The Art of Engraving and Skeletonising
The engraving and skeletonising artists have dedicated themselves to a new technical and artistic challenge. “It is indeed a high art to pare away as much ‘flesh’ as possible from a movement without adversely affecting its qualities”, master engraver Dominique Vuez explains.
The engravers know the necessary tricks. “Our customers want to be able to see as many of the details as possible. But when we skeletonise a movement, we must assure that neither its rigidity nor its reliability could potentially be undermined.” The engraver began by obtaining the relevant documents forCalibre 876 from its designers. He then determined which components could safely be pierced and which portions of those components could be cut away. In collaboration with watchmakers from the ateliers for Complications Horlogères, he specified every tiny detail in his sketches and plans. Of course, he could rely on the many years of experience and on the legacy handed down to his generation from his predecessors in the Manufacture, who had used similar technical aids to accomplish the intricate tasks of skeletonising.
Alongside the technical aspect, the Master Grande Tradition à Quantième Perpétuel 8 jours SQ prioritises and embodies lofty aesthetic standards because its creators were eager to pay tribute to the model from 1928 and simultaneously to prove that the non plus ultra had not yet been achieved.
After completing a detailed skeletonising plan, the master and his team take their traditional jigsaws and limes in hand and begin the delicate work. Millimetre after millimetre are meticulously sawn away to eliminate superfluous “flesh” from the movement. The skeletonising process is irreversible, so even the slightest error would be fatal. All parts of the movement are then bevelled, polished and elaborately engraved by hand, one by one. The farther the work progresses, the more clearly this synthesis of the horological arts comes into view.
The Art of Enamelling
The next task is to decorate the white gold rings, one adorning the dial and another one for the case back of the watch. First finely chiseled by hand, they are then covered with blue transparent enamel using the grand feu “champlevé” method. Master enameller Miklos Merczel and his team begin by applying the enamel on the surface of the piece using a very small paintbrush. Afterwards the piece is repeatedly fired in a kiln until it acquires the desired blue hue. Each firing, which reaches temperatures between 800 and 820 degrees Celsius, jeopardises the artwork because the torrid heat could cause cracks or undesired inclusions. The piece is then delicately polished with diamond powder. Enamelling always demands plenty of patience, and the Manufacture’s most experienced enamellers need 2 days of work to complete the two enamel rings that surround the dial and movement.
Now a watchmaker from the atelier for Complications Horlogères begins to unite the more than 200 springs, levers, program wheels, pinions and gears with the tiny artworks from Dominique Vuez and Miklos Merczel. But anyone who assumes that this ticking objet d’art is finished would be mistaken, because the assembled timepiece is now subjected to meticulous tests of its functions and to numerous stress tests, which are performed in the Jaeger-LeCoultre’s 1000 hours control unit. The examiners here are unforgiving because the Manufacture’s high standards of quality must be unconditionally upheld. Only now is the artwork of the Master Grande Tradition à Quantième Perpétuel 8 jours SQ complete.
2004 Master Eight Days Perpetual model
Our main subject is the Master Grande Tradition à Quantième Perpétuel 8 jours SQ, but let us take a closer look at the model which served as its basis. The Master Eight Days Perpetual equipped with Jaeger-LeCoultre calibre 876 ranks among the most interesting complications currently made at the Manufacture in the Vallée de Joux. Unveiled in 2004, it’s a beautiful example of timekeeping artistry and a genuine jewel for the wrist. In addition to the time of day or night, its dial also hosts several calendarical displays: the date, the day of the week, the month, the complete year as a four-digit number, and the age of the moon. A power-reserve indicator and a day/night display with a red safety zone highlighting the calendar’s daily switching phase further increase the already plentiful array of information. All displays on the dial are intelligently conceived and structured in accord with their significance so the viewer always enjoys a clear overview, despite the high density of the data presented. The time, the day of the week, the date and the month are all depicted in large, readily legible fashion. The power- reserve display and the day-night indicator are harmoniously and symmetrically integrated into the upper half of the dial. The complication is a so-called “perpetual calendar”, which means that all of its displays are mutually synchronised so no manual corrections are necessary — not even in leap years when February has a 29th day. The next exception to this rule will occur in 2100, a secular year that is not evenly divisible by 400 and is therefore not a leap year. If the watch is left to languish without running for a lengthy interval, its owner can press a button to advance its displays in single-day increments: all indicators respond by switching exactly one day forward, thus eliminating the need for elaborate resetting.
Hand-wound Jaeger-LeCoultre Calibre 876 concatenates 262 components, including 37 rubies, but is a mere 6.6 mm tall. To the greatest practicable degree, this calibre is manufactured, assembled and elaborately decorated on the Manufacture’s premises. A glance at its surfaces instantly discovers côtes soleillées decorations, which are reserved for the exclusive creations from Jaeger-LeCoultre. The balance, which has no regulator, oscillates at a frequency of 28,800 semi-oscillations per hour. After the mainsprings have been fully wound, the power reserve suffices to keep the movement running for eight full days. Only afterwards must one take the watch in hand and turn its crown, thus refreshing the supply of energy stored in its two barrels.
A total of 200 Master Grande Tradition à Quantième Perpétuel 8 jours SQ wristwatches will leave the Manufacture in the Vallée de Joux, and each one of them is unique! The engravers and enamellers cannot possibly fabricate two absolutely identical models. Numerous tiny details necessarily distinguish one skeletonised movement from all others, and the grand feu enamel in one watch will never be wholly identical with its counterpart in another.