No technique emerges, is transmitted or deployed in isolation. Techniques are the combined results of practices, political and economic circumstances, cultural choices, material opportunities, and converging social forces. This interdependency between contingencies and structures results in a multitude of intersections, overlaps, and con-nections. This section therefore intends to explore the interconnections of techniques and the social fabric. We want to look at these issues on a global scale as practices, uses, objects, and methods in a variety of fields of human activity circulate. In each major field of practice, different types of techniques have emerged from encounters between specific frameworks and the possibilities offered by the wider technological context. The chapters follow the twists and turns of how a range of techniques variously connected to social structures along the nineteenth and twentieth centuries. In the process, the section explores some of the key global transformations witnessed in these two centuries. Liliane Hilaire-Pérez's historiographical chapter unpacks the various meanings of the term 'technology'. Initially conceived of in the early modern period and eigh-teenth century as including all practices in all their diversity, the nineteenth-century concept of technology, particularly in England, became centred on machines. Later a more procedural rationale prevailed where technology as understood not only as machinery but as encompassing all the processes and practices necessary to imple-ment them. In addition to outlining conflicting definitions of the term, Hilaire-Pérez draws attention to the lively, mostly French, research tradition that has considered technology as part of the humanities. This position is both a methodological choice (to capture all forms of human practice) and a heuristic one (to avoid considering technology as an end in itself). This conceptual discussion allows us to foreground 'technique' (rather than 'technology') at the heart of different types of human activity, while the following chapters investigate the main technical developments witnessed in the nineteenth and twentieth centuries. The laboratory, which has been a special place for experimentation since the beginning of the early modern period, is defined and shaped by various structures and conventions -be they social, epistemological, or political, while being naturally also at the centre of technical questions. Joris Mercelis explores the ways in which laboratories as places specifically devoted to science have integrated technical compo-nents (notably through instrumentation) as well as produced new techniques (as, for example, the optical equipment that came out of Fraunhofer's laboratory).

Due to the rise of scientific practices involving a large number of researchers, engi-neers, and technicians, large-scale organizational procedures and a vast deployment of technologies, a truly Big Science emerged after the Cold War. Olof Hallonsten highlights the many transformations that have affected Big Science since the 1950s, including the development of nuclear and particle physics, the increasingly diverse uses for large particle accelerators, and the emergence of combined instrumental structures. Spreading beyond laboratories, techniques come into contact with the regulatory frameworks of human activities, starting with that of the law. Legal formats are a good indicator of transformations;