2018 marks 240 years since the creation of John Arnold’s historically significant Chronometer No. 1/36, the first time-measuring instrument to be called a “chronometer” for its unprecedented precision. To mark the historical milestone, Arnold & Son is proud to introduce a modern homage edition of the Tourbillon Chronometer No.36, a COSC-certified Tourbillon wristwatch. 

The first commemorative edition of the Tourbillon Chronometer No. 36 unveiled last year featured a more traditional English frosted gilt finish on the movement, produced as a limited edition series that immediately become a must-have for aficionados of Arnold & Son timepieces and precision chronometers. The 240th anniversary Tribute Edition of the Tourbillon Chronometer No.36 offers the opportunity to acquire this exceptional and contemporary reinterpretation of John Arnold’s revered chronometer, and thus will be produced as a non-limited production series in red gold and stainless steel models.

The John Arnold Chronometer No. 1/36 or “Arnold 36” as it is more commonly called was not only the first pocket watch by John Arnold to use a larger movement with his compensation “T” balance, but also the first to be referred to as a “chronometer” for its extraordinary timekeeping performance. A technical revolution at the time, the John Arnold No. 1/36 built in 1778 displayed vastly superior chronometry compared to every other watch at the time, that after the hugely successful 13-month trials at the Greenwich Observatory in 1779, John Arnold coined the term “chronometer” to refer to the No. 1/36 pocket chronometer, which marked a new era of unprecedented precision in timekeeping. In this respect, the Tourbillon Chronometer No.36 pays tribute to the legendary high-precision chronometer in a faithful yet contemporary manner. 

Following the classical codes of traditional English chronometer movements, the main pivoting elements such as the wheels, barrels, the tourbillon, and others are each mounted on their own bridge. The triangular, multilevel bridges (no less than thirteen) are mostly skeletonized, providing a more contemporary sense of three-dimensional depth to the entire timepiece. 

The tourbillon, a central element of this timepiece, is highlighted in a most magnificent manner. Held by a skeletonized and mirror-polished top bridge, the one-minute tourbillon features a typically Arnold & Son three-spoke design. Weighing mere fractions of a gram, the tourbillon cage consists of no less than 58 components. Prominently positioned on the dial side, the tourbillon can also be viewed from the back, thanks to an opening in the main plate. The same kind of opening is made below the small seconds display, adding to the symmetry of the Tourbillon Chronometer No.36.

The apparent technical virtuosity of the Tourbillon Chronometer No.36 is not only a treat for the eyes, as the watch is a COSC certified chronometer; something of a rare achievement for a tourbillon-equipped timepiece. 

The decorative haute horlogerie arts are also lavishly demonstrated in the Tourbillon Chronometer No.36. The entirely in-house conceived and manufactured A&S8600 movement features a lightly grained sand-blasted main plate treated with a main plate in NAC grey in the Red Gold version, while the Steel version has a more contemporary black DLC surface. The bridges are satin-brushed with chamfered and polished edges, and are done in a lighter palladium tone on the Red Gold version, and NAC grey in the Steel version. The main plate also is set with several mirror-polished 18k white gold chatons, while the wheels in the gear train are embellished with circular satin finishing with chamfered and polished edges. Even the screws are beveled and feature with mirror-polished heads.

The heart of the watch, the tourbillon, features a traditional construction with a top bridge, while the mirror-polished cage has the signature Arnold & Son three-spoke design, making a complete turn in 60 seconds. 

The double barrels, embellished with laser-engraving decoration, provide a considerable power reserve of 90 hours when fully wound. 

Main technical characteristics:

Tourbillon Chronometer No.36

Caliber: A&S8600
Manufacture Arnold & Son caliber, hand-wound, 33 jewels, diameter 37.8 mm, thickness 5.9 mm, power reserve 90 h, double barrel, 4 Hz / 28’800, COSC certified

Functions: Hours, minutes, small seconds, tourbillon

Movement decoration: Palladium treated bridges and NAC treated main plate for red gold version and NAC treated bridges and black DLC treated main plate for stainless steel version, with Haute Horlogerie finishing: satin-finished bridges with chamfered and polished edges, 18k gold chatons, screws with bevelled and mirror-polished heads Tourbillon cage: mirror-polished with hand-chamfered polished edges and circular satin-finished surfaces

Dial: Red Gold: Anthracite open dial with golden indexes Stainless Steel: Black open dial with silver indexes

Case: 18-karat red gold or stainless steel, diameter 46 mm, cambered sapphire with anti-reflective coating on both sides, see-through sapphire case back, water-resistant to 30m

Strap: Hand-stitched brown or black alligator leather

References:   Red Gold: 1ETAR.S01A
                          Stainless Steel: 1ETAS.B01A