Press release

BASELWORLD 2008
Patek Philippe, Geneva
April 2008
Patek Philippe World Time watch Ref. 5131
The watch as a work of art
At this year’s Baselworld, Patek Philippe is unveiling the World Time watch Ref. 5131. It is a debutthat will charm many people for many different reasons. Its mechanism for the permanent display ofall 24 time zones and its amazingly fast adjustability to any local time, constitute a technical coupthat will appeal to everyone who admires useful complications. In turn, its cloisonné enamel dial will
delight connoisseurs of the art of enamelling. Finally, watch collectors will be pleased to see thisparticular type of timepiece – at international auctions, its predecessors meanwhile fetch
astronomical prices – back in the Geneva workshops’ standard collection.
24 time zones with a glance at the wrist
Patek Philippe’s multiple time zone watches belong to the category of so-called usefulcomplications. They serve their owners well with practical functions of relevance in contemporary
everyday life. A World Time watch indicates the hour in all major cities at a glance. The local time
indicated by the hour and minute hands applies to the location on the city disk that is directly alignedwith 12 o’clock. The crown is used to set the correct time in conjunction with the 24-hour ring, so a
distinction can be made between 4 am and 4 pm. Now, switching from one time zone to another isaccomplished simply by pressing the button at 10 o’clock. Every time it is pressed, the hour handwill advance by one hour while the city ring and the 24-hour ring will rotate counterclockwise by one
hour (equivalent to one time zone). Pressing the button 24 times emulates a trip around the world
and a return to the point of departure.
This mechanism was devised by the gifted Geneva watchmaker Louis Cottier in the early 1930s. He
offered his invention to Patek Philippe first and in 1959, the company protected it with Swiss PatentNo. 340 191. Subsequently, the ingenious inventor created another mechanism for the Genevabased manufacture. It was able to display two time zones simultaneously. In the late 1990s, thissecond invention inspired the development of the Calatrava Travel Time.
With a solution patented in 1999, Patek Philippe further optimized the caliber 240 HU (HeureUniverselle = World Time) movement by totally isolating the World Time mechanism with the cityand 24-hour rings from the going train of the watch. Thus, when the mechanism is switched from
one time zone to the next, the accuracy of the movement and the progression of the minute handare not affected. Caliber 240 HU is an ultra-thin self-winding mechanical movement that features a22K gold mini-rotor recessed in the plate. It beats with a frequency of 21,600 semi-oscillations perhour (3 Hz). In 2000, Patek Philippe used this movement to reintroduce the World Time watch intoits standard collection; it proved to be an instant bestseller.

CHEMIN DU PONT-DU-CENTENAIRE 141 - CH-1228 PLAN-LES-OUATES
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Continued 2Watches for connoisseurs and collectors
The exclusivity of these complications is no doubt the principal reason why Patek Philippe’s 1940sand 1950s World Time watches fetch higher prices at international auctions than any otherwristwatches. Bids in the magnitude of several hundred thousand Swiss francs are now the rule, but
the record today is still held by an early platinum model that changed hands in 2002 for the fantastic
sum of 6.6 million francs (in excess of US$6 million).
Models showcasing a small, hand-made cloisonné enamel miniature in the center of the dial areparticularly coveted. The eclectic motifs range from clusters of palm trees to solitary lighthouses, but
the most popular ones are colorful, stylized world maps because they best match the purpose of thetimepiece. Such a map also adorns the dial of the new Patek Philippe Ref. 5131, finally giving
collectors the renewed opportunity to find a watch in this category within the company's current
portfolio.
Due to the complex processes involved in the making of cloisonné enamel dials, only a small
number of Ref. 5131 watches will be available each year.
The art of cloisonné enamelling
In addition to Geneva enamel and champlevé enamel, cloisonné enamel is one of the three classic
techniques traditionally used to decorate watches and dials. The motifs are always silhouettes
whose contours define the shapes of the “cloisons” (French for partition, or cell) that ultimately
contain the differently colored zones of the finished enamel opus. A characteristic shared by all
enamelling techniques is the stunning brilliance of the colors: unlike paintings that use conventional
pigments, they do not fade and retain their luster for centuries.
A cloisonné enamel piece begins as a wafer of copper or gold into which the contours of the motif
are scored by hand. Subsequently, the lines are retraced with very thin, flattened gold wire. Like adainty ribbon standing on its edge, the wire is bent with tweezers to follow the contours and thensecured in a first firing; eventually, the entire drawing is composed of a number of cloisons which
now need to be filled with the enamel mass. Enamel consists of finely crushed glass ground topowder. The addition admixture of various metal oxides produces the colors when the glass ismelted. After the powder has been filled into the cloisons, the work of art can be fired in a special
furnace at temperatures between 850 and 900°C. To prevent distortion, the reverse side of thewafer must also be coated with a layer of enamel, the so-called: “contre-email”.
Because the metal oxides added to the powder can change their color at different temperatures,enamel work can involve numerous firings passes. The end result is a colorfully arrayed glass motif
from which the gold wires forming the cells protrude. These wires are then polished down to thelevel of the glass layers, and in the final phase, the entire work of art is protected by the fondant, acolorless, highly transparent layer of enamel applied in a last firing process. At the end of every
firing pass, the enamel miniature must be allowed to slowly cool to room temperature in a precisely
controlled manner. Otherwise, thermal stresses could cause the hard, fused glass to crack.
Thus, The art of cloisonné enameling not only requires virtuosity and a highly developed sense ofaesthetics. The artisans who master it must also be fully aware of the technical, physical, andchemical processes involved in preparing, mixing, applying, and firing the enamel mass. Until theearly 20th century, cloisonné enameling, champlevé enameling, and miniature painting according to
the acclaimed Geneva enameling traditions were precious skills needed to embellish watches andContinued 3other luxury objects. Elsewhere, the tradition sank into oblivion, but Patek Philippe never stopped
crafting beautifully decorated enameled wristwatches, pocket watches, and table clocks featuringlavish decorations based on venerable enameling techniques. After all, an art must be preserved inorder to ensure a successful future.

Continued 4

Technical data
World Time watch – Ref. 5131 in 18K yellow gold
Movement:Caliber 240 HU
Self-winding mechanical movement, display of 24 time zones,
day/night indicator

Diameter:Height:Number of parts:
Number of jewels:
Power reserve:
Winding rotor:
Balance:Frequency:
Balance spring:
Balance spring stud:

27.50 mm
3.88 mm
239
33
Max. 48 hours
Mini-rotor in 22K gold, unidirectional winding
Gyromax
21,600 semi-oscillations/hour (3 Hz)
Flat
MovableFunctions:Two-position crown:- Pulled out: to set the time
- Pushed in: to wind the watch

Time zone correction
button at 10 o’clock:

Synchronized clockwise advance of the hour hand in one-hour
increments and counterclockwise rotation of the city and 24-hourdisks in 15° increments. This correction takes place without
affecting the rate of the movement or the progression of the minutehand (Patent No. 99124527.5 dated December 9, 1999).

Displays:

Hours and minutes
City disk
24-hour disk with day/night indication by color and sun/moonsymbols

Hallmark:

Geneva SealFeatures
Case:

18K yellow gold with engraved Patek Philippe signature at 12o'clock and Genève at 6 o'clock
Screwed back in 18K yellow gold with sapphire-crystal window
Water-resistant to 30 meters

Dimensions:

Diameter: 39.50 mm
Height: 10.61 mm
Width between lugs: 21 mm

Continued 5

Dial:

18K yellow gold, center of dial with world map in hand-crafted
cloisonné enamel
Disks:- Black printed city disk with new italic face
- 24-hour disk with day/night indication by color and sun/moonsymbols (blue day numerals on silvery background, white night
numerals on blue background)

Hands

Ring-shaped hour hand in 18K yellow gold
Dauphine minute hand in 18K yellow gold

Strap:

Alligator with rectangular scales, hand-stitched, matt chocolate,fold-over clasp in 18K yellow gold