The river, as it flows through literary history, traces the course of poetry's spatial relations to the environment. In particular, there is a strong case for seeing in river poetry a slow change in ways of thinking about the natural and the geographical. In the eighteenth century, the poetic river describes an observable transition from the national to the local, and in this course it seems to confirm the well-known narrative of Romanticism as a reactive movement. Rivers do, of course, speak for themselves in the long tradition of their personification in genius loci, but they do so through a kind of Lacanian subjectivity that emphasizes the contextual, triangulated nature of their identity, either established against other rivers, or divided against itself. The gradual industrialization of Britain in the eighteenth century produces a new kind of self-consciousness about nature that we can see clearly in the tradition of river poetry.