Vacheron Constantin Maître Cabinotier retrograde tourbillon armillary sphere

91990-000G-9882 Montre pièce unique calibre 1990In the wake of Reference 57260 (the most complicated watch in the world, with 57 complications), Vacheron Constantin presents the Maître Cabinotier retrograde tourbillon armillary sphere. This watch, certified by the Hallmark of Geneva, was produced by the same three master watchmakers who created Reference 57260 and contains two of its characteristic complications, namely the tourbillon armillary sphere and the double retrograde display. The skeleton dial allows one to admire the construction of the high-precision hand-wound movement, the 1990 calibre, housed in a 45.7 mm diameter white gold case. Four patent applications have been filed for this unique model. On 17 September 2015, Vacheron Constantin presented a watch with 57 complications, the most complicated watch ever made. This mechanical marvel, conceived by three master watchmakers in the Manufacture's Atelier Cabinotiers workshops, took eight years to make and was unveiled on the occasion of the Maison's 260th anniversary. Made to order, this timepiece made it possible to preserve the traditional watchmaking principles certified by the Hallmark of Geneva. The research and expertise acquired to create this extraordinary timepiece remained a source of inspiration as well as a development resource for the three watchmakers dedicated to perfecting certain specific complications. The Maître Cabinotier retrograde tourbillon sphere model is the first result of this project. It is a remake of two complications used on Reference 57260, namely the double retrograde display and the armillary sphere tourbillon in a contemporary version. The retrograde function concerns the hours and minutes, while the tourbillon rotates on two axes and features a spherical balance spring. The movement coated with NAC (a special metal alloy) is visible through the side windows in the large case. The timepiece is part of the exclusive Maître Cabinotier collection, a showcase of Vacheron Constantin's watchmaking excellence, offering personalised pieces. The hand-wound 1990-calibre movement, developed and manufactured by Vacheron Constantin, features a retrograde hour and minute display with instantaneous flyback. The hands return to zero at such a speed that, to ensure an accurate display, great care must be taken in the use of materials, which must be light and resistant, such as the titanium of the hands. The lightning-fast action of the retrograde hands contrasts with the more solemn rhythm of the tourbillon armillary sphere with spherical spiral. The elegant structure of the tourbillon behaves like a sphere in continuous rotation on two axes, under a sapphire crystal dome at 9 o'clock. The name tourbillon armillary sphere derives from the armillary sphere found in the astronomical watch made by the French watchmaker Antide Janvier in the 18th century. The tourbillon visually recalls the rings and circles of the ancient celestial sphere model. The spherical balance spring, first developed by Jacques-Frédéric Houriet in 1814, is particularly rare in today's watches. The shape ensures the concentric development of the balance spring and thus the isochronism of the balance wheel. The tourbillon cage, made of a light aluminium alloy, incorporates Vacheron Constantin's emblem, the Maltese Cross, which is fully visible every 15 seconds thanks to the rotation of the tourbillon. This spectacle can be admired every 30 seconds through a sapphire crystal opening on the side of the case. The tourbillon armillary sphere fascinates with its action and architecture, as well as with its incredible chronometric precision. In addition, it features a new type of escapement, developed and manufactured by Vacheron Constantin, with a silicon escape wheel and lever with diamond pallets to resist wear and last. The escapement, made as light as possible thanks to the use of hi-tech materials, contributes significantly to the performance of this watch, which far exceeds the criteria of the COSC (Swiss Official Chronometer Testing Institute). The level of precision is even more remarkable when one considers the large amount of energy absorbed by the double retrograde display. The originality of the Maître Cabinotier retrograde tourbillon sphere also lies in the modern style that characterises its architecture and the finishing of the movement. The 1990 calibre is electroplated with a dark anthracite NAC treatment that creates a mirror effect. On the dial side, the movement exhibits a modern architecture with bridges with sharp angles, softened by Côtes de Genève and satin-sunlit finishes. The back has a more conventional appearance, with the Côtes de Genève creating an elegant contrast with the dial of this unique watch in the Vacheron Constantin range. It also took 130 hours of anglage machining on all the profiles to define the excellence of the timepiece. The displays are located inside two dials that partially cover the mainplate to reveal the contemporary profile and finishing of the movement. On the right, the retrograde hour and minute hands describe a semi-circle on a sunbrushed satin finish, punctuated by white gold applied hour markers and a black minute scale. In a symmetrical position, the tourbillon cage carries the seconds indicator rotating around a scale on a silvered disc. The Hallmark of Geneva symbol is also engraved on the dial side, above the words "Armillary Tourbillon", to certify the very high quality of the timepiece.