Abstract
William Thomson, Lord Kelvin, was the best-known scientist of his day, an eminent natural philosopher, engineer, and mathematician. His Popular lectures and addresses cover many aspects of science in a non-technical way. After a general introduction on popular scientific writing, Kelvin's varied topics are listed, and just one is described in more detail: his lecture ‘On ship waves’. This paper was first presented at a colloquium at the University of Glasgow, Glasgow on Literature and Mathematics in May 2011.