The book attempts to draw together the various strands of evidence that have led to present knowledge of the distribution of density throughout the interior of the Earth. Details are also given of other properties with which the density is closely linked, including pressure, compressibility and compression, rigidity, seismic velocities, Poisson's ratio and gravitational intensity. Questions of thermodynamics and chemical composition and phase enter discussions where they bear more or less sharply on the density determination; but the book does not purport to be a comprehensive text on the...