With its time-related and astronomical complications regulated by a tourbillon and completed by a minute repeater, the manual-winding 2755 TMRCCQP calibre powering this watch is a masterpiece of complexity with its 774 components.
Representing one of watchmaking’s most sophisticated grand complications, this white gold single-piece edition displays its indications in a perfectly legible manner. Stemming from an aesthetic quest dedicating elegance and purity of style to the service of technical sophistication, this timepiece is notably distinguished by the Maison’s characteristic retrograde function as well as by the refined finishes highlighting the double moon phase display that is the key feature of this watch.
On the front of the watch, the eye is drawn to the depiction of the moons in the two hemispheres on a disc coaxial with the central hands and shaped like a starry dome. Its deep blue colour makes a striking contrast with the silvery hue of the dial as it performs a complete rotation in 59 days, 12 hours and 45 minutes. Such is the tempo given to so-called astronomical moons, which scrupulously respect the duration of the synodic months with a discrepancy of only 24 hours every 122 years and 16 days.
The age of the Moon is indicated around a periphery scale graduated from 1 to 29½. On this titanium dome graced with rhodium-plated moons on a blue-sky background obtained by physical vapour deposition (PVD), the meticulous care devoted to details – orchestrated in nine stages and involving nearly 56 hours of work – adds an additional original touch. The uneven surface of the moon, like the brilliance of the tiny stars, was achieved by diamond cutting: a micron-level high-precision machining process which gives faceted depth to the material that shines or sparkles differently depending on the angle from which the light plays across it.
The display of the hours and minutes of mean civil time complete with lunar cycles has been slightly off-centred upwards to enable the harmonious integration of calendar indications. Instead of the traditional pointer-type dials used for perpetual calendar indications, Vacheron Constantin's Master Watchmakers and designers opted for rotating discs. This solution adopted for a mechanism that follows the vagaries of the Gregorian calendar without any need for correction before 2100, is admittedly more complex on a technical level yet offers greater flexibility in the arrangement of the indications to ensure more convenient readings.
The semi-instantaneous display of the day and the instantaneous display of the month and leap-year appear through apertures, as does the date display. Here again, this display positioned on the upper rim of the dial is shown through a semi-circular window, but with a retrograde hand. A technical and stylistic signature of Vacheron Constantin since the early 20th century, retrograde mechanisms require great precision in the doubling of the gears used to store the energy required for the return of the indicator.
The four-part dial construction and the finishing of each fully matches the technical nature of the model. A 0.35 mm thick sapphire dome is placed on a silver-toned metal baseplate with a sandblasted finish and openworked calendar apertures. This dome beneath which the moonphase disc turns is fitted with two ‘masks’ whose smoky appearance is achieved by metallisation. It is held in place by a curved brass ring, satin-brushed with an opaline varnish, which in turn bears the white gold hour-markers.
The likewise multi-part rear dial construction ensures the clarity and understatement of the various displays. To ensure the moon phases take priority on the front of the watch, the opening revealing the tourbillon regulator has been placed on the back. Invented at the beginning of the 19th century, this device enclosing the escapement and the balance-and-spring assembly in a mobile carriage is designed to compensate for the effects of Earth’s gravity on the isochronism of the regulator and thus ensure enhanced precision. The one-minute-rotating tourbillon is distinguished by its carriage shaped like Vacheron Constantin’s Maltese cross emblem, with its delicately hand-polished bar. To diminish the weight (hence improving performance) as well as for aesthetic reasons, the tourbillon components have been skeletonised – notably the fixed wheel which is entirely openworked.
A fixed dial, bearing a blue dot representing the celestial horizon, is positioned below a movable sapphire crystal engraved with the constellations, while the rim features month markings as well as five-day graduations. By performing a complete rotation according to sidereal time, this mobile disc gives the exact position of the constellations – delimited by the celestial horizon – at the time when the watch is consulted by pointing it Northwards. Sideral time is read off counter-clockwise, facing the current date on the fixed PVD-treated blue outer ring bearing a 24-hour scale along with the cardinal points.
