The resolution of the sixty-year debate over continental drift, culminating in the triumph of plate tectonics, changed the very fabric of Earth science. This four-volume treatise on the continental drift controversy is the first complete history of the origin, debate and gradual acceptance of this revolutionary theory. Based on extensive interviews, archival papers and original works, Frankel weaves together the lives and work of the scientists involved, producing an accessible narrative for scientists and non-scientists alike. This second volume provides the first extensive account of the growing paleomagnetic case for continental drift in the 1950s and the development of apparent polar wander paths that showed how the continents had changed their positions relative to one another, more or less as Wegener had proposed. Paleomagnetism offered the first physical measure that continental drift had occurred and helped determine the changing latitudes of the continents through geologic time.