The White Gold Calibre 89, by Patek Philippe, Genève

The most complicated watch in the world with its 33 Complications.

Introduction and historical information

The Movement

Level 1

The movement of the Calibre 89 is on four levels contained on three plates made of maillechort - an alloy also known as German silver. The 126-jewel movement is driven by a single mainspring barrel and regulated by a tourbillon regulator. Two other mainspring barrels power the chime and the alarm. The movement has a diameter of 71.5 millimeters, including the mountings for the plates, and is 28.05 millimeters thick. It weighs 600 grams (19.29 oz). On this side of the main plate (fig. 1) are found the mechanisms for the chime, the alarm, the 12-hour recorder and the power reserve (up-down) indicators for the chime and movement.

Level 2

he movement contains 1278 parts, including 332 screws, 184 wheels, 61 bridges, 68 springs, 126 jewel bear-ings, 24 hands, eight discs, two main dials and 429 composite mechanical components. The mechanisms for mean time, the chronograph, the 30-minute recorder, as well as the tourbillon, are mounted on the other side of the main plate (fig. 2). The tourbillon can be seen on the left at about 8 o?clock.

Level 3

The functions of the watch are controlled and set by 12 external slide-pieces, push-pieces and winders. The second plate (fig. 3) holds the mechanisms for the functions of the sidereal dial, namely: sidereal time, the sea-sons, solstices, equinoxes and zodiacs, the times of sunset and sunrise, the equation of time, the date of Easter and the star chart. The crenellated cam for the date of Easter, surmounted by its snail cam, can be seen just below theengraved bridge at the top.

Level 4

The mechanisms for the secular perpetual calendar, the second time-zone indicator, the phases of the moon and the thermometer are supported by the third plate (fig. 4), which faces the mean time dial. The secular perpetual calendar mechanism is under the disc bearing the names of the months at the right of the move-ment. The century wheel and its satellite that completes a revolution every 400 years, are hidden by the bridge plate at 3 o?clock

The tourbillon regulator (fig. 5), invented by Abraham-Louis Breguet (1747-1823), compensates for errors ari-sing when the watch adopts different positions in relation to the prevailing gravitational field. The design requires the balance wheel and escapement mechanism to be mounted in a cage which itself revolves, usually at one revolution per minute. The tourbillon ensures that the load is evenly distributed on all sides of every bearing in the regulator, largely irrespective of the changing position of the watch. In the Calibre 89, improvements were made to Breguet?s original concept. Instead of placing the tourbillon regulator in its traditional position as part of the fourth wheel of the main drive-train, the fourth wheel engages the cogged rim of the tourbillon?s cage. The fourth wheel of the train not only drives the seconds hand and the tourbillon, but also the chronograph and the 32-wheel mechanism of sidereal time. The principal elements of the cage are made of titanium. The cage and escapement are made of 54 pieces and weigh 0.73 grams. The cage revolves once every two minutes. The escapement is of the straight-line, Swiss lever type. The escape wheel has 20 teeth.

The balance-wheel is of the Gyromax type (fig. 5) with variable inertia, vibrating at 18,000 beats an hour, or five times a second. The balance-wheel and its inertia blocks are cut from 14K gold. The Gyromax is a monometallic balance-wheel having inertia blocks arranged around its circumference. The inertia blocks, which are slotted gold weights mounted on pins, provide an elegant means of adjusting the ba-lance- wheel, for they may be turned to increase or reduce the effective radius of the balance-wheel at one or another point on its circumference. The Gyromax balance-wheel enables the regulatory mechanism of the Calibre 89 to be adjusted with greater precision and convenience than regulators equipped with the conventional index. The hairspring is free-sprung with a Breguet overcoil. The 19 pieces making up the balance-wheel assembly, with its arbor and mounting, weigh 0.98 grams. The Gyromax balance-wheel was invented by Patek Philippe & Cie, and is protected by Swiss patent No. 261431 of May 15, 1949 and Swiss patent No. 280067 of December 31, 1951.

The hours, minutes and seconds of mean time

A gold Breguet hours-hand indicates the hours of a second time-zone against the main scale of the solar dial.^The independent hours-hand is mounted on the canon pinion of the hours-wheel, but it can be moved forwards in increments of one hour with each pressure on the push-piece at 11 o?clock. The mechanism for the independent hours-hand is based on a design patented in Switzerland by Patek Philippe & Cie on July 31, 1959 under number 340191. The independent hours-hand enables a traveler to adjust his watch according to the standard time in different time-zones without advancing the minutes-hand

19 Hours of sidereal time	22 Time of sunrise	25 Stars chart
20 Date of Easter	23 Equation of time	26 Sun hand
21 Minutes of sidereal time	24 Seconds of sidereal time	27 Time of sunset

The equation of time

The equation of time is indicated by a blued steel hand against a penannular scale at 12 o?clock on the sidereal dial. The scale ranges from minus 17 minutes to plus 17 minutes. The movement of the hand is governed by a cam driven off the mechanism for sidereal time. The equation of time indicated corresponds to the season shown by the sun hand, which is also driven by the sidereal time mechanism. The equation of time is the difference in minutes between mean time and apparent solar time. It is a conversion factor that ranges from plus 14 minutes and 59 seconds (on or about February 12) to minus 16 minutes and 15 seconds (on or about November 3). On or about April 15, June 14, September 1 and December 24, the value of the equation of time is zero. A knowledge of the equation of time is necessary for navigators who observe the altitude of the true sun at a time noted from a watch keeping mean time.

The hours, minutes and seconds of sideral time

The sidereal time is shown on the sidereal dial by blued-steel hands in the Breguet style against a 24-hour scale. The sidereal seconds are indicated by a straight, small seconds-hand revolving in a subsidiary dial at 12:00. The 32-wheel movement for sidereal time is driven from the fourth wheel of the main movement. The con-version of mean time to sidereal time is made through a reduction train which results in a sidereal second equal to 0.9972677 of a mean second in the Calibre 89 watch. The sidereal second recorded by the Calibre 89 is thus slightly shorter than the true sidereal second, which is 0.9972696 of a mean second. The sidereal time shown by the Calibre 89 gains on mean time at a rate of 3.94512 minutes a day, which means that it will have gained a full 24 hours in a year. Sidereal time may be set by pulling the winding crown to position B and setting the slide-piece to CS. The hands of sidereal time are advanced by turning the winding crown anti-clockwise. Advancing the hands indi-cating sidereal time also causes the sun-hand and the star chart to advance proportionally. The unit of sidereal time is the sidereal day, which is the period between the successive transits of the observer?s meridian by the vernal equinox, also known as the first point of Aries. The first point of Aries, being a hypothe-tical point, is at an infinite distance from the observer. As a point of reference it enables a more regular scale of time than that afforded by using the sun as a reference. Sidereal time is of interest to the navigator who needs to determine the hour-angle of a star.

The times of sunrise and sunset

The hours and minutes of sunrise at Geneva (latitude 46° 11? 59? north), corresponding to the time of year indicated by the sun-hand, are shown on a clock-face in a subsidiary dial at 16:00 on the sidereal dial. The hours and minutes of sunset are shown on a similar clock-face at 08:00. The indication of the time of sunset and sunrise is governed by cam-based mechanisms. The cams can be replaced for latitudes other than that of Geneva. The times indicated are within five minutes of true sunset or sunrise, which is when the sun?s upper limb is on the true horizon of an observer at sea level. True sunset or sunrise is normally corrected to allow for the refrac-tion of the earth?s atmosphere.

The astronomical calendar

The sun-hand (seasons, equinoxes, solstices and houses of the zodiac)

Agold hand decorated with a sun, and set in the center of the main dial, completes a circuit of the dial in the period of a mean solar year, indicating the days of the month, the zodiac, the seasons and the solstices and equinoxes on three concentric scales. The annual circuit of the sun-hand thus represents the apparent journey of the sun around the celestial sphere along the path of the ecliptic. The mechanism of the sun-hand is integrated with those of the hours of sunrise and sunset, the equation of time and the date of Easter. The outer scale of the dial is divided into 12 months and marked with the numerals at intervals of 10 days. It serves to set the sun-hand so that the times of sunset and sunrise correspond to the right day. Setting the sun-hand also sets the times of sunset and sunrise and the equation of time. The sun-hand may also be advanced by setting the winding-crown to the position A and the slide-piece at CS. When the sun-hand has been brought to a position near the intended setting, it may be advanced with greater precision by advancing the hands of side-real time.

The calendar functions The secular perpetual calendar

The secular perpetual calendar regards as leap years the century years divisible by 400 without remainder: the years 2000, 2400, 2800, and so on. In accordance with the provisions of the Gregorian calendar reforms of 1582, the other century years are not taken as leap years. Patek Philippe?s invention of the secular perpetual-calendar mecha-nism with retrograde indicator was granted Swiss patent number 653841 on July 31, 1986. The perpetual calendar shows the century, decade, year, the year in the four-year cycle, the date, the month, and the day of the week. The centuries, decade and year are shown in an aperture in the mean time dial. Two con-centric discs show the century and decade, and the numerals of the year are shown on a separate disc. (In the year 2699, the disc bearing the numerals of the century will have to be changed, as it does not accomodate numerals for the 28th century and beyond.) The number of the year in the four-year cycle is shown in a small aper-ture next to the year aperture. The numerals 1, 2, 3, and 4 are on a disc concentric with the year disc. A straight, blued-steel hand, set in the center of the main dial, indicates the days of the month against a scale in an arc on the mean time dial. It records the months having 31 days and 30 days and accords 29 days instead of 28 days to February in each leap year. Having indicated the last day of a given month, the hand, which is on a sprung ratchet-wheel, flies back to the beginning of the scale to point to the first day of the following month. A three-letter abbreviation of the name of the month and the first three letters of the name of the day appear in apertures in the lower half of the solar dial. The perpetual-calendar mechanism governs a lever on which there are four steps (1). One of these steps is presented to stop the day-of-the- month indicator at the 28th, 30th, or 31st day. The indicator is stopped by a finger (2) which engages one of the four steps. The presentation of the right step is governed by a cam that revolves once a year (3). This cam gov-erns the months with 30 and 31 days. On the circumference of the cam is a four-point satellite (4) which is moved a quarter turn every year. The satellite stops the day-of-the-month indicator on February 28 for three con-secutive years and on February 29 on the leap year. A second mechanism, consisting of a wheel (5) and a satellite (6) in a similar arrangement to that of the perpetual-calendar cam and satellite, overrides the perpetual-calen-dar mechanism at the end of every century for three consecutive centuries. At the end of the fourth century it allows February 29 to be shown. The wheel revolves once every century, and the satellite on its circumference makes a revolution once every 400 years.

The phases and age of the moon

The moon disc, made of corundum crystal, rotates inside an aperture representing the lunar terminators in the solar dial. The disc, decorated with two moons, makes a revolution in 59 days, one hour and 30 minutes - the period of two lunations of 29 days, 12 hours, and 45 minutes. Thus the lunation recorded by the Calibre 89 is 57.2 seconds longer than the mean period between successive new moons, which is 29 days, 12 hours, 44 min-utes and 2.8 seconds. The moon disc advances one day when the watch shows 04:30. It may also be advanced a day at a time with successive pressures on the push-piece at 7 o?clock.

The star chart

The star chart is a disc of corundum (sapphire) crystal marked with 2800 distinct stars in five sizes according to their orders of magnitude. On the other side of the transparent disc is a fine gold-dust background repre-senting the Milky Way. The disc revolves in an aperture in the sidereal dial. The edge of the aperture is so posi-tioned relative to the disc as to represent the horizon at the latitude of Geneva (46° 11? 59? north). For the star chart to show the movement of the stars at a different latitude to that of Geneva, the aperture would have to be repositioned relative to the disc. The movement is designed to accomodate a star chart for the southern or north-ern hemispheres. The star chart is governed by the movement of sidereal time, and can be adjusted by advan-cing the hours and minutes of sidereal time.<

The religious calendar

The date of Easter

The scale bearing the possible dates of Easter, which range from March 22 to April 25, is on the sidereal dial. A straight blued-steel hand points to the date of Easter in each year. The hand points to the letter C on the right of the scale to indicate that the cam governing the date of Easter mechanism should be replaced. The crenellated cam (1) determines the date of Easter for 29 years and causes the hand to point to C in the 30th year. Every year a new radius of the cam engages a shaft (2) which transmits the new position to the hand via a rack and pinion (3). Every year a spiral cam (4) disengages the shaft from the crenellated cam via a system of levers. (5). The cam is then advanced and the shaft is allowed to spring back to engage a new radius. The year wheel of the date-of-Easter mechanism is driven off the hour wheel of sidereal time via a reduction train which also converts sidereal time back to mean time. It was not possible to drive the date-of-Easter mecha-nism directly from mean time because the two mechanisms are on opposite sides of the movement. The date-of-Easter mechanism is unique to the Calibre 89 watch and was accorded patent number 649673 for Patek Philippe by the Swiss federal bureau for intellectual property on December 13, 1985. The principle for determining the date of Easter, a major festival of the Christian church celebrating the resurrection of Christ, was agreed at the first Council of Nicaea in 325 AD. It was based on reports that the resurrection took place shortly after the spring equinox and a full moon. Easter is therefore observed on the first Sunday after the full moon of the calendar vernal equinox, that is to say the full moon that happens upon, or immediately after, March 21 (the astronomical vernal equinox is the time of the sun?s transit of the equator and can happen between March 20 and March 22). If that full moon occurs on a Sunday, Easter falls on the following Sunday. The earliest possible day of Easter is March 22 and the latest, April 25. Other movable feasts in the Christian calendar depend upon the date of Easter; Ascension 39 days after, and Pentecost (Whitsun) 49 days after. The calculation of the date of Easter depends on various astronomical and calendar cycles. These include the luna-tions of the ecclesiastical moon that are considered to be 29 and 30 days alternately, the 19-year lunar cycle denoted by the golden number, the equinox, the civil calendar and the seven-year cycle which determines the position of the first Sunday of the year and which is denoted by the dominical letter. The date of Easter does not reoccur in any pattern that can be represented by a perpetual mechanism in a watch. The cam determines the date of Easter until 2017. A second cam which determines the date of Easter from 2018 to 2046 is provided with the Calibre 89. The date of Easter can be set by advancing the sun-hand past December 31, at which point the date-of-Easter hand will indicate the next date of Easter.

The chronograph functions

The split-seconds (fly-back) chronograph

Non-horological function

The thermometer Asmall, blued-steel, swallow-shaped hand indicates the temperature in degrees Celsius against a scale graduated in degrees Celsius against a scale graduated in degrees from minus 10 to plus 50 and marked with numerals at 10-degree intervals. The scale is set in a semicircle above the aperture of the moon phase indicator and within the mean time records scale. The thermometer works by the expansion and contraction of a bimetallic strip.

The ultra-complicated watches

The table lists and compares the functions of the Calibre 89 and those of two other ultra-complicated watches made in the 20th century: the Graves watch completed by Patek Philippe in 1932 and the Leroy 01, com-pleted by Leroy, the Besançon watchmakers. The Graves watch took seven years to complete and contains more than 800 parts in a movement arranged on four levels. The Leroy watch, which also took seven years to complete, contains 975 parts on four levels. A complication is an additional mechanism in a timepiece that already tells the hours, seconds and minutes. The additional mechanism should be integrated with the movement of the timepiece or be necessary to its time-keeping function in order to qualify as a complication.