 An account of the early history of Fundamentalist movement to prohibit the teaching of evolution in schools leads off the third category.There is also a biography of Populist politician Ignatius Donnelly focusing on his speculations regarding Atlantis and like matters, and then a speculative chapter regarding future languages, essentially a didactic piece on language change with application to science fictional treatments of time-travel.It leads into a discussion of nonscientific claims about the "fourth dimension" in general.