4 December 2025

11:45 AM – 12:30 PM

Amphi Petit Kursaal

Rossella Baldi

Trained as an art historian, Rossella Baldi has been working in the field of science and technology history for several years. Former director of the Institut l’Homme et le Temps at the International Watch Museum in La Chaux-de-Fonds, she currently works as an independent historian, particularly in the field of watchmaking. Winner of various academic awards, her research focuses mainly on the history of watchmaking in the 17th and 19th centuries, as well as the history of collections, botany, and travel.

How reliable were the first stopwatches in the 18th century?

Our presentation will focus on the emergence of chronometry in the second half of the 18th century and, in particular, on the relationship between the first users of pocket chronometers and their instruments. We will address this question using the example of timepieces produced between 1782 and 1794 by the London workshop of Swiss-born watchmaker Josiah Emery. At that time, Emery was one of the few craftsmen capable of manufacturing these pieces, along with John Arnold in London and Louis Berthoud in Paris. His timepieces, equipped with an anchor escapement, were considered by contemporaries to be the most accurate ever made. We will therefore discuss the challenges and limitations faced by Emery’s customers as they sought to understand the workings and potential of a scientific instrument that was new to them. The accuracy and reliability of a chronometer are not guaranteed solely by the technical sophistication of the piece and the perfection of its execution. They result above all from the interaction between the object and its user. Thus, between broken chronometers, inaccurate measurements, and a great deal of emotion, the pocket chronometer of the late 18th century reminds us that the success and spread of an innovation depend on a multitude of factors, not just its technological advancement.