Handbook of Hydraulics: For the Solution of Hydraulic Problems (Classic Reprint)

Excerpt From Handbook Of Hydraulics: For The Solution Of Hydraulic Problems In Applied Hydraulics Rational Theory Must Give Place To Experimental Knowledge. Though Every Particle Of owing Water Moves In Accordance With Definite Fixed Laws, Such Laws Are Intricate And Imperfectly Understood. In Many Instances The Basic Formulas Used In Hydraulic Computations Are De Rived From Theoretical Considerations, But They Must Invariably Be Corrected By Experimental Coefficients And Frequently They Become Thereby So Transformed As To Bear But A Slight Resem Blance To The Original Formulas. Many Thousands Of Experiments On owing 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 Peculia