Quelques travaux - Some works
Inventaire et documentation du patrimoine scientifique
Inventory and documentation of scientific heritage
1980 - Present
Study of astronomical computing and astronomical clocks.
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I started to experiment with astronomical computing around 1980, and this in turn got me interested in astronomical clocks, a vast topic which is very badly documented.
2002 - Present
Study of mechanical computers.
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Starting in 2002, I have been working on mechanical computers, in particular on Babbage's first difference engine and on some early calculating machines from the 1840s.
2002 - Present
Study of tower clocks.
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In 2002, I also began to examine and study many tower clocks, now amounting to a thousand. I have in particular examined practically every tower clock in Paris, including the destroyed clock of Notre-Dame cathedral.
Some publications - Une sélection de publications
August Stolberg : Les peintures de Tobias Stimmer sur l'horloge astronomique de la cathédrale de Strasbourg, 1898 (translation and notes by Denis Roegel, 2005, currently with limited access)
Denis Roegel : Annotation of George Biddell Airy's On the Forms of the Teeth of Wheels (published in the Transactions of the Cambridge Philosophical Society, volume 2, p. 277-286, 1827). (14 November 2006)
Denis Roegel : Annotation of George Biddell Airy's On the Disturbances of Pendulums and Balances, and on the Theory of Escapements (published in the Transactions of the Cambridge Philosophical Society, volume 3, p. 105-128, 1830). (25 September 2006)
Denis Roegel : Annotation of George Biddell Airy's On the Vibration of a Free Pendulum in an Oval differing little from a Straight Line (published in the Memoirs of the Royal Astronomical Society, volume XX, p. 121-130, 1851). (3 November 2006)
Denis Roegel: An Early (1844) Key-Driven Adding Machine, IEEE Annals of the History of Computing, vol. 30, no. 1, pp. 59-65, January-March 2008.
Denis Roegel : Review of Joseph Flores' book on Klinghammer's computus model, Mitteilungen der Deutsche Gesellschaft für Chronometrie, Nr. 113, Frühjahr 2008, pp. 58-60. (in German)
Denis Roegel : Review of Joseph Flores' book on Klinghammer's computus model, NAWCC Bulletin (Bulletin of the National Association of Watch and Clock Collectors), vol. 50/4, n. 375, August 2008, pp. 471-472
Denis Roegel: Prototype Fragments from Babbage's First Difference Engine, IEEE Annals of the History of Computing, vol. 31, no. 2, pp. 70-75, April-June 2009.
Denis Roegel: The "Villarceau circles" in Uhlberger's staircase (ca. 1580), 2014
Denis Roegel: An overview of Schwilgué's patented adding machines, Bulletin of the Scientific Instrument Society, volume 126, pages 16-22, 2015
Denis Roegel: A mechanical calculator for arithmetic sequences (1844-1852): part 1, historical context and structure, IEEE Annals of the History of Computing, vol. 37, no. 4, pp. 90-96, October-December 2015
Denis Roegel: A mechanical calculator for arithmetic sequences (1844-1852): part 2, working details, IEEE Annals of the History of Computing, vol. 38, no. 1, pp. 80-88, January-March 2016
Denis Roegel : Une rare table-bascule décimale (ca 1839), Histoire & Patrimoine hospitalier (Les Amis des Hôpitaux Universitaires de Strasbourg), numéro 28, décembre 2016, pp. 6-9
Denis Roegel : De Maybaum à Ungerer, en passant par Schwilgué --- l'ancienne horloge de la plate-forme, Bulletin de la cathédrale de Strasbourg, numéro XXXII, 2016, pp. 175-180
Denis Roegel: A new early adding machine by Schwilgué (c. 1840?), Bulletin of the Scientific Instrument Society, volume 130, pages 24-27, September 2016
Denis Roegel: Before Torchi and Schwilgué, there was White, IEEE Annals of the History of Computing, vol. 38, no. 4, pp. 92-93, October-December 2016
Denis Roegel: Carries Stripped to the Bone: Episodes in the History of Coaxial Modular Digital Counters, IEEE Annals of the History of Computing, vol. 39, no. 3, pp. 55-64, July-September 2017
Denis Roegel : La grande horloge de la cour d'honneur, In: Saint-Louis-des-Invalides, la cathédrale des armées françaises, 2018, pp. 265-269
Alfred and Théodore Ungerer : L'horloge astronomique de la cathédrale de Strasbourg, new edition with corrections and important new material, 2018 (290 pages, currently with limited access)
Denis Roegel : Petit guide d’intervention sur le patrimoine horloger, à l’usage des conservateurs des musées, des conservateurs du patrimoine, des municipalités, des châteaux, des restaurateurs et des particuliers, 2019
Denis Roegel : 3D model of the former tower clock of the Notre-Dame cathedral in Paris, 2020 (and Android application, animations and 3D printing in 2021)
Denis Roegel : L'horloge de la chapelle, In: Un palais pour l'empereur. Napoléon Ier à Fontainebleau (catalogue), 2021, pp. 54-55
Denis Roegel : L'horloge astronomique de Bernard Joyeux (vers 1750), 2021
Denis Roegel : The electromechanical clock of the city hall in Cluses and its restoration, 2021
Denis Roegel : Passemant's moving sphere clock in Versailles - A plea for better restorations and documentations, Horological Science Newsletter (NAWCC Chapter 161), 2022, issue 1, p. 2-35
Denis Roegel : Clocks as astronomical models: The nineteenth and twentieth centuries, In: A general history of horology, dir. par Anthony Turner, James Nye
et Jonathan Betts, p. 273-287, Oxford : Oxford University Press, 2022
Denis Roegel : La documentation du patrimoine scientifique par les restaurateurs. L'exemple des horloges, 2022
Denis Roegel : L'horloge astronomique à dix cadrans du château de Fontainebleau (Inv. F 472 C) --- Quelques compléments à la restauration de 2020-2021, 2022
Denis Roegel : The first 3D clock mobile application, 2022
Denis Roegel : A prototype for a scalable virtual technology museum, 2022
Denis Roegel : A complete analysis of Schwilgué's computus model constructed in 1821, 2024? (forthcoming)