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Results for Chronometer (COSC)

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Chronometer (COSC)

The Swiss accuracy certification at -4/+6 s/day across 15 days.

In-Depth: Breguet’s Constant-Force Magnetic Escapement SJX Watches
Breguet s Constant-Force Magnetic Escapement Dec 4, 2025

In-Depth: Breguet’s Constant-Force Magnetic Escapement

Earlier this week, Breguet rounded off its grandiose 250th anniversary with the unexpected launch of the Expérimentale 1 chronometer in Paris. Showcasing modern Breguet’s most impressive innovation to date - a magnetic constant-force escapement - the watch left many scratching their heads simply because the novel invention defies easy explanation. Here we explain the actual functioning of this remarkable invention, and why it represents such a significant step forward in terms of chronometry and escapement technology. The origins of the concept Before turning to the decidedly modern and futuristic Expérimentale 1, we must first take a short trip to the past and consider how the idea of using magnets in mechanical escapements first came to life. For that we must turn to the late 1930s, when Cecil Frank Clifford, Fellow of the British Horological Institute (BHI), started experimenting with oscillators maintained by magnetic rails or escape wheels.  He was granted a British patent in 1954 for a variety of magnetised escape wheels paired with elastic vibrating magnetic blades. The device would operate silently and Clifford envisioned it being used for naval underwater torpedoes, so the lack of ticking would be harder to pick up by sonars.  Iterations of Clifford magnetic escapements. His designs were rudimentary. The principle was that the escape wheel would be braked by a vibrating pair of magnetised blades (in several possible configurations), while simultaneously ...

Breguet’s Magnificent Magnetic Expérimentale 1 SJX Watches
Breguet s Magnificent Magnetic Expérimentale Dec 1, 2025

Breguet’s Magnificent Magnetic Expérimentale 1

Breguet concludes its 250th anniversary with the brand’s most forward-thinking watch, the Expérimentale 1 that boasts a magnetic, true constant force escapement. Equipped with a frictionless escape wheel and pallet lever driven by magnetic forces, the movement runs at 72,000 beats per hour, or 10 Hz – arguably making the Expérimentale 1 the ultimate Breguet chronometer. Impressively innovative with its use of silicon, magnets, and clever teeth geometry, the limited edition watch also marks the start of the Expérimentale line, a collection that will serve as a platform to debut new complications, technology, and designs. Initial thoughts While some might have been expecting an updated Sympathique, Breguet instead surprised with perhaps the most advanced wrist-borne mechanical chronometer in modern watchmaking. Taking cues from Abraham-Louis Breguet’s own “constant force” escapements, Breguet today harnessed the power of permanent magnets and unique teeth geometry to built a genuinely friction-less, constant torque escapement. In fact, the new escapement appears to be the only truly frictionless and constant force escapement on the market today.  Magnets have been employed in escapements in the past, but this approach was historically unreliable. Breguet appears to have discovered the right formula for a magnetic escapement. Several functioning prototypes were on show at the launch event. Moreover, Breguet chief executive Gregory Kissling explained that the ma...

Highlights: Pocket Watches at Phillips Hong Kong SJX Watches
Patek Philippe Nov 14, 2025

Highlights: Pocket Watches at Phillips Hong Kong

The upcoming Phillips Hong Kong auction includes a diverse and spectacular selection of pocket watches spanning two centuries. From early 19th‑century enamel masterpieces crafted for the Chinese market to 20th‑century tourbillon chronometers that triumphed at observatory trials, the lots on offer demonstrate the technical and aesthetic evolution of the watch over the last two hundred years. Lot 1086 – S. Smith and Son No. 1899-1 Tourbillon Chronometer with Kew Class A Certificate Albert Pellaton-Favre constructed the first of two tourbillons in the auction, which was later retailed by S. Smith & Son. The other, by Patek Philippe, is the work of his son, Jämes-César Pellaton. Both are depicted in Reinhard Meis’s famous Das Tourbillon. The English and Swiss disagreed on what constitutes a chronometer. The English argued that a chronometer must use a chronometer (detent) escapement, while the Swiss considered any watch a chronometer if performed well enough – which the English would call a “Half-Chronometer”. As the Willis enamel dial boasts, the first is a chronometer by both English and Swiss reckoning, with a spring detent escapement and “Especially Good” certificate from the Kew Observatory. While S. Smith and Son retailed quite a number of tourbillons, including others with detent escapements, most were sourced locally, while the present lot uses a Swiss movement. The London branch of Baume Frères ordered six tourbillon chronometers from Albert Pella...

The Greatest Horological Masterpieces of All Time: the Harrison H4 – A Groundbreaking Timepiece That Solved The Longitude Problem Worn & Wound
Oct 27, 2025

The Greatest Horological Masterpieces of All Time: the Harrison H4 – A Groundbreaking Timepiece That Solved The Longitude Problem

A series of features identifying the most extraordinary mechanical masterpieces in history, blending precision, innovation, and craftsmanship. We all have our favourite timepieces either in our collection or those incredible horological masterpieces that have been invented or created through the ages. This series will showcase examples from the previous centuries up to the present day and look at the importance and impact on modern day timekeeping.  John Harrison’s H4 Chronometer was a groundbreaking timepiece that solved the longitude problem, a major challenge for navigation during the 18th century. Before Harrison’s work, sailors had no reliable way to determine their precise east-west position at sea, leading to deadly navigation errors. The British government, through the Longitude Act of 1714, offered a large prize to anyone who could develop a practical solution. Sir Cloudesley Shovell, by Michael Dahl, about 1702-5 (L); The Association with the Eagle, Rumney and the Firebrand, Lost on the Rocks of Scilly, October 22, 1707 (R). Image courtesy of the © National Maritime Museum, Greenwich, London The Catalyst for the Longitude Act In the early 18th century, determining longitude at sea was one of the greatest challenges in navigation. While sailors could measure latitude using the position of the sun or stars, longitude required precise timekeeping-something that was nearly impossible with the unreliable clocks of the time. The inability to determ...

Introducing – Formex Dresses its Bestseller in Full-Ceramic with the New Essence Ceramica Monochrome
Formex Dresses Sep 25, 2025

Introducing – Formex Dresses its Bestseller in Full-Ceramic with the New Essence Ceramica

Formex, founded in 2000, is renowned for its rugged action watches. The brand’s bestselling Essence, a sporty, all-terrain model with sharp case architecture, a patented suspension system, and COSC-certified movements, made its debut in 2018 and was refreshed in 2021 with a wider range of dial colours. Marking its 25th anniversary, Formex released its first […]

Hands-On With The New Lederer CIC 39 Longitude Fratello
Sep 19, 2025

Hands-On With The New Lederer CIC 39 Longitude

Just one year ago, I was introduced to Lederer watches. The brand, founded by Bernhard Lederer, creates incredible movements with complex mechanisms. Constant-force escapements and twin gear trains are some of the impressive details. Last year, I fell in love with the Triple Certified Observatory Chronometer, a set of 44mm watches that had traveled to […] Visit Hands-On With The New Lederer CIC 39 Longitude to read the full article.

In-Depth: Ferdinand Berthoud Tests the Limits of ‘Hand Made’ SJX Watches
Chopard Sep 4, 2025

In-Depth: Ferdinand Berthoud Tests the Limits of ‘Hand Made’

Few brands approach marine chronometer-style wristwatches with the intensity of Ferdinand Berthoud (FB). Fewer still have the capacity to produce a watch that is truly hand made. The brand has leaned into these strengths to good effect with the Naissance d’une Montre 3, which is perhaps the most labour-intensive wristwatch ever created. Marking the third official chapter of the Time Æon Foundation’s Naissance d’une Montre project, the Montre 3 is the byproduct of a six year quest to thoroughly document the steps required to make a chain and fusee wristwatch using only hand-operated tools. While the production of the Montre 3 involves more than 80 individuals from both FB and its parent Chopard, the labour involved equates to roughly a full year’s work for five people to produce each of the 11 pieces that will be made in the coming years. Initial thoughts It’s easy to feel jaded about the smoke and mirrors of luxury watch marketing, with terms like ‘hand made’ and ‘in-house’ used all too freely, making it difficult to separate the signal from the noise. Make no mistake, the Montre 3 is, in some ways, what all traditional haute horlogerie watches aspire to be, and takes the concept of hand craftsmanship to its absolute limit. The Montre 3 is neither inventive nor complicated, but the intrinsic quality of its construction is immediately obvious and breathtaking in its own right. To some extent, the simplicity of the 44.3 mm white gold case demonstrates the ...

The 15 Best British Watch Brands (2026) Teddy Baldassarre
Aug 18, 2025

The 15 Best British Watch Brands (2026)

While Switzerland is regarded today as the world leader of watchmaking, Great Britain can lay claim to a wealth of horological milestones throughout its history as well. From Thomas Mudge’s development of the lever escapement in 1755 to John Harrison’s invention of the marine chronometer in 1759 to the innovations of clockmaker Thomas Tompion and his protegé George Graham in the areas of science and astronomy, England was an undisputed leader in timekeeping throughout the 18th and 19th centuries. The 20th century brought the decline of the British Empire and, with it, British watchmaking, as nations like Switzerland, Germany, and (for a while) the United States stepped in with modern mass-production techniques while the Brits held fast to traditional, artisanal methods. The United Kingdom essentially ceased being a major producer of timepieces by the end of World War II, but as the 21st Century dawned, a handful of entrepreneurial Britons have made great strides in bringing high-end watchmaking back to their native land, establishing new brands - and in some cases, resurrecting old ones - to make watches that appeal to today’s discerning enthusiasts in the U.K. and across the world. Whether the focus is military-style tool watches, avant-garde complications at approachable prices, or ultra-high-end pieces for well-heeled collectors, each brand boasts an identity that is proudly British and at the same time distinct from its peers. Here are 15 British watch bran...

Voutilainen Realises a Collector’s Dream, the 28 Kohan SJX Watches
Vacheron Constantin Jul 17, 2025

Voutilainen Realises a Collector’s Dream, the 28 Kohan

Voutilainen recently completed a custom commission with the 28 Kohan, a one-off example of its signature chronometer wristwatch that blends Finnish cultural symbols with Japanese decorative arts. Much of the decoration on the watch is maki-e, traditional Japanese lacquer, that is the work of artisan Tatsuo Kitamura, a frequent collaborator who was also responsible for past Voutilainen maki-e timepieces. Initial Thoughts Unique pieces and commissioned watches were historically the norm at the highest end of the watch market, which was then much smaller. Clients could be more demanding, and for the watchmaker, the risk of being unable to find a buyer was very real. Today off-the-rack watches dominate, largely for commercial and production reasons. Even brands with a long history of bespoke or custom watchmaking eschew custom dial colours. Some, however, keep the practice alive, like Vacheron Constantin with its Les Cabinotiers. Many independents also remain amenable to customisation, even established names that no longer need to, like Voutilainen, albeit with a long wait. Bespoke watches are inherently difficult to criticise – such watches are a success as long as the commissioner is satisfied, even if it’s the most hideous thing ever. Fortunately that isn’t the case here, the adjective that comes to mind is bedazzling. I suspect maximalist designs are often common on Voutilainen’s custom watches because collectors want to make the most of the opportunity. Some deta...

Introducing – The new IWC Portugieser Tourbillon Retrograde Chronograph in Armor Gold Monochrome
IWC Portugieser Tourbillon Retrograde Chronograph Jul 7, 2025

Introducing – The new IWC Portugieser Tourbillon Retrograde Chronograph in Armor Gold

The Portugieser line is one of IWC’s iconic collections, tracing its origins back to the late 1930s when Portuguese businessmen sought precision marine chronometer-grade wristwatches with oversized cases and clear dials. Since then, the Portugieser family has evolved into a flagship line balancing classic elegance with technical prowess, blending clean, legible design with complications that […]

In-Depth – The New Chopard L.U.C Qualité Fleurier 20th Anniversary Edition Monochrome
Chopard L.U.C Qualité Fleurier 20th Jun 27, 2025

In-Depth – The New Chopard L.U.C Qualité Fleurier 20th Anniversary Edition

In the world of fine watchmaking, certifications have always played a reassuring role for clients regarding the quality of their beloved watches. Of course, COSC, the standard for chronometric certification, which is primarily focused on the precision of the watch, is the first to come to mind. But many other initiatives have surfaced over the years. […]

Introducing – The Arnold & Son Perpetual Moon 41.5 Red Gold Cliff Grey Edition Monochrome
Arnold & Son Jun 27, 2025

Introducing – The Arnold & Son Perpetual Moon 41.5 Red Gold Cliff Grey Edition

Swiss watchmaker Arnold & Son is named after the 18th-century English watchmaker John Arnold, the ingenious inventor who popularised the expression ‘chronometer’ to describe his precision marine timekeepers. Before the advent of marine chronometers to determine longitude at sea, navigators relied on the position of the Sun, Moon and stars to determine their position. Astronomy, […]

Introducing – The New Salmon Version of the Brellum Duobox Triple Calendar Moonphase Monochrome
Apr 18, 2025

Introducing – The New Salmon Version of the Brellum Duobox Triple Calendar Moonphase

Founded in 2016 in the Swiss Jura by Sébastien Muller, a fourth-generation watchmaker, Brellum is an independent brand known for its direct-to-consumer model and limited annual production of no more than 299 COSC-certified chronometers. The brand debuted with the Duobox collection, recognised for its classic design, accessible pricing, and limited editions, including models featuring a […]

Introducing: The Salmon-Dial Brellum Duobox Triple Calendar Moonphase Fratello
Apr 17, 2025

Introducing: The Salmon-Dial Brellum Duobox Triple Calendar Moonphase

Brellum releases many small runs of watches during any given year, so I was surprised to find that it’s been nearly six months since our last review. Now we’re back with a look at the new Duobox Triple Calendar Moonphase LE Chronometer. Yes, that’s a mouthful, but the welcome news is that the watch now […] Visit Introducing: The Salmon-Dial Brellum Duobox Triple Calendar Moonphase to read the full article.

Hands On: Zenith G.F.J., Calibre 135 Revived SJX Watches
Zenith G.F.J Calibre 135 Revived Apr 12, 2025

Hands On: Zenith G.F.J., Calibre 135 Revived

Zenith has finally started to look beyond the El Primero with the G.F.J., which features a new version of the storied chronometer cal. 135. Conceived to mark the brand’s 160th anniversary, the G.F.J. moniker is a reference to the brand’s founder, Georges Favre-Jacot, whose initials grace the facade at the manufacture in Le Locle. This new model marks the return of the famous movement phased out about 60 years ago. But production has officially restarted, and the new cal. 135 features modern upgrades that differentiate it from the vintage original used in the Calibre 135 Observatoire introduced in 2022. The “new old stock” cal. 135 that Zenith dusted off for the 2022 edition. Image – Zenith The movement returns to market in a 160-piece limited edition in platinum and features an elaborate blue dial that that is made from lapis lazuli and mother of pearl. For about double the price, owners can request a full platinum bracelet, which endows the watch with impressive heft. Initial thoughts I’ve always liked the cal. 135 and wished Zenith would bring it back. That said, I was not convinced by the first stock images I saw of the G.F.J. I felt like the dial was overwrought, and the basketweave pattern on the movement was distracting. Having spent some time with the watch, I would soften my criticism of the dial as it’s more subtle on the wrist and up close the details are finely done. Moreover, subsequent non-anniversary versions will likely have these details toned...

Zenith Introduces the Blue Ceramic Chronograph Trilogy SJX Watches
Audemars Piguet having already done it Apr 6, 2025

Zenith Introduces the Blue Ceramic Chronograph Trilogy

In celebration of birthday, Zenith presents a trio of chronographs entirely in blue ceramic, the 160th Anniversary Editions of the Chronometer Sport, Defy Skyline Chronograph, and Pilot Big Date Flyback. Each retains the specifications of its steel equivalent, with the only distinction being the case and bracelet material. Initial thoughts Best known for the El Primero high-beat automatic chronograph, Zenith arguably does best at chronographs, and that’s exactly what it’s doing for its anniversary. The reimagining of Zenith’s best-known models in blue ceramic is on trend – maybe a bit too trendy – with brands like Audemars Piguet having already done it. That said, the anniversary trilogy does offer a striking new alternative to anyone seeking an El Primero with a whole new aesthetic. The use of ceramic for both the case and bracelet, however, means each of the trilogy models is notably pricier than the equivalent model in steel. That’s acceptable for an anniversary limited edition, but not quite the same value proposition as the steel variants. Blue ceramic The Chronomaster Sport, Defy Skyline Chronograph, and Pilot Big Date Flyback each retain the same dimensions and movement as their respective steel models, except that the case and bracelet are now in blue ceramic modelled on Zenith’s signature hue. According to Zenith, blue ceramic was an undertaking that involved months of research and development. Blue ceramic is significantly more challenging to finish...

First Look – Chopard Celebrates 25 Years of the Quattro with a Refreshed & Compact L.U.C Quattro Monochrome
Chopard Celebrates 25 Years Apr 2, 2025

First Look – Chopard Celebrates 25 Years of the Quattro with a Refreshed & Compact L.U.C Quattro

The ultra-thin, 3.7mm Calibre 98.01-L, certified by both the Poinçon de Genève and COSC, was the second developed by the Chopard manufacture and followed the groundbreaking Calibre L.U.C 96.01-L, which was created in collaboration with Michel Parmigiani and laid the foundation for future movement development. The manually wound 98.01-L featured Chopard’s so-called Quattro technology: a […]

Zenith Celebrates Its 160th Anniversary In Style With The New G.F.J. Fratello
Zenith Celebrates Apr 1, 2025

Zenith Celebrates Its 160th Anniversary In Style With The New G.F.J.

For a long time, Zenith kept us guessing about what its celebratory 160th-anniversary release would be. But if you know something about Zenith, the social media posts hinted at something special related to the brand’s rich history in observatory chronometer competitions. With the release of the Zenith G.F.J., the watchmaker from Le Locle brings its […] Visit Zenith Celebrates Its 160th Anniversary In Style With The New G.F.J. to read the full article.