The 18th Century, the Century of the Great Watchmakers (Part 10)
This article closes a series of ten. It was a long task involving many hours of historical research, but it was also a fascinating one, uncovering and sharing the history of watchmaking, and of the watchmakers, of the 18th century, just as the history of the 17th century, regarded as the golden century of Horology, had been before. I hope you have enjoyed it; I had tremendous fun writing it. Thank you to everyone who had the patience to read these ten long parts of the article.
Best wishes to you all.
Sílvio Pereira
With this 10th part we conclude a long article devoted to the history of 18th-century watchmaking, regarded as the century of the great watchmakers.
We conclude our fairly detailed look at Breguet's subscription watches and examine the Swiss watch industry, still in its infancy at the time, even though that country was the cradle of one of the greatest watchmakers the world has given us; we are speaking of Jacques – Frédéric Houriet, who made a remarkable contribution to the understanding of the fundamentals of isochronism, temperature compensation and the effects of magnetism on chronometers.
Sílvio Pereira
1. Evolution of the Breguet Souscription Watch Movement – first experimental version
After the initial prototype, the oldest version is considered an experimental movement, known as the first experimental version. This movement strongly reflects the early influence of Jacques-Frédéric Houriet, featuring a two-plate construction with a smaller back plate. A distinctive feature of these first experimental versions is the arrangement of the wheels around a large centred barrel (25 mm in diameter), although it is not located centrally as in Houriet's version. The balance is placed under the dial to keep the overall construction very thin.
Characteristics of the First Experimental Versions:
Design and construction: the wheels are arranged around a large centred barrel. The ruby cylinder escapement is not yet present in these early versions, and the balance wheel is housed under the dial.
Winding: done from the front with a key, on the square arbor located inside the seat for the hand.
Development period: begun around 1791; although the invention is sometimes attributed to Breguet during his exile in Switzerland, these watches were sold shortly after his return to Paris in 1795.
Signature and Numbering: The plates (which support the wheel trains) of these versions are not signed. The signature and number, when present, are found on the rim.
Production and Numbering: The production numbers of these experimental versions range from 96 to about 350 (third series). The overlap in numbering suggests that both the experimental versions and the first intermediate-size version were being improved at the same time.
Conclusion
These first experimental versions of the “souscription” movement represent a crucial phase in the technical and stylistic development of Breguet's watches. They combine innovative elements with influences from other contemporary watchmakers, showing the gradual evolution towards the design finally adopted by Breguet. The overlap in numbering points to a continuous process of refinement and improvement, culminating in the version that became emblematic of the brand.
Abraham – Louis Breguet, Paris, No. 178, 1791 – 1795
Gilt brass watch with a full-plate movement of the experimental “souscription” type, front-wound and 55.7 mm in diameter. This model has a large central arbor, suspended in the centre and held by a steel spring clip. It is fitted with the first type of lever escapement developed by Breguet, without a balance bridge, and a four-spoke brass escape wheel and pallets with grooves to retain oil. The regulator acts through an intricate linkage system and is adjustable at the rim of the movement.
The white enamelled copper dial bears Roman numerals and five-minute divisions and is signed “Breguet” in Roman capitals, a style introduced in 1795. This dial lacks the secret signature, which was only introduced in 1796, and is fixed to the movement by a screw and a pin at the edge. The rim of the movement is engraved “BREGUET A PARIS No. 178”. The watch is fitted with a single flat blued-steel hand in the “Breguet souscription” style, which has been restored, preserving the elegance and functionality characteristic of Breguet's watches.
The movement described is one of only four known with this experimental calibre using lever escapements. The other known examples are No. 319 (3rd series), No. 106/4291, and an unnumbered version (3rd series) with no date of sale.
Movement No. 106/4291 is almost identical to the one presented here. This particular example is the only one with Roman numerals on an enamel dial. There are distinctive features of these early examples, such as the dial being fixed by two screws or by a screw and a pin on the rim and the prominent position of the balance under the dial.
It is not surprising that some work begun in the early 1790s was completed after Breguet's return from his Swiss exile in 1795. Another interesting fact about this movement is that it has the same production number as a carriage clock sold to General Napoleon Bonaparte on 24 April 1798, which was auctioned by Antiquorum in Geneva on 14 April 1991. The same production number also applies to watch No. 179, a quarter repeater sold to Marie Antoinette. In addition, there is a carriage clock with the same number 179, which was sold at Christie's, Sale 7864, on 8 July 2010 in London (Lot 98). According to Breguet certificate No. 2889 of 1945 (revised by Emmanuel Breguet in 2010), its manufacture was begun in 1796 and the clock was sold in 1804 to the King of Naples, Ferdinand IV of Bourbon.
Carriage clock No. 178 was the first of its kind produced by Breguet, followed by No. 179, the second. The overlapping numbering with pocket watches No. 178 and No. 179 may reflect uncertainty about how to integrate the numbering of carriage clocks into the production records. This complexity in numbering underlines the experimental, transitional phase that Breguet's workshop went through, consolidating its legacy of innovation and excellence in watchmaking.
Breguet's lever escapement:
In 1787, Abraham-Louis Breguet succeeded in building extremely reliable lever escapements, whose design was clearly inspired by the work of the English watchmakers. However, Breguet did not merely adapt the existing lever escapement; he redesigned it completely, improving it and raising it to a level above anything that could be seen in London, and renamed this new design “échappement libre”.
As we have already seen, the original lever escapement was invented by Thomas Mudge around 1755. Mudge, an apprentice of George Graham (known for refining the cylinder escapement), created a mechanism that, although excellent in terms of accuracy, was considered excessively complicated to produce. Because of its complexity, the lever escapement was rarely used, despite the significant benefits it offered for the accuracy of timekeeping.
Thomas Earnshaw and George Margetts took up Mudge's lever escapement and worked hard to develop it further. It was then that Breguet managed to simplify it and produce it more economically, without sacrificing its effectiveness. Breguet's innovation made the lever escapement a practical and affordable solution, contributing significantly to the advancement of watchmaking.
2. Evolution of the Breguet Souscription Watch Movement – second experimental version
The second experimental version, which predates the final three-bridge construction, also has a full-plate layout, like all subsequent versions, but it already features a ruby cylinder escapement. The balance is positioned at the back of the watch, unlike in the earlier versions, where it sat under the dial. Examples of this version are No. 324 (Breguet Museum, Paris), No. 267/2267 (British Museum, 1927,0513.2) and No. 258 (sold on 11 August 1799 to Monsieur Maleszewki and later at Antiquorum, Geneva, on 14 April 1991).
Winding is done from the front, with the arbor located within the area where the hand is fitted. Placing the balance at the back of the movement makes servicing easier. As this type of movement does not yet have the three-bridge layout, it is also considered an experimental version. The plate is signed and numbered, reflecting the attention to detail that characterises Breguet's work.
Abraham – Louis Breguet, Paris No. 258, 1796
3. Evolution of the Breguet Souscription Watch Movement – first experimental version
The first experimental version begins to show the three-bridge design. The central barrel is visible and supported by a straight bridge. The other bridges have curved shapes. This version was widely copied by contemporary watchmakers who tried to share the market with Breguet. However, the quality of the copies did not compare with that of the Breguet originals. The watch is wound from the front, with the winding arbor located within the area where the hand is fitted. Signatures and numbers, when present, are engraved on the plate, between the bridges. In some cases an additional bridge, possibly not original, was added to stabilise the barrel, sometimes partly covering the serial number. The production numbers of these versions range from 200 to approximately 420 (third series).
Abraham – Louis Breguet, Paris, No. 220, 1796
4. Evolution of the Breguet Souscription Watch Movement – second experimental version
In the second experimental version, the side supports are straighter, except for the balance support, which keeps a curved design. The bridge holding the barrel is more stable, and the third and fourth wheels are still supported by a bridge, which is now straight. The watch is wound from the front, with the winding arbor located within the area where the hand is fitted. The signature and number on the plate between the bridges are arranged more symmetrically, although their orientation is not uniform. The production numbers for these versions range from about 400 to 500 (third series).
Abraham – Louis Breguet, Paris, No. 447, 1799
Gilt brass watch with a “souscription” movement of the second experimental version, front-wound. It has a three-spoke balance wheel without a shock-protection system. The cylinder escapement, with ruby, is located under the dial. The plate is engraved with signature and number arranged opposite each other, a typical feature of this version. The dial is enamelled copper, with small Arabic numerals placed outside its central area. There is no visible signature on the dial, but a secret signature is engraved below 12 o'clock as “Souscription, No. 447, Breguet”. The original hand is blued steel, with a slight swelling at the tip. The back of the case is silver, with gold hinges (dating from the mid-19th century, probably of American manufacture) and a guilloché back.
This movement retains earlier features, such as the absence of a balance protection system, the slightly curved balance bridge and a single straight bridge supporting the third wheel and the seconds wheel. Other distinctive elements point to the final version of the “souscription” watch, such as the secret signature, the ruby cylinder escapement and the general layout of the movement.
Very few Breguet watches have a visible signature on the dial. The reasons for this are a matter of speculation: perhaps it was forgotten during manufacture, or the owner preferred not to reveal publicly that he owned a Breguet watch. Another intriguing possibility is that, given the antipathy Napoleon Bonaparte felt towards Breguet after his return from the Egyptian campaign in 1801, some owners may have chosen not to display the brand ostentatiously.
5. Final version of the Breguet Souscription Watch Movement
The final version of the “souscription” movement is the most common and the most refined. All the bridges are straight, with the third wheel and the seconds wheel supported at first by two symmetrically positioned bridges, and later by a single central bridge. This design achieves greater harmony and symmetry than all the earlier versions. The signature and number are placed on the plate between the bridges, in a highly symmetrical arrangement. Unlike the earlier versions, the watch can be wound from either the front or the back.
The signature and the number have the same orientation, reinforcing the symmetry of the design. The production numbers of this version range from 500 to 4300 (third series), and many of these watches were sold long after the death of Abraham-Louis Breguet, which occurred in 1823.
This final version also served as the basis for the development of the “montre à tact” and of the design of the “montre simple, nouveau calibre”.
Abraham – Louis Breguet, Paris, No. 1498, 1806
This is the most common version of the “souscription” watch, marked by some subtle variations in the layout of the bridges supporting the third and fourth wheels, as well as in the position of the balance protection system. The balance may be made of different materials, such as brass or steel. The dials are predominantly enamelled copper, with some notable exceptions. The signatures on the dial can vary considerably. Most of these versions are housed in gold cases, reflecting the sophistication and attention to detail typical of Breguet watches.
The “montre à tact” or “tactile watch”
The “montre à tact” or “tactile watch” is an ingenious invention by Breguet, created in 1799. Without significantly reinventing the layout of the movement, Breguet found a very clever way of making it possible to check the time without resorting to sound, which disturbed the opera, for example, a pertinent issue at the time. The solution consists of a hand on the back of the case. This hand can be turned freely with a finger and stops at the correct hour; moreover, whenever the hand turned, this could be felt in the pocket. The most luxurious models were adorned with large diamonds or pearls.
In this way it was possible to estimate the time accurately without having to take the watch out of the pocket.
Iconic pieces made in Breguet's workshop, some of them finished during the 19th century
The Evolution of Swiss Watchmaking During the “Siècle des Lumières”
During the “Siècle des Lumières”, the watch trade in Geneva and other Swiss centres, such as La Chaux-de-Fonds and Le Locle, focused on producing high-quality enamelled watch cases and ébauches for the French workshops. The overall production of good-quality watches, which had flourished at the beginning of the 18th century, declined at the end of that century. At that time, the movements used locally were mostly of low quality and unsigned. To boost international sales, many movements were falsely signed with the names of renowned watchmakers such as Tompion, Graham and, later, Lépine and Breguet. These counterfeit movements can easily be identified by the poor quality of their construction and engraving.
A notable exception was the production of watches of the very highest quality in spectacular enamelled gold cases, intended for the growing Ottoman, Chinese and Indian markets. Another highlight of the late 18th century was the development or refinement of escapements, the invention of the “Pouzait escapement”[1] being particularly noteworthy.
Alexandre Deonna, Geneva, No. 579, 1720
This gilt brass watch exemplifies the fusion of technical precision and artistic design, featuring a movement with a verge escapement, verge fusée, with a single bridge and front winding. The structure is adorned with small Egyptian columns supporting the main pinion and the verge escapement, evoking a sense of classical elegance.
Every detail, from the Egyptian columns to the elaborate eared cock, reflects the commitment to excellence and dedication to the art of watchmaking, making this watch a true masterpiece.
The Influence of the Deonna Family and the Evolution of Ébauche Production
The Deonna family, widely recognised in Geneva, stood out for producing high-quality watches with richly decorated cases, especially in the mid-18th century. The style in which these watches were made reflected the elegance and refinement of the French Régence period, showing the skill and talent of Genevan craftsmen.
At the beginning of the 18th century, Swiss watchmakers began supplying raw movements (ébauches) to French watchmakers, establishing a collaboration that would intensify over the years. This exchange was fundamental to the development of European watchmaking, with the Swiss workshops earning a reputation for the quality and precision of their movements.
With the arrival of more suppliers of ébauches in France, such as Frédéric Japy, who began his activities around 1775, the French watch industry developed rapidly. By 1780 Japy was already using a steam engine, revolutionising production and setting new standards of efficiency. His workshop, which produced 40,000 ébauches in 1777, reached the impressive figure of 300,000 units in 1813 and 640,000 in 1861, exceeding the total production of ébauches in Switzerland, which was 515,000 in the same year.
This growing French output was made possible by close collaboration between French and Swiss workshops. Many French suppliers of ébauches bought components in Switzerland, acting as intermediaries and distributors. This synergy between the two countries not only increased production capacity but also raised the standards of quality and innovation in European watchmaking.
Gilt Brass Watch: An Example of Technical Transition in Watchmaking
Johann Conrad Pfenninger, Zurich, No. 657, 1740
This gilt brass watch, with a front-wound movement, displays a unique experimental escapement, making it a piece of great technical and historical interest. The dial plate, 35.5 mm in diameter, is elegantly housed in a silvered case at the back, offering a harmonious combination of materials and finishes.
The cock, small and decorated with prominent “ears”, is a distinctive feature of the French Régence period, meticulously made in steel. The balance, made of brass, is accompanied by a flat blued-steel spring, which demonstrates the precision and attention to detail of the period. The silvered regulator dial adds a touch of sophistication, completing the refined aesthetic of the watch.
The movement, consisting of two plates, is separated by short, square baluster pillars, a design choice that reflects the robustness and elegance of the watchmaking of the period. The back plate, engraved “Pfeñinger” and numbered “No. 657”, adds authenticity and historical value to the piece.
Although the dial is missing, this remarkable watch stands out for its harmonious combination of traditional and innovative components, representing the transition and technical evolution of watchmaking at the time. The integration of an experimental escapement with classical elements underlines the relentless pursuit of precision and innovation, making this watch a true masterpiece of horological engineering.
Pfenninger's unique horizontal double-wheel escapement:
A Unique Experimental Escapement: A Simplification of Pierre Le Roy's Innovation
The experimental escapement of this movement is a remarkable simplification of the development made by Pierre Le Roy, the son. It is an innovative horizontal escapement made up of two wheels: the upper wheel acts on a pallet, in a similar way to verge escapements, while the lower wheel, without vertical pivots, acts on a cylinder. This unique configuration combines elements of cylinder and duplex escapements, creating an elegant and functional synthesis.
Pierre Le Roy's watch number 3449, dated 1759, has a comparable system, but with the functions reversed: the upper wheel, fitted with vertical pivots, acts on a cylinder, while the lower wheel acts on a pallet. The similarity between these two systems suggests a possible interaction between the watchmakers.
It is unlikely that this escapement was conceived independently both by one of the most inventive French watchmakers and by a relatively unknown Swiss craftsman. It is possible that Pfenninger met Pierre Le Roy or was even his apprentice. However, there are no historical records confirming this hypothesis, which leaves the connection in the realm of speculation.
By combining elements of cylinder and duplex escapements, this experimental escapement exemplifies the continuous search for innovation and efficiency in 18th-century watchmaking. The interplay between tradition and technical experimentation reflects the dynamic evolution of the watchmaker's art, in which masters such as Pierre Le Roy and craftsmen such as Pfenninger contributed to significant advances, even if the direct interactions between them remain shrouded in mystery.
Johann Conrad Pfenninger: A Watchmaker and Engraver of Excellence in Zurich
Johann Conrad Pfenninger (1725 – 1795) was a prominent watchmaker and engraver, notable for his skill and for his political involvement in Wollishofen, Zurich, between 1777 and 1782. Recognised as one of the last Zurich watchmakers to make his own watches entirely, Pfenninger incorporated unique technical features into his creations, giving them a special place in the history of watchmaking.
Johann Conrad Pfenninger's works are often signed “Pfenninger Zürich”, “Pfeñinger”, “Pfeñinger Zürich” or “Pfeñinger à Zürich”, reflecting his identity and excellence. In 1760 he took on Johann Sebastian Clais, from Winterthur, as an apprentice, passing on his knowledge and skills to future generations. Several pocket watches made by Pfenninger are known, bearing witness to his mastery and innovation.
Johann Conrad had a cousin, Johann Caspar Pfenninger, who also practised the art of watchmaking in Zurich. Johann Caspar's creations are signed “Caspar Pfenninger Zürich”, “Caspar Pfeñinger à Zürich” or “JC Pfenninger à Zürich”. Both Pfenningers contributed significantly to Zurich's watchmaking tradition, each leaving his own distinctive mark on history.
Expansion to the East
Unknown maker, Switzerland for the Chinese market, 1770
Gold Watch with Enamelled Case: An Example of Elegance and Symbolism
This meticulously constructed gold watch stands out for its single-bridge, front-wound movement with a verge escapement, in gilt brass. Although of simple French-style construction, the movement is remarkably compact, reflecting the technical skill of the period.
The dial, made of white enamelled brass, displays clear Arabic numerals and elegant brass “Breguet” hands, combining functionality and refined aesthetics. The bezel, which opens by pressing a small button on the pendant, is exquisitely enamelled in shades of blue and adorned with a “white collar”[2] imitating pearls, adding a touch of opulence and artistic detail.
The back of the case is a work of art in itself, precisely chased to depict three phoenixes in a scene that includes a pine tree and undergrowth. This iconography is rich in Chinese cultural symbolism. The phoenixes (traditional: 鳳凰, simplified: 凤凰; fènghuánɡ) symbolise virtue, duty, correct behaviour, humanity and reliability – the Five Human Qualities – as well as strength, resilience, good luck and opportunity. In Chinese culture, phoenixes are revered as the most important of winged creatures, a symbol of rebirth and eternity. The pine tree, in turn, is a powerful symbol of longevity, known for its endurance and perennial nature, symbolising a long and prosperous life.
This watch is not only an example of technical precision and aesthetic beauty, but also the bearer of deep cultural symbolism, uniting art and function in a piece that transcends time.
European Watchmakers and the Art of Cultural Adaptation in Luxury Watches
From the early 16th century, some skilled European watchmakers turned their talents to creating watches for the prosperous Ottoman Empire. These master watchmakers adapted their designs to the cultural specifics of the Empire, creating dials and regulators numbered in Turkish script. Many craftsmen from watchmaking centres such as Blois and Geneva settled in Constantinople to meet the growing demand for these exclusive pieces.
At the end of the 18th century, a new trend emerged among the Chinese elite: a growing interest in European watches. The Chinese nobles of the time began commissioning watches that not only fulfilled their practical function but were also adorned with Chinese-style decoration. The cases of these watches often featured scenes from Chinese mythology or symbolic decorations of deep significance. Enamelling, especially when brilliant and refined, became highly prized in China, reflecting a taste for meticulous and detailed art.
As the 19th century progressed, a more radical change occurred in the dials of watches ordered by the Chinese. Instead of the traditional Roman or Arabic numerals, dials now began to be inscribed with elegant Chinese characters, adding a touch of cultural authenticity to these luxury pieces.
Thus, the history of European watchmaking for the Ottoman Empire and the Chinese elite is not just a story of trade and production, but also a testament to the watchmakers' ability to adapt and integrate into diverse cultural contexts. This fusion of European watchmaking techniques with local cultural styles and symbolism not only enriched the global market for luxury watches but also established a legacy of art and innovation that endures to this day.
Etienne Gille, Geneva, ca 1788
This gilt brass watch displays a front-wound movement and an extremely rare Pouzait escapement. With a generous dial plate 47.2 mm in diameter and an overall depth of approximately 14.2 mm, including the central arbor, the movement is a masterpiece of two-plate construction, the plates being separated by short round pillars, and it stands out for its complexity and exclusivity.
The enamelled copper dial adds a unique elegance, with off-centre subsidiary dials that not only show the hours and minutes accurately but also display dead-beat seconds with refined subtlety. This dial is signed “Etienne Gille”, a testament to the expertise and commitment to excellence in this extraordinary piece of watchmaking.
The Pouzait Escapement: A Legacy of Precision in Watchmaking
Jean Moïse Pouzait (1743 – 1793), a distinguished Geneva watchmaker, played a fundamental role in the evolution of watches with dead-beat seconds (a seconds hand that moves in discrete steps rather than continuously). During the last quarter of the 18th century, several master watchmakers devoted themselves to creating watches with central dead-beat seconds hands, a feature highly valued both by the scientific community and by the Chinese market.
Pouzait stood out by developing an innovative solution with the lever escapement, accompanied by a large seconds balance. Despite its sensitivity to inertia, the spectacular design of Pouzait's escapement won admirers in China, preceding the invention of the “Chinese duplex” escapement[3] by Jacot. This latter advance made it possible to produce watches with central dead-beat seconds more affordably.
In 1786, Pouzait presented a model of his escapement to the Société des Arts in Geneva, where it is still preserved in its collection. Pouzait's concept apparently derived from the "weathervane" escapement[4], but with significant differences: the pallets were not simple pins but small rectangular teeth resembling pivots, making it an escapement with "divided lift"[5].
Jacques – Frédéric Houriet 25.02.1743 – 12.01.1830
The Influence of Jacques-Frédéric Houriet
Jacques-Frédéric Houriet, born in 1743 at La Chaux d'Abel, near La Ferrière, Switzerland, is a seminal figure in the history of watchmaking. His professional career began in 1759, when he became an apprentice to Abraham Louis Perret-Jeanneret, contradicting the popular belief that he had trained with Perrelet. Between 1759 and 1768, Houriet honed his skills in Paris under the tutelage of Pierre Le Roy, son of the renowned Julien Le Roy. Although Julien died shortly after Houriet's arrival, Houriet continued his development under the guidance of Pierre Le Roy and Ferdinand Berthoud, working closely with Pierre Louis Berthoud, Ferdinand's nephew.
In Paris, Houriet formed significant ties with prominent figures in watchmaking, such as Abraham-Louis Breguet, Jean Romilly, Antide Janvier and Louis Recordon. After completing his studies in the French capital, Houriet returned to Switzerland in 1768 and settled in Le Locle. At first he worked alongside his brother and his two sisters, and he later became a partner of David Courvoisier in the firm “Courvoisier & Fils”, which was later renamed “Courvoisier & Houriet”.
The French Revolution brought significant challenges to Houriet's business, but it also offered unique opportunities. During this turbulent period, he collaborated with the exiled Abraham-Louis Breguet, contributing to the development of Breguet's famous “souscription” watch.
In 1797, the Dane Urban Jürgensen joined Houriet as an employee and apprentice. Jürgensen later worked with Abraham-Louis Breguet in Paris and John Arnold in London, and subsequently married Sophie-Henriette, Houriet's daughter.
The Napoleonic Wars brought new challenges, but Houriet persevered, trying to bring his son into the business, though without the hoped-for success.
In 1818, at the age of 75, Jacques-Frédéric Houriet decided to carry on working alone, demonstrating his unwavering dedication to and passion for the art of watchmaking.
Jacques-Frédéric Houriet is an emblematic figure in the history of Swiss watchmaking, famous for making pocket chronometers and bespoke movements for illustrious watchmakers such as Abraham-Louis Breguet, Louis Berthoud, Louis Recordon and Robert Roskell. Even in old age, Houriet remained firmly devoted to experimentation and research, making a remarkable contribution to the fundamentals of isochronism, temperature compensation and the effects of magnetism on chronometers.
Around 1814, Houriet introduced spherical balance springs for chronometers, an innovation that exemplifies the relentless pursuit of precision and efficiency in watchmaking. His meticulous work and technical contributions laid the foundations of Swiss chronometry, earning him the title of founder of that discipline.
Beyond his technical achievements, Houriet was widely recognised by the scientific and artistic community. He was a member of the prestigious Paris Academy of Sciences and an honorary member of the Société des Arts of Geneva, reflecting his international impact and recognition.
The life and work of Jacques-Frédéric Houriet remain a source of inspiration in the art of watchmaking, representing the combination of technical innovation and dedication to perfection that characterises the Swiss tradition. His legacy is a testament to the excellence and passion that drive the continuous development of chronometry, ensuring that his name remains inseparably linked to the history of world watchmaking.
Jacques – Frédéric Houriet, Le Locle, No. 12, 1790
We present a magnificent example of watchmaking in gilt brass, showing the incomparable mastery of Jacques-Frédéric Houriet. This superb pocket watch displays a sophisticated "multi-armed thermometer" mechanism[6], distinguished by the use of a fine bimetallic half-curb and a rack-and-pinion transmission system, skilfully complemented by a spiral return spring. The pure white enamelled copper dial bears a temperature scale graduated in degrees Réaumur, adorned with elegantly arranged Arabic numerals.
Gracefully signed in script “Fred: (eric) Houriet” and numbered “No. 12” below the signature, this dial reflects the precision and attention to detail that are hallmarks of Houriet's creations. The remarkably fine hand is meticulously forged in blued steel, exemplifying the technical excellence and attention to detail characteristic of the master watchmaker.
The polished silver case is adorned with an intricate engraved star design on the back, adding a touch of refinement and sophistication to the whole. With an overall diameter of 63 mm, this watch transcends its function as a mere measuring instrument and asserts itself as a true work of art. It encapsulates not only technical innovation but also the refined aesthetics of the 18th century, embodying the perfect combination of function and elegance.
Jacques-Frédéric Houriet: The Pioneer of Chronometry and His Innovative Collaborations
Jacques-Frédéric Houriet, like his contemporary Abraham-Louis Breguet, was an experimental watchmaker, tirelessly seeking maximum precision and adopting a scientific approach to watchmaking. This shared pursuit of technical excellence secured a deep friendship between the two over the years. Houriet collaborated with Breguet during the latter's exile in Switzerland, between 1793 and 1795, further strengthening this remarkable partnership.
Houriet's manuscripts, dating from 1777, already set out the concept of a watch with a single hand, minimising the number of parts—the same idea that would inspire Breguet's celebrated “souscription” watches. Looking closely at Houriet's pocket thermometer, which predates Breguet's “souscription” watches by a few years, we find significant similarities in construction and in the materials used. The first cases of the “souscription” watches were all silver, similar to the thermometer's case, as were the layout of the dial, the overall size and the use of a single hand.
Houriet's pocket thermometer mentioned above is unique of its kind, numbered and retaining the old system of a double-folded bimetallic half-curb, with a rack and a central stabilising strut, as well as a recess in the plate for the rack. Later versions lack these features and have a more simplified construction. Reference literature often attributes the invention of the bimetallic thermometer to Urban Jürgensen, but this claim lacks substantial evidence. It is evident that Frédéric Houriet was already exploring the physical properties of bimetallic strips long before Jürgensen, as can be seen in his handwritten notes.
The bimetallic strip, crucial for temperature-compensated balances in chronometers, was introduced by Houriet around 1790. This date is confirmed by a similar pocket thermometer, also by Houriet, auctioned at Sotheby's in 2010. The temperature-dependent deformation of the bimetallic strip was transmitted by a simple arrangement of rack and wheels, moving a single hand that indicated the temperature in degrees Réaumur. Houriet held that the cases of these thermometers should be made of silver for better conduction of temperature to the bimetallic half-curb, and that the hand should be as light and well balanced as possible.
Around 1801, Urban Jürgensen simplified Houriet's system, modifying the shape of the bimetallic strip and producing his own pocket thermometers, signed 'invenit et fecit'. Breguet, for his part, adopted and further improved the system, adding a second rack for more precise transmission from the bimetallic half-curb. Jürgensen's simplified version was miniaturised by Houriet and incorporated into high-quality pocket watches, both by him and by other makers, as in the celebrated Breguet No. 160, the “Marie-Antoinette”.
The Réaumur Scale: A Relic of the History of Temperature
The Réaumur scale (°Ré, °Re, °R), also known as the “octogesimal division”, is a venerable temperature scale in which the freezing and boiling points of water are set at 0 and 80 degrees. First proposed by René Antoine Ferchault de Réaumur in 1731, this scale found wide acceptance and use in Europe, especially in countries such as France, Germany and Russia.
In the 1790s, France, by officially adopting the Celsius scale as part of the metric system, relegated the Réaumur scale to a secondary role. However, its persistent influence and regional acceptance allowed it to remain in use in some parts of Europe until the mid-19th century.
Although the Réaumur scale has few applications today, it is still used in specific niches of the food industry. In traditional cheese-making, such as “Parmigiano Reggiano” in Italy and Swiss Alpine cheeses, the scale is used to measure the temperature of the milk, a crucial step in the process. In the Netherlands, it is used for cooking sugar syrup, essential for various desserts and confections.
The transition from the Réaumur scale to other temperature scales, such as Celsius and Fahrenheit, in science and technology reflects the evolution of measurement standards. Nevertheless, the Réaumur scale remains a testament to the rich history of thermometry and of European scientific development. It represents a significant milestone in the chronology of thermometric science, reminding us of the ingenuity and innovation of 18th-century scientists.
Notes
[1] The “Pouzait escapement” is a type of watch escapement developed by Jean-Moïse Pouzait, an 18th-century Swiss watchmaker. This escapement is notable for its innovation and for the impact it had on the development of watchmaking at the time.
Here are the main points about the “Pouzait escapement”:
Innovation in Design: The Pouzait escapement introduced a new approach to escapement design. Unlike cylinder and lever escapements, the Pouzait escapement provided better accuracy and reliability in watches.
Constant Frequency: This escapement helped maintain a constant oscillation frequency, which was crucial for the watch's accuracy. The constancy of the oscillation frequency reduced the timekeeping errors that were common in other types of escapement.
Lower Friction: One of the advantages of the Pouzait escapement was the reduction of friction between the moving parts of the mechanism. Less friction meant less wear on the parts and a reduced need for maintenance.
Limited Production: Despite its advantages, the Pouzait escapement was not widely adopted, possibly because of the complexity of its production and the need for precision in manufacturing the parts.
Historical Influence: Although it did not become a standard in watchmaking, the Pouzait escapement influenced the development of other types of escapement and helped promote technical innovation in the field.
In short, the “Pouzait escapement” represents a significant advance in the history of watchmaking, introducing improvements in the accuracy and reliability of the watches of the time. Although it was not widely used, its innovative design influenced future innovations in escapement technology.
[2] In contexts relating to objects, such as watch cases or other accessories, “white collar” refers to a decorative technique that imitates the lustre and appearance of pearls. In the specific case of this watch, the white collar imitating pearls describes a decoration in which the material or enamel used on the case is worked so as to visually recall the lustre and texture of pearls. It is a common technique in jewellery and goldsmithing for creating an elegant and luxurious aesthetic effect.
[3] The “Chinese duplex” escapement is a mechanism that allows the seconds hand to move at regular one-second intervals, imitating the behaviour of quartz watches and providing greater accuracy.
[4] The "weathervane" escapement is an old mechanism used in watches to regulate the release of energy but, unlike later escapements, it had no safety action.
[5] A "divided lift" escapement (also called a "divided lift escapement") is a type of escapement mechanism in watchmaking in which the lifting process (lift) is divided between different parts of the mechanism. To understand it better, it is useful to explain some basic terms relating to escapements in watchmaking:
Escapement: A mechanism that controls the release of energy from a watch's movement, transforming continuous motion into impulses.
Lift: The phase of the escapement cycle in which the escape wheel pushes the pallet, transmitting energy to the balance (oscillator) and keeping it in motion.
In the case of the divided-lift escapement, this phase of energy transmission is divided between different elements or phases of the mechanism, instead of occurring all at once at a single point of contact. This can result in smoother and more controlled operation of the escapement, potentially improving the accuracy of the watch.
In the context of the Pouzait escapement:
Pallets: The components that interact with the escape wheel. In Pouzait's mechanism, the pallets are not simple pins but small rectangular teeth resembling pins, which divide the lifting process.
This specific design of the Pouzait escapement allowed more precise regulation of the release of energy, contributing to the dead-beat seconds motion, in which the seconds hand moves in regular one-second increments.
In short, a "divided lift escapement" is a configuration in which the lift phase of the escapement is segmented, distributing the work of transmitting energy in a way that can result in more precise and efficient motion.
[6] The term “multi-armed thermometer mechanism” refers to an advanced system that uses several levers or arms to measure temperature precisely. This mechanism allows greater sensitivity and precision in measurement, essential for high-quality watches.
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