Incluye índice: páginas 395-413

1. Introduction -- 2. The origin of the solar system -- 3. Relevant facts and inferences from field geology -- 4. Elastic properties of materials of the earths crust -- 5. The crust of the earth and Its relation to the interior -- 6. Observed temperatures in the earths crust --7. The cooling of the earth and the temperature in its interior -- 8. Forces in the earth -- 9. Hypotheses on the development of the earth -- 10. Evidence on the interior of the earth derived from seismic sources -- 11. Evidence from deep-focus eartquakes -- 12. Structure of the crust. Continents and oceans -- 13. Density, gravity, pressure and ellipticity in the interior -- 14. The elastic constants in the interior of the earth -- 15. Viscocsity, strength and internal friction in the interior of the Earth