William Stukeley's (1687-1765) drawing of the brass machine which Stephen Hales constructed in college to demonstrate the movements of the planets. Stephen Hales (1677-1761) was an English clergyman who made major contributions to a range of scientific fields including botany, pneumatic chemistry and physiology. He and Stukeley were very close friends after meeting at Cambridge. Hales studied astronomy and was famliar with the Newtonian System.