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Discussion Starter #1 (Edited)
The Standard French (and Swiss) Lepine Key-Wound Calibers of the 19th Century

By SilkeN and mkws

Photos: SilkeN

Blancs (~ebauche, blanc roulands) - that means just the corpus of a movement. “Blancs” first came around in 17th century England. Of course, the blanc business wasn’t really a widespread trade those days. On the continent, it was only at the beginning of the 19th century, that manufacturing of watches has expanded to an industrial scale. The division of labour began. Little workshops and watchmakers became specialized in the production of various individual components. Only the production of the “blancs” was done in larger factories. Usually such a “blanc” contained the plates, the wheels and the pillars, but never the escapement or the finished balance- the balance wheel could have been included, but never the hairspring. Japy, founded in Besancon, France in 1771 by Frédéric Japy, was the first to use machines for the production process, and so became the role model for the quick development of the Swiss and French watchmaking industry. The watchmaking of these two countries was closely intertwined. (Just have a look at the map: Besancon/Locle).

To get an idea of the production volume, here as an example- figures for the year 1861 (A. Chapiro) :
Japy Frères & Cie 640.000 pieces
France (without Japy) 160.000 pieces
Fontainemelon 260.000 pieces
Swiss without F. 25.000 pieces

The average price for a Lepine blanc was 2,50 francs and a blanc for the balance staff- 1,50 franc. A a Lepine caliber is defined as a Swiss bridge movement invented by the famous Antoine Lepine (1720-1814), and of course the further developments of that design, made by other watchmakers.

For a long time, Japy remained by far the largest raw material producer, and therefore shaped the style and technology of the continental “utility” pocket watch. His production rate went up rapidly. As early as 1795, he manufactured 40.000 blancs, and in 1805, 10 years later, the output reached 180.000 pieces. During a period of dominance of Japy, from about 1830 onwards the mechanised mass production took place, but still a lot of smal “companies” - often “one-family” workshops – had the standard calibers modified, which occurred quite frequently. The creators of the caliber are still unknown today, and the manufacturer of a watch cannot be determined in most cases.
Reduced to the most common basal caliber, Adolphe Chapiro has divided the Lepine calbers into type I until V. This classification is still used today among collectors. In particular the dating provides only a rough clue since it is exception almost the rule.

1. Lepine (round bridges) 1795-1800 (1815)
2. Lepine I 1800-1825
3. Lepine II 1825-1835 (1850)
4. Lepine III 1830-1840
5. Lepine IV 1835-1850 (1900 in simple watches)
6. Lepine V since 1850 and IV and V also as stem-winders since 1870

In the last third of the century, the variety of calibers increased with the crown winders. A lot of the still operating, famous and reputable Swiss manufactures started their own production of in-house movements on a perceptible scale. (exempli gratia: Omega- founded in 1848, Tissot- 1853, Revue Thommen -1853, Heuer - 1860, Longines - 1862, Zenith - 1865, IWC – 1868, etc.) Close to the period when these brands were founded, you usually can find a lot of watches with the standard Lepine calibers as well.

The beginning of the 19 century was still an exciting era in terms of the development of various escapements, and the manufacturers’ attempts at optimizing the construction and performance of this important part of the movement. In this small thread, we have only limited it to what was typical and common at that time. For Lepine key-winders, it’s definitely the cylinder escapement. In the very early period of production of these movements, you can find them also in high-end watches with a ruby cylinder, while at the end of the century it became obsolete, sort of an easy and cheap technical solution you’d find in simple and fairly inexpensive watches. The new “star” was the modern lever (produced on a much larger scale from 1825 on), placed on the side of the escape wheel . Since ca. 1840 you an also find the “ancre ligne droite” who gets shorter by the timeline who is still the most common escapement. The older type remained in production for a long time, and that outdated solution wasn’t a sign of quality in later movements.
The purpose of this thread is only to provide a very rough overview of watches that are very common to find, so that they are easier to classify.

Lepine I, with the flying barrel

Lepine I movements

Considering the production rates in that period, it isn’t seen as often as other standard calibres, but still, it isn’t rare. The earlier specimens were equipped with a spring limiter with two gears, later had the Geneva stop work (aka the Maltese cross mechanism).

Spring limiters used in Lepine I, on the right: the Geneva stop work

Lepine II

Lepine II

The Lepine II is easily recognised by its curved bridge over the mainspring barrel. It was in production for quite a long time, due to the fact, that its layout was suitable for extremely small and thin movements. Mostly they were equipped with the cylinder escapement, but specimens with the lever escapement exist.
Here, an example of a fully jewelled Lepine II layout, with lever escapement:

Lepine II, fully jewelled, lever escapement

Lepine III

The Lepine III is surprisingly rarer than the Lepine II- mostly because of the latter staying in production for quite some time, due to high demand for it. Until recently, almost no ladies‘ version of the Lepine III seems to have surfaced anywhere, on the contrary to the Lepine II.
Small, ladies' version of the Lepine III, with lever escapement

The main difference between the III and the older II is the relocation of the mainspring barrel and its bridge, and the minute wheel cock is now in the centre (between the barrel bridge and the balance cock).
Lever escapement Lepine IIIs are seen quite often, but they’re still in the minority.

Lepine III with the cylinder escapement

You can also see, how over the entire production period the click has been moved from the top to the side of the bridge.

Evolution of the Lepine III click

Of course, sometimes it’s hard to classify a Lepine movement- here, for example, a “chimera“, combining the features of the Lepine IIA and Lepine III, with one cock for two wheels (separate cocks in the Lepine III on the right).

he Lepine “chimera“(left)

Lepine IV

The Lepine IV, in production since approximately 1835, marks the beginning of a period of transition to even cheaper mass production, and a growing abundance of design variations. A distinctive feature of that layout is that for the first time, the minute wheel is located under a bridge- with an easily recognisable, curved end.
The wheel cocks are still arranged radially.
Let’s see some nice examples- here, a Lepine IV with the standard layout and cylinder escapement, next to a fine, modified design with the lever escapement, which falls into the trend for more “individual“, customised movements, typical for that era. Early examples of the cal. IV always have cocks and bridges narrowing from the base to the end.
tandard, cylinder escapement (left) and modified, lever Lepine IV

On the dial side, you will always find a plate for every pin, like in the older Lepine layouts.
Dial sides of the two Lepine IV (shown in the previous photo)

The Lepine IV layout has also been used for even cheaper mass production- on the left, an example dating to circa 1890, with not particularly impressive finishing to it. On the right, a high-grade Lepine IV made circa 1850, with lever escapement. Notice the early shock protection, and the temperature compensation curve. Such things can be found on earlier examples of the cal. IV, but are far less common in later specimens.
1890 low-grade and 1850 high-grade Lepine IV movements

Lepine V

The last generation of the key-wound Lepine movements is the Lepine V. The radial arrangement of the wheel cocks gives way to a tidy, elegant layout of bridges running parallel to each other. The lever escapement became a standard in these, and the cylinder escapement is only found in examples from the lowest, “budget“ price segment. Often you can find specimens with a half or full plate, made for the English market. While it might look unlike the typical Lepine V, the layout of the components stays the same as in other Lepine V, with no major changes.
Here, an example of a simple, cylinder escapement Lepine IV. Its dial side is very similar to the one found on late Lepine IV specimens.

Cylinder escapement Lepine V

The new machines achieved an unprecedented level of precision, a level high enough to render useless the individual plates for every single pinion. Only several high-end suppliers of blancs, including LeCoultre, insisted on still using that solution. Key-wound Lepine V movements were made until circa 1870, when the layout was modified to a stem-winding one, but the evolution of the remontoir is a long story, for another time.
Here we can see two lever escapement Lepine V movements:

Lepine V, lever escapement

The specimen on the right has “dummy“ chatons, not performing any actual function, as they have no contact with the pinion. As you can see, one of them is missing.
Real chatons can, of course, be found in high-grade examples of the Lepine V- here, a chronometer with a pivoted detent escapement (aka “the seesaw“).
Lepine V chronometer, pivoted detent escapement

That’s it- we hope you have enjoyed this reference thread, and that you will find all the information useful, should you seek to get into 18th and 19th century PWs. Any additional info to improve and expand this reference thread is most welcome!

1,632 Posts
I just want to add some fotos with blanc's to get a better idea.
Here are a copy from FHF blancs some years later but in the typical finish they were sold:


I've also put some structural mathing movements you see above on a copy of a japie booklet with blancs from their museum but unfortunately the copy is quite unreadable.


Regards Silke

Thank you MKWS for all your laborious work

5,522 Posts
What an interesting thread, thankyou both


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1,632 Posts
Thank you guys but its not really a research the most content you can find in this book: Adolphe Chapiro: Taschenuhren. Aus vier Jahrhunderten. Callwey, München 1995 but unfortunately a english version doesn't seen to excist. It was our intention to explain the environment where most common "attic findings" was born. Unfortunately pocket watch books usually only show the high lights of watchmakers art. As well its always hard to transport a picture in a short answer like (ironic modus on) " Hey, I guess big parts of your watch was build by watchmakers who are a farmers in their main occupation ":) .

Of course within 100 Years the structure of watchmaking changed a lot usually forced by crisis and technical progress. Also big regional differences excist. You can't compare for example Geneve with strong rules, laws and a protective powerfull wachmaker union with the unrestricted Canton Neuenburg. The economic protection rules of france also forced a hidden trafficking and wrong declarations. Therefore for a special watch there is still a lot to find if you've hints but under the line basically they are all Lepine in a quite simular structure you see above. Caliber wasn't protected and other blantiers than Japy seems to use the same or simular structures.

Regards Silke
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