Renowned for his quest for precision, Julien Le Roy is considered, rightly, as one of the greatest French watchmakers in history. Early genius, he knew how to synthesize two watchmaking cultures then in opposition, the French and the British, in particular by paying tribute to the big English names of the sector. This famous watchmaker is also known for inventing the horizontal building clock.

Julien Le Roy, early genius

This young man who was born in Tours in 1686 is a phenomenon. It is only at the age of 13, indeed, Julien Le Roy already manufactures small books of his invention, a demonstration of a rare intelligence, and a delicacy that is just as much. These singular arrangements for mechanics, the young boy will quickly destine them to a major art, which was once the glory of the nation, but whose splendor is passed on the side of the English: watchmaking.

Left to Paris to improve in the mechanics of timepieces, Julien Le Roy, at only 27 years old, joined the very closed corporation of master watchmakers in the capital. He is soon known for his talents as well as for his particularity: his obsessive almost unhealthy for the most absolute precision, which will push him first to perfect existing mechanisms before designing his own. It tackles repetitive watches, greatly reducing volume while improving both strength and accuracy.

Defeat the English at their own game

At the time, it was therefore the English who held the pinnacle of watchmaking: their masters in the field certainly show an undeniable technical superiority. Julien Le Roy will help reverse this trend, but with no intention of harming. While his reputation grew throughout Europe, rather than confronting his British rivals, the young man chose to pay tribute to them.

In 1728, he brought to Paris one of the cylinder watches designed by George Graham, to which he had great admiration. (Graham, in return, does not hide his enthusiasm for his French colleague, whom he particularly appreciates the improvements on the repeating watches.) He also borrows from Newton the results of his work on fluids to apply them to the pendulums of watches , and thus achieve significantly reduce friction, and therefore the wear of the mechanisms.

The British, however, are defeated when the name of Julien Le Roy replaces those of English watchmakers engraved on Geneva watches.

Watches and clocks

In 1739, appointed watchmaker Louis XIV, Le Roy moved to the Louvre. From then on, he attacks the perfecting of the clocks. He designs pendulums with seconds and equations of different kinds, each time with absolute precision. It develops a compensation mechanism that allows them not to suffer the effects of hot or cold.

Above all, it revolutionizes the field of the public clock by inventing a horizontal model for buildings, both cheaper, easier to manufacture and much more precise. This clock, designed thanks to a new arrangement of the wheels, Julien Le Roy chooses to enrich it with several recent inventions, among which the universal dial with compass and pinnules. Among the many advantages of the horizontal clock compared to the old model, note that fewer parts are needed for its manufacture, that the friction is reduced, and that the construction and maintenance are facilitated. The master will detail the secrets of his conception in a work published in 1737, Artificial Rule of Time.

But Le Roy is not only a watchmaker of genius, one of the most important of his country: he is also a good man. Not only does he ensure that his colleagues can benefit from his knowledge and experience, but he willingly distributes his earnings to the workers of his workshop to reward their work, so much so that he will leave his death only a thin heritage.

Julien Le Roy died in 1759 in Paris. His son Pierre Le Roy, who takes over the workshop, will be considered one of the fathers of modern chronometry.

His inventions

In the career of Julien Le Roy, inventions mingle with improvements. Here is a selection:

– In 1720, in front of the Academy of Sciences, he presents an equation clock marking the true time, the sunrise and the declination – an invention that his audience considers wonderfully accurate and practical.
– Around 1721: he invented an adjustable stem for the wheel escapement verge, found in most escapements of this type until the late eighteenth century.
– In 1738, he designed the compensating pendulum.
– Around 1740, it is the invention of the horizontal clock.
– In 1744, he removes the box from the watch box and places the striking mechanism under the dial.
– In 1755, he developed a new ringing cadence using the anchor escapement as a moderator.
Among others, Julien Le Roy is sometimes credited for having invented: the blade stamps (which allow to design flatter mechanisms), the so-called toc repeats (in which the hammer strikes a block fixed to the box) or the exhaust miniaturized anchor to regulate the speed of the clocks. This list is without