Pernicious silo effect in the wall Terzaghi's experiments. Reimbert's experiments. Interpretation. Discussion on these two points. Results for wall calculations. Silo Janssen's experiments. Exponential or hyperbolic lateral pressure ? Results for silo calculations. Connexity between silos (closed contour) and retaining strucures (open contour). The retaining wall Terzaghi's theory. Phase of elasto-plastic equilibrium. Rotational, translational and counter passive pressures. Screen displacements : form and formulary. Rankine's theory : anomalies. The ignored active pressure. The evanescent obliquity. Maximum excessive active pressure. Reflection on the perpetuation of Rankine's theory. The Tables.