acheron Constantin celebrates its 270th anniversary and its quest for excellence with a new series of Les Cabinotiers watches entitled ‘La Quête’, which pays tribute to astronomy and the odysseys of ancient times. Representing significant technical and aesthetic challenges, these watches highlight Vacheron Constantin’s expertise in creating grand complication watches enhanced by the decorative crafts.

The Les Cabinotiers Grande Complication High Jewellery – Moon Dust watch illustrates this vision. Incorporating 16 complications and crafted in 18K white gold, engraved and guilloché by hand and set with diamonds, it offers a poetic interpretation of a journey from Earth to the Moon, celebrating the link between watchmaking artistry and celestial exploration.

The observation of the stars, the cycle of the seasons and the alternation of day and night have always aroused human curiosity, and from very early times, mankind sought to model these phenomena. Thanks to the first astronomical observatories, space-time became a more concrete concept, explained in terms of measurable cycles. Since ancient times, astronomers have proposed various cosmological systems capable of explaining these rhythms in a logical and scientific manner.

The Les Cabinotiers Grand Complication High Jewellery – Moon Dust pays tribute to them not only through its multiple astronomical complications, but also through decorative arts illustrating the great laws of the cosmos as described since Copernicus. These appear on either side of the case with two representations of the solar system as seen during a journey from Earth to the Moon.

The Les Cabinotiers Grande Complication High Jewellery – Moon Dust watch, equipped with Calibre 2755 GC16, benefits from the research and development carried out for the Tour de l’Ile watch, created to mark the Maison’s 250th anniversary in 2005.

Calibre 2755 GC16 is a hand-wound manufacture movement equipped with a tourbillon regulator. This horological complication compensates for the effect of Earth’s gravity on the mechanism by constantly changing the positions of the escapement and regulator. Contained within a Maltese cross-shaped cage reminiscent of the Vacheron Constantin emblem, the tourbillon completes one full rotation per minute and serves as a small seconds indicator.

The watch also incorporates a minute repeater that chimes on demand to indicate the hours, quarters and minutes. To minimise background noise while also reducing wear on the mechanism, the striking of the gongs is controlled by an ingenious rotating regulator. This singular system is distinguished by its two weights, which act with centripetal force generate a kind of ‘engine brake’ on the striking bar. Operating in complete silence, it regulates the duration of the musical sequences and smooths the energy released by the barrel, thus producing clear, distinct and perfectly rhythmical sounds.

The calendar and astronomical functions are positioned on both sides of the watch. Beginning with the front dial, an aperture at 6 o’clock reveals the mechanical ballet of the tourbillon, and the perpetual calendar is displayed on the three counters: the date at 3 o’clock, the day at9o’clockandthemonthat12o’clock.Taking into account the particularities of the Gregorian calendar does not require any correction until 2100, which is a secular non-leap year. The leap year indication is displayed in a small window at 1 o’clock, next to a hand that indicates the minute repeater torque. The power reserve indicator for the movement is displayed on the counter at positioned at 9 o’clock, by a serpentine hand mounted coaxially with the day of the week hand, echoing the power reserve indicator for the chime.

This mechanically complex calibre provides an astronomical reading of time. The equation of time is indicated on a gauge on the upper left- hand edge of the dial.

Since the Earth’s orbit around the Sun is elliptical rather than circular, and since the Earth’s axis is tilted at 24° to the plane of its orbit, the time between two passages of the Sun though its zenith differs from day to day throughout the year. This difference between the solar (or true) day and the 24-hour civil (mean) day ranges from -16 to +14 minutes depending on the time of year is shown as the equation of time, which coincides only four times a year at the solstices and equinoxes. On the lower part of the dial, to the left and right of the tourbillon, the times of sunrise and sunset for a reference city are displayed.

On the reverse side of the watch, sidereal time is marked on a fixed disc with an aperture that reveals a rotating disc showing the constellations that can be observed from the Northern Hemisphere. Taking a fixed star in the celestial vault as a reference point, the time it takes for Earth to complete a full 360° rotation, or sidereal day, is exactly 23 hours, 56 minutes and 4 seconds. As the Earth rotates on its axis and revolves around the sun, it takes approximately four minutes less than a calendar day to return to its original position in relation to the given star.

On this watch, the disc engraved with the constellations makes an “accelerated” rotation by 4 minutes, according to sidereal time. The time is displayed on a fixed, open-worked dial, graduated in 15-minute increments. The date is located on the periphery of the rotating disc, opposite the hour, and is also indicated on the fixed outer flange, graduated in 5-unit increments, by the large central hand. This hand also indicates the four dates corresponding to the solstices and equinoxes, the signs of the zodiac and the seasons, which are marked on a series of concentric circles. The smaller central hand indicates the age of the moon, meaning the number of days since the last new moon.

Comprising 839 meticulously finished components, the caliber measures 33.90 mm in diameter and 12.15 mm thick. Beating at 18,000 vibrations per hour (2.5 Hz) and offering a 58-hour power reserve, it is set in an 18k white gold case. Measuring 47 mm in diameter, the case has been specifically designed to provide the best sound quality for the minute repeater. This feat of technical skill and miniaturization displays all its functions with perfect legibility on both sides.

To showcase this grand complication calibre, Vacheron Constantin called on the talents of its masters in the arts of engraving, gem-setting and guilloché work. A ‘celestial’ decoration evokes the great laws of the universe and the intersidereal journeys that took man to the Moon.

The gem-setting is particularly complex and involves several techniques. Baguette-cut diamonds are rail-set on the flat areas of the case: in a double row on the front dial bezel and a single row on the reverse dial bezel, as well as on the top of the lugs and the folding clasp. The case middle and lugs are illuminated by snow setting, a technique created by a seemingly random paving of brilliant-cut diamonds of different diameters that creates an almost unbroken expanse of reflected light, with minimal visible metal. Harmonising with the engraving on the case middle, the diamonds evoke the moon dust that gave this watch its name.

Amplifying the astral theme, the spaces between the lugs are engraved using the taille-douce technique and setting en masse with diamonds to evoke a comet and the Milky Way. The gem-setting represents 230 hours of work, with total of 200 baguette-cut diamonds ( 9 carats) and 165 brilliant-cut diamonds ( 0.92 carats) – in nine sizes ranging from 0.7 to 2 mm – adding radiance to this immersion into the heart of the solar system.

The engraver’s work brings the richness of the decoration to life. On the crown side, engraved sunrays shine through clouds towards Earth, while the opposite side of the case depicts a view of the planets as seen from the Moon. This spectacle is created by taille-douce engraving – a combination of drypoint and burin engraving, that creates incisions of around 0.1 millimetres deep.

To bring out the slightly domed surface of the moon at 9 o’clock and the contours of Earth on the crown side, slightly more pronounced incisions of around 0.5 mm are made. Once the volumes have been created, the engraver alternates between polished surfaces, particularly on the planets, and finely chased surfaces to accentuate the sense of depth and perspective of the panorama. To complete the engraving on this watch required 180 hours of meticulous work.

The front dial is guilloché by hand in a radiating pattern that adds visual depth to the blue PVD coating and evokes the immensity of the universe. The dial is also enhanced by a black opaline border, which is repeated on the three perpetual calendar counters and the sunrise and sunset indicators to accentuate the sparkle of the diamonds set on the case.

TECHNICAL SPECIFICATIONS

• REFERENCE 9717C/000G-289C Hallmark of Geneva certified timepiece

• CALIBER 2755 GC16 Developed and manufactured by Vacheron Constantin Mechanical manual-winding 33.90 mm diameter, 12.15 mm thick Movement power reserve: approximately 58 hours 2.5 Hz (18,000 vibrations/hour) 839 components 42 jewels 16 complications

• INDICATIONS Hours, minutes, tourbillon, small seconds on tourbillon carriage, perpetual calendar, equation of time, sunrise and sunset time, minute repeater, striking mechanism torque, celestial chart for the Northern hemisphere, Moon phase, Moon age, sidereal hours and minutes, seasons and zodiac signs

• CASE Hand-engraved 18K white gold set with 184 baguette cut diamonds (approx. 8.68 cts, IF-VVS, D-G) and 165 brilliant-cut diamonds (approx. 0.92 ct, IF-VVS, D-G) 47 mm diameter, 19.10 mm thick Double-sided

• DIAL Blue hand-guilloché with black opaline edge and black opaline and blue azuré counters 18K white gold appliques for hour markers 18K white gold hands

• STRAP Dark blue Mississippiensis alligator leather with alligator leather inner shell, hand-stitched, saddle-finish, large square scales

• CLASP 18K white gold folding clasp set with 16 baguette-cut diamonds (approx. 1.02 cts, IF-VVS, D-G)