In spring 1939, Springer-Verlag requested the writing of a new engineering geology book to replace the 1929 edition of "Ingenieur-Geologie" by Redlich Terzaghi-Kampe, which had been out of print for years. Since I possess extensive practical and theoretical experience in all areas of engineering geology and have been operating the first soil mechanics testing facility in Switzerland since 1929, I took on this task out of a desire for systematic evaluation of my own experiences and for a similar methodological treatment of the factual material I had read. My only condition was to have freedom in the structure, selection, and treatment of the material. The publisher generously accommodated my request in every respect. In determining the scope of the material, I assumed that an engineering geology book should fundamentally include all the essential aspects.