This paper is a contribution to the study of the relations between science and technology in seventeenth-century China. I hope that its unusual perspective may help to illuminate the problem of how these two areas of human activity relate to each other in a more general context. Outside the small group of interested scholars the relations between science and technology are not seen as problematical. In the popular stereotype, scientists are trie people who make discoveries, while technologists simply find out how to use what they have discovered. This crude view has some support from historical fact. Over the last hundred years there has undoubtedly been a steady flow of useful ideas from (for instance) the physicist to the engineer and from the biochemist to the agronomist.