The Earth Manual comprehensively covers the engineering of earthen structures. Chapter 1, Properties of Soils, covers soil classification, index properties, and engineering properties, including many mathematical relationships. Chapter 2, Investigations, focuses on methods for determination of the qualities of the earth that structures are built with and upon. This chapter includes sections on Principles of Investigations, Exploratory Methods, Sampling and Testing Methods, and Recording and Reporting of Data. The Third Edition expands upon previous editions' treatments of drilling and remote sensing. Chapter 3, Control of Earth Construction, details the considerations necessary to ensure that the nearby materials used in various types of earth construction meet the design specifications. This chapter describes construction control for foundations, embankment dams, canals, pipelines, miscellaneous features, and stabilized soils.