Evaluating John Theophilus Desaguliers' Newtonianism: the case of waterwheel knowledge in A course of experimental philosophy

John Theophilus Desaguliers (1683–1744) was a French-born English Huguenot who made his name as a public lecturer in London and a demonstrator at the Royal Society, writing a very popular introduction to Isaac Newton's natural philosophy, the two-volume A course of experimental philosophy (1734–1744). This paper looks at the influence of three French natural philosophers, Edme Mariotte (1620–1684), Antoine Parent (1666–1716) and Bernard Forest de Bélidor (1698–1761), on the account of waterwheel functioning in the second volume of that work. The aim of the paper is to show that, although Desaguliers demonstrated a commitment to Newton's work, his own natural philosophical objectives also led him to borrow ideas from natural philosophers outside Newton's direct sphere of influence. To do this I shall give an account of what Desaguliers appropriated from Newton's Principia, how it fitted in with his own project and how he also made use of other natural philosophers' theories in his discussion of fluid mechanics. This will hopefully result in a more nuanced conception of Desaguliers' ‘Newtonianism’ that takes into account the diverse sources and influences in his work.