The chapter is concerned with the use of computers to represent historical time visually, typically as ‘timelines’. Research into the sophisticated practice and theory of early modern paper timelines in the eighteenth century reveals the weakness of current practice, especially on the Web. Behind the work of the early pioneers lay a vision of mechanising knowledge. At that time, this proved a productive metaphor, but in our own time the mechanistic properties of computers have tended to encourage an approach to visualising history that excludes all but the crudest aspects. Solutions are needed which use computing in ways that do justice to the demands of historiography.