This is a subtle book. Its contribution lies almost as much in what it does not do as in what it does. Without fanfare or polemic, Grace Yen Shen breaks from the common assumption that studies of science in modern China must be studies of the movement of ideas from one place (specifically the West) to another (specifically China) and what happens to them once they get there. As she says, "The central concern of this work is not how science travels, but how it is refracted in a new medium, and how this process illuminates both the workings of science itself and the distinctive features of its novel surroundings" (6). In shifting the focus away from what Jim Secord has called "knowledge in transit" (though she does not explicitly reference Secord), Shen is able to produce a history of a community of scientists in one place, who built their knowledge and their craft in ways that are as significant as the operations of any other scientific community anywhere.