he Naissance d’une Montre 4 project is remarkable from the outset. Carried by the exacting standards of the Time Æon Foundation and supported by Greubel Forsey, it embodies the ultimate expression of fine making and contributes to the perpetuation of its noblest traditions.

Its singularity? To announce the launch of a new independent watchmaking house – Bonniksen – a name recognised by the discerning collector for its contribution to the pursuit of horological precision at the turn of the 20th century. With its first project, Naissance d’une Montre 4 – Le Carrousel, Bonniksen sets out to establish itself as a key figure in 21st-century watchmaking crafted by hand, uniting a tradition of artisanal excellence with a scientific horology that transcends borders.

Founded in 2006, the Time Æon Foundation has devoted nearly two decades to a single and urgent mission: to index, preserve and transmit the rarest hand-made watchmaking skills before they are lost. Its Naissance d’une Montre programme has become the most demanding expression of that mission.

The first project – a hand- made tourbillon led by Michel Boulanger under the guidance of Robert Greubel, Stephen Forsey and Philippe Dufour – was unveiled in 2012 and demonstrated that 19th-century craft standards could be achieved in the 21st century. Naissance d’une Montre 2 followed, entrusted to Dominique Buser and Cyrano Devanthey with the support of Greubel Forsey and Urwerk, and sold as a pièce unique at Phillips in 2023. Naissance d’une Montre 3, led by Chronométrie Ferdinand Berthoud, applied the same exacting principles to a chain and fusée wristwatch of extraordinary complexity, completed in 2025.

Here, the transmission of rare craft knowledge finds its fullest meaning. A pupil of Michel Boulanger – professor at the Paris school of watchmaking and a central figure in Naissance d’une Montre 1 – Maximin Chapuis learned to combine technical mastery with a passion for horological history. It is through a defining encounter with Jason Chevrolat, entrepreneur, collector and consultant to the watchmaking industry, that the Bonniksen adventure begins.

Naissance d’une Montre 4 – Le Carrousel is fully aligned with the mission of the Time Æon Foundation, dedicated to the preservation and transmission of rare hand-made expertise. The support and confidence granted by Greubel Forsey attest to the level of rigour sought, while fully respecting the creative and operational independence of Bonniksen.

Led by Jason Chevrolat and Maximin Chapuis, the Bonniksen house is established in 2026, with its workshop in La Chaux-de-Fonds. It rests upon a simple and radical principle: to conceive, shape and assemble every component in accordance with watchmaking in its most demanding form.

At the heart of their approach lies a revolving regulating device long overlooked and yet fundamental to the history of precision timekeeping: the Carrousel, reinterpreted after more than 5,500 hours of historical and technical research, with the support of the descendants of Bahne Bonniksen.

This exploration is rooted in the golden age of English high horology (1870–1920) and draws inspiration from such eminent houses as Bonniksen, Dent, Charles Frodsham, Nicole Nielsen and Smith & Son. The two founders thus place themselves within a cross-border tradition of craft knowledge, linking British mechanical rigour to the Swiss expertise of the Vallée de Joux in complicated mechanisms.

The Naissance d’une Montre 4 project pays homage to the Carrousel, invented by Bahne Bonniksen, a Danish watchmaker established in Coventry, England. This mechanism left its mark on the British watchmaking industry of his era and remains a symbol of ingenuity and technical rigour. this mechanism.

In 1892, he patented and commercialised his celebrated ‘position equalising karrusel’, which he retained exclusively until the decline of the British watchmaking industry at the turn of the 20th century. The Carrousel enjoyed remarkable success at observatory trials for more than two decades, adopted by the foremost English, Swiss and German watchmakers, who made of it a mechanism of rare distinction. The conversion of the mechanical industries to the service of the nation during the Great War brought about its gradual disappearance, carrying with it the refinements Bonniksen had envisioned.

The Carrousel was invented to meet a fundamental challenge in chronometry: to ensure consistent timekeeping in all vertical positions. Its dynamic system features a rotating cage carrying the escapement and balance-spring assembly, compensating for positional errors caused by gravity. A train derived from traditional going train drives the cage independently, without any wheel fixed to the main plate, offering a robust alternative to the traditional tourbillon.

True to the idea inaugurated by Abraham-Louis Breguet, the Carrousel averages positional errors and extends the history of high horology. Its uniqueness lies in its innovative design: unlike the tourbillon, where the seconds wheel remains fixed to the plate, the Carrousel is a carried-wheel device, fitted with a mobile seconds wheel. This configuration requires that the relative speeds of the wheels carried within the cage with respect to one another be accounted for in the equations governing the rotation – represented by the ‘±’ of the house’s emblem.

Beyond the precision it affords, this mechanism is distinguished by its exceptional robustness: no fixed wheel, no risk of set-up or butting, every component pivoting with absolute accuracy. This subtle technical balance confers upon the Carrousel its exceptional singularity and bears witness to the horological excellence that the house of Bonniksen is committed to perpetuating and bringing back to life today.

The independent house of Bonniksen is setting out to offer a contemporary interpretation of the great works of the British chronometer makers – historically reserved for pocket watches – expressing this cross-border horology at its summit. Naissance d’une Montre 4 – Le Carrousel will introduce the first-ever Carrousel crafted by hand in a wristwatch under 40 mm. Two domed crystals will offer exceptional depth, revealing the movement from every angle.

The three-hand inverted calibre will be distinguished by its atypical three-quarter plate. The hours and minutes, off-centred at twelve o’clock on a chapter ring, will be indicated by modernised English pear-shaped hands, while a large central seconds hand will pay homage to the great scientific pocket watches. The peripheral seconds track will underline the symmetry of the movement, and a subtle eccentric aperture will reveal the mechanical splendor of the fully pivoted Carrousel, completing one full rotation in 30 seconds.

Every technical detail reflects the highest mechanical standards: screwed chatons, a mainspring barrel boss, six-spoke wheels, a maker’s mark, black polish... The noble English codes will be upheld and enriched by contemporary materials and finishes, faithful to the spirit of haute horlogerie. The rotation of the large seconds hand in 60 seconds, that of the Carrousel in 30 seconds, and the clockwise and counter-clockwise motion of the respective trains will create a perpetual interplay, as captivating to the eye as it is effective for the precision of the movement.

Naissance d’une Montre 4 – Le Carrousel will be the first timepiece crafted by hand to incorporate a Carrousel, opening the way to the Bonniksen collection and to the exploration of overlooked chapters of horological history. Supported by the Time Æon Foundation, the project embodies Bonniksen’s vision of 21st-century watchmaking crafted by hand, where technical mastery and artisanal know-how converge to deliver both excellence and performance.