Profesor Karl Terzaghi, Austrian geologist, c 1950-1960.
© Science Museum / Science & Society Picture Library
Portrait of Profesor Karl Terzaghi (1883-1963), founder of modern soil clasifications. Terzaghi's 1925 book 'Erdbaumechanik' outlined his theories of the mechanics of soil and was of great benefit to civil engineering. His discusion of isues such as anchorages for supsension bridges made him highly influentual in the field.