Courtesy of Frodsham

The full story of the Charles Frodsham Double Impulse Chronometer

The first new English watch in nearly half a century has been in development for 25 years. One man has been following the story since the early years; now he charts the various paths that led to the first wristwatch ever to bear the name of Charles Frodsham

ByJames Dowling

31/01/2019

There hasn't been a mechanical wristwatch made in England since Smith’s closed its factory half a century ago (geographical pedants know that the Isle of Man is not in England) so when Charles Frodsham introduced its new Double Impulse Chronometer watch in 2018, it marked the return of watchmaking to the country which played the most important part in its development.

I have known the guys behind Frodsham for over a quarter-century, but that is a mere blink of an eye compared to the 184 years since Charles Frodsham founded the firm and 175 years since they became England’s premier maker of chronometers after purchasing the firm of John Roger Arnold. The Victorian era was one of consolidation among the great English watch and clock makers and by the end of the 19th century, there were just two great firms trading in London – Dent and Frodsham. Dent built the clock in the tower of Pugin’s new Houses of Parliament, while Frodsham built chronometers for the Royal Navy and regulators for astronomical observatories around the world.

The first Frodsham prototype watch

Courtesy of Frodsham

Through two world wars (including being bombed out of their premises in 1941) and the austerity following them, the firm continued production, but in the mid 1990s it was purchased by Philip Whyte, one of London’s leading dealers in marine chronometers and precision timekeeping.

He brought in as a partner Richard Stenning, who had previously worked for seven years in the watch and clock department at Sotheby’s. Prior to this he had studied horology at Hackney, under Peter Roberts. By then, the Frodsham business specialised in buying and selling timepieces from their premises in St James and servicing & repairing them from their workshop in Heathfield, Sussex.

The firm came swiftly to the conclusion that they needed to get back into manufacturing, but whether to make chronometer desk clocks or a watch?

Although Frodsham’s history had been based on chronometer clocks and precision regulators, by the end of the 19th century it had been regularly winning awards for its watches, one of its tourbillons achieving the highest marks ever attained by an English watch at Kew observatory, in 1906. So, it was an easy decision to go ahead with a watch.

Courtesy of Frodsham

In keeping with the firm’s long history of chronometer making, their first thoughts were to produce a wristwatch using the detent escapement as used in most marine chronometers. And therein lay a problem; chronometers are almost always held in a box, kept in one position and often fitted with gimbals to ensure that the timepiece stayed flat, no matter how much the ship might move.

Obviously, a wristwatch needs to operate in any position and to be able to accept the occasional shock. Knowing all this, their first attempt at an in-house movement featured a detent escapement, fitted to that ubiquitous horological workhorse, the Unitas 6497. The problem with the detent escapement, as distinct from a lever escapement is that it is impulsed only in one direction and is incredibly susceptible to shock. Frodsham got it to run, but random movements of the wrist or external impacts could cause the escapement to either gallop or to set. Despite these problems (or perhaps because of them) the production of a detent escapement wristwatch became something of a watchmakers’ holy grail.

The Detent itself

Martin W Dorsch

Breguet filed a patent for one in 2003, while Christophe Claret unveiled his Maestoso watch in 2014, but the first company to actually introduce a detent wristwatch was Urban Jurgensen in 2011. I was present at the launch of the watch and listened as Jean-Francois Mojon & Kari Voutilainen explained the procedures and modifications needed to make this delicate mechanism work in such a hostile environment. They told how the project had begun when the firm was under the ownership of Peter Baumberger and that the initial research had been done by the firm’s technical director, Derek Pratt. Neither of whom, unfortunately, lived to see the launch of the Urban Jurgensen detent watch.

But Pratt, who was one of the greatest watchmakers of the 20th century, although one of the least known, was engaged on a major personal project along with his work for Urban Jurgensen – he was building a perfect replica of Harrison’s H4. This necessitated frequent visits from his workshop in Switzerland to Greenwich to examine the original, and while in London he would often pop into Frodsham’s and chat about the problems and progress that they were both experiencing with the detent. On one occasion in May 2004, he showed them his Double Wheel Escapement pocket Tourbillon and suggested that this escapement might be a solution.

The beautifully finished winding works of the production movement

Courtesy of Frodsham

There were, at this time, including Pratt’s watch only eight Double Wheel Escapement pocket watches in the entire world and nobody had yet shrunk the mechanism enough to fit into a wristwatch. In fact, its developer George Daniels had always said that it would be a huge challenge to miniaturise the escapement to fit into a wristwatch, but materials, tools & technology had all progressed since and the Frodsham team decided to try.

Once again using the reliable Unitas base, they produced their first proof-of-concept movement in 2005; it was cased up and then tested for almost 3 years while a brand new, in-house English movement using the new escapement was designed on the metaphorical blank sheet of paper. Three prototypes of this new movement were built; the first one, uncased, was ready in time to be displayed at the 150th anniversary of the British Horological Institute in June 2008.

The proof-of-concept movement

Courtesy of Frodsham

Then began the hard work of developing the prototypes into production ready versions; the Unitas ‘mules’ had been built with no thought given to aesthetics, the only target being to get the thing to work. But now great thought and care was given to the appearance of the movement and the challenge became to retain the aesthetics without compromising the mechanical integrity. The decision was made that mechanics would come first and that aesthetics would always play second fiddle, but the Frodsham team had cut their teeth (in both senses of the phrase) on vintage movements. So they were inspired by the aesthetics of the vintage Frodshams to produce a movement which not only worked flawlessly, but also looked perfect.

Early on in the development process, it was realised that individual components could rarely be designed in isolation. While a wheel or bridge might look better if it was five per cent slimmer or had a different finish, once fitted to the movement it could look wrong next to its fellow components, so the decision was made never to work on individual components alone – visual changes and modifications to parts were done in context with their surrounding components.

The balance between mechanics and aesthetics is best shown in the wide range of materials used in the watch – titanium for the detent, 18ct rose gold for the train wheels, black polished steel for the balance bridge, tungsten carbide for the balance timing weights and a special three metal copper alloy (copper/nickel/tin) for the balance wheel.

The prototypes were now fitted in simple steel cases and worn regularly, one by Philip Whyte who repaired his car, mowed the lawn and commuted daily into London wearing it, while another member of the team regularly wore his on long bike rides. They were determined that the new movement would be reliable.

The final prototype movement

Martin W Dorsch

One of the three prototypes was left exactly as it was when produced, for comparison with the other two which underwent a huge number of iterations. Initially, the escapement geometries were made to George Daniels’ original designs for a pocket watch, but subtle changes were incorporated into the wristwatch version, for example a change in the roller diameter and the position of the secondary locking jewels. They experimented with different materials for the escape wheels; many were tried and rejected before they finally decided on titanium. The dynamic workings of the escapement are very different to any theoretical modelling. The variables measured included wear, lubricity, how quickly the escape wheel released, how quickly it accelerated, and its terminal velocity at the point of impulse.

The Double Chronometer escapement

Colin Crisford

One of the most beautiful aspects of the movement is the asymmetric three-armed balance bridge, which combines exceptional stability with an almost unhindered view of the balance assembly. It was not always this way. Over the development period, the bridge was tried with two arms and also as a simple balance cock. It takes an astonishing 11 hours of hand polishing to achieve the desired finish.

Their search for the correct method and materials is best exemplified in the use of zirconium oxide on the dial. While the prototypes used conventional silver dials with engraved and filled numbers, for the production watches they wanted something similar to enamel without its drawbacks – the propensity to crack and the ‘dipping’ at any holes in the dial (centre and subsidiary second posts or around applied numerals).

Martin W Dorsch

Used in ‘gauge blocks’ – perfectly flat and parallel surfaces – to calibrate precision engineering tools, zirconium oxide ceramic was available in samples no thinner than 1mm thick, so it was lapped down to only 45 per cent of its former height. The resulting perfectly flat surface was too reflective, so it was bombarded with a micro-grained aluminium oxide to provide a finish which is neither too matt nor too glossy.

When it came to printing the dial, conventional methods were discarded in favour of methods hitherto only used in the eyepieces of telescopic sights & microscopes. Using a variant of physical vapour deposition, it is possible to produce consistent lines less than half the width of a human hair. Because the material deposited onto the dial is a metallic oxide, it does not degrade in any way and is much more permanent than any other dial printing method yet used anywhere else.

I mentioned earlier that Derek Pratt had been working on a perfect replica of Harrison’s H4 when he was discussing detent wristwatches with Frodsham’s; unfortunately, a recurrence of prostate cancer prevented him from finishing the project and Frodham’s agreed to complete it in time for the 2014 tercentenary of the Longitude Act. Concentrating on this project, and on a replica of H3 for the same event, caused work on the wristwatch to slip behind. But skills learned during the production of the H4 replica proved their worth, particularly in such fields as machining the detent, which weighs a microscopic 0.0037 of a gram.

Funded totally from internal funds with no outside investors, the Double Impulse Chronometer has taken what seems to be an inordinate length of time to come to market; but it seems more reasonable when you realise that this was so much more than just designing and building a watch. It was a project where experimentation, trial and error and the endless search for perfection each played a role, and the wait has proved to be well worth it.

Christopher Beccan

The watch that changed everything: the 90th anniversary of the Rolex Oyster

A unique 90-year-old Rolex gives us cause to look back at the invention that cemented not just the reputation of watchmaking’s most famous house, but the very viability of the wristwatch itself.

ByJames Dowling

14/03/2016

Rolex did something truly astonishing in 1927: it released a genuinely waterproof wristwatch that, unlike earlier efforts from other firms, neither looked nor felt unusual, and could be worn on a daily basis. The seasoned Rolex enthusiast may well recognise the model above as an early example of that historic game-changer: a first generation Rolex Oyster.

That would make it 89 years old. But its markings tell us that it is, in fact, one year older than that. While the first models dodate from 1927 – famously, the English swimmer Mercedes Gleitze was given one to wear as she swum across the Channel that October – it was in 1926 that the Oyster was conceived and prototyped; and indeed, the one pictured here is just such a 90-year-old prototype. On such an anniversary, the details of how and why the Oyster came to be are worth examining. 

Hans Wilsdorf, the founder of Rolex, was never a watchmaker. In all his legal documents he gave his profession as “merchant” – someone who buys and sells. This is important to understand, because for the five decades and more that he ran the firm, Rolex didn’t make watches from scratch as it does now; rather, it assembled them. Movements were bought from one firm and cases from another, as were dials, bracelets and all the other components. Rolex was able to take commonly made items and assemble them into something special, thanks in particular to Wilsdorf’s talent for spotting a hole in the market. Nowadays we would call him a marketing genius, and nothing exemplifies this skill more than the story of the Rolex Oyster.

The trench warfare of WWI had demonstrated the advantages of the wristwatch over the pocket watch, and Rolex had been one of the first watch manufacturers to capitalise on this shift. But in the following years civilian users of wristwatches had two complaints: they weren’t as accurate as their pocket watches of old, and they had a tendency to need servicing much more often than pocket watches, since the oils got clogged with dust and detritus or the movements succumbed to water ingress.

The first problem could be expected, since smaller movements meant smaller balance wheels. Wilsdorf attempted to overcome buyers’ prejudice by submitting many of his watches for testing at both Swiss and Kew laboratories to prove their accuracy. That continues to this day, of course, with Rolex being by far the largest producer of COSC-certified chronometers.

The second problem, of dust and water invading the mechanism, was much more difficult to solve, although many had tried. In the Victorian era, for instance, pocket watches used by explorers were fitted with a screw-down cap over the winding crown, attached to the body of the watch by a small chain – a clumsy system that necessitated a very tiny winding crown to fit under the screw cap. (This design was reintroduced, incidentally, by Cartier in the 1990s with the Pasha).

Christopher Beccan

The first attempts at making a water-resistant wristwatch came with “hermetic” cased watches from the early 1920s. Here, the watch was completely encased in a second outer case, and could be wound and set by unscrewing the bezel and flipping the watch out on its hinge. This design had two major problems, due to the use of gold or silver for the cases. Both being very soft metals, the daily unscrewing of the bezel caused the screw threads and bezel knurling to wear out, the former meaning that the watch was no longer waterproof and the latter meaning it became difficult to unscrew the bezel anyway.

An astute reader will have noticed that both of these early attempts focussed on protecting the crown, this being the most obvious entry point for unwanted substances. What was needed was a method of securing the crown and making it waterproof itself, and in May 1926 fate intervened

.

Christopher Beccan

Wilsdorf would have made it a habit to scour the entries in the Swiss patent register for anything he thought that he could use, and patent 114948 certainly fitted that description. It was filed by two gentlemen from La Chaux-de-Fonds, Paul Perregaux and Georges Peret, and proposed a system for a winding crown that screwed down on to a threaded tube protruding from the case. As the crown was in the normal position and unencumbered by a cap or an extra case, it was much easier to use and therefore much more likely to achieve sales success; Wilsdorf lost no time in acquiring the patent from its owners, and within months the Rolex Oyster was on the market.

Or so the accepted history has it, though recent research refines the story. In a 2010 article in the US National Association of Watch & Clock Collectors (NAWCC) Bulletin, watch historian David Boettcher showed that the patent was in fact transferred to one Charles Rodolphe Spillmann, who owned a casemaking firm in La Chaux-de-Fonds, on July 19, 1926. Then, five days later, it was transferred from Spillmann to Wilsdorf himself – interestingly, not to Rolex directly. After a further five days, on July 29, Mr. Wilsdorf registered the trademark “Oyster” and the package was complete: case, crown and name were all in place.

I believe Spillmann was much more than an intermediary used by Wilsdorf to conceal his interest in the patent. I think Spillmann brought the Perregaux/Perret patent to Wilsdorf himself, and explained to him how combining this crown with a waterproof case he had recently invented could make the world’s first waterproof watch. While I have no proof for this theory, if you look at the image of the inside caseback on the 1926 Oyster prototype pictured, you will see a small hammer head at the bottom. This is a Swiss casemaker’s stamp, and inside it is the number 136, which indicates that the case was made by C. R. Spillmann & Cie of La Chaux-de-Fonds. This mark can be found inside almost all early gold Rolex Oyster cases, indicating that Spillmann’s firm alone was responsible for all of them.

Christopher Beccan

Christopher Beccan

The design of the original Oyster case itself is quite interesting, as the movement is not attached directly to the case body. Rather, the case is composed of three parts: a central case with the lugs attached to it, and separate bezel and case-back, both screw-on. The movement, dial and hands are held in a metal ring with external screwed threads, with a hole at the 3 o’clock position and a pin at the 9 o’clock position. The ring is inserted into the case body, and the pin at 9 fits into a matching hole in the case; the crown and winding stem are then fitted into the hole at 3 and the bezel and case back are screwed into place.

At this time Rolex made much in its advertising about using no cork or leather washers in its watches, stating that it only used metal to metal contact; this was true but it did use a washer inside the caseback, in order to ensure a perfect seal. However, this was made from a thin sheet of lead, which deformed when screwed down to allow for any irregularities in the machining of the caseback surfaces.

The shape of the case is known as a “cushion” and was used by Rolex and others from the second decade of the century, and Rolex itself continued to make use of it until the end of WWII. The Oyster was also launched in an alternative case style, the Octagon, which was never as popular as the Cushion and which lasted less than a decade in the firm’s catalogue; most likely because it was seen as looking old-fashioned even then.

Rolex

As with all Rolex watches of the period, the movements were made by Aegler in Bienne, and this particular movement was known as the 10½ Hunter: 10½ being the size in lignes (23.7mm) and “Hunter” being the layout of the watch design, meaning that the winding crown was at 3, as in a hunter pocket watch (one with a lid that closed over the dial), rather than at 12 as in an open-face pocket watch.

The movements came in three versions: Prima, Extra Prima and Ultra Prima. They are all 15 jewel constructions, and differentiated only by the timing tests carried out after construction: the best 10 per cent were given the coveted Ultra Prima designation, while the balance were split between Prima, which were the less accurate and Extra Prima, which fell in between. The Ultra Prima watches were also usually marked as such on the dial, as can be seen in this case.

Christopher Beccan

In the mid-1930s Rolex moved from the complex three-part Oyster case to a simpler two piece design which integrated the bezel into the case body and did away with the movement holder, and Spillmann seems to have vanished from the Oyster story – but not, in fact, permanently. In the 1960s the initials “C.R.S.” are to be seen inside the casebacks of Rolex chronographs, and this relationship continued for almost two decades. Neither was it the end of the cushion case, of course: in the late 1930s Rolex produced an oversized version of this case for an obscure Italian instrument maker, Officine Panerai. The rest, on that front at least, is the stuff of watchmaking legend.

So it is for Rolex too. Despite external changes as watches grew larger during the late 1940s, the essential design of the Oyster case remained pretty constant until the early 1950s, when (as with the introduction of the original Oyster) a new case and crown came along together. The crown was called the Twinlock, and as you can probably guess used two gaskets to ensure it was watertight – initially guaranteed waterproof down to 50m, it was a genuine breakthrough in making watchcases impermeable.

Christopher Beccan

In 1953 Rolex also introduced a heavier two-piece case, but with the provision for a rotating bezel; the first to use it was the reference 6202 Turn-O-Graph, which had a bezel insert marked with 60-minute markers. Marketed as a waterproof alternative to a chronograph, it wasn’t a commercial success; but it became the basis for one of the most iconic watches ever made by Rolex, the Submariner. That launched the following spring at the Basel Fair, following Swiss explorer Jacques Piccard’s historic bathyscaphe dive with a specially built Rolex attached to his submersible.

Over the years, the parallel development of cases and crowns has continued, via the Sea Dweller in the 1960s and the Deepsea in 2008. For the latter, Rolex abandoned the 60-year history of the two-piece case and reverted to the original Oyster design with a separate movement ring inside the main case body. It proves that a now 90–year-old design is capable of 21st century performance; and also that, sometimes, going forward can mean going back to your starting point. 

Crisis? What crisis? A short history of high-frequency, super-accurate quartz watches

The introduction of quartz watches may be blamed for decimating the watch industry, but in the fifty years since, top-end quartz makers have been engaged in a rigorous pursuit of accuracy - the pinnacle of which is Citizen's Calibre 0100

ByJames Dowling

17/10/2019

The story of the mechanical timepiece has always been one of relentless progress towards accuracy, usually by tiny, gradual increments. From Christiaan Huygens’ first watch to the observatory tests of the Seventies, it has been 300-plus years of constant development, but the introduction of quartz timepieces in the early Seventies brought that progress to a grinding halt. Quartz was so accurate that mechanical timepieces were considered irrelevant and development ceased for around 30 years. The very best mechanical timepieces were accurate to one or two seconds a day while the first quartz watches offered accuracy of five seconds per month.

Nobody in normal life actually needed the accuracy of the best mechanical watches, so the quartz models could be seen as overkill, but the desire for improved accuracy wouldn’t lie down and die. The researchers at Omega, who were one of the major participants in the Beta 21 project (the first commercially available Swiss quartz movement) decided to develop their own quartz movement. At the end of the Sixties a lot of research was being put into faster balances in the search for accuracy in mechanical timekeeping; Seiko, Girard-Perregaux and Zenith all introduced watches beating at 36,000 beats per hour (or 5Hz) — twice the rate of most other watches.

So it was natural that the Omega researchers working on their own quartz movement looked at the possibility of increasing the rate at which the quartz crystal oscillated. The Beta 21 used a rate of 8,192Hz; the lens-shaped, Omega-developed crystal had a rate of 2,359,356Hz and promised accuracy of one second per month. Launched in 1974 as the Omega Marine Chronometer, it came with a certificate stating that every watch had been tested by the Besançon Observatory for 63 days and listed the results achieved at the tests.

When Seiko introduced the world’s first quartz wristwatch at the end of 1969, it presented its Japanese rivals Citizen with a problem. It made no sense to announce themselves as the world’s second producer of quartz watches, so they decided to make the world’s most accurate quartz watch: the Citizen Crystron Mega. It took them until 1975 to do it but the Crystron outperformed the Omega, both in the rate at which the crystal oscillated and in its accuracy of three seconds a year. 

Unfortunately, such accuracy came with two costs. First, the energy needed to vibrate the crystal at 4.1mHz meant the battery usually lasted only a few months — and, of course, the watch stopped and had to be reset when the battery was changed — so the much-vaunted long-term accuracy was ephemeral. The second was financial: at 4.5m yen (I think Citizen missed a trick not selling the watch for 4.1m yen to match the frequency) the watch cost around £6,500 in 1975 (or £15,500 today), around the price of a new Porsche 911S. Nevertheless, Citizen managed to sell around 3,000.

Seiko, not wanting to be eclipsed by its rivals, took the unusual step of pitting its two factories against each other. The Suwa factory (which had produced the world’s first quartz wristwatch) was first with its 38 calibre in 1971. Initially capable of 20 seconds a month accuracy, by 1974 it had been refined down to a mere two seconds a month. While this was well below the Citizen Crystron Mega’s performance, it also boasted an 18-24-month battery life, so its real world performance was much better.

The original Seiko Astron, the world’s first quartz wristwatch

Seiko

Although Seiko submitted mechanical chronometers which ran up to 20Hz to the Swiss observatories, it had experimented with some as fast as 50Hz. And yet despite its obvious preference for faster-beating mechanisms, the brand decided not to follow Citizen and Omega down this path, instead choosing a completely different route to obtain accuracy. It looked at the influences which caused inaccuracy in quartz watches and identified temperature as the biggest problem; the solution was to fit the watch with an additional quartz crystal, which was used to measure temperature. This info was fed to a chip which contained the accuracy variations which could be expected of the timekeeping crystal at various temperatures. The chip used this data to adjust the accuracy of the timekeeping crystal. This technology came to a peak with the calibre 9983 of 1978, capable of five seconds a year while still offering an 18-24-month battery life.

Rolex was a late entrant to the quartz race, waiting until 1977, but did so in its own idiosyncratic way with the 5035/5055 movement, which utilised a totally new approach by controlling the crystal’s frequency through voltage input. Rolex used a thermistor to measure temperature variations; this then was fed into a compensation circuit which varies the voltage by tiny amounts, but just enough to force the crystal to vibrate at the correct rate, irrespective of temperature.

The predecessor to the 5035 was the Rolex 5100 Beta-21, also known as "the Texan"

Christopher Beccan

Other Swiss manufacturers saw the success of high-accuracy quartz watches from Japanese brands and realised there must be a market for them. Longines embarked on a joint project with ETA which took the twin crystal idea first introduced by Seiko and improved on it. In this method, the secondary crystal vibrated at a much faster rate than the timekeeping crystal, which meant its reaction to temperature changes was different than that of the primary one. (If you can measure the two different frequencies then you can work out the temperature and adjust the rate of the principal crystal in order to eliminate the effects of temperature.)

A quartz crystal

Citizen

This thermal compensation method became widespread throughout the Swiss industry and was also used by Breitling, who called watches fitted with these movements “SuperQuartz”.

By the mid-Eighties, something happened in the Swiss watch industry. In the same way that quartz had almost killed off mechanical horology in the Seventies, the resurrection of traditional watchmaking almost did for the high-accuracy quartz watch. Very little further development was done until the start of the following decade and in 1993, Seiko brought high-accuracy quartz back with a bang with its new 9F movement.

Like the Rolex Oysterquartz movement, it looked more like a mechanical movement than a quartz one — fully jewelled and all-metal, with only the presence of a battery showing that electricity played any part in its operation. The 9F guaranteed 10 seconds a year accuracy, and in 2009 the brand brought out a small series of watches to commemorate the 40th anniversary of the original Seiko Quartz Astron and these watches were regulated to five seconds a year.

Last year, another limited edition was released to commemorate the 25th anniversary of the 9F (and these too were regulated to five seconds per year).

The Grand Seiko 9F calibre

Seiko

Seiko’s domestic rival had not been sitting on its hands. In 1995, Citizen introduced its calibre A660 which offered five seconds a year accuracy from the start; and the brand used it to power its top of the line watch, the Chronomaster (known in some markets as “The Citizen”). Similar to the Grand Seiko quartz watches fitted with the 9F movement, it went even further by being equipped with both a perpetual calendar and an hour hand which could be moved in discrete one-hour jumps, meaning that time zone and seasonal changes could be performed without affecting the accuracy of the watch.

Five seconds a year has become the new standard, as exemplified by the introduction of ETA’s PreciDrive movements, available as simple three-hand watches, chronographs, or four-hand GMT Models. Last year, Longines used this movement in the reintroduction of its VHP line, featuring the unexpected adjustable hour hand and perpetual calendar, but predictable is its decision to follow the Citizen-Seiko path of sealing both the quartz crystal and the associated integrated circuit in a vacuum case — here a ceramic one — to protect from humidity and temperature. Although Longines was the launch brand, the movements can now be found in watches from Tissot to Certina, and also in the very Bauhaus-influenced watches from London’s Uniform Wares.

Citizen

One of the most intriguing watches at Baselworld this year was Citizen’s ultimate high-accuracy quartz watch: the boringly-named Caliber 0100. Offered in a white gold case with an almost clinically austere dial, it’s the most accurate autonomous wristwatch ever made, guaranteed to keep the phenomenal rate of one second per year. In order to do this, Citizen has reverted back to the technology of the Crystron Mega, using a crystal vibrating at the frequency of an unheard-of 8.4mHz. And while the Crystron Mega struggled to get more than a few months out of its battery, the 0100 has no such worries, being driven by Citizen’s light-powered Eco-Drive solar cells.

Citizen

If competition continues to drive progress — as it always has — I wonder what the next level of accuracy will be? To put things into perspective, a mechanical clock built to a 250-year-old design but made with modern materials was certified by the Guinness World Records team in 2015 as being accurate to 0.625 of a second in 100 days. This equates to an annual performance of around two seconds a year. So, if mechanical horology can do that, who knows where quartz may lead us?