A practical treatise on hydraulic and water-supply engineering; relating to the hydrology, hydrodynamics, and practical construction of water-works, in North America - Softcover

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. 1886 Excerpt: ...are readily obtained for the several depths, from measurement of the channel. To compare new depths, velocities, and volumes, with the depth, velocity, and volume accurately measured by experiment, as unity, The relative values of new depths, velocities, volumes, etc., will be d' v' q' elC' and v: Vi:: 1:--: In long straight channels of uniform section, ix will he less than i for iucreased depths, and greater than i for reduced depths; but ordinarily (except with great velocities) their values will be so nearly equal to each other that they may be omitted from the equation without serious error, when the equation of velocity will become, The variations in To cannot be neglected in relatively shallow channels. For illustration of the equations, let Fig. 57 be a smooth trapezoidal channel, 6 feet broad at the bottom, = e, and with side slopes inclined thirty degrees from the horizon, = p. During the experimental measurement, let the depth be 4 feet; the slope, one foot in one mile = i =.000189; the experimental velocity, 1.201 feet per second; and the experimental volume, 62.128 cubic feet per second. The velocities and volumes are to be computed when the depths are 2 feet and 6 feet, respectively. Let d be any given depth; e " the bottom breadth, = 6 feet; & " the mean breadth; the slope of the sides, = 30; the sectional area; the wetted earth perimeter. With increase of depth, there is also increase of velocity; hence there are two factors to increase of volume. Some practical considerations relating to open canals are given in Chap. XVII, following. SECTION III. Practical Construction Of Water-works. CHAPTER XVI. RESERVOIR EMBANKMENTS AND CHAMBERS. 345. Ultimate Economy of Skillful Construction.--An earthwork embankment appears to the uniniti...