Reviewed by: Engineers, unity, expansion, fragmentation (19th and 20th centuries), volume 1: The production of a social group ed. by Antoine Derouet and Simon Paye Alain P. Michel (bio) Les ingénieurs, unité, expansion, fragmentation (XIXe et XXe siècles), Tome 1: La production d'un groupe social [Engineers, unity, expansion, fragmentation (19th and 20th centuries), volume 1: The production of a social group] Edited by Antoine Derouet and Simon Paye. Paris: Classiques Garnier, 2018. Pp. 364. Les ingénieurs, unité, expansion, fragmentation (XIXe et XXe siècles), Tome 1: La production d'un groupe social [Engineers, unity, expansion, fragmentation (19th and 20th centuries), volume 1: The production of a social group] Edited by Antoine Derouet and Simon Paye. Paris: Classiques Garnier, 2018. Pp. 364. This book is a collection of the initial proceedings of an international conference held in Paris in 2011 called "Engineer, Engineers: Expansion or Fragmentation?" The conference posited that the designation of a single polysemic professional title corresponded in fact to a variety of deeply heterogeneous jobs. It questioned both the making of a profession and its ability to endure as an emblematic figure of the industrial world. The first volume covers the emergence of "engineers" as a social group. The second one—to be published in 2022—will deal with the construction of a transnational communication space for civil engineers in Europe from the late eighteenth to the twentieth century. Both volumes follow the emergence of a social network that revolves around the mobility of experts, the circulation of knowledge, and the constitution of professional organizations. This 2018 volume illustrates the dynamism of engineering in the history of technology in France and Europe. It is edited by two young engineering historians, Antoine Derouet and Simon Paye, while the next volume will be overseen by two pioneers in the field (Irina Gouzevitch and Claudine Fontanon). In a published conference proceedings of 1980, A. Thépot noted that "beyond clichés and superficial judgments, engineers constituted a relatively poorly understood socio-professional category" (L'ingénieur dans la société française, 1985). In the wake of the social construction of technology (SCOT) approaches, French sociologist and historian of engineers André Grelon precociously formed an informal multinational group, bringing together researchers from West, East, and South Europe; Latin America; North Africa; and more recently Asia. In parallel, Hélène Vérin's La gloire des ingénieurs (Albin Michel, 1993) analyzed the emergence of a "technical intelligence" from the sixteenth to the eighteenth century. In addition to the state engineers of the modern era, a new category of civil engineers emerged in the nineteenth century to meet the needs of industrialization. By the end of the 1990s, the "cultural turn" in social sciences and the idea that the industrial world had disappeared tended to turn the gaze of historians (even historians of technology) away from manufacturing subjects and the people behind production (Edgerton, Shock of the Old, 2006). Even in the western world, however, engineers survived this deindustrialization process, with their role expanded from an essentially [End Page 638] technical function to one managing the "human factor." In France, the historical exploration of engineering as a profession faded, but it has now resurfaced with the 2017 publication of an edited book in homage to the work of Hélène Vérin, entitled Penser la technique autrement (Classiques Garnier, 2017). Antoine Derouet and Simon Paye's 2018 volume (and the forthcoming second volume) extends this historiography, now published in the same series: Histoire des techniques. Its twelve monographic chapters question both the representations and the practices of engineers to reveal a global consolidation of the profession. They open a field that has so far been dominated by Anglo-Saxon studies, considering more diverse countries in Europe as well as other continents. The case studies compare the situation in France (5 chapters), Spain (2), Italy (2), Belgium (1), and India (1). Despite this somewhat heterogeneous geographical distribution, the volume presents a unified statement concerning the emergence of various groups of engineers. The introduction by Derouet and Paye sets the main thesis: the idea of persistent and fruitful tensions between the heart and the...