In the Victorian era, James Watt became an iconic engineer, but in his own time he was also an influential chemist. David Philip Miller examines Watt's illustrious engineering career in light of his parallel interest in chemistry, arguing that Watt's conception of steam engineering relied upon chemical understandings.

David Philip Miller is emeritus professor of history of science at the University of New South Wales, Sydney. He is a fellow of the Australian Academy of Humanities and a member of the International Academy of the History of Science.