For centuries, in his infinite modesty, Man imagined himself to be the centre of the universe, convinced that Earth remained stationary and all else revolved around it. Had not the most eminent scholars, Aristotle and Ptolemy among them, formed models to prove this, just as they had calculated the distance between Earth, the two “luminaries” that are the Sun and the Moon, and the five planets - Mercury, Venus, Mars, Jupiter and Saturn - which are visible to the naked eye. With the notable exception of Aristarchus of Samos (third century BCE), ancient cosmologies were exclusively geocentric. The Church was an ardent supporter of this theory, pointing to Holy Scripture which placed Earth at the centre of the universe: Psalm 93 tells us that “the world is established; it cannot be moved.” Few opposed this dogma, all too aware of the fate the Inquisition reserved for anyone who challenged the Church’s view. The Italian philosopher Giordano Bruno, who was burned as a heretic in 1600, paid the price. 

A true Renaissance man, Nicolaus Copernicus had his own ideas on the matter. A scholar in the widest sense, he read humanities at the University of Krakow in his native Poland before turning his mind to medicine, mathematics and, importantly, astronomy, which he studied in Bologna under Domenico Maria Novara. Returning to Poland, his duties as canon and administrator for the diocese of Frombork left him time to continue his astronomical studies from the town’s observatory. It was here that he conceived of his heliocentric theory, whereby Earth rotates around its axis with the Moon as its satellite, and all the planets orbit the Sun. He expounded his theories in two major works though, nothing if not cautious, he delayed publication such that the first appeared only in the nineteenth century while the second, which he completed in 1530, was published 13 years later on the day of his death. Copernicus’s theories were to be read in secret, for fear of ending up in one of the Holy Office’s cells. 

The Copernican model would find an outspoken proponent in Galileo. This brilliant mathematician, geometer, physicist and astronomer was also the inventor of a telescope with which he observed Saturn’s rings and the phases of Venus, which he took as irrefutable proof that Copernicus was right. The Italian scholar also had friends in high places: Cardinal Maffeo Barberini, future Pope Urban VIII, invited him to present his work before the pontifical college in Rome… resulting in the first in a long series of rebukes by the Church, which ordered him to cease his defence of heliocentrism. He refused, continued his controversial writings and was summoned multiple times to appear before the Holy See. The “affair” took on such proportions that Galileo was made to stand trial on suspicion of heresy. Under duress, he recanted before the Holy Office but, thanks to the pope’s intervention, was saved from the stake. He spent the rest of his life confined to residence in Florence. It wasn’t until 1992 that Galileo was formally vindicated by Pope John Paul II, and declared “more perceptive in this regard than the theologians who opposed him.” 

While the laws outlined by Isaac Newton (1643-1727) would eradicate any last doubt, Copernicus and Galileo played a decisive role in the teaching and defence of heliocentrism. Copernicus was forced to defy religious belief to put forward a new worldview based on mathematical calculations, supported by the findings of Galileo who was also first to formally state the pendulum’s chronometric properties. From observations of the stars to the measurement of time, the gates were wide open. 

The seventeenth-century Dutch Republic enjoyed a golden age of intellectual freedom, made possible by religious toleration. It was thanks to this freethought that an individual such as Christiaan Huygens, a true scientific mind, was able to pursue his research in mathematics, physics and astronomy, and make important discoveries in all three fields. However, the area that most benefitted from his insight would be horology. Having studied Galileo’s observations, he applied the pendulum to a clock. In 1675 he developed his theory of a flat balance spring to regulate a mechanical watch, earning him his place in history as the father of modern horology. The balance spring is today considered a strategic component of a watch movement, produced by a handful of specialist manufacturers. 

It was during his sojourn in Paris, where he arrived in 1666 at the invitation of Colbert, controller-general of finances under Louis XIV, that Huygens developed the balance spring. A scientist, not a clockmaker, he went in search of an individual capable of building a timepiece that would incorporate his discovery. That person would be Isaac Thuret, Horologist to the King and to the Academy of Sciences, to which Huygens had been elected. Thuret was himself a man of intellect and competence who had already produced two clocks for astronomical observations. Needless to say, he showed great enthusiasm for the idea and secretly presented Colbert with his model of a spring-driven watch, declaring it to be of his invention. While Thuret persisted in his claims, the matter was settled by a patent awarded to Huygens, whom we remember as the inventor of the balance spring. 

England at the turn of the eighteenth century was home to some of the greatest clockmakers ever to have lived, renowned for the quality and inventiveness of their production. Thomas Tompion, who was the first to produce watches in numbered series, together with his protégé and successor George Graham, were worthy representatives. Among other innovations, we owe George Graham an escapement that is still used in precision clocks today, as well as the mercurial pendulum which reduced the effects of temperature change on a mechanical movement. A renowned scholar who placed great importance on the advancement of science, Graham offered advice and financial assistance to a young John Harrison, for his work to develop a reliable marine chronometer – a strategic instrument in an age of seafaring expeditions and rivalry between nations. 

It would be many years before the scientific establishment swallowed its pride and recognised the importance and inventiveness of Harrison’s work. A carpenter by trade, this natural genius learned clockmaking with no formal instruction, through trial and error. He first came to his peers’ attention for his wooden clocks and for his invention of a bimetallic strip that was unaffected by changes in temperature. And this was just the beginning: John Harrison would devote himself entirely to the making of a marine chronometer. Both the British Parliament and the Academy of Sciences in Paris had promised vast rewards to whomever should discover a means of calculating longitude at sea - an impossible task without a precise and reliable timepiece that could be carried onboard ship. After years of experimentation, in 1759 John Harrison presented his now famous H4. A sea trial the following year demonstrated that Harrison's chronometer fulfilled all requirements. Even so, it would take a further twenty years and the intervention of King George III for him to receive the acknowledgement he was due, three years before his death. John Harrison is, quite simply, the inventor of mechanical precision. 

In the eighteenth century, two “schools” vied to produce a timekeeper capable of maintaining sufficient precision to enable the calculation of longitude at sea. In England, the work of John Harrison would prevail. In France, all eyes were on Ferdinand Berthoud. A Swiss watchmaker living and working in Paris, his precocious talent quickly came to the fore. Appointed Horologist to the Navy then Horologist to King Louis XV, he produced a number of brilliant marine chronometers - so brilliant, there were whispered accusations that Berthoud was spying on his English rival. Did he need to? The talent he deployed as a clockmaker, alongside his extensive writings on the subject, made him one of the eighteenth century’s most eminent figures. Ferdinand Berthoud left a remarkable body of work that includes marine chronometers but also watches, clocks and scientific instruments, which he described in detail in the dozens of essays and treatises he published, filling four thousand pages. 

Like Berthoud, his contemporary, Jean-Antoine Lépine was a young man when he arrived in the French capital. It was here that he made the acquaintance of André-Charles Caron, Horologist to the King, whose daughter he would marry (Caron also had a son, Pierre-Augustin, future Beaumarchais, a prominent figure of the Enlightenment). His fame and reputation established, Lépine was able to present certain items of his making to Louis XV. These included an astronomical watch complete with equation of time and perpetual calendar. Suitably impressed by such a remarkable achievement, the king appointed Lépine as his watchmaker - a title he retained under Louis XVI and again under Napoleon I. Today we most associate Jean-Antoine Lépine with the calibre that bears his name and which laid the foundations for the modern mechanical movement. Lépine’s construction abandoned the fusee-chain transmission and replaced the top plate, with its pillars, by separate bridges to hold the various wheels. A revolution in its day, Lépine’s calibre made possible ever slimmer watches; a goal that makers continue to pursue. 

Both accomplished watchmakers, one working in England, the other in France, John Arnold and Abraham-Louis Breguet held their work in such mutual high regard that they sought to meet in person, ultimately becoming firm friends and each sending his son to serve an apprenticeship under the other. On Arnold’s death, Abraham-Louis Breguet would pay him a fitting tribute. This affinity, this cross-Channel meeting of minds, is sufficiently rare to warrant mention, knowing that watchmakers have been more inclined to view their contemporaries with disdain rather than admiration, and collaborations are rare. John Arnold excelled as a maker of extraordinary miniature watches. One, a repeater mounted in a ring, earned him the favour of the royal household under King George III. Like other prominent horologists of his day, he also turned his talent to the small matter of how to measure longitude at sea, and his N°3 marine chronometer would sail with Captain James Cook on his second voyage to the Pacific. In addition, Arnold devoted a large part of his work to simplifying mechanisms; a prelude to series production. 

A pupil of Berthoud and Lépine, Abraham-Louis Breguet left his native Switzerland for Paris, where he would cement his reputation. Considered one of the most gifted watchmakers ever to have lived, having revolutionised every aspect of watchmaking, from a technical perspective as well as aesthetically, Abraham-Louis Breguet enjoyed fame and esteem during his lifetime. His work was celebrated in the royal courts of Europe; his patrons frequented the highest political, scientific and military circles. Among the master’s many inventions, too numerous to mention here, is the tourbillon. Patented in 1801, this ingenious mechanism compensates errors in rate caused by Earth’s gravitational pull and is today considered to be among the most prestigious mechanisms in the pantheon of watchmaking complications. On the passing of John Arnold, Abraham-Louis Breguet incorporated his invention into one of the Englishman’s early pocket chronometers. The first tourbillon regulator ever made, he gifted it to Arnold’s son in “revered memory” of his friend and esteemed contemporary.