has been tremendously exaggerated in the animation.

it is offered by:
zVisuel
and
Montres-Passion

Three hands perform the classical display of a mechanical watch. Two are placed in the middle: a small hand for the hours and a large one for the minutes, while the small seconds-hand is traditionally positioned at the bottom at six 0'clock and called the small seconds. The seconds-hand is called centre seconds or sweep seconds if positioned in the centre of the dial.

The rotation of the hands is provided by various mobiles located between the barrel and the escapement (see the two previous animations).

The centre-wheel which is touching the barrel with its pinion, rotates 360 degrees per hour. It also carries the minutes-hand with the help of the cannon-pinion. The centre-wheel is connected to the seconds-hand via the small intermediate wheel being itself in contact with the escapement wheel.

The hand of the seconds-wheel usually advances five steps within a second. We sometimes call it the direct-drive when positioned in the centre of the dial.

The hours-hand is activated by the motion-work which makes it turn twelve times slower than the minutes-hand. It is carried by the hours-wheel.

The first watches only had one hand to indicate the hours. The minutes-hand appeared at the end of the 18th century, thanks to the Englishman Daniel Quare.

The manufacturing and the shape of the hands progressed a lot in the course of the years, adding robustness and aesthetics.

Amongst the hundreds of models, the most common types today are Stick, Tree, Dauphine and Alpha. Classical or antique watches often use the Breguet or Pear types.

In the past, pushing the hands with a finger performed the time adjustment. However, since the 16th century, the "chevillot", a kind of small key, was used. Nowadays the time adjustment is performed by the winding-shaft thanks to a mechanism containing various levers and springs. A small intermediate wheel allows to turn the hands via the motion-work.

The whole mechanism is covered by the lever-spring which specific form serves as an identification of a family of clockwork movements (for the experts).

Until the 70's, half of the watches manufactured in Switzerland were equipped with other mechanisms called lever-spring (old and inexpensive) or large lever (simpler).

In summary, three steps: an engine, a heart and a display are all the basic elements which have been showed and which are now combined.

On this basis, watchmakers have never stopped imagining and to developing additional mechanisms to perfect their product, to ensure its working in severe conditions, to increase its precision and to ad other information, such as the days' date, the days' name or the lunation, to offer more functionality such as the ringing or the short time interval measurements.

These are what we shall discover with the coming animations over the next months.

Just apply the 3D navigation instructions appearing below the window and try to manipulate the watch.
Click on the various parts to remove or to reposition them in order to better see the mechanisms.
Try to adjust the time by clicking on the crown then by sliding your mouse up or down.
These first three animations complete the basis on which the watchmakers will ad more functionality and mechanical complications.

it is offered by:
Eterna

Trying to develop a mechanical watch that would be self-winding is a very old idea. Various solutions have been imagined during the course of the years. The «father» of the self-winding movement is Abraham Louis Perrelet (1729-1826), who in 1770 already developed a pocket watch, equipped with a rotor able to arm the mainspring regardless the direction which the rotor was moving. Then all the basics were already there, but one and a half centuries were needed to see this genius invention used to its full potential when it was applied to wristwatches.

Meanwhile, Abraham Louis Breguet (1747-1823) proposed a system equipped with a "shaked" oscillating mass which was adapted to the essentially up and down motion of the pocket watch.

By wearing a wristwatch, one shakes it in all directions thousands of times per day. This is why an oscillating mass, rotating around its axle - the rotor - is the ideal solution, provided the energy produced can be used to rewind the mainspring.

In 1925, the Englishman John Harwood (1893-1965) filed the first patent for an automatic wristwatch. He proposed his prototype to the "ébauche" manufacturer A. Schild at Grange (which later created Eterna and ETA). Three brands did market this invention: Fortis, Selza and Blancpain. The oscillating mass was equipped with thrusts to absorb the too violent movements and to move the oscillating mass backwards.

In 1931, Rolex came back to the original Perrelet rotor with its «Perpetual» movement. In 1942, Felsa developed the "Bidynator"a rotor which operated in both directions when moving. In 1949, Eterna developed a solution which became the standard: the rotor mounted on microscopic ball bearings. This solution was combining the robustness, the smoothness of the rotation and the wears resistance.

The automatic watch really took off in the 50's with the filing of hundreds of patents for fine tuned and noticeable improvements.

Mido reduced the number of components with its Powerwind, while Girard-Perregaux with its 39 jewels "Gyromatic" reduced down to three screws the way the automatic module was fixed on the movement basis introducing a modular maintenance approach. Jaeger-LeCoultre and Zodiac introduced the power reserve. In the 60's, the de Büren manufacture, Universal Geneva and Hamilton launched the micro-rotor integrated to the movement.

Technically speaking, today's automatic movement has three key elements:

1. The rotor, which is as heavy as possible for the smallest overall dimensions mounted on microscopic ball bearings.

2. The reverser, which enables to rewind the barrel main spring regardless the rotating direction of the rotor.

3. The reduction-mobile, which transforms a rapid but very low power rotation of the oscillating mass into a much slower but powerful movement able to arm the barrel mainspring.

On top of these, some specific mechanisms are added to uncouple the automatic mechanism when users are manually rewinding their automatic watch. A sliding brace is also mounted that avoids to over rewind the mainspring when fully wound.

Just apply the 3D navigation instructions appearing below the window and try to manipulate the watch to focus on some details.
Click on the small person to discover how the mechanism powers the watch using every motion of the wristwatch wearer.

Observe the ingenious clicks system, which keeps the ratchet rotating in the same direction, here by powering the watch, regardless the direction of which the rotor is moving.

this animation is offered by:
Panerai

Shocks, water and dust are the lethal enemies of the delicate watch mechanisms. The old escapement cylinder and even more so the balance axle were for long the Achilles' heel of the fine mechanics. When a pocket watch fell, the balance axle had a good chance to break. Here again Abraham-Louis Breguet brought the first answer to this problem. He imagined a device called parachute, a kind of pivot-stone atached to on a spring strip. But this first shock-resistant device was only efficient for the vertical shocks produced in the balance axle direction.

The La Chaux-de-Fonds engineers, Georges Braunschweig and Fritz Marti, developed the Incabloc device, which also worked efficient for lateral shocks and became the standard in the 1930's. Worldwide known and easily identifiable with its spring lyre, it equipped up to 70% of the anchor Swiss watches. A competitor system, the KIF Parechoc device, was developed in the Joux Valley in the 1940's. There have been numerous devices, which disappeared since, while the Incabloc descendants (Novodiac) and KIF Parechoc (Duofix et Duobil) are still dominating the "airbag" market of the watch.

Dust and water were real problems for the daily use of a pocket watch. The water and dust resistance concept, as specified by the "Water resistant" Swiss certification authorities, was more in line with the damages provoked by water. This because of the increasing popularity of the wristwatch, which is more exposed to water in its daily use, if kept worn when washing hands or having a shower for example.

The first protection seals for the sensitive parts of the pocket watch appeared at the end of the 19th century: namely for the bottom, the glass, the winding mechanism and the push-pieces of the time adjustment. Patents filing multiplied for the wristwatch in the 1920's: dust-resistant devices, double cases, crown-wheel tubes, screwed bottom and screwed glasses compressing the seals.

History will remember Hans Wilsdorf, the Rolex house founder, and the 1926 year when the first true water-resistant wrist watch appeared: the famous Oyster. From then on and during the next two decades, more than 60 watchcases makers and over 200 Swiss watch brands offered water-resistant models in their watch series.

Some brands did specialize in water-resistant models with genuine solutions. Mido and its "aquadura" system replaced rubber band seals with natural cork.

The cork was pressured and soaked in secret liquid. Cork had the advantage of not becoming bristle and was not deformed compared to regular seals.

Officine Panerai was another emblematic name of the water-resistant watch-making story, which stayed in the dark for long as they equipped the combat divers' commandos of the Italian army during World War II.

It developed a unique lever system, pressing the crown-wheel to ensure an efficient water resistance. Its professional diving model equipped with a helium valve withstands to a 1000 meter dive.

Water-resistant watches without other specification will withstand to a normal use and short bathing for example. They will usually withstand to a 30 atmospheres pressure, so about 30 m of water.

On the other hand, the ones which mention "diving resistant" must pass more severe testing conditions, which correspond to a 100 m. water column and good visibility of the time indications within submarine conditions. Divers' lives depend on this.

Using your mouse, move the pointer in the 3D animation and manipulate the watch according to the 3D navigation instructions appearing below the window. Whenever the pointer turns into a little hand, click and watch! For example:
Remove or reposition the various parts of the watchcase especially the bottom and click on the balance bar to isolate the shockproof device
Click on the shockproof ruby part to shake the watch and to see how the shock-resistant device reacts and prevents the breakage of the balance axle.

this animation is offered by:
Breguet

Displaying hours, minutes and seconds was a feat in its time, but watchmakers were not happy with this. First they imagined and developed mechanisms to display simple calendars, with the day's date, the day's names and sometimes the week-numbers or more often the months' names. In any case, it was necessary to adjust the mechanism at the end of 30 days months to compensate for the missing day, as well as for the 28th or 29th (leap year) of February.

The moon phases display also needed a dedicated invention. When based on 29 days lunation (instead of 29 days 7 hours 43 minutes and 11 seconds), a correction was necessary every three years. But some systems were based on a 29,5 days lunation, which only required a correction every 132 years.

At the 18th century, perpetual calendars appeared, taking care of the months having less than 31 days, as well as leap years.

The manual correction was therefore only necessary for the century changes without leap year (next time for example in 2100).

Watchmakers studied in depth astronomy to replicate the real movements of the stars and planets, first for pocket-watches and then for wristwatches. They also developed other calendars (Hebraic or Islamic ones), Easter dates and other movable holy days. Other phenomena such as see tides or sky maps for specific areas of the Earth also interested them.

One particular astrological phenomenon that is the fluctuating relation between the sun time and the clock time, which is known under the name of "Equation-of-time" did interest watchmakers. Once again, A.-Louis Breguet (1747-1823) developed a small clock displaying this very specific data, which he offered in 1793 to his mathematician and astronomer friend, Pierre Simon marquis Laplace who is the author of a scientific explanation of this phenomenon.

A sun day means the time that very precisely flows between two Sun passes at the meridian line. Conventionally the mean time between these two passes is fixed at 24 hours. In fact this time fluctuates between 24 hours 0 minute and 30 seconds and 23 hours 59 minutes and 40 seconds. There are only of few seconds of difference from one day to another (however up to 30 seconds around Christmas), but these small variations cumulate in the course of the year.

They produce a time difference between the Sun midday and the clock midday of up to +14 minutes (on the 12th of February) and down to -16 minutes (on the 3rd of November).

This difference is due to the elliptical pathway that the Earth takes around the Sun, which produces a speed variation of the Earth's motion. Therefore, in the course of the year, the difference between the Sun midday and the clock midday varies, with some period of time being in advance or delayed.

Only four times a year, the Sun midday matches exactly the clock midday (April 16th, June 15th, September 2nd and December 26th).

The A.-Louis Breguet invention was further developed to have a perpetual adjustment (leap years). We find it in the most prestigious astronomical pocket-watches. The most difficult part was to design the specific cam part of the Equation-of time display mechanism.

The display device is made either by a supplementary minute hand, such as in the Patek Star Calibre, or by a specific display positioned separately in the dial, which indicates the minutes difference between the Sun midday and the clock midday for the current day.

In 1991, the Breguet brand adopted this latter solution to produce the first wristwatch showing the Equation-of-time.

Using your mouse, move the pointer over the 3D animation and manipulate the watch according to the instructions appearing below the window.
Click on some parts to remove them in order to better watch the inside mechanisms.
Click on the and signs to select a date, then on GO; the dial will show the difference between the Sun midday and the clock midday at the selected date, that is to say the Equation-of-time.
Observe the very specific cam, which allows displaying this value.

This animation is offered by:
Girard-Perregaux

In 1862, Adolphe Nicole, a Joux Valley watchmaker designed the first chronograph, which worked with the basic elements (start, stop, reset) still in use today. However, before him (in 1777) Jean-Moïse Pouzait designed the first additional time-keeping mechanism, with an independent second hand, which moved by one-second increments.

In 1868, Auguste Baud designed the first chronograph with an additional mechanism not located under the dial, but on the backside of the watch (bridges side).

The sports or professionals time-keeping devices, which only show the fifth of seconds and the minutes have been there since 1878.

The creativity and imagination of watchmakers, the originality and improvements of chronographs' movements generated about 40 inventions. Over 369 patents were filed in Switzerland from 1880 up to the end of WW II.

The most significant progress dated 1937 when Dubois Dépraz, the Joux Valley company, designed a system without a column wheel.

This invention dramatically reduced the cost of manufacturing and got a tremendous commercial success. Based on a basic Ebauche SA (nowadays ETA) movement-blank with a Dépraz or Aubert mechanism, this chronograph was offered with a tachometric dial to measure the speed and a telemetric graduation to measure the distances. This was a very efficient assembly, which was manufactured from more than 3.5 millions of parts, a considerable amount for a chronograph in those days. We can still find some pieces today under the simple "chronographe suisse" trademark.

The forth-wheel (small second wheel) is the main force of the chronograph mechanism. It has on one side the small second hand and on the side of the chronograph mechanism a similar wheel constantly geared with the coupling lever, which starts or stops the chronograph mobile mechanism. This centre wheel splits the time in fifth of seconds; the corresponding dial is called the direct-drive (trotteuse). The chronograph dial usually has a minute counter and a 12 hours (or 3 hours) dial.

How does the minute counter hand works? The chrono centre wheel is equipped with a brass finger. Each time the centre wheel make a full revolution, it drives another wheel which moves the minutes counter dial forward. This brass finger must be flexible to not interfere with the reset operation of both the centre wheel and the minute counter. The reset operation is performed by the hammer which knocks the cam with a very special heart shape.

In 1999, Girard-Perregaux, the La-Chaux-de-Fonds manufacture distinguished itself by designing the first automatic wristwatch chronograph with strike second (means that a supplementary centre hand makes a full revolution in one second, allowing to read one 8th of second).

Other firms such as Dubois Déparz, Valjoux, Kelek and Lemania did deliver chronographs movements for the most prestigious brands mostly cam based mechanisms instead of column wheel based ones.

However, the latter has not disappeared but it is reserved for top quality models offered by the most prestigious brands. We find column wheel based chronograph at Breguet, Girard-Perregaux, IWC, Jaeger-LeCoultre, Patek and a few others.

Using your mouse, move the pointer over the 3D animation and manipulate the watch according to the instructions appearing below the window.
Click on the various pieces to assemble them in the right order! (Start with the column wheel.)
Once the mechanism is assembled, click on the dial to see the mechanical parts.
Click on the push-pieces or on START, STOP and RESET to see how the various time-keeping phases are linked together. They are considerably slowed compared to reality.

This animation is offered by:
Patek Philippe

Annual 9 Messidor 7th of the French republican calendar, in other words June 26th 1801, is the official date when the "Tourbillon" was born, date of the acceptance of the patent delivered by the French Domestic Ministry for a new type of regulator named "Tourbillon" by its inventor, Abraham-Louis Breguet.

The brilliant Swiss watchmaker living in Paris filed three months earlier a 10 years patent for a mechanism, which was supposed to offset the disturbing effect of gravity on the good working of pocket watches.

The great idea was to place the regulatory mechanism (the balance and balance-spring) and the escapement (refer to the second animation) in a metallic cage, rotating on itself. Making one revolution per minute, this device would offset the running differences generated by the vertical position of the pocket watch, while placed in its owner's pocket.
Since it was considered a technical achievement showing evidence of the mastering and skill of the handcrafted watchmaker, the Tourbillon inspired the best watchmakers during the course of the 19th and 20th centuries.

Frederic Houriet, Louis-Urban Jürgensen, James Pellaton or Constant Girard can be named for example with a special mention for Fritz Charrue-Charrue, who in 1945, after six years of work, presented the smallest Tourbillon ever made: the cage did not exceed 8 mm in diameter and the steel anchor measured 2.5 mm long.

The Tourbillon can be combined with various types of escapements, such as trigger, often used in pocket watches.

However, only the anchor escapement eventually succeeded with the Tourbillon. Patek Philippe paved the way from the beginning of the 50's. During the 50's and the 60's the Patek Philippe calibres, based on the Tourbillon-anchor escapement pair, distinguished themselves in the most famous chronometers' competitions.
During that time, there were some attempts to equip wristwatches with a Tourbillon, more for technical achievement than for its real use, because a watch worn on the wrist is less affected by the offset of gravity.

Prototypes came to life, but only in 1986 Audemars-Piguet, with the creative assistance of André Beyner and Maurice Grimm, launched the first automatic wristwatch equipped with a Tourbillon. This piece was very thin and demonstrated that the use of modern numeric tooling as well as electro-erosion processes was not incompatible with the high end watch manufacturing art. However this meant the end of the monopoly of the handcrafting watchmaker-masters in the complications manufacturing.

The Tourbillon became very popular in the 90's. It was used in the most prestigious brands collections, such as Girard-Perregaux, which miniaturised the Tourbillon "sous trois ponts d'or" for the wrist, which was not an easy task. But it was also used by less prestigious brands, mostly delivered by the Joux Valley manufactures. These are now restricting a bit the access to such a prestigious mechanism to avoid its trivialisation. Not everyone deserves a Tourbillon…

Using your mouse, move the pointer over the 3D animation and manipulate the watch according to the instructions appearing below the window. Discover the name of the parts while moving your pointer over these.
Click on the Tourbillon-cock to isolate the mechanism and to observe the details.
Click on the bottom-cage to dismantle the various parts and to observe them one by one.

This animation contains audio.



it is offered by:
Patek Philippe

The first watches containing a striking mechanism already appeared at the end of the 15th century. The Englishmen Edouard Barlow, Daniel Quare, Thomas Tompion et Thomas Mudge contributed to the development of mechanisms striking the time on request. Abraham-Louis Breguet imagined a ring made with a steel strip, which was further developed by François Crespe. The big advantage of this device was the little room it needed while producing a nice tone.

The popularity of watches striking the hours came from the fact that people were using candles; therefore it was the most convenient way to get the hours during the night. Even though this practical use disappeared, watchmakers continued to develop striking repeater pocket watches during the 19th and 20th centuries. The amateurs of fine mechanical complications were still in love for one of the achievements of the watchmaking art.

One problem remained: bringing the minute-repeater to the wrist. he mechanical movements used for this purpose were first the ones made for ladies' pendant -watches. It was necessary to find smaller calibres compared to pocket-watches, but big enough to produce a nice tone. In 1982, Audemars-Piguet produced the first wrist-watch with a minute-repeater.

Amongst other manufacturers, LeCoultre produced very sophisticated movement-blank before 2000 to develop minute-repeater wristwatches. The first known Patek Philippe complex wristwatch is a lady's five minute-repeater, a unique piece dated of 1915.

The manufacturing of minute-repeater watches remained confidential. For example, the Geneva brand produced no more than forty between 1925 and 1942.

We had to wait a half of a century and the renewal of mechanical watches after the "quartz" years to find again striking watches at the forefront of the watch industry news. The bet of the miniaturisation was launched with technical outstanding performances to follow.

In 1992 in Basel, Philippe Dufour created a sensation by showing the first wristwatch with a small and grand strike. In 1998, Audemars-Piguet developed a 22,3 mm diameter lady's minute-repeater wristwatch with carillon.

In 2000, Girard-Perregaux was awarded the Montres Passion - Uhrenwelt Jury Special "Watch of the Year" price for its "Opera One", an automatic wristwatch Westminster carillon minute-repeater with tourbillon.

A minute-repeater watch is immediately identifiable with its lever or push button on its case for the setting of the mechanism. There are two types of strikes. The minute-repeater gives the precision of a minute using a series of three tones using two timbres.

The lower timbre counts the hours, the double striking of the upper and lower timbres counts the quarters and finally the upper timbre counts the minutes up to the last quarter. At 11h58 we shall hear therefore eleven lower timbre three double lower-upper timbres and finally thirteen upper timbres.

The quarter-repeater only gives the hours and the quarters, while the five minute-repeater strikes the hours and the number of periods of five minutes.

There are also, but rarely, half-quarter repeaters that strike on two timbres the hours and the quarters with a supplementary tone if the half of the next coming quarter is over.
A grand strike automatically rings the hours and the quarters in the course of the time and rings the full strike, namely the hours, the quarters and the remaining minutes on request. Another variation consists in the regular strike which only rings the quarters, while the grand strike repeats the hours' strike at each quarter. All these rings are equipped with a bolt to silent them when needed.

The ringing with carillon gives the quarters with three timbres. The Westminster carillon, very rare, plays the London Parliament famous clock melody on four timbres. Until the beginning of the 21st century, pocket watches could not truly reproduce the famous Haendel melody, having problems repeating the same tone in one sequence. Amongst the six major innovation included in the Star Calibre 2000 Patek Philippe pocket-watch, one is a true Westminster carillon which has been patented.

Using your mouse, move the pointer over the 3D animation and manipulate the watch according to the instructions appearing below the window. Discover the name of the parts while moving your pointer over these.
Click on the hour's icon to have the mechanism striking at your PC time.
Click on to select one animation.
Turn the part over on the hammers side to isolate the mechanism !

This animation is offered by:
Audemars Piguet

The power reserve indication has had a great appeal since a few decades, animating the dials of numerous timepieces. It gives useful information on how the barrel mainspring is armed, therefore on how much autonomy remains to power the watch, for both manual and automatic movements.

The principle of such a measurement is quite old, well known and quite simple. At its origin, we see once again the brilliant and inevitable Breguet.

At the end of the 18th century, he developed watches with a barrel mainspring arming indication as well as with a striking spring arming indication for minute repeater watches.

The principle of the power reserve indication is quite simple. A hand running through a dial sector displays the number of revolutions made by the barrel mainspring while unwinding.

It usually takes six to nine revolutions to fully rewind the 20 to 60 cm mainspring, while there are four to six unwinding revolutions per day. Depending on timepieces, it takes about 24 to 72 hours to fully unwind the barrel mainspring.

Strictly defined, the power reserve is the time during which the movement will run over the guarantied 24 hours running period for a wristwatch (or 7 days for a clock). Practically, it is the full duration of the movement running period, and the hand shows the decreasing of the mainspring unwinding up to zero.

Knowing the time remaining before the complete unwinding of the barrel mainspring is one thing. However, the power reserve does not show anything about the quality of the remaining power. We have to know that a watch does not run with the same accuracy as the mainspring unwinds. The accuracy depends on the couple delivered by the mainspring which is the expression of two mechanical forces.

The mainspring does not produce the energy in a linear way. It is strong at the beginning when the mainspring is armed to its maximum.

It is then a plateau or a slow decreasing slope which represents the ideal energy level produced during an important part of the unwinding mainspring period. At a certain time, the energy produced decreases rapidly. There remains however enough energy to keep the movement running, but the top accuracy may not be there anymore.

When should we rewind our watch to ensure the best possible accuracy? The answer was brought by Audemars Piguet.

The Joux Valley manufacturer developed the Dynamograph which measures th