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...