For almost two and a half centuries, Vacheron Constantin has been imagining and developing the finest testimonials to horology. Each of its creations is meticulously registered in its archives spanning the long history of the venerable House. 2015 brings a new milestone marking 260 years of uninterrupted history. On this occasion, the Manufacture is celebrating its boldness and expertise with new creations in the Métiers d’Art collection: 12 crystal table clocks. Each is equipped with a new Vacheron Constantin movement comprising a constant-force mechanism and a 30-day power reserve. The series will be progressively unveiled throughout this exceptional year and the first rock crystal model is being given an exclusive preview at the SIHH.
While the 12 table clocks each beat to the pace of the same movement, each crystal arch reveals a unique expression. Four of them celebrate the natural beauty of rock crystal, evoking a “mineral” architecture shaped by the Earth across endless ages.
Exceptionnal stones have been patiently cut and facetted to reveal the geological mineral process that has shaped it. Rare gem-hunters have travelled the world for more than a year to find a spectacular-sized rock crystal corresponding to the architecture of this composition. In this instance, the expertise of the stone-cutter lies in highlighting this natural wonder sometimes described as “solidified light”, which has found its way through several millennia. Such an outstanding result stems from the longstanding expertise and the great sensitivity of the master stone-cutter who reveals the intrinsic beauty of the stone and exalts its radiance.
Heralding a range of splendid objects, the decorated translucent crystal clocks pay tribute to artistic crafts and to purity. Using a metal cane, the master-glassmaker “gathers” the molten crystal from the crucible within the furnace heated to 1500°C, in order to shape a 60-kilogram block using methods that have remained unchanged for centuries. The block is then left to rest for around three days to allow it to cool progressively, before being entrusted to a master-cutter who slices it into several blocks. Five facetted, polished and engraved blocks progressively form the crystal arch, while a last crystal slab is prepared to support the clock movement.
Vividly reflecting Vacheron Constantin’s commitment to perpetuating artistic crafts, these 12 unique creations once again demonstrate the intelligence and talent of the master-artisans such as master crystal makers, stone-cutters, engravers, guillocheurs and enamellists. All have in their own way contributed to enhancing this perpetually changing heritage, these traditions in which the future of the Manufacture is firmly rooted and vividly revealed.
Above and beyond the work on the crystal, two decorative techniques are particularly in the spotlight on the chapter ring and the feet of each table clock: Grand Feu enamelling and guillochage. The 12 satin-brushed silver Roman numerals have been individually crafted and then coated with black Grand Feu enamel. This delicate stage requires finely controlled operations, since the melting point of enamel is 860°C, whereas that of silver is 900°C. The facetted silver feet supporting the table clock feature 12 unique hand-guilloché motifs that shimmer with the translucent colours of Grand Feu enamel. Since each foot is an all-of-a-piece construction, the guillocheur has had to extend the décor to five faces, thereby considerably increasing the difficulty of creating the motifs.
Such a beautiful “jewel-case” naturally deserved to house a mechanism delivering exceptional performances. The transparency of the cabinet provides a delightful view of the new manual-winding (using a key) caliber made by Vacheron Constantin, open worked Caliber 9260. This open worked construction reveals the interior beauty of the movement built around seven patiently hand-bevelled bridges. By combining a 30-day power reserve and a constant -force mechanism, Caliber 9260 displays exceptional functionality qualities entirely in keeping with the grand horological traditions of Vacheron Constantin.
Any mechanical device designed to measure time has a “motor organ” (the barrel) that delivers energy to a “regulating organ” (composed of an escapement and an oscillator, the sprung balance), which divides time into equal units and guarantees precision rating. The precision of a movement depends on the stability of its frequency, achieved by the regularity of the regulating organ’s oscillations. This in itself results from the regularity of the energy transmitted by the escapement to the sprung balance so as to ensure that it always oscillates in the same way and according to the same amplitude. However, the force delivered to the motor organ varies according to the degree of wind, a fact that inevitably leads to periodical variations in energy, which is often too strong in the beginning and too weak towards the end. These variations result in instable frequencies and thus variations in rate. Therefore, only a constant force can ensure a reliably regular frequency.
Various constant-force auxiliary devices have been developed to deal with the significant variations in the energy delivered by the barrel and to ensure the stable and regular oscillation amplitude of the oscillator. The principle behind these devices consists in absorbing and neutralising the excesses and variations in the driving force acting on the escapement pinion, so as to ensure that the latter can transmit equal and constant impulses to the oscillator. In other words, constant-force auxiliary mechanisms may be regarded as a kind of filter intended to cancel out the effects of the variable force that the motor organ delivers to the escapement.
To regulate the excess energy transmitted by the motor organ (twin barrel) to the escapement, this table clock has a subsidiary device that filters the energy delivered to the escapement. This device is notably composed of a mobile lock and release system linked to a spring, with the latter’s degree of tension regulated to contain a predefined and constant quantity of energy. In concrete terms, as variable energy is delivered from the barrels, the mobile lock and release system of the subsidiary power drive locks and tightens its spring.
When the system is released, the spring is let down, transmitting only the defined degree of energy to the escapement. That is how this device serves to supply a constant force to the escapement, which can thereby maintain the stability of the oscillator’s amplitudes and thus the rating precision of the movement.
Such a mechanism proves particularly useful on a horological movement endowed with a substantial power reserve such as that of Caliber 9260. The duration of the power reserve notably depends on the length of the barrel springs. The longer the spring, the greater the number of oscillations, and hence the higher the risk of isochronism flaws.
The constant-force mechanism of Caliber 9260 endows the table clock with remarkable rating
precision corresponding to less than a one-minute deviation per week: an impressive feat for a caliber with such a low frequency (2.5 Hz) and that requires winding just once a month.
Métiers d’Art Arca
Reference: 99900/001-B034 – Rock crystal
Only available in Vacheron Constantin Boutiques
Vacheron Constantin caliber
Mechanical, manual-winding (with a winding key)
106 mm x 131.1 mm x 58.7 mm (L x H x D)
Approximately 720 hours (30 days) of power reserve
2.5 Hz (18,000 vibrations/hour)
Exterior arch in rock crystal; Frosted crystal base below the caliber
Two silver bases decorated with unique patterns in hand-guilloché and translucent Grand Feu enamelling
Obsidian base with silver border
202 mm x 219 mm x 105 mm (L x H x D)
Grand Feu enamelled Roman numerals on a silver base
Lacquered metal hands
Dedicated table clock presentation box in wood
Delivered with a magnifying glass, a pair of gloves and two winding keys
One-of-a-kind model from a collection of 12 unique creations
“Pièce unique” inscription engraved beneath the base of the table clock