[Footnote 2:] A full discussion may be found in the writer’s “Retaining Walls.”] [Return to text]
[Footnote 3:] The experiments pertaining to [Figs. 7], [8], and [9] are due to Curie. See Curie’s “Poussée des Terres” and “Trois Notes,” Gauthier-Villars, Paris. They are of especial interest in that they were undertaken to attempt to overthrow the theory advocated above.] [Return to text]
[Footnote 4:] All the experiments of Leygue referred to in what follows may be found in Annales des Ponts et Chaussées, November, 1885.] [Return to text]
[Footnote 5:] We can suppose, here, the horizontal force to be the pull of a cord extending horizontally from the box and passing over a fixed pulley, and that at the free end of the cord a weight is applied. The friction of the pulley and carriage wheels could be found experimentally and allowed for, so that some fraction of this weight would equal
[Footnote 6:] This method is an extension of that given by Professor H. T. Eddy in his treatment of earth thrust, in “Researches in Graphical Statics.”] [Return to text]
[Footnote 7:] To attain the greatest accuracy, in constructions like that shown in [Fig. 11], the scale should be as large as possible; the arcs of circles, especially, must be drawn with a large radius, and the points,
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