Handbook of Hydraulics e-bog

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Many thousands of experiments on flowing water have been performed during the last two centuries, the results of which form the basis of our present science of hydraulics. These experiments present many incongruities and as they do not cover the range of conditions required in practice, it is difficult to devise from them accurate working rules and formulas. The hydraulic engineer is therefore confronted with the task of making what appears to be the most reasonable application of the available data to each problem that he encounters. A great number of empirical formulas have been devised, which provide an indirect method of transferring experimental results to practical problems. In using such formulas, however, the engineer should not lose sight of the fact that results obtained by them will be subject to errors corresponding to the discrepancies in the experiments on which the formulas are based. The active interest in experimental research during recent years has been productive of such a rapidly increasing number of hydraulic formulas that engineers generally are not in a position to make critical comparisons and select those that possess the greatest merit. The result has been a tendency to cling to the old and accepted formulas. The author believes that unless the newer formulas have apparent advantages over the old, the latter are preferable inasmuch as their peculiari ties are known and it is easier to select coefficients for them.