ft. and the level upper surface of the surcharge being 4.26 ft. above the top of the wall. The surcharge extended over the wall at the angle,
, corresponding to damp sand. Experiment gave
. The wall was of brick in Portland cement. The ratio,
. It was found, using the construction of [Fig. 1], that taking the thrust,
, as acting 1.24 ft. above the base, or at one-third of the height of the surface,
