rance and England: while historical accounts have sought to portray the two nations’ watchmakers as rivals, closer examination of their lives and work reveals that they were virtually all acquainted, shared many of the same values, were all equally determined to measure time with the greatest precision, and that their exchanges overrode national divisions. Far from the usual clichés, they were more often in competition with their fellow countrymen than with their foreign competitors!

Inventions were jealously guarded but there was also generosity and a willingness to share knowledge, and this wave of innovation would take watchmaking into a new dimension, ready to conquer the world. To echo our latest issue’s editorial, no-one “fired first”. Rivals and allies, they are all the pioneers of modern watchmaking whose discoveries, while still as valuable and relevant as ever, today’s watchmakers must challenge and surpass, as their counterparts did in their day. This article looks back at this important period for horology, which also defined the figure of the great master watchmaker.

THOMAS TOMPION (1639-1713): inventor of the cylinder escapement

Rarely celebrated outside his home country, Thomas Tompion, the “father of English clockmaking”, made numerous contributions to the field, not all of them mechanical. Long before the concept of the division of labour, Tompion divided work between his employees according to their skills, and was almost certainly the first to develop a numbering system for the 650 clocks he produced during his career.

Thomas Tompion

Among his horological inventions, Thomas Tompion is credited with the development, in 1695, of the cylinder escapement which his nephew-in-law, George Graham, later refined. The cylinder escapement would be widely used by both John Arnold and Abraham-Louis Breguet, before turning to systems that enabled improved timekeeping precision.

Tompion enjoyed the support of the physicist Robert Hooke, who was both a friend and an associate. It would be Hooke who introduced Tompion into royal circles, and this earned him royal commissions. Among Hooke’s innovations was a coiled spring, what we today call a balance spring, which maintained consistent oscillations of the balance wheel. Tompion’s association with Hooke gave him access to this technology and he built several prototypes, including one with two interconnected balance wheels. Having refuted Christiaan Huygens’ 1675 claim to have invented the balance spring, Hooke commissioned Tompion to build a watch containing his spring. Presented to King Charles II, it was engraved “Robert Hooke invent. 1658. T. Tompion fecit, 1675”. A prolific maker, Thomas Tompion, whose premises were on Fleet Street in London, also assisted Edmond Halley (1656-1742) in building astronomical instruments, as would George Graham after him (for other astronomers and for himself).

Notable contributions

• The division of tasks according to workers’ and apprentices’ individual competencies.
• A watch fitted with Robert Hooke’s prototype balance spring.
• An individual numbering system.
• The foundations of the cylinder escapement.
• Investigations into the deadbeat escapement for a pendulum clock.

GEORGE GRAHAM (1664-1751): a gentleman of many talents

A man of science, known for his modesty and generosity of spirit, George Graham was born in Kirklinton, in the English county of Cumbria, to a Quaker family. He was a precocious child, a characteristic noted by the parish priest, with a distinct aptitude for working with his hands. Clockmaking was a thriving trade, boosted by the invention of the balance spring, and so in 1688, at the age of 13, George Graham left the family home for London, where he would learn the rudiments of his future profession under Henry Aske.

George Graham

Alongside his seven-year apprenticeship, Graham studied mathematics, geometry and algebra. His reputation as an inquisitive and industrious young man earned him a place at Thomas Tompion’s workshop in 1695 (in 1704 he married Tompion’s niece, Elizabeth). Having inherited part of Tompion’s estate on his death in 1713, George Graham continued to do business at his employer’s premises, “at the sign of the Dial and Three Crowns”, at the corner of Water Lane in Fleet Street, London.

As early as 1714, Graham began fitting his watches with jewelled escapements. He is credited with the invention of a silencer for striking watches, and is also said to have invented, in 1715, the deadbeat escapement for clocks (sometimes referred to as the Graham escapement). However, recent research suggests that Graham made improvements to the system developed by his mentor, Thomas Tompion, by modifying the form of the escape wheel teeth and adjusting the angle of the pallets, to eliminate recoil. Tompion himself had amended his escapement in 1676 on the basis of research carried out the previous year by the English astronomer Richard Towneley.

In 1720 Graham moved his business closer to Fleet Bridge, at new premises, the “Dial and One Crown”, where he would later show John Harrison’s H1 marine timekeeper to the scientific community. When the patent for the cylinder escapement, granted to Booth, Houghton and Tompion, expired in 1725, Graham made important modifications to its design, giving it almost its modern form. Unlike many of his contemporaries, George Graham did nothing to protect his work and even went as far as to share his discoveries with French watchmakers, such as Julien Le Roy — in 1728 he sent Le Roy a clock of his making, equipped with a cylinder escapement.

Between 1715 and 1726 he developed various mercury compensation systems. In 1722 he was made a master of the Worshipful Company of Clockmakers. His invention of a watch with an independent seconds hand made for considerably more accurate reading of the time. Graham’s interests were wide-ranging and, as a man skilled with his hands, he built numerous scientific instruments of excellent quality. Circa 1723 he observed the diurnal variation of the Earth’s magnetic field — something he would have studied as a maker of magnetic compasses.

Keen to encourage the talent he perceived in others, Graham took Thomas Mudge as an apprentice, between 1730 and 1738. Mudge would go on to apply improvements his master made to the escapement in his own watches. The same year that he engaged Mudge as an apprentice, George Graham met John Harrison, who showed him his design for a marine timekeeper. Convinced that this self-taught clockmaker was on the right lines, Graham loaned him 200 pounds sterling, interest-free, so that he might continue his research. This was a large sum and most other watchmakers would have stolen Harrison’s work and claimed it for themselves. Not Graham, whose integrity had gained him a reputation as “Honest George Graham”. Generous and at pains to promote ideas that would further the advancement of science, Graham would even publicise Harrison’s work by exhibiting his first sea clock, the H1, in his shop.

As well as a clockmaker, George Graham was renowned as a physicist and an astronomer. Celebrated for his knowledge and for his contributions to science and his country, he died on November 20th, 1751, at his home on Fleet Street, London, and was buried in Westminster Abbey alongside his mentor, Thomas Tompion.

Notable contributions

• A watch with an independent seconds hand.
• Improvements to the deadbeat escapement developed by his master and mentor, Thomas Tompion, who had borrowed and refined a study by the English astronomer Richard Towneley.
• A temperature-compensated mercury pendulum that would improve the timekeeping precision of regulator clocks.
• Numerous astronomical instruments including a mechanism which suspended the balance’s oscillations to measure fractions of time and is generally considered the forerunner of the chronograph.
• His loan of 200 pounds sterling enabled John Harrison to complete his H1, the first sea clock. Graham realised that the self-taught clockmaker was making progress towards solving the thorny question of how to calculate longitude at sea. By assisting Harrison, he gave the British Navy a decisive lead over its great rival, the French, in the race to conquer the waves.

JOHN HARRISON (1693-1776): paving the way for precision

Born in Foulby, Yorkshire, the eldest of five children, John Harrison was a bright and well-read individual who followed in his father’s footsteps to become a carpenter. Helped by his brother, Harrison spent much of his spare time building wooden clocks - a material that was both familiar to him and less costly than steel or brass - which kept surprisingly accurate time.

John Harrison

After reading Henry Sully’s 1726 treatise on a clock for the accurate measurement of time at sea, Harrison began to consider the possibility that he might himself build such a timepiece, and in 1730 showed his plans to George Graham. The latter was in no doubt that Harrison, despite having no formal training in clockmaking, was on the right lines and provided the financing he would need to begin production of his first timekeeper, the H1.

Harrison used the award made to him in 1736 by the Board of Longitude to build a second clock, the H2, which he submitted in 1741. After the H3, and having observed a highly accurate watch by Thomas Mudge, successor to George Graham, Harrison set to work on his H4: a project that would occupy him for the next six years and which, in its finished form, resembled a large pocket watch (13.2 centimetres in diameter). Its verge escapement, with diamond pallets, showed itself to be extraordinarily precise. This H4 would, however, prove virtually impossible to replicate. Only Larcum Kendall, apprentice to John Jefferys, succeeded (his K1 accompanied Captain James Cook on his second South Seas voyage).

John Harrison H1 Marine, 1735

Throughout his career as a clockmaker, Harrison had a formidable opponent in the person of the Reverend Nevil Maskelyne, a Commissioner of Longitude who had devised a method of determining longitude using lunar tables. Maskelyne’s one legitimate criticism was that Harrison failed to devise an instrument that could be easily reproduced, at a time when the American War of Independence loomed and the British Navy was in urgent need of accurate and reliable timekeeping instruments.

Maskelyne instead championed the work of John Arnold, who succeeded where Harrison, despite his talent, had fallen at the last hurdle. Although the carpenter’s son did receive the 20,000 pounds sterling prize promised by the Board of Longitude, it would be paid to him in fragments over the course of his long career. Four of Harrison’s five marine timekeepers are displayed at the National Maritime Museum in Greenwich.

Notable contributions

• The grid pendulum, a thermally compensated bi-metallic pendulum (steel and brass) which he later adapted to his clocks.
• The practical demonstration of the longstanding theory that it was possible to measure longitude at sea by means of a clock.

THOMAS MUDGE (1715-1794): the visionary

Famed as the inventor of the escapement that equips the majority of mechanical watches today, Thomas Mudge was born into a well-off and cultivated family in Exeter, in the English county of Devon. As a young boy, he showed a natural inclination for clockmaking, considered a profession with good prospects, and at the age of 14 was sent to London where his father used his influence to secure him an apprenticeship with George Graham, a master watchmaker and astronomer of growing renown.

Thomas Mudge 

Having qualified as a watchmaker in 1738 and admitted to the Worshipful Company of Clockmakers, following George Graham’s death in 1751, Thomas Mudge carried on in business. His reputation soared and his repeaters and other complicated watches were prized by a prestigious and wealthy clientele.

In 1755 this gifted horologist adapted, for the pocket watch, an escapement he had first seen at George Graham’s workshop, when the latter was working on a regulating system for pendulum clocks that improved on an escapement devised by his own master, Thomas Tompion. Mudge’s lever escapement was the first known detached escapement.

Detached lever escapement for the pocket watch presented to Queen Charlotte, wife of George III.

Sensing that his ideas had potential, in 1770 Mudge submitted a timekeeper to the Board of Longitude. Astronomer Royal and a member of the Board, the Reverend Nevil Maskelyne declared Mudge’s chronometers insufficiently precise and too complex to replicate. However, Maskelyne’s judgement was almost certainly biased, for two reasons. Firstly, he was intent on promoting his own method of calculating longitude at sea using the position of the Moon. Secondly, Maskelyne was close to John Arnold and was therefore inclined to support his solutions – that same year, Arnold presented four quality timekeepers which were also fitted with an innovative escapement. Thomas Mudge was vindicated in 1792 when Parliament awarded him financial compensation for his efforts to determine longitude at sea. He died two years later and his son, despite his father’s glowing reputation, was unable to keep the business afloat amidst fierce competition.

Even as today’s brands propose alternative regulating systems, modern mechanical watchmaking would not be the same without the lever escapement. Yet as surprising as it may seem, Mudge’s invention was slow to catch on for general production. It wasn’t until the early 1800s that it became a serious competitor to the detent escapement (a lever escapement is self-starting) and it was only towards the middle of the century that it became widespread in quality timepieces.

Notable contributions

• A detached lever escapement, an alternative to the pivoted detent or spring detent escapement. This system would prove easier to produce in large quantities and, fitted into pocket watches, significantly improved timekeeping precision.

PIERRE LE ROY (1717-1785): the foundations of the French marine chronometer

While the English are credited with the earliest reliable marine chronometers, the “first” to achieve a satisfactory result with a timekeeper that could be replicated without any great difficulty was a Frenchman, Pierre Le Roy.

The son of Julien Le Roy, a talented watchmaker himself, Pierre Le Roy demonstrated the same confidence and ease in his writing as in his horological mechanisms, and would enjoy great success. He was a precursor in many domains but had to contend with an equally gifted rival, Ferdinand Berthoud, a man with lofty ambitions and, above all, the charm and manner to achieve them.

Petite Ronde with adjustable compensation blades on the back plate.

After his father’s death in 1759, Le Roy carried on his business. He earned a reputation for complex instruments and would specialise, early on, in timekeepers for the calculation of longitude at sea. In 1748 he developed what is considered the first ever detached escapement (although with characteristic honesty, in his essay, Les Etrennes Chronométriques, he recalls having seen another escapement, developed along the same lines, in the workshop of Jean-Baptiste Dutrertre). Specialists argue over whether it should be categorised as a prototype lever escapement or a form of pivoted detent escapement.

Le Roy incorporated this original escapement, which is neither fully a lever nor a detent, into the marine chronometer which he completed in 1763. This highly accurate timekeeper incorporated several other innovations such as a refined temperature-compensated balance and a form of proto-ball bearing, designed to reduce friction on the balance staff in the absence of a jewelled bearing for the pivot. In 1766 Le Roy presented his treatise on La Meilleure Manière de Mesurer le Temps en Mer (the best way to measure time at sea) to Louis XV.

Le Roy escapement mechanism

Despite their great precision, none of the systems Le Roy developed found practical application, being too difficult to replicate and incorporate into smaller mechanisms. His work was, nonetheless, foundational and recognised as such by the Académie des Sciences which in 1769 awarded him a prize for his chronometer’s performance at sea. The remarkable achievements of this visionary and methodical watchmaker were often overshadowed by those of his rival, Ferdinand Berthoud, who was appointed Horloger de la Marine, a title Le Roy had coveted. Pierre Le Roy died in Viry-Châtillon, near Paris, in 1785.

Notable contributions

• A rational and analytical approach to chronometry.
• A pioneering escapement, partway between a lever and a detent.
• Research into balance spring isochronism.

JEAN-ANTOINE LEPINE (1720-1814): a modern mechanism

Jean-Antoine Lépine was born in Challex, in France’s Ain region, and apprenticed to a Mr Decroze, watchmaker in Saconnex-en-Genevois. Aged 24, he moved to Paris where he was hired by André-Charles Caron (1697-1775), Horloger du Roy and father of the future playwright, Beaumarchais. In 1756 Lépine married Madeleine-Françoise Caron, his employer’s daughter, and became a partner in Caron’s shop on Rue Saint-Denis in Paris. Awarded the title of master watchmaker on March 12th, 1762, he was appointed Horloger du Roy in 1766.

Lépine Calibre IV

From 1772 until 1779, Lépine did business on Place Dauphine and Quai de l’Horloge, as did the Le Roys, Ferdinand and Louis Berthoud, as well as Abraham-Louis Breguet, who was apprenticed to Lépine. Lépine was friends with Voltaire and when the latter moved to Ferney in Switzerland for 18 months, establishing a manufacture that would employ as many as 600 craftsmen, Lépine travelled there to train watchmakers, while taking advantage of lower labour costs, compared with Paris, for the production of his movement blanks or ébauches.

Lépine would be closely involved with the manufacture, sending his son there as an apprentice in 1776 and in 1784 taking delivery of movements worth 90,000 livres – a colossal sum. In 1778 George Washington, the first President of the nascent United States, purchased two watches from Lépine, who was by then Paris’s most fashionable watchmaker. Lépine was a prolific inventor although not all his innovations are known to us today, as watchmakers in France were unable to register their inventions until 1791 and the passing of the patents law. We do know that he developed a new type of repeating works (quadrature) and, above all, a calibre that watchmakers everywhere, won over by its many advantages, were quick to adopt.

Slimmer and easier to assemble, the Lépine calibre could incorporate cylinder, duplex, virgule or double virgule escapements that eliminated the need for the costly fusee-and-chain mechanism that was used with verge escapements to regulate tension in the mainspring. Jean-Antoine Lépine may also be the true inventor of the virgule escapement, despite claims to the contrary by Pierre-Augustin Caron (Beaumarchais) and Jean-André Lepaute.

Among his lesser-known innovations, we can note an original and practical keyless winding system, operated by pressing several times on the pendant, similar to actuating a repeater watch. We owe the first biography of this master to a member of his family, Abbot Lépine, vicar general for the episcopal see of Gap, published on February 8th, 1879 in the Journal Suisse d’Horlogerie. Often in the shadow of his equally brilliant contemporaries, Jean-Antoine Lépine passed away on May 31st, 1814 at the ripe old age of 94. In his 1988 monography, Adolphe Chapiro notes that during his lifetime, he produced no fewer than 6,000 watches and more than 300 clocks.

Notable contributions

• The Lépine calibre with a single plate and bridges. The same construction is still in use today.
• Keyless winding via the pendant.
• Believed to be the initiator or inventor of the virgule escapement.
• Repeating works (abandoned in favour of more reliable mechanisms).

FERDINAND BERTHOUD (1727-1807): an explorer of solutions

Ferdinand Berthoud was born in the Principality of Neuchâtel, then under Prussian rule. Having learned his craft in a family of distinguished watchmakers, at the age of 18 he moved to Paris with the intention of completing his education. He did so under Pierre Le Roy (1717-1785), later becoming his greatest rival.

Ferdinand Berthoud

A brilliant and prolific craftsman who received the title of master watchmaker in 1753, like his contemporary Caron de Beaumarchais, Berthoud wrote with skill and verve. A contributor to Diderot and d’Alembert’s Encyclopédie, he also produced multiple treatises on watchmaking, between 1753 and 1807. At the behest of Louis XV, in 1763 he travelled to London with instructions to return with information on John Harrison’s sea clock, but the only details of its workings that he was able to glean were indiscretions by Thomas Mudge. While inconclusive, these elements were nonetheless sufficient for Berthoud to enter a race that pitted the era’s greatest horological minds.

The Conseil d’État under Louis XV granted Berthoud an income and the title of Horloger Mécanicien du Roi et de la Marine, which infuriated the Le Roys, father and son. An inventive maker, Berthoud experimented with various constructions, rather than limit himself to a single solution. By 1768 he had lost the advantage he had gained over John Arnold by failing to consider the need to produce in quantity and for standardisation.

Ferdinand Berthoud’s marine chronometer

Over the course of his career, Ferdinand Berthoud made some 80 marine chronometers and his nephew almost twice that amount. Even so, this was less than the number which the English were able to produce over the same period. Like Breguet, Ferdinand Berthoud was granted French nationality, of which he was immensely proud. He died in Groslay, to the north of Paris, where he is buried. A number of his works are displayed at the Musée des Arts et Métiers in Paris.

Notable contributions

• A distinctive approach to marine chronometry and the aesthetics of timekeeping instruments.
• Numerous books on chronometry and watch construction.
• Essays on watchmaking in Diderot and d’Alembert’s Encyclopédie.

JOHN ARNOLD (1736-1799): a pre-industrial genius

John Arnold was born in Bodmin, a modest town in the county of Cornwall, to a middle-class family. With a clockmaker for a father and an uncle who was a gunsmith, there seemed little doubt as to what his future profession would be, although his decision, in 1755 at the age of 19, to study in the Netherlands would have surprised many. He returned to Cornwall in 1757 where he continued his education, moving from master to master until 1762.

John Arnold

Legend has it that a certain William McGuire gave Arnold a loan sufficient for him to set up in London. The de facto capital of western Europe, the city was fast expanding thanks to a rising social class, eager for the latest technologies. Having impressed King George III with a half-quarter repeater watch, the size of a large ring, John Arnold came to the attention of the Reverend Nevil Maskelyne, a Commissioner at the Board of Longitude and creator of lunar tables: a method for calculating longitude at sea that rivalled John Harrison’s sea clocks.

Both men realised they were on the cusp of a revolution in maritime navigation and worked together so that England might have dominance of the world’s oceans before any other nation, including France. From 1769 John Arnold directed his attention to what would be his life work: the marine chronometer and precision watches (deck chronometers).

For Arnold, there could be no question of using a verge escapement, as Harrison had. Instead, his scientific approach led him to develop a revolutionary regulating system of his own design. It comprised a helical balance spring with terminal overcoils, a new type of escape wheel that gave impulse directly to the roller (“lost beat”) and a pivoted detent escapement. This latter innovation, still unequalled in terms of chronometric precision, allows the balance wheel to swing freely, except when receiving impulse from the escape wheel. Throughout their entire career, Arnold and his son worked on improving and refining this system.

A silver key wind Arnold type detent open face pocket watch.

The resulting timekeepers, which Arnold himself named “marine chronometers”, fulfilled the requirements of the Board of Longitude. Three would accompany Captain James Cook on his second voyage in 1772. In 1780 Arnold developed a variation on the detent escapement, which he called a spring detent.

In 1785 Abraham-Louis Breguet took John Arnold’s son as an apprentice in Paris and the two men, from opposite sides of the Channel, would share the results of their research. The English watchmaker would, in turn, welcome Breguet’s son to his workshop during the early months of the Reign of Terror in France (1792-93), while working on a mechanism that would reduce or eliminate errors caused by the imperfect balance of the balance wheel - including an initial concept for a tourbillon regulator, referred to by Thomas Reid in the second edition of his Treatise on Clock and Watch Making, Theoretical and Practical (1826).

The ageing watchmaker retired in 1796, leaving his son at the head of a remarkably prosperous business. He passed away in 1799 with the satisfaction of knowing that he had helped England rule the waves, thanks to his development of an accurate and reliable chronometer which could be mass-produced to equip British ships – something neither French nor Spanish nor Dutch watchmakers had been able to do.

Notable contributions

• Ruby cylinder escapement, an evolution on George Graham’s design (1765).
• Pivoted detent escapement (1772).
• Helical balance spring with terminal overcoils (1775).
• Spring detent escapement (1780).
• Modern compensation balance (1785).
• The initial idea for the tourbillon cage to compensate for positional errors of the balance wheel in a detent escapement (c. 1789-92).

ABRAHAM-LOUIS BREGUET (1747-1823): an aesthetic revolution

Few, if any, would have bet on the young man, aged 15, who in 1762 was sent to study watchmaking in Les Verrières. And yet barely a year later, Abraham-Louis Breguet was in Versailles, where his natural talent did not go unnoticed. Instructed in mathematics and astronomy by Abbot Joseph-François Marie – to whom he would be greatly indebted later in life –, he was apprenticed to his fellow countryman, Ferdinand Berthoud, then to Jean-Antoine Lépine, taking from each the elements that would make him one of the great minds of his century. From Berthoud, he learned that modesty and calm were infinitely preferable to hurtful controversy. From Lépine, he took a solid collaboration studying avant-garde solutions such as the single mainplate and separate bridges.

Abraham-Louis Breguet

Thus exposed to the inventions of his day, Breguet continued to refine his technique, to offer wealthy patrons his particular conception of the watchmaker’s art. His arrival on Quai de l’Horloge in Paris coincided with his marriage in 1775 to Cécile-Marie-Louise L’huilier, prompting some to suggest that it was his wife’s dowry that had set the couple up in their new apartments, and Breguet in business. Admired by the aristocracy, held in high regard by Louis XVI (the king was interested in all types of mechanism) and Queen Marie-Antoinette, Breguet forged an outstanding reputation in the most influential circles, thanks to the elegant design of his watches and for the combinations of complications they contained.

Watercolor plate for the patent for the Tourbillon regulator.

National Institute of Industrial Property, Paris.

In 1787 Breguet entered into a brief partnership with Xavier Gide, who was to sell his production. His political sympathies prompted him to join the Society of the Friends of the Constitution, more commonly known as the Jacobins, and in the early months of the French Revolution he frequented Jean-Paul Marat. Originally from Neuchâtel, Marat practiced as a physician (some would say a quack) and was elected to the National Convention as a member of the radical Montagne group. Both men were close to John Arnold, maintaining personal and professional relations with the English watchmaker. When Breguet travelled to London, hoping to recover money owed to him by customers who were already fleeing France, or from English aristocrats, he would spend time with Arnold and asked him to take his son as an apprentice, as he had done for Arnold’s own son. However, the time came when revolutionary turmoil and Breguet’s associations meant that he too would be forced into exile.

Breguet Tourbillon no°1176

Rather than head for London, where he could have rebuilt his business, he chose Switzerland, in 1793, settling first in Neuchâtel then Le Locle. He returned to Paris in 1795, bringing with him countless new ideas such as the Breguet balance spring (a variation on the terminal overcoil that was invented and patented by John Arnold), the first ever carriage clock (which he sold to Napoleon Bonaparte), the “sympathetic” clock, the à tact watch and probably the first iterations of the tourbillon regulator, building on an idea given to him by Arnold, which he patented on June 26th, 1801 or 7 Messidor Year 9 in the new Republican calendar. As a tribute to Arnold and a reminder of the bond between them, Breguet incorporated his very first tourbillon into an early chronometer made by his friend, which he presented to Arnold’s son, engraved with an inscription that leaves no doubt as to the origin of this major invention.

The parachute shock protection system

The innovative aesthetics of Breguet’s watches brought him success throughout the courts of Europe and in 1810, for Caroline Murat, Queen of Naples, he made what is considered the first ever bracelet-watch. He was appointed to the Bureau des Longitudes and made Horloger de la Marine Royale. He was inducted into the Académie des Sciences and presented with the Légion d’Honneur by Louis XVIII. On his death in 1823, the horological community was unanimous in its praise of a man whose genius and ability to compile ideas into a distinctive and elegant aesthetic revolutionised so many facets of watchmaking.

Notable contributions

• The perpétuelle watch, automatically wound by the wearer’s movements and a tangential weight (1778-1780).
• Spring gongs for repeater watches (1783).
• The pare-chute shock-absorber (1790-1792).
• Flat balance spring with overcoil, a variation of Arnold’s overcoil on his helical balance spring (1795).
• A detached escapement, known as a “natural” escapement (1789).
• The à tact watch for telling the time by touch (1799).
• Registered a patent for the tourbillon cage (1801).
• Twin barrels (1815).

THOMAS EARNSHAW (1749–1829): the unsung innovator

Historical accounts have painted Thomas Earnshaw as a man embittered by the battle with his greatest rival, John Arnold, to build the best possible marine chronometer, and yet as a watchmaker, born on February 4th, 1749 in the Lancashire town of Ashton-under-Lyne, his inventions are ample demonstration of his mechanical genius.

Thomas Earnshaw

A penniless artisan, Earnshaw earned his living repairing other makers’ timepieces for Thomas Wright (much as in today’s customer service centres). As part of his duties, he was given one of Arnold’s chronometers to work on and immediately observed its qualities as well as its shortcomings. Thus in 1781 he set about developing an escapement which he considered would be superior to that of Arnold, mounting the detent on a spring rather than pivots.

Lacking the 100 guineas it would cost to register a patent, Thomas Earnshaw sought the assistance of various entrepreneurs. Inevitably, news of his invention reached John Arnold’s ears, who convinced Earnshaw’s employer to show him this new-generation escapement. Eight days later, on May 2nd, 1782, Arnold filed a patent that would spark a prolonged dispute between the two watchmakers. Revealingly, Arnold’s diagram suggests that his application, though accepted, had been committed to paper somewhat hastily.

After years of bitter quarrelling, in 1805 the Board of Longitude granted both men a prize in recognition of their contributions to marine chronometry. While the award came too late for Thomas Earnshaw to better his condition, he made other notable innovations such as the bimetallic compensation balance that is now commonplace. He died in London on March 1st, 1829, with the belated satisfaction of knowing that his detent escapement outperformed that of his rival. In Earnshaw’s escapement, the escape wheel and impulse pallet roll together rather than slide, hence there is less friction and the mechanism can operate without lubrication. In an age when oils could solidify within weeks, with adverse effects on precision, this was a considerable benefit.

Notable contributions

• A spring detent escapement in which the escape wheel and impulse pallet roll together (1781).
• Steel and brass bimetallic compensation balance, a forerunner to modern balance wheels.
• Thomas Earnshaw’s groundbreaking inventions were used in all English marine chronometers from 1810 and for those of every other nation from the first third of the nineteenth century.

ANTIDE JANVIER (1751-1835): the celestial clockmaker

Born to a family of farmer-clockmakers in a hamlet in the French Jura, Antide Janvier has been long overlooked, despite a brilliant career. Abbot Tournier de Saint-Claude saw the young Janvier’s potential and gave him instruction of the highest level, including in mathematics and astronomy, his passion. At the same time, he taught his student how to use a lathe so that he could become a watchmaker, a profession in growing demand.

Antide Janvier

Janvier was 15 years old in 1766 when he presented a planetary sphere before the Académie des Sciences in Besançon. Arriving in Paris in 1773, he presented an armillary sphere to Louis XV. Ten years later, in 1784, and now Horloger Breveté de Monsieur (Monsieur being the title granted to the oldest brother of the king), he presented two astronomical spheres to Louis XVI, who was known to be fascinated both by astronomy and mechanisms. In 1794 Antide Janvier was appointed to the commission tasked with establishing the decimal time system that was introduced after the French Revolution.

Astronomical clock with planetarium and musical mechanism

An ingenious watchmaker, many of his precision clocks and watches incorporated astronomical complications for the benefit of science. He was, before Abraham-Louis Breguet, the first to make a resonance clock, based on principles established by Antoine-Laurent Lavoisier (1743-1794). Janvier produced his clocks in medium to large quantities and in this respect faced little competition. Throughout most of his career, he benefited from a public pension but lived largely beyond his means and died in poverty, childless, forgotten and cheated by the many who claimed his inventions as their own. His contributions to horology are now more widely recognised, thanks to figures such as François-Paul Journe.

Notable contributions

• The conviction that precision horology must serve the needs of science (seconds counters, resonance clock, accurate armillary spheres, complicated clocks incorporating precision moon phases, equation of time, etc.).