This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1881 Excerpt: ...character of the material; obviously, within the limit of height of possible vertical face no active pressure against a wall could be expected until by the access of air, weather, &c., a change had taken place. Time would probably be found to be a more important element when the material was wet than when dry, but assuming sufficient time to be allowed the results would be more constant. Coulomb"s theory applied only to cases of purely frictional action without any adhesion or tenacity to influence the result; every case in which sidelong ground was formed into steps illustrated the advantages which were found to be practically available by paying attention to the tenacity of earth. The greatest possible height of vertical face appeared to furnish the best available index as to the effect of tenacity in influencing the result, being just sufficient to successfully resist the action of gravity in the particular case, and in other cases to vary directly as the height; in a greater or less degree a similar action obtained in every case in which the ultimate angle of repose was not assumed at once. The Author appeared to have had most trouble with silty matter, in this agreeing with the experience of all engineers, and also where water had free access, and where the mass of the backing might be assumed to be in a condition approximating to that of material exposed to the weather; the backing of dock walls was in most cases in a similar condition, and the pressure was probably very near that obtained by Coulomb"s rule, compensated for the effect of tenacity. To ascertain the absolute pressure within close limits was impossible, but it was nevertheless desirable to Mr. Sutcliffe. make the closest estimate, though not to place much reliance upon it. Experiment...