The Past And Present Of Ultra-thin Watches (Part 1)

For the appreciation of ultra-thin watches, most watch fans are long overdue. In fact, many enthusiasts never even pay attention to them. As for the reason, perhaps the appeal of ultra-thin watches is inherently ‘narrow’. In a way, ultra-thin watches are just a small category in modern watchmaking. However, in most of the history of mechanical watchmaking, ‘ultra-thin’ is not only an aesthetic ideal, but also regarded as a testament to the talent of extraordinary watchmaking.
   Let’s start with the definition. For the interpretation of watchmaking terminology, Berner’s ‘Illustrated Professional Dictionary of Horology’ (including four versions in French, English, German and Spanish, now available from FH) . Surprisingly, the definition of ultra-thin watches included in the book does not appear to be more robust and generally accepted. It is defined as an ultra-thin watch, ‘Extra flat (adj.) Extremely flat’. It looks like a casual cold humor, ‘ultra thin’ and ‘extra flat’ are interchangeable, but this is not useful for people who like precise terminology.

An early German clock from Augsburg in the mid-16th century
   To understand why the definition is ambiguous, it may be helpful to go back in time to the history of ultra-thin watches. The picture above shows an early German clock from Augsburg in the middle of the 16th century (then one of the main centers of European watchmaking). This is the first generation of a small, portable clock with a metal spring, and the first watch to evolve from it. There is no particularly strict difference between a portable clock and a watch, both of which are made possible by the development of metal springs and use them as power (earlier clocks used weights on ropes as power) . This portable clock, or prototype, is obviously very thick for two main reasons: the axle escapement and the equalizing cone. This was also a common feature of clocks of that era.

   In the next two centuries or so, the general structure of the watch did not change much: the wheel train was installed between the top and bottom plates, separated by pillars. The watch became more beautiful and complex, but its size did not shrink until about the middle of the 18th century. The picture below shows a engraved watch, made by Chauvel, produced in London around 1730. It can be seen that the hammer is on the left, the reed adjuster is on the right, and it works through air resistance. This engraved watch is very beautiful, but it is still too heavy, and still depends on the axle escapement and the double-pillar structure of the pillar.

A engraved watch, made by Chauvel, produced in London around 1730
   By the mid-18th century, the demand for thinner watches was growing. French watchmaker Jean-Antoine Lépine has promoted changes in the architecture of the movement, making it possible to make thin watches. He greatly changed the way the watch was built: abandon the top plate and use plywood to fix the pivot position on the wheel train; discard the complex sesame chain and try the sickle-hook and lever escapement. The design of Jean-Antoine Lépine is very successful. In fact, the Lépine movement is still the reference basis for most movement designs.

Jaeger-LeCoultre Caliber 145, only 1.38 mm thick
   A major driving force for the growth in demand for ultra-thin watches is the shift in men’s fashion styles from the late 18th and early 19th centuries. The famous playboy George Bryan ‘Beau’ Brummel is a typical example. He discarded the gorgeous men’s fashion popular among European nobles and promoted tailoring. Tailor-made clothing fits slim fit, which requires a slim profile. European watchmakers responded by trying to push the limits of slim watchmaking as much as possible (Mr. Breguet’s own slim watch is equipped with a variant of the Lépine movement). In Europe, slim watches are more popular than in the UK. In the UK, the watchmakers have instead adhered to the heavy movement structure and refused to give up the sesame chain.

‘Knife’ pocket watch, produced in 1930

   Making ultra-thin movements was, and still is, an extreme technical challenge, which makes the production of truly ultra-thin watches the exclusive domain of a very small number of watchmakers. Of course, one of the most outstanding watchmakers in this field in the early 20th century was Jaeger-LeCoultre. In response to the demand for ultra-thin watches led by Paris watchmaker Edmond Jaeger, LeCoultre began to try to produce models with movements less than 2 mm thick. Perhaps the most famous is Caliber 145. This movement is only 1.38 mm thick, which also makes the pocket watch shown in the picture above possible-the so-called ‘knife’ pocket watch, produced in 1930. The Caliber 145 movement has a long production cycle, from about 1907 to the mid-1960s.

Jaeger-LeCoultre Caliber 19 RMCCVEP movement, with both minute repeater and timing functions, only 3.55 mm thick
   Complex models are also starting to become slimmer and even reach incredible sizes. The Jaeger-LeCoultre Caliber 19 RMCCVEP movement, shown above, has both minute repeater and timing functions, and is only 3.55 mm thick. Of course, not all watchmakers try to make their watches as thin as possible. On the one hand, designing and manufacturing ultra-thin watches requires more investment, which will increase costs and selling prices. On the other hand, for watches with the highest accuracy and reliability, the ultra-thin structure does not make any sense. Ultra-thin watches are indeed very fashionable, but many customers still prefer watches that feel solid and reliable.

   In any case, the ability to make ultra-thin simple or complex movements is regarded as a symbol of watchmaking strength. In the next article, we will look at modern practitioners of ultra-thin watchmaking art; explore why there is no unanimous definition in the industry after decades of ultra-thin movement development; and why, even today, whether it can be produced Ultra-thin watches should still be regarded as an important distinction. In addition, it should be understood that ‘thin’ is a relative concept. As the saying goes, today’s unusually thin watch may be Chinese cabbage tomorrow.
Past and Present Life of Ultra-Thin Watches (Middle)

Past and Present Life of Ultra-Thin Watches (2)