The Breguet Classique Tourbillon Sidéral 7255 Celebrates the Brand’s 250th Anniversary

It will come as no surprise that the fourth instalment of Breguet’s 250^th-anniversary celebrations honours Abraham-Louis Breguet’s most celebrated invention: the gravity-defying tourbillon. Following the Souscription, the Seconde Rétrograde and the Type XX Chronograph, the release of the latest celebratory watch coincides with the day and month Abraham-Louis Breguet obtained a patent for his tourbillon 224 years ago on 26 June 1801. Marking the first flying tourbillon to spin into Breguet’s collection, it is also a mysterious tourbillon concealing components to create a magical levitation that defies explanation. While the flying tourbillon and gorgeous Grand Feu aventurine enamel dial are novel, the movement is based on the first modern-era Breguet tourbillon wristwatch, introduced in 1990.

As a figure of the Enlightenment, A.L. Breguet’s (1747-1823) inquiring scientific mind produced some of the most important innovations in watchmaking, including the tourbillon regulator (don’t miss Brice’s extensive coverage and our video). Designed to compensate for the effects of gravity on the regularity of pocket watches, A.L. Breguet installed the escapement inside a mobile, rotating carriage and named his invention the tourbillon, a term Descartes used to describe celestial bodies rotating on a fixed axis. During his lifetime, A.L. Breguet produced around 35 tourbillon pocket watches, including five clocks regulated by his invention. According to Emmanuel Breguet, a descendant of the legendary horologist and Head of Patrimony at Breguet, a quarter of the tourbillon-regulated timekeepers were used for naval purposes to calculate longitude at sea.

A Mysterious Flying Tourbillon

Now, in the capable hands of CEO Gregory Kissling, the 250th-anniversary flying tourbillon and novel blue aventurine enamel dial reflect his roadmap for the brand. As Kissling told MONOCHROME in the interview: “We don’t replicate the past, we use it as a source of inspiration.”

Perpetuating A.L. Breguet’s rich legacy, the traditional tourbillon enters new territory, interpreted as a more complex and mysterious flying tourbillon. Supported only by its lower bridge, with no upper bar to obstruct the view, the flying tourbillon necessitates a distinct construction. With no pivot at the top, the tourbillon has to be more solid, more adjustable and better balanced than a traditional tourbillon. To recreate the sensation of celestial bodies floating in the vast expanse of space, the flying tourbillon is raised to protrude 2.2mm above the plate and 0.9mm above the enamel dial. In fact, the entire movement and proportions of the watch are built around the majestic tourbillon.

Increasing the spectacle of the tourbillon in suspension, Breguet has factored in a mysterious tourbillon complication. As its name suggests, a mysterious complication is invisible and often used, for example, to conceal the mechanism that advances a clock’s hands. Here, the lower bridge and lower support of the tourbillon carriage are made of sapphire glass and vanish like magic into the ether. Hiding the point of contact between the gears and carriage, the invisible drive powering the flying tourbillon produces a spellbinding effect.

Aventurine Grand feu Enamel Dial

The aventurine enamel dial, also a first for the Maison, pays tribute to Breguet’s fascination with astronomy. To create the rich, blue, sparkling night sky, artisans at Breguet have treated aventurine glass in a manner similar to Grand Feu enamel. Crushing the glass into a powder, five layers of aventurine are applied to the gold dial, each layer fired in a kiln at 800 °C. The large aperture for the tourbillon is protected by a raised gold ring, allowing the enameller to layer the aventurine without compromising the magical display. The hours and minutes are displayed in an excentred gold hour ring with a blue PVD coating at noon, indicated by classic Breguet Arabic numerals and gold open-tipped Breguet hour and minute hands. Last but not least, the dial features the secret signature and the applied gold inscriptions ‘Breguet’ and ‘Tourbillon’ on the equator of the dial.

Breguet Gold

Like the other 250^th anniversary pieces, the case is crafted in the brand’s 18k Breguet gold. Breguet gold, used for the case and dial, is a proprietary alloy (75% gold enriched with silver, copper, and palladium) developed to commemorate the brand’s 250^th anniversary. Inspired by the gold used by 18^th-century watchmakers, it has a subtle pink hue and is resilient to discolouration. The compact 38mm case has a thickness of 10.2mm with the signature fluting on the caseband and straight, welded lugs. Protected by a spherical sapphire crystal on the dial and a sapphire glass caseback, it’s worth pointing out that the tourbillon alone is responsible for the height of the calibre and the case.

Guilloché

Another technique closely associated with A.L. Breguet is hand-guillochage, which he introduced to his dials in 1786 to enhance legibility and protect his watches against counterfeiting. A new pattern, known as Quai de l’Horloge, inspired by the River Seine as it meanders around the Île de la Cité (the site of Breguet’s workshops in 1755), is featured on the caseback, tourbillon support, and mainplate.

Daniel Roth & the new calibre

Although Breguet’s manual-winding calibre 187M1 is tucked away under the beautiful guilloché bridges, CEO Kissling points out that the movement of the anniversary watch is a reinterpretation of the famous Breguet Tourbillon reference 3350, the first Breguet tourbillon wristwatch unveiled in 1990, powered by the manual-winding calibre 558 of Lema,ia. Developed by Daniel Roth while he was master watchmaker at Breguet, the one-minute tourbillon was fully exposed through an aperture in the dial.

A more recent source of inspiration resides in the calibre 558 SQ2 powering the Classique Tourbillon Messidor 5335. Sharing the same diameter, 2.5Hz frequency and 50-hour power reserve, the layout of the functions is also similar. However, calibre 187M1 has undergone significant modifications for the flying tourbillon and, unlike the Messidor 5335, hides its mechanics beneath the closed gold bridges. Measuring 30mm across, the movement’s thickness is 4.8mm (excluding the 2.2mm tourbillon projection). It beats at 2.5Hz and is equipped with a Nivachron balance spring to enhance resistance to magnetic fields, temperature fluctuations and shock.

The watch is paired with a handsome navy blue alligator leather strap, matching the colour of the dial, and an 18k Breguet gold triple-blade folding clasp. The Classique Tourbillon Sidéral is a limited edition of 50 numbered pieces, retailing for CHF 190,000 (including tax). More information at breguet.com.