This essay examines how William Wordsworth and Charles Babbage used mathematical analogies in order to imagine an ideal medium free from the distorting biases of the printed book and industrial machinery, respectively. The argument focuses principally on the episode of the shell and the stone in Book Five of The Prelude, in which Wordsworth pairs poetry with Euclidean geometry as “the knowledge that endures,” and Chapter 2 of The Ninth Bridgewater Treatise, in which Babbage uses the mathematical structure of the difference engine, a forebear of the digital computer, as a model for the divine first cause. By way of a conclusion, the essay considers the relationship between Wordsworth and Babbage’s “media-less media theory” and recent work on mediation, including the actor-network theory of Bruno Latour, which posits a non-dualistic relation between medium and technology, on the one hand, and nature and society, on the other.