The unique Maître Cabinotier Astronomica watch is inspired by the world’s most complicated wristwatch that paid tribute in 2005 to the 250th anniversary of Vacheron Constantin’s very famous Tour de l’Ile. Calibre 2755-B1 is one of the most complex ever made by the Manufacture. This mechanical manual-winding movement with a 58-hour power reserve offers 15 complications driven by 839 parts, while measuring a modest 33.90 mm in diameter and 12.15 mm thick.
These many useful functions can be read off on both the dial side and the back of this watch, constitute an authentic technical feat. Both this unique wristwatch and its movement bear the prestigious Hallmark of Geneva.
This Grande Complication model also evokes the spirit of the “Atelier Cabinotiers” created by Vacheron Constantin in 2006, an extremely specialised service of creating bespoke Haute Horlogerie watches.
Grandes complications horology and astronomical indications
Minute repeater, equation of time, tourbillon, perpetual calendar, date, day of the week, month, leap years, power reserve, sunrise and sunset times. In addition to the hours and minutes, 11 complications are displayed with both clarity and distinction on the front, or dial side. The minute repeater is fitted with an ingenious centripetal flying strike governor, developed by the Manufacture Vacheron Constantin. Perfectly silent and preventing undue wear of the frequently solicited striking mechanism, it serves to regulate the duration of the musical sequence in order to ensure that the notes chimed for the hours, quarters and minutes are both melodious and distinctly audible when the hammers strike the gongs.
The dial reveals a stunning tourbillon at 6 o’clock, equipped with the traditional carriage shaped like a Maltese cross. The perpetual calendar is capable of keeping up with the complexities of the Gregorian calendar without any need for human intervention other than a date change every 400 years.
The displays are symmetrically arranged with the day of the week appearing at 9 o’clock, the month at 12 o’clock and the date at 3 o’clock, while the leap-year indicator is discreetly positioned at 1 o’clock. The equation of time is shown by means of a short hand positioned at 10.30. It serves to measure the difference in minutes between solar time and standard legal time.
The sunrise and sunset times complication provides an accurate indication of this information for a given location on Earth – which in turn means that client must first choose the city for which he wishes to have the sunrise and sunrise times. The display of this “customised complication” is rigorously symmetrical, with sunrise appearing at 8 o’clock and sunset at 4 o’clock.
The mysteries of the cosmos
The back of this timepiece features four complications and displays seven functions: a sky chart, the solstice, the equinox, sidereal time, the age and phases of the moon, the seasons, and the zodiac signs. This rare dial exclusively dedicated to displaying astronomical functions is built on two levels. The central disc bears a sky chart of the northern hemisphere, as well as the four cardinal points. Through two South and North openings, it symmetrically displays the months of the year and sidereal time, corresponding to “true” time. The latter indication is a necessity for watchmakers and enables them to adjust the sky chart according to the reference city chosen by the sole client. A small hand sweeping around the rim of the first dial level shows the age of the moon, meaning the number of days since the last full moon. On the second dial, a long and slender central hand, tipped with a sun on its counterweight, points to the date on the outer rim of the disc and also indicates the zodiac sign, the season, and the equinox or the solstice corresponding to the current date.
Uniqueb by its very essence
Calibre 2755-B1 fits smoothly inside the 47mm white gold. Each part is finely adjusted and harmonised so as to guarantee optimal performances, making each movement a unique masterpiece. Its impressive level of finishing is expressed through meticulously hand-bevelled bridges adorned with Côtes de Genève, a circular-grained mainplate, as well as the smoothly rounded-off tourbillon carriage bar.
This highly unusual combination of 15 particular complications within a single watch demands a degree of mastery that is truly exceptional in the spheres of Haute Horlogerie. In light of its complexity and originality, the Maître Cabinotier Astronomica is quite naturally issued as a limited edition of one.
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