The Moderne art of the form movement
One of the rarest delicacies produced by the horological crafts of the last century is the form movement. The great scarcity of form movements in our own day is of course linked to the overall decline of handwound calibres in the age of automatic winding, but the unavailability of shaped ebauches from major manufactures like ETA, Lemania, and Frederic Piguet, is a deeper systemic problem for the Swiss wristwatch industry.
The elegance of the form watch on the wrist is something that must be experienced to be fully understood, and so it largely remains a special indulgence for the connoisseur. Sadly, the superficial “replica” mentality of much of the mechanical watch revival generally sees the shaped watch recreated in form but not in essence, fitted with small women’s-size round calibres of the automatic (as shown at left) or handwound persuasions — in sum becoming a frivolous indulgence rather than the work of a real and serious watch making tradition.
In a time when pocket watches continued to be manufactured and used as the primary personal timekeeping instrument of choice, and when adapted wristlet watches were only beginning to make inroads into military applications, the shaped wristwatch became the first kind of watch developed and designed solely to adorn the wrist. This innovative trend was largely led by a scion of the House of Cartier — perhaps the last great Parisian influence upon the world of watch design — Louis-Joseph Cartier (1875 – 1942).
His dislike of the overwrought Art Nouveau style of the closing decades of the 19th century led him to his own very Moderne philosophy of design. Thinking as a designer of haute joaillerie rather than as a watchmaker, he was able to break free from the round case tradition and classicism of two centuries, while retaining much of the facade of the ancien regime in his signature bold roman numerals, his frequent use of Breguet hands, and in some cases guillochage. From the turn of the century and throughout the “Art Deco” period he introduced the wristwatch to many non-round shapes like the square, tonneau, tank, tortue, and others — while using movements produced by Edmond Jaeger (later of Jaeger-LeCoultre).
While the optimal form of the spring-driven mechanical movement is round, the thinner and longer form watches like the rectangle and tonneau have a great deal of wasted space in both ends of the case when equipped with a small round calibre. For the best quality timekeeping movement designers always attempt to maximize the size of the mainspring barrel and that of the balance wheel. The virtue of the form movement is that it expands the movement into most of the otherwise dead space in a shaped case, permitting the use of a full-size mainspring and balance.
It has been said that today’s large, often oversized tonneau watches can function adequately with full-size round calibres (as shown at right), and that with the market preference for automatics there is little call for new form movements to fit these watches. The use of round calibres here has also allowed some manufacturers to create curved watches without the use of curved calibres — which is itself an art lost to modern
watch making. I feel that in both of these cases, even though the full-size round calibres permit perfectly acceptable timekeeping qualities, the integrity of concept and authenticity of the form has suffered greatly, and that an opportunity to do more with the extra case space has been squandered.
The strongest need for the form movement lies with rectangular watches, as even when oversized they have difficulty fitting anything other than the smallest of round movements — which greatly compromises real-world performance and reliability. Even the super-sized “Much More” rectangular watches from Roger Dubuis use small women’s handwinds as base movements.
Square, cushion, and tortue shaped watches are usually better served by round calibres than tonneau or baguette shaped ones — and traditionally this has been the case even in the heyday of form movement production. While one could make a calibre with square plates, it probably would not result in a useful increase of mainspring or balance size over a round calibre of equivalent diameter. Note that form movements typically have “cut corners,” and that a square with cut corners is, well, almost round.
Here is the first example of what is possible on the path not taken by most makers of large shaped watches — the calibre L931.3 used in the Cabaret by A. Lange & Sohne. Its unusually large size — 17.6mm in diameter, 25.6mm in length, and 4.6mm in height — makes it correspondingly more robust than the average form movement (historically speaking), and mechanically equivalent to wider round calibres of the 10”’ class (slightly smaller than the 1815 and Saxonia), with a power reserve of 42 hours at a 21,600 v/h rate.
This calibre also shows the difference between a simple “form” movement, and a truly form-fitted movement for a specific watch — the latter is a rather expensive luxury not commonly encountered. The use here of a 3/4 plate top plate design is especially interesting as all of the vintage Lange form movements that I have seen were four-bridge calibres, making this an
unusual modern reinterpretation. You’ll note that the corners of the rectangular plates are dead space, which is why they are normally “cut-off” in most form movements — as with all of the ones shown below.
IWC calibre 87 is a vintage example of a large form movement, one which I think has one of the most elegant top-plate designs ever produced. The example shown is the most highly jeweled version with 17 jewels, and dates from 1931 — the first year of production (1931 to 1947). Due to the use of rather thin non-water-resistant cases during that period, this large calibre measuring 19.7mm in diameter, 24.8mm in length, and 3.65mm in height could be used in form watches of only modest size. Like many movements of the pre-quartz era, it is equipped with an overcoil hairspring.
It is one of only a few form movements created by IWC to replace the small round calibres it first used in its form wristwatches. The loss of calibres 89 and 8541 have long been lamented by IWC aficionados and collectors, but movements like calibre 41, 87, and 92 are a largely forgotten part of IWC’s history as a manufacture —
totaling nearly 50 years of form movement production (1924 to 1972). This legacy is unlikely to be continued in IWC’s future reinvestment in movement manufacture.
Jaeger-LeCoultre no doubt remains the most serious house of form movement development and manufacture in the world — from simple time-only movements and chronographs, to limited edition minute repeaters and tourbillons. Through their efforts, what ultimately might be considered a frivolous novelty with a mechanical case has been made horologically significant both in its vintage and many modern variations. The Reverso is widely acknowledged as a wristwatch icon.
In terms of design, the basic calibre 822 is the most classical form movement in production today. Executed in four bridges in the traditional fashion of Jaeger-LeCoultre’s handwound calibres, it is without apparent flaw. A form-fitted movement like the Lange L931.3, it was made specifically for the new larger Reverso Grand Taille case. It runs at a stately 21,600 v/h, bears a full 21 jewels, and is a relatively robust 2.9mm thick, 17.2mm in diameter, and 22.6mm in length. The size of the balance and the 45 hour power reserve indicate that it is probably equivalent to a 9”’ round calibre like Jaeger-LeCoultre’s calibre 818. Like most of their handwound movements, the escape wheel cap jewel is held with a spring clip (it looks deceptively like shock resistance).
The most “exclusive” class of form movements are those equipped with a tourbillon regulator. A full account of such movements and watches would read almost like a “who’s who” of haute horlogerie, including old greats like Audemars Piguet and Vacheron Constantin, independent master watchmakers like Kiu Tai Yu, and many others. Considering the limited interest in form watches and inherent exclusivity of tourbillons, the form watch tourbillion must be one of the most rarefied examples of the watchmakers craft.
The 19 jewel calibre TFM96 shown above in Franck Muller’s Imperial Tourbillon is the only form movement in his extensive collection of tonneau wristwatches. The same ebauche is also used by Audemars Piguet in its “Edward Piguet” tourbillons, though executed in a very different fashion. While the Imperial Tourbillon uses a highly engraved 3/4 top-plate, Audemars Piguet calibre 2871 has four bridges and is decorated with Cotes de Geneve.
Like the others shown before it, it is a large calibre 20.9mm in diameter, 27.65mm in length, and like most tourbillons is very thick at 6.1mm. Also like most modern tourbillons it is equipped with an overcoil hairspring. It has a power reserve of 48 hours at a 21,600 v/h beat rate. The ebauche was most likely designed and produced by Audemars Piguet subsidiary Renaud et Papi, though the movement was introduced in 1995 — long before the recent acquisition, and before AP began to use it in 1996. The movement is no doubt an example of why AP finally did make the acquisition, and why they remain at the top of the haut de gamme.
While not quite a trend, a new
development in larger form calibres is the form watch with extra-long power reserve. First seen in the 8-day Ionica by Parmigiani Fleurier and the related Emperador by Piaget, they were recently joined by the 10-day ref. 5100 by Patek Philippe shown above. Making full use of their larger case sizes, these movements use two mainspring barrels to quadruple and quintuple (respectively) the normal 2-day autonomy of most mechanical movements. Naturally, both include power reserve indication as a standard feature.
What does appear to be a trend is the growing use of “new-old-stock” vintage form movements in special (read: expensive) limited edition shaped watches by a number of different watch manufacturers. Dubey & Schaldenbrand is probably best known for this practice, though Paul Picot, RGM, Jaquet Droz, and others have followed their lead. What may have been almost ordinary tonneau calibres in their heyday are now treated like precious gems, as the form watch becomes a pedestal for the display of the form movement. These watches elevate the simple form movement to a kind of rare treasure far beyond its intended function and raison d’etre.
This fad of form wristwatches has only been with us now for ninety years or so — obviously too ephemeral to be taken seriously by most manufactures. Thus we find that the Moderne Parisian “1920s look” is now just a retro chic that teeters precariously with only a few real supports in the living craft. I think that the authenticity of the 21st century form watch as a valid horological work hangs upon the fitted form movement — both in the integrity of concept and in the actual quality of the watchmaking. If this challenge to present-day manufactures can be met, the form watch may yet remain the alternative wristwatch of the modern gentleman and connoisseur for another century.
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