Yelda Nasifoglu (University of Cambridge) : titre à venir

Nicolas Joannes (IMJ-PRG, Sorbonne Université) : Engraving Geometry : How Engravers and Booksellers Influenced Le Clerc’s Geometrical Illustrations (1690-1835). 

• During the 18th century, it was not uncommon to find hundreds of figures in mathematics books. The printed production of these figures required the intervention of a number of intermediaries, starting with booksellers, draftsmen and engravers. The last ones are responsible for the final copy of the illustration, and their work is therefore of real importance in the diffusion and circulation of mathematical images. In order to study some of the ways in which this work was carried out, we will focus on illustrations produced in reprints and translations of some books, starting with the Traité de Géométrie by Sébastien Le Clerc (1637-1714). Originally illustrated with 400 engravings by the author himself, the work's wide distribution, with a dozen editions and translations between 1690 and 1835 featuring engraved figures in different configurations, makes it an interesting example of certain reproduction methods, as well as the role and knowledge mobilized by the actors involved. The study of the figures present in these different editions enables us to identify different sets of engraved supports, sometimes used for several decades, and to trace the filiation and sources of these editions. By analyzing the differences between the illustrations in these editions, we can establish a typology of modifications and their mathematical impact. Finally, the study of their distribution through filiations sheds light on certain choices made by booksellers and producers (draftsmen, engravers) and informs us about the mobilization of their mathematical knowledge during their work.