A Manual of Civil Engineering

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Charles Griffin, 1883 - 808 من الصفحات
 

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الصفحة 313 - The properties of earth with respect to adhesion and friction are so variable that the engineer should never trust to tables or to information obtained from books to guide him in designing earthworks, when he has it in his power to obtain the necessary data either by observation of existing earthworks in the same stratum or by experiment.
الصفحة 378 - Rankine'e rule for the proportion of stones : " In order that the stones may not be liable to be broken across, no stone of a soft material, such as the weaker kinds of sandstone and granular limestone, should have a length greater than 3 times its depth. In harder materials the length may be 4 or 5 times the depth. The breadth in soft material may range from lj time to double the depth; in hard materials it may be 3 times the depth.
الصفحة 797 - Text from HEYNE and WAGNER. English Notes, original, and selected from the leading German and English Commentators. Illustrations from the antique. Complete in One Volume.
الصفحة 171 - Friction is that force which acts between two bodies at their surface of contact so as to resist their sliding on each other, and which depends on the force with which the bodies are pressed together.
الصفحة 149 - Cases I. and II. (B) ; to a couple, as in Case III. (C) ; to a force, combined with a couple whose axis is parallel to the line of action of the force, as in Cases IV. and V. This can occur...
الصفحة 403 - The objects of this are, at once to distribute the pressure over a greater area than that of any bed-joint in the body of the wall, and to diffuse that pressure more equally, by bringing the centre of resistance nearer to the middle of the base than it is in the body of the wall. The power of earth to support foundations has already been considered in Article 199.
الصفحة 501 - ... bubbling or agitation ; but a larger proportion is not to be used, as it would make the steel brittle. The presence of manganese in the iron, or its introduction into the crucible or vessel in which steel is made, improves the steel by increasing its toughness and making it easier to weld and forge. Steel is distinguished by the property of tempering; that is to say, it can be hardened by sudden cooling from a high temperature, and softened by gradual cooling; and its degree of hardness or softness...
الصفحة 783 - The first result of the experiment was to show conclusively that the retarding effect of a wheel sliding upon a rail is much less than when braked with such a force as would just allow it to continue to revolve.
الصفحة 42 - CB : CA : : sin A : sin B. For, with A as a centre, and AD equal to the less side...
الصفحة 723 - ... a reliable purifier of water tainted with animal impurities. Among other purifying agents may be mentioned, distillation, the exposure of water in minute divided currents to the air, the immersion of pieces of charcoal or of iron wire, and the effects of plants and fish. In store reservoirs, the presence of a moderate quantity of living plants exerts a decidedly purifying influence, while the destruction of fish has been followed by an excessive multiplication of the small crustacean animals...

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