Over the past twenty years or so, historians of science have become increasingly sensitized to issues involved in studying and interpreting scientific and medical instruments. The contributors to this Focus section are historians of science who have worked closely with museum objects and collections, specifically instruments used in scientific and medical contexts. Such close engagement by historians of science is somewhat rare, provoking distinctive questions as to how we define and understand instruments, opening up issues regarding the value of broken (...) or incomplete objects, and raising concerns about which scientific and medical artifacts are displayed and interpreted in museums and in what manner. It is hoped that these essays point historians of science in new directions for reengaging with scientific objects and collections. (shrink)