This essay introduces a special issue of the BJHS on communities of natural knowledge and artificial practice in seventeenth- and eighteenth-century London. In seeking to understand the rise of a learned and technical culture within a growing and changing city, our approach has been inclusive in terms of the activities, people and places we consider worth exploring but shaped by a sense of the importance of collective activity, training, storage of information and identity. London's knowledge culture was formed by the public, pragmatic and commercial spaces of the city rather than by the academy or the court. In this introduction, we outline the types of group and institution within our view and acknowledge the many locations that might be explored further. Above all, we introduce a particular vision of London's potential as a city of knowledge and practice, arising from its commercial and mercantile activity and fostered within its range of corporations, institutions and associations. This was recognized and promoted by contemporary authors, including natural and experimental philosophers, practical mathematicians, artisans and others, who sought to establish a place for and recognition of their individual and collective skills and knowledge within the metropolis.

This paper looks at a genre of meetings that, while neither purely ‘scientific’ nor ‘diplomatic’, drew on elements from both professional spheres and gained prominence in the interwar decades and during the Second World War. It proposes to make sense of ‘technical conferences’ as a phenomenon that was made by and through scientific experts and politicians championing the organizing power of rationality, science and liberal internationalism. Against the background of swelling ranks of state-employed scientists, this paper documents the emergence of technical conferences as the forums where they got down to work. To make this case the paper traces the influence of a new way of thinking about the function and organization of conferences, originating in the time around the First World War, on one international organization in particular: the United Nations Relief and Rehabilitation Administration (UNRRA), as a new hub of scientists and technicians.

This article, through a case study of the Royal Dublin Society (RDS), traces the reception, experimentation with, and uses of radium in early twentieth-century Ireland. Throughout the nineteenth century there was increasing state intervention in the provision of scientific and technical education in Ireland. This culminated in the loss of the RDS's traditional role in this area. The article demonstrates that the RDS was forced to re-envisage its role as a scientific institution by actively seeking to support experimental research. Using radium as a case study, the article argues for the success of this tactic. It demonstrates that radium played a central role within the RDS as a nexus for the maintenance of an experimental and philanthropic culture that permeated much of the society's scientific output in this period. In doing this it highlights the importance of sociability in the promotion of science in Ireland in the early twentieth century. In addition, it explores the role of the RDS as an arbiter of scientific authority.