Roel Sterckx is Joseph Needham Professor of Chinese History, Science, and Civilization at the University of Cambridge and Fellow of Clare College. He is the author of Food, Sacrifice and Sagehood in Early China (Cambridge, 2011) and other studies on the cultural history of pre-imperial and early imperial China. Martina Siebert works as area specialist for China at the Staatsbibliothek zu Berlin and as an independent scholar. She has written on the role of nature studies in the Chinese world of learning, the classification of animals and the construction of technological pasts. Dagmar Schäfer is Director of Department III, 'Artefacts, Action and Knowledge', of the Max-Planck-Institut für Wissenschaftsgeschichte, Berlin. She has published widely on materiality, the processes and structures that lead to varying knowledge systems, and the changing role of artefacts – texts, objects and spaces – in the creation, diffusion and use of scientific and technological knowledge.