Jaeger-LeCoultre, the architect of sound

For a native to Switzerland’s Vallée de Joux, the historic home of complex mechanical watches, silence is golden. So much so, in fact, that the only sounds tolerated here are the chimes that count the passing hours and minutes from within watches considered as veritable musical instruments in miniature with the added complexity of dozens of interlocking parts. As Jaeger-LeCoultre explains, “to make such a watch requires an ear for music as well as extreme dexterity.” Coming from a Manufacture that has made chiming (or striking) watches an exercise in excellence, it’s a statement that shouldn’t be taken lightly. From its first minute repeater in 1870, the Grand Maison can pride itself on having developed no fewer than 200 chiming watch calibres, including more than 100 minute repeaters prior to 1900. As well as producing its own chiming timepieces, for many years it also supplied other manufacturers with quality striking movements.

Multiple innovations

These days the brand reserves this expertise entirely for its own benefit, while taking it into new terrain. “Since the mid-1990s, Jaeger-LeCoultre has revisited its heritage, harnessing the possibilities opened up by new materials and by the latest machining technologies,” said Stéphane Belmont, Director of Heritage, at a recent online walk-through of the brand’s new releases for 2020. Crystal gongs, which are soldered to the watch’s dial crystal, produce a louder, clearer sound. Square gongs provide a flat surface for a more powerful strike. “Duplex” gongs, rather than lying flat, form a circle then divide into two semi-circles around the movement to increase resonance. Trebuchet hammers use a similar principle to a counterweight catapult to increase the speed and force of the hammer strike. The brand has also pioneered a means to reduce the silent interval between strikes, an innovation that joins the silent strike governor, invented in 1895, which eliminates the background buzz typical of older striking mechanisms. This concern with giving its watches a voice also extends to alarm watches, such as this year’s Memovox.

A decade ago, Jaeger-LeCoultre presented the extraordinary Duomètre à Grande Sonnerie which, in addition to grande and petite sonneries, incorporates a flying tourbillon and an instantaneous perpetual calendar. And if this weren’t enough, its Westminster chimes play the longest melody ever achieved in a watch. Further demonstrations of this formidable expertise have followed, not least the Master Grande Tradition Gyrotourbillon Westminster Perpétuel from 2019. It combines three consummate examples of the watchmaker’s art: a bi-axial Gyrotourbillon incorporating a constant-force mechanism (both increase timekeeping precision), a Westminster minute repeater that replicates the chimes played by Big Ben, and a perpetual calendar that can be adjusted forwards and backwards. Also that year the Manufacture unveiled the Master Grande Tradition Répétition Minutes Perpétuelle. It reprises the same concept, this time without a tourbillon but with the addition of duplex gongs in Calibre 950.

A three-dimensional sky

After such a run of exceptional timepieces, the brand could easily have rested on its laurels for a while. Instead, it is back this year with a Master Grande Tradition Grande Complication that aligns a minute repeater with astronomical functions inside the automatic-winding Calibre 945. Jaeger-LeCoultre is no novice in this department, having already combined the technical innovations of its new-generation minute repeaters with an astronomical display, first in 2010 then in 2015 prior to this new iteration. The original model introduced a 60-second orbital tourbillon which, as well as turning on its own axis, makes an anti-clockwise circuit of the dial in one sidereal day. Measured according to the rotation of the Earth in relation to a fixed star (rather than its movement around the Sun) a sideral day is four minutes shorter than the solar day used for civil timekeeping.

Nor is this the only “action” taking place on the dial. In its centre, a star map on a convex disk reproduces the constellations as seen from the Northern Hemisphere. It makes the same rotation as the orbital tourbillon. This three-dimensional effect is accentuated by a lattice resembling an atomic structure. Cut from a single piece of metal, it forms a dome above the dial and acts as a support for the sky chart. The movement of the stars appears in real time inside a white circle that represents the visible portion of the night sky. A sun-shaped pointer circles the edge of the outer ring to show the day and the month, as well as the signs of the zodiac. It also indicates day and night on a 24-hour scale. Jaeger-LeCoultre will produce eight of this Master Grande Tradition Grande Complication watch in pink gold and eight in white gold with diamonds on the bezel. The order book is filling up fast.