, therefore
ft., or is very small. In fact, as in the experiments, no cracks were formed, the cohesion on the vertical planes should be included, which would lead to the results given.
After the thrust, for earth endowed with cohesion, has been computed, the next question is, at what point on the retaining wall does it act? This can be answered at once, when the inner face of the wall is vertical and the earth surface horizontal, for then the earth thrust acts at
of the height,
, [Figs. 24] and [25], as hitherto proved. The case is not so simple when the wall is inclined, either toward or from the earth. In [Fig. 25], the thrust,
