The first half of the nineteenth century saw new scientific disciplines begin to take shape, while new concepts of the natural world and its processes - concepts of evolution and the vastness of geological time - began to spread. Jim Secord, Director of the Darwin correspondence project, captures the changing times through the nature and reception, by genteel ladies and working men as well as among the intelligentsia, of a selection of key books from the 1830s, including Charles Lyell's Principles of Geology, Mary Somerville's Connexion of the Physical Sciences, and Thomas Carlyle's satirical work, Sartor Resartus. Set in the context of electoral reform and unrest in continental Europe, of debates about the extension of education to working people to meet the demands of a new industrial, machine-dominated world, Secord shows how the books were published, disseminated, admired, attacked, and satirized.