Arnold & Son Constant Force Tourbillon 11

Arnold & Son's Constant Force Tourbillon 11, cloaked in 18-carat yellow gold, stands as a remarkable embodiment of horological artistry and historical reverence. This timepiece, a limited edition of merely 11 pieces, doesn't merely mark time; it recounts a story of friendship, innovation, and a relentless pursuit of precision that defined the golden age of watchmaking. The decision to encase this horological marvel in yellow gold is deeply rooted in history. John Arnold, a prominent figure in 18th-century watchmaking, often favored this precious metal for his prestigious pocket watches. The warm glow of the yellow gold on the Constant Force Tourbillon 11 harmonizes seamlessly with the openworked bridge of the constant force mechanism, also crafted from 18-carat yellow gold.

The Constant Force Tourbillon 11 is more than a tribute; it's a continuation of a legacy. The watch is a physical manifestation of the profound bond between John Arnold and Abraham-Louis Breguet, two titans of horology. Their collaboration was legendary, even, crossing national boundaries and political turmoil. While Arnold was captivated by Breguet's elegant designs and understanding of mechanics, Breguet was drawn to Arnold's ingenious, simplifed mechanisms and his quest for chronometric precision. They were visionaries, that recognized each other's brilliance. This mutual respect led to a cross-pollination of ideas, with each watchmaker sending their sons to train under the other's tutelage. Arnold focused on perfecting his detent escapement and developing balance springs for his mass-produced chronometers. These instruments were crucial for the British Admiralty, which demanded ever-increasing quantities at lower prices. Breguet, inspired by his conversations with Arnold, refined the concept of the tourbillon during his exile in Switzerland.



Breguet patented his rotating carriage invention, the tourbillon, in 1801, two years after Arnold's death. As a tribute to their friendship and shared research, Breguet's first tourbillon regulator was based on the movement of John Arnold’s marine chronometer no. 11. A silver plate was engraved and screwed onto the main bridge, bearing the inscription: "The first tourbillon regulator by Breguet incorporated in one of the first works of Arnold. Breguet's homage to the revered memory of Arnold. Presented to his son in the year 1808." The Constant Force Tourbillon 11, in its intricate design and technical brilliance, echoes this remarkable exchange of knowledge and mutual admiration.

The watch's case, measuring 41.5mm in diameter, is a study in classic design. Its curved middle case contributes to a slender profile, further enhanced by a thin bezel. The slightly domed sapphire crystal, treated with an anti-reflective coating on both sides, provides an unobstructed view of the captivating dial. A similar sapphire crystal on the open case back unveils the hand-wound manufacture caliber A&S5219, a testament to the watchmaker's skill. The watch's water resistance, rated at 3 bar (30 meters or 100 feet), ensures its practicality for everyday wear, while the alligator leather strap, secured by an 18-carat yellow gold pin buckle, adds a touch of luxury.



The dial of the Constant Force Tourbillon 11 is a masterpiece of meticulous craftsmanship. Arnold & Son chose a white Grand Feu enamel, reminiscent of the dials found on the marine chronometers John Arnold supplied to English naval officers. This enamel disc, crafted on an 18-carat yellow gold base, is produced by a specialist artisan. The process involves melting powdered materials in a kiln heated to over 800°C. Multiple firings are required to achieve the desired thickness, followed by lapping to create a smooth, even surface. A final firing with translucent enamel imparts depth and transparency, showcasing the inherent beauty of the material. Openings are carefully made in this delicate disc to accommodate the constant force mechanism and the white opal subdial. This subdial, a hallmark of Arnold & Son, is recessed for the first time, enhancing its visual presence and improving the legibility of the black Roman numerals.

At the heart of the Constant Force Tourbillon 11 lies the A&S5219 movement, a caliber developed specifically for this watch. The hand-wound movement, inspired by historical designs yet thoroughly modern in its execution, boasts two identical barrels mounted in series. This configuration provides a substantial 100-hour power reserve. The barrels work in tandem, with the second activating when the torque of the first diminishes, ensuring consistent power delivery. To further enhance the isochronism (the regularity of oscillations) of the regulating group over the 100-hour operation, the movement incorporates a patented constant force mechanism.



This constant force mechanism, positioned between the going train and the tourbillon, is prominently displayed on the dial side. Its purpose is to mitigate variations in torque delivered by the barrels, preventing excessive or insufficient power from affecting the balance's oscillations within the tourbillon carriage. Held in place by an 18-carat yellow gold bridge, the mechanism rotates once per minute. In the Constant Force Tourbillon 11, this mechanism replaces the fusee-and-chain configuration, a system often found in John Arnold's historical chronometers. Besides providing constant force, this system also enables a 'dead-beat seconds' indication. The direct-drive hand doesn't sweep smoothly but rather makes distinct jumps of one second. This is similar to the direct-drive seconds found on marine chronometers, which also exhibited similar jumps. However, in this watch, the seconds are not indicated by a conventional hand. Instead, the tip of a flame-blued anchor, which serves as a structural bridge for the constant force mechanism, marks the passing seconds.

The transparent sapphire crystal case back showcases the architecture of the A&S5219 calibre, drawing inspiration from the back of the historical timepiece housed in the British Museum. The tourbillon carriage, rotating once every minute, echoes the design of the carriage used by Breguet in the watch dedicated to their friendship. The meticulously refined tourbillon features a thin, polished, linear carriage bridge that reveals a variable inertia balance with inertia blocks, a design influenced by the sophisticated oscillators found in John Arnold’s chronometers. Arnold & Son also incorporated a T-shaped retaining spring, reminiscent of the one used in Abraham-Louis Breguet's 'pare-chute' shock protection system, visible on the tourbillon bridge of the original instrument. However, for practical reasons and increased shock resistance, a Swiss lever escapement was chosen over the detent escapement of the historical timepiece.



The finishing of the mainplate, bridge, and tourbillon cock closely mirrors those of the original timepiece. The grained and chamfered barrel bridge of the Constant Force Tourbillon 11 features hand-engraved inscriptions and the iconic plate, bearing a new text inspired by the original: "To the revered memory of John Arnold and Abraham-Louis Breguet. Friends in their time, legendary watchmakers always." These words emphasize the historical and horological significance of this Arnold & Son edition, limited to only 11 pieces, where friendship and the pursuit of horological excellence were the paramount driving forces.

Arnold & Son, a brand with English roots and Swiss watchmaking expertise, has a reputation for defying convention. They create unique timepieces that combine the precision of Swiss craftsmanship with a distinctive aesthetic. John Arnold, as a renowned watchmaker, crafted some of the most accurate marine chronometers of the 18th century. He was a prolific inventor, securing numerous patents, including those for a compensation balance with a bimetallic balance spiral and a helical balance spring. His simplified chronometer designs allowed for mass production, making these instruments more accessible, particularly to the Royal Navy. Arnold also played a crucial role in defining the modern term 'chronometer,' which now refers to a high-precision timepiece whose accuracy has been certified by an official body.

Arnold & Son's ability to produce grand complications, such as tourbillons, true seconds, dual time zones, and moon phases, is a testament to their mastery of horological traditions, all based off of John Arnold's legacy. The impressive power reserves of their watches pay homage to Arnold’s marine chronometers, known for their exceptional autonomy. The brand's approximately twenty calibers are entirely conceived, designed, developed, machined, decorated, assembled, and adjusted within their sister Manufacture, La Joux-Perret. This vertical integration showcases the House’s commitment to perpetuating John Arnold’s legacy of innovation.



Arnold & Son’s signature aesthetic is characterized by the unique architecture of their movements, a relentless pursuit of multiaxial symmetry, and exquisitely crafted dials, often incorporating rare gemstones and minerals. These design elements are harmoniously integrated with the brand’s manufactured calibers, ranging from simple single-barrel movements to complex grande complications.

The Arnold & Son Constant Force Tourbillon 11 in yellow gold is available in a limited edition of 11 pieces, with a price of $134,100 (excluding VAT). This timepiece is more than a collector's item; it's a tangible representation of a pivotal moment in horological history, a tribute to two visionary watchmakers, and a showcase of Arnold & Son's dedication to preserving and advancing the art of fine watchmaking.

Case: 18-carat yellow gold (3N). Diameter: 41.5 mm. Thickness: 13.7 mm. Domed sapphire crystal with anti-reflective coating on both sides. Domed sapphire crystal case back with anti-reflective coating. Water resistance: 3 bar (30 meters/100 feet).

Movement: Calibre A&S1001. Hand-wound. Jewels: 35. Diameter: 33 mm. Thickness: 10.48 mm. Power reserve: 100 hours. Frequency: 3 Hz / 21,600 vph. Constant force mechanism. Tourbillon.

Dial: White Grand Feu enamel. 18-carat yellow gold (3N) base. White opal subdial.

Strap: Midnight blue alligator leather. Black alligator leather lining. Pin buckle in 18-carat yellow gold (3N).

Price: $134,100 (excl. VAT).

Reference Number: 1FCBJ.E01A.C246J

Notes: Limited edition of 11 pieces. Celebrates the 260th anniversary of John Arnold's legacy and his relationship with Abraham-Louis Breguet. Features a constant force mechanism visible on the dial and a tourbillon visible on the back. "Dead-beat seconds" indication.