James Watt and the Business of Natural Philosophy

This chapter re-evaluates the place of natural philosophical inquiry in Watt’s life and work, and its relationship to his practical projects. It examines how family, education and working life opened up natural philosophical inquiry for him, and shaped his orientation towards it. Watt’s bursts of experimentation on steam and on the nature of airs are described, which led to his claim to have discovered the compound nature of water, and to his work in pneumatic medicine. It is argued that Watt developed a coherent chemistry of heat that has not been fully appreciated and that informed his steam engine improvements in fundamental but indirect ways, providing a framework for understanding its internal processes. Finally, the varied sites of Watt’s inquiries beyond the laboratory are considered, as is his problematic relationship with the community of natural philosophers, showing that the business of natural philosophy was his primary concern.