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. 1908 Excerpt: ...It was quite evident to them that it extended a short distance up the face of the dam. Reference had been made to the memoir of Messrs. Pearson and Pollard, in which it was stated that the stresses obtained from a model slab dam could not agree with those in a solid dam. The Authors had satisfied themselves that in all parts of their models above line 6, the stresses investigated could not be very different from those in a solid dam. Below line 6, they recognized that there might be differences, and these were discussed in the Paper. They were glad that Mr. Martin had entered into this discussion; he was no novice at the application of the higher mathematics to practical problems, and in his correspondence in the technical journals with Professor Karl Pearson1 he had proved 1 Engineering, vol. lxxxiv, p. 405 ct acq. Nature, vol. lxxvii, p. 198 et »fg. conclusively that the stresses measured in a model slab dam must Messrs. Wilson agree closely with those in a solid dam. The Authors could endorse Mr. Martin"s statement regarding the impracticability of obtaining pressure-curves from the shear-curves. The pressure on any particular element of the section-line consisted of the difference between the total shears taken over the vertical section-planes added to the weight of the prism of masonry. In effect, the pressure depended on the small difference between two large figures. Pressures thus deduced, even from perfectly smooth assumed shearcome--unless calculated in the most careful and laborious manner--lay very irregularly when plotted. This method, however, was the only possible one to adopt where the correct ratio between the fluid and masonry densities was not maintained. In reply to Professor Smith"s criticism, the Authors had always been careful th...