The book about John Michell (1724-93) has two parts. The first and longest part is biographical, an account of Michell?s home setting (Nottinghamshire in England), the clerical world in which he grew up (Church of England), the university (Cambridge) where he studied and taught, and the scientific activities he made the center of his life. The second part is a complete edition of his known letters. He has been called a geologist, an astronomer, and a physicist, which he was, though we best remember him as a natural philosopher, as one who investigated physical nature broadly. His scientific contribution is not easy to summarize. Arguably he had the broadest competence of any British natural philosopher of the eighteenth century, equally skilled in experiment and observation, mathematical theory, and instruments, his field of inquiry was the universe. From the structure of the heavens through the structure of the Earth to the forces of the elementary particles of matter, he carried out original and far-reaching researches on the workings of nature.