WATER POWER ENGINEERING THE THEORY, INVESTIGATION AND DEVELOPMENT OF WATER POWERS. BY DANIEL W. MEAD. Member American Society Civil Enginet Consulting Engineer Professor of Hydraulic and Sanitary Engineering University of Wisconsin NEW YORK McGRAw PUBLISHING Co. 1908 GENERAL Copyrighted 1907-1908 BY DANIEL W. MEAD STATE JOURNAL PRINTING COMPANY MADISON, WISCONSIN A PREFACE In the development of a water power project the engineer is fre- qently called upon to do more than design and construct the power plant. He may be required to report on the adequacy of the supply, the head and power available and the probable variations in the same, the plan for development, the cost of construction and opera- tion, and the advisability of the investment. A study of the entire project, therefore, becomes essential, and each factor must be care- fully considered in detail to assure ultimate success. Each of the features of the development is of equal importance to the commer- cial success of the project. The majority of the failures in water power development have occurred from causes other than structural defects, and a knowledge of these other important and controlling- factors is therefore quite as essential as a knowledge of design and construction. It must be said, however, that in respect to some of these controlling factors current practice has not been what it should be. This has resulted in many over-developments and illy advised installations, from which the power generated has not been equal to tfiat anticipated, and in many poor financial investments amount- ing frequently to practical failures. The engineer has given much attention to design and construction but too little attention to the other fundamental considerations mentioned above on which the success of the project depends to an equal extent. In the preparation of this book the author has endeavored to con- sider, briefly at least, all fundamental principles and to point out the basis on which successful water power development depends. The method of study and investigation outlined herein was developed by the author during twenty-five years of professional practice and in his efforts to illustrate the principles underlying the subject in his lectures to the senior class in water power engineering at the Uni- versity of Wisconsin. A somewhat extended acquaintance with the literature relating to water power engineering leads the author to believe that in a number of features the principles and methods de- scribed in this book are somewhat in advance of present practice. vi Preface. In current practice, the hydraulic engineer, to determine the ex- tent of a proposed hydraulic development, commonly depends on a study of the monthly averages of stream flow and of observed maxi- mum and minimum flows. He usually assumes from his previous knowledge and study that the development should be based on a certain minimum or average stream discharge per square mile of drainage area. The value of this method depends on the breadth of the engineer's local knowledge of rainfall and run-off relations. With a sufficient knowledge of these conditions, this method may form a safe basis for water power development but it fails to give the complete information which is essential for a full comprehension of the subject. In other cases the development is predicted on a single, or on a very few, measurements of what is believed, or as- sumed to be, the low water flow of the stream. This method, even when accompanied by careful study of rainfall records, is a danger- ous one to employ as many over-developed water power projects demonstrate. Neither of these 'methods compares favorably with the more exact method of studying flow by actual or comparative hydrographs as is described in Chaps. IV, V, VIII and IX. In current practice the head available is usually determined for average conditions, or, perhaps, occasionally for low, average and high water conditions, and no detailed study of the daily effect on power is attempted. In Chaps. IV and V this subject is presented in detail and a method of the investigation of this important subject, under all conditions of flow and all conditions of use, is outlined. On the basis of the knowledge gained from the study of flow and head, the study of the power that can be developed for each day in the year and during each year for which actual or comparative hy- drographs are available, is outlined. An outline of a method for the consideration of possible variations in flow during periods for which no measurements are available based on the available rain- fall records, is also given in Chaps. VI, VII and VIII. A study of the effect of pondage on power, a most important matter, though not always carefully considered, or appreciated, is also discussed in considerable detail in Chaps. IV, V and XXVI. In the selection of turbines for a water power project, the current practice has been for the engineer, while drawing certain conclu- sions from the tables of manufacturers' catalogues, to present to the manufacturer the conditions under which the power is to be devel- oped and to rely largely or entirely on the manufacturer for advice Preface. vii as to machinery to be used. In such cases he is dependent for re- sults on guarantees which are usually quite indefinite in character and seldom verified by actual tests, under working conditions, be- fore the wheels are accepted and paid for. This has resulted in many cases in the installation of wheels which are entirely unsuited to the particular conditions under which they are installed. Practical turbine analysis has not been treated except in the most general way in any publications except the various German treatises on the turbine in which the subject is discussed from the basis of turbine design. The author has developed the method of turbine analysis and selection, outlined in Chapters XIV and XVI, which applies to all wheels when tests of wheels of the series or class considered are available. These methods are based on the practical operating conditions of actual tests and are both theoreti- cally and practically correct. The engineer should be able to intel- ligently select the turbines needed for the particular conditions of his installation and to determine, with a considerable degree of accuracy, the results on which he can depend during all conditions of head and flow. It is believed that this treatment of the subject is sufficiently complete to place the selection of turbines on a better footing and that, when adopted, it will lead to the selection of better and more improved designs and assure more satisfactory results. The subject of turbine governing has, for electrical reasons, be- come an important one. While a number of important papers have appeared on this subject, there is, so far as the author knows, no discussion in English which offers the engineer a basis for a com- plete consideration of this subject. Chap. XVIII, on the principles of turbine governing together with appendixes A, B and C, offer, it is believed, suggestions for the consideration of this subject which may prove of value to water power engineers. The report on a water power project should involve a careful and complete investigation of the entire subject, and should be based on the broadest considerations of the project in all its rela- tions. Many reports which have come to the author's attention have been too limited in scope and have included only general opin- ions which have not, to his mind, been sufficiently specific or based on sufficient information to warrant approval without extended in- vestigations. In Chap. XXVIII the author has outlined his idea viii Preface. of the extent and scope of such investigation and report, which he believes is essential for an intelligent investigation and a reliable opinion on this subject. ACKNOWLEDGMENTS. There can be little which is strictly new or original in any technical work, and in offering this book to the profession, the author wishes to acknowledge his indebtedness to the large number of technical ar- ticles that have already appeared on various phases of the subject. Many references to such literature have been given at the end of the various chapters. Many illustrations have been taken, with more or less change from Engineering News, Engineering Record, Cassier's Magazine and Electrical World and Engineer. Various manufacturers have furnished photographs and, in some cases, cuts of their wheels, gov- ernors and apparatus, in connection with which their names appear. The author has been greatly aided by his assistants, both of his own private office and of the University staff. He wishes especially to acknowledge the assistance of Mr. L. F. Harza to whom Chap. XVIII on The Speed Regulation of Turbine Water Wheels and appendixes A, B and C are largely due. Mr. Harza has also been of much assistance in the editorial work of publication. Es- pecial acknowledgment is also due to Professor G. J. Davis, Jr., for the preparation of the diagrams of friction of water in pipes and of Bazin's and Kutter's coefficients, etc. Mr. Robert Ewald assisted in the selection of material for illustrations, in the investigation of German literature, and the preparation of various graphical diagrams, including the first development of the characteristic curve. The author also desires to acknowledge his indebtedness to his principal assistant, Mr. C. V. Seastone, for advice and assistance in the arrangement of many of the chapters in this work and assist- ance in the editorial work of publication. The sources of various other tables, illustrations, etc., are ac- knowledged in their proper places. D. W. M. Madison, Oct. i, 1908. CONTENTS CHAPTER I. INTRODUCTION. The History of Water Power Development Every Development of Water Power The Earliest Type of Water Wheel The Undershot Wheel The Overshot and Breast Water Wheel The Development of the Turbine Fundamental Ideas of the Turbine The Modern Turbine. The American or Francis Turbine Modern Changes in Turbine Practice Historical Notes on Water Power Development Development of Water Power in the United States Literature 1 CHAPTER II. POWEB. The Development of Potential Energy Definition of Energy Solar Energy the Ultimate Source No Waste of Energy in Nature Laws of Energy Conservation Efficiency Natural Limit to Efficiency < Practical Limits to Efficiency Efficiency of a Combined Plant Capacity of Each Part of a System not Identical The Analysis of Losses The Losses in a Hydro-Electric Plant Units of Energy- Conversion of Energy Units Kinetic Energy Uniform Motion Uniform Varied Motion Compound Motion, Graphical Representa- tion of the Laws of Motion Transformation Literature 19 CHAPTER III. HYDRAULICS. IBasis of Hydraulics Mathematical Expression for Energy Velocity Head. Entrance Head Submerged Orifices Friction Head Kut- ter's Formula Bazin's Formula Efficiency of Section Determina- tion of Canal Cross-Section The Back Water Curve Flow of Water in Pipes The Flow of Water Through Orifices Flow over Weirs Literature 40 CHAPTER IV. WATER POWEK. The Study of the Power of a Stream as Affected by FlowSource of Water Power Factors of Stream Flow Broad Knowledge of Contents. Stream Flow Necessary The Hydrograph The Use of Local Hydrographs Use of Comparative Hydrographs Reliability of Comparative Hydrographs When no Hydrographs are Available The Hydrograph as a Power Curve 79 CHAPTER V. WATER POWER (Continued) The Study of the Power of a Stream as Affected by Head Variations in Head The Rating or Discharge Curve The Tail Water Curve The Head Water Curve Graphic Representation of Head Effects of Design of Dam on Head Effect of Head on the Power of the Plant Graphical Representation of the Relations of Power, Head and Flow Graphical Study of Power at Kilbourn Power of the Kilbourn Wheels Under Variations in Flow Effects of Low Water Flow Effects of Number of Wheels on Head and Power. . . 93 CHAPTER VI. RAINFALL. Importance of Rainfall Study Distribution of Rainfall The Rainfall Must be Studied in Detail Local Variation in Annual Rainfall. Local Variations in Periodical Distribution of Annual Rainfall Accuracy of Rainfall Maps and Records Rainfall and Altitude Value of Extended Rainfall Records Accuracy in Rainfall, Obser- vation, District Rainfall Study of Rainfall as Affecting Run-off Literature.. Ill CHAPTER VII. THE DISPOSAL OF THE RAINFALL. Factors of Disposal The Rate or Intensity of Rainfall Condition of Receiving Surfaces and Geological Strata Effects of Wind Effects of Vegetation Percolation Evaporation Evaporation Relations Practical Consideration of Losses Literature 133: CHAPTER VIII. RUN-OFF. Run-off Influence of Various Factors Relations of Annual Rainfall and Run-off of W r ater Year Relation of Periodic Rainfall to Run- off Monthly Relation of Rainfall and Run-off Maximum Stream Flow Estimate of Stream Flow 146 Contents. A.1 CHAPTER IX. RUN-OFF (Continued) Relation of Run-off to Topographical Conditions Effects of Geological Condition on the Run-off The Influence of Storage on the Distri- bution of Run-offEffects of Area on the Run-off The Study of a Stream from Its Hydrographs Comparative Runoff and Compara- tive Hydrographs Comparative Hydrographs from Different Hydrological Divisions of the United States, Literature. . 175 CHAPTER X. STREAM FLOW. Flow in Open Channels Changes in Value of Factors with Changes in Flow Effects of Variable Flow on the Hydraulic Gradient- Effects of a Rising or a Falling Stream on Gradient Effects of Channel Condition on Gradient Effect of Change in Grade and of Obstructions Relation of Gauge Heights to Flow Variations in Velocity in the Cross-Section of a Stream Effects of Ice-Covering on the Distribution of Velocities CHAPTER XI. THE MEASUREMENT OF STREAM FLOW. Necessity for Stream Flow Measurements Methods for the Estimate or Determination of Flow in Open Channels Estimates from Cross-Section and Slope Weir Measurement Measurement of Flow by the Determination of Velocity The Use of the Current Meter Current Meter Observatons and Computation- Float Measurements The Application of Stream Gaugings Literature. 218 CHAPTER XII. WATER WHEELS. Classification of Water Wheels Gravity Wheels Reaction Wheels Impulse Wheels Use of Water Wheels Classification of Tur- bines Conditions of Operation Relative Advantage of Reaction and Impulse Turbines Relative Turbine Efficiencies Turbine De- velopment in the United States The American Fourneyron Tur- bine The American Jonval Turbine The American Type of Re- action Turbine The Double Leffel Turbine Other American Wheels Early Development of Impulse Wheels American Im- pulse Wheels Turbine Development in Europe 237 xii Contents. CHAPTER XIII. TURBINE DETAILS AND APPURTENANCES. The Runner Its Material and Manufacture Diameter of the Run- ner The Details of the Runner Vertical Turbine Bearings, Hori- zontal Turbine Bearings Thrust Bearing in Snoqualmie Falls Turbine The Chute Case Turbine Gates The Draft Tube 284 CHAPTER XIV. HYDRAULICS OF THE TURBINE, Practical Hydraulics of the Turbine Nomenclature Used in Chapter First Principles impulse and Reaction The impulse Wheel Effect of Angle of Discharge on Efficiency Reaction Wheel Graphical Relation of Energy and Velocity in Reaction Turbine- Turbine Relations Relation of Turbine Speed to Diameter and Head Graphical Expression of Speed Relations Relations of q> and Efficiency Discharge of Turbine at Fixed Gate Opening, Power of a Turbine The Relation of Discharge to the Diameter of a Turbine The Relation of Power to the Diameter of a Turbine Relation of Speed to Discharge of Turbines, Relations of Speed to Power of Turbines Value of Turbine Constants Literature.... 309 CHAPTER XV. TURBINE TESTING. The Importance of Testing Machinery The Testing of Water Wheels Smeaton's Experiments The Early Testing of Turbine Water Wheels The Testing of Turbines by James Emerson The Holyoke Testing Flume The Value of Tests Purpose of Turbine Testing Factors that Influence the Results of a Test Measurement of Dis- charge Measurement of Head Measurement of Speed of Rota- tion Measurement of Power Efficiency Illustration of Methods and Apparatus for Testing Water Wheels Tests of Wheels in Place Literature 355 CHAPTER XVI. THE SELECTION OF THE TURBINE. Effect of Condtions of Operation Basis for the Selection of the Tur- bine Selection of the Turbine for Uniform Head and Power The Selection of a Turbine for a Given Speed and Power to Work under a Given Fixed Head To Estimate the Operating Results of a Tur- bine under one Head from Test Results Secured at Another Head To Estimate the Operating Results of a Turbine of one Diameter from Test Results of Another Diameter of the Same Series To Estimate the Operating Results of a Turbine under Variable Contents. xiii Heads from a Test Made under a Fixed Head A More Exact Graphical Method for Calculation- The Construction of the Char- acteristic Curves of a Turbine The Consideration of the Turbine from its Characteristic Curve Other Characteristic Curves Graphical Analysis as Proposed by Mr. W A. Waters 384 CHAPTER XVII. THE LOAD CURVE AND LOAD FACTORS, AND THEIR INFLUENCE ON THE DESIGN OF THE POWER PLANT. Variation in Load Load Curves of Light and Power Plants. Factory Load Curves Load Curve of London Hydraulic Supply Company Railway Load Curves Load Conditions for Maximum Returns. The Load Curve in Relation to Machine Selection Influence of Manage- ment on Load Curve Relation of Load Curve to Stream Flow and Auxiliary Power Literature 420 CHAPTER XVIII. THE SPEED REGULATION OF TURBINE WATER WHEELS. The Relation of Resistance and Speed Self-Regulation in a Plant with Variable Speed and Resistance The Relations Necessary for Con- stant Speed The Ideal Governor Present Status Value of Uni- form Speed The Problem Energy Required to Change the Pen- stock Velocity Hunting or Racing Nomenclature Shock of Water Hammer Due to Sudden Changes in Velocity Permissible Rates of Gate Movement Regulation of Impulse Wheels Influences Opposing Speed Regulation, Change of Penstock Velocity Effect of Slow Acceleration on Water Supplied to Wheel Value of Racing or Gate Over-Run Energy Required to Change the Penstock Velo- city Effect of Sensitiveness and Rapidity of Governor The Fly- Wheel The Stand-Pipe The Air Chamber Predetermination of Speed Regulation for Wheel set in open Penstocks Predetermina- tion of Speed Regulation, Plant with Closed Penstock, Predeter- mination of Speed Regulation, Plant with Standpipe Application of Method, Closed Penstock Application of Method, Open Penstock Application of Method, Plant with Standpipe Literature 440 CHAPTER XIX. THE WATER WHEEL GOVERNOR. Types of Water Wheel Governors Simple Mechanical Governors Anti- racing Mechanical Governors Details and Applications of Wood- ward Governors The Lombard-Replogle Mechanical Governors Essential Features of an Hydraulic Governor Details of Lombard Hydraulic Governor Operating Results with Lombard Governor The Sturgess Hydraulic Governor Test Results with Sturgess Gov- xiv Contents. ernor Control from Switchboard Connection of Governors to Gates Relief Valves Lombard Hydraulic Relief Valves Sturgess Relief Valves 470 CHAPTER XX. ARRANGEMENT OF THE REACTION WIIKKL. General Conditions Necessary Submergence of Reaction Wheels Ar- rangement of Vertical Shaft Turbine Arrangement of Horizontal Turbine?, Classification of Wheels Vertical Wheels and Their Con- nection Some Installations of Vertical Water Wheels Some In- stallations of Vertical Wheels in Series Some Installations of Horizontal Water Wheels Some Installations of Multiple Tandem Horizontal Wheels Unbalanced Wheels . 500 CHAPTER XXL THE SELECTION OF MACHINERY AND DESIGN OF PLANT. Plant Capacity Influence of Choice of Machinery on Total Capacity Effect of Size of Units on Cost Overload Economy in Operation Possibilities in Prime Movers Capacity of Prime Movers The In- stallation of Tandem Water Wheels Power Connection Various Methods of Connection in Use Use of Shafting The Wheel Pit Turbine Support Trash Racks 525 CHAPTER XXII. EXAMPLES OF WATER POWER PLANTS. Sterling Plant, Plant of York-Haven Water Power Company Plant of South Bend Electric Company Spier Falls Plant of the Hudson River Power Transmission Company Plant of Columbus Power Company Plant of the Dolgeville Electric Light and Power Co. Plant of the Shawinigan Water and Power Company Plant of the Concord Electric Company Plant of Winnipeg Electric Railway Co. Plant of Nevada Power, Mining, and Milling Co. Literature. . 537 CHAPTER XXIII. THE RELATION OF DAM AND POWER STATION. General Consideration Classification of Types of Development Con- Centrated Fall Examples of the Distribution of Water at Various Plants Head Races only Plants Located in Dam High Head De- velopments 561 Contents. xv CHAPTER XXIV. PRINCIPLES OF CONSTRUCTION OF DAMS. Object of Construction Dams for Water Power Purposes Height of Dam Available Head The Principles of Construction of Dams The Foundations of Dams Strength of Dams Flood Flows. Im- pervious Construction, The Stability of Masonry Dams Calcula- tions for Stability Further Considerations Types and Details of Dams Literature 579 CHAPTER XXV. APPENDAGES TO DAMS. Movable Dams Flood Gates Flash Boards Head Gates and Gate Hoists Fish ways Logways Literature 603 CHAPTER XXVI. PONDAGE AND STORAGE. Effect of Pondage on Power Effect of Limited Pondage on the Power Curve Power Hydrograph at Sterling, Illinois Effect of Pondage on other Powers Effect of Limited Storage Effect of Large Stor- age Effect of Auxiliary Power Effect of Maximum Storage Cal- culation for Storage Method of Storage Calculation Analytical Method Literature 624 CHAPTER XXVI T. COST, VALUE AND SALE OF POWER. Financial Consideration Purpose of Development Cost of Water Pow- er Depreciation Annual Cost of Developed Power Cost of Distri- bution Effect of Partial Loads on Cost of Power Cost of Auxil- iary Power or Power Generated from other than Water Power Sources Market Price of Water Power Sale of Power An Equi- table Basis for the Sale of Power Value of Improvements Intended to Effect Economy Value of a Water Power Property Literature. G46 CHAPTER XXVIII. THE INVESTIGATION OF WATER POWER PROJECTS. The Extent of the Investigation Preliminary Investigation and Re- portStudy of Run-off Study of Rainfall Study of Topographi- cal and Geological Conditions Study of Flood-flow Study of Back Water Curve Study of Head Study of Storage and Pond- ageStudy of Probable Load Curve Study of Power Development Study of Auxiliary Power Study of Site of Dam and Power Sta- tion Study of Plant Desigrv The Estimate of Cost The Report. . 675 xvi Contents. APPENDICES. A. Water Hammer B. Speed Regulation, a more Detailed Analysis than in Chapter XVIII C. The Stand-Pipe D. Test Data of Turbine Water Wheels E. Effect of an Umbrella upon Formation of Vor- tices F. Evaporation Tables G. Two New Water Wheel Governors H. Miscellaneous Tables Including: Equivalent Measures and Weights of Water Equivalent Units of Energy Velocities in Feet per Second Due to Heads from to 50 Feet Three Halves Powers of Numbers, to 100 Five Halves Powers of Numbers, to 50 Re- lation of mean Rainfall to Maximum and Minimum Discharge of Various Rivers Rainfall, Run-off and Evaporation for Storage, Growing and Replenishing Periods or 12 Streams of the United States.. ..685-75T WATER POWER ENGINEERING. CHAPTER I. INTRODUCTION. THE HISTORY OF WATER POWER DEVELOPMENT. 1. Early Development of Water Power. Most methods of power generation can be traced to an origin at no very remote period. Their development has been within historic times. The first development of water power, however, antedates history. Its origin is lost in remote antiquity. Air and water, both physical agents most essential to life, have ever been the most obvious sources of potential energy and have each been utilized for power purposes since the earliest times. Beside the Nile, the Euphrates, and the Yellow Rivers, thou- sands of years ago the primitive hydraulic engineer planned and constructed his simple forms of current wheels and utilized the energy of the river current to raise its waters and irrigate the otherwise arid wastes into fertility. Such primitive wheels were also utilized for the grinding of corn and other simple power purposes. From these simple forms and primitive applications have gradually been developed the modern water power installa- tions of to-day. 2. The Earliest Type of Water Wheel. The crude float wheel driven directly by the river current developed but a small por- tion of the energy of the passing stream. The Chinese Nora, built of bamboo with woven paddles, is still in use in the east (see Fig. i), and was probably the early form of development of this type of wheel. The type is by no means obsolete for it is yet used for minor irrigation purposes in all countries. These wheels, while inefficient, served their purpose and were exten- sively developed and widely utilized. One of the greatest de- velopments of which there is record was the float wheel installa- Introduction. Fig. 1. Chinese Nora or Float Wheel Used From Earliest Times to Present. tion used to operate the pumps at London Bridge for the first water supply system of the city of London, and constructed about 1581 (see Fig. 2). In all such wheels the paddles dip into the unconfined current which, when impeded by the wheel, heads up and passes around the sides of the wheel and thus allows only a small part of the current energy to be utilized. 3. The Undershot Wheel. The introduction of a channel con- fining the water and conducting it to a point where it could be applied directly to the undershot wheel, was an improvement that permitted the utilization of about thirty per cent, of the theo- Fig. 2. Float Wheel Operating Pumps for Water Supply of London 1581. (From Matthews' Hydraulia Lond. 1835.) The Overshot and Breast Water Wheel. 3 retical power of the water. This form of water wheel was most widely used for power development until the latter half of the eighteenth century. In the float and undershot wheels the energy of water is ex- erted through the impact due to its velocity. The heading up of the water, caused by the interference of the wheel, results also in the exertion of pressure due to the weight of the water, but this action has only a minor effect. The conditions of the application of the energy of water through its momentum is not favorable to the high efficiency of this type of wheels and the determination of this fact by Smeaton's experiments undoubt- edly was an important factor in the introduction and adoption of the overshot water wheel. Fig. 3. Breast Wheel Used From About 1780 to About 1870. 4. The Overshot and Breast Water Wheel. In the overshot water wheel the energy of water is applied directly through its weight by the action of gravity, to which application the design of the wheel is readily adapted. Such wheels when well con- structed have given efficiencies practically equal to the best modern turbine, but on account of their large size and the serious effects of back-water and ice conditions, they are unsatisfactory for modern power plants (see Fig. u). Following the work of Smeaton, the breast wheel (see Fig. 3) was developed in England largely through the work of Fairbairn and Rennie. The latter in 1784 erected a large wheel of this type to which he applied the sliding gate from which the water flowed upon the wheel instead of issuing through a sluice as formerly. About this time the fly-ball governor, which had been designed and adapted as a governor for steam engines by Watt, was applied to the governing of these wheels and by means of these governors the speed of the wheel under varying loads was Introduction. Fig. 4. Breast Wheel About 1790 Showing Early Application of Governor. (After Glynn.) kept sufficiently constant for the purpose to which they were then applied. (See Fig. 4.) Another mode of applying water to wheels under low falls was introduced by M. Poncelet. (See Fig. 5.) Various changes and improvements in the form of buckets, in their ventilation so as to permit of complete filling and prompt emptying, and in their structure, took place from time to time, and until far into the middle of the nineteenth century these forms of wheels were widely used for water power purposes. Fig. 5. Poncelet's Wheel. 5. The Development of the Turbine. The invention of any important machine or device is rarely the work of a single mind. In general such inventions are the result of years of experience of many men which may be simply correlated by some designer,. Fundamental Idea of the Turbine. 5 to whom often undue credit is given. To the man who has gathered together past experiences and embodied them in a new and useful invention and perhaps through whose energy practical applications are made of such inventions, the credit is frequently assigned for ideas which have been lying dormant, perhaps through centuries of time. Every inventor or promotor of val- uable improvements in old methods and old construction is en- titled to due credit, but the fact should nevertheless be recalled that even in the greatest inventions very few radical changes are embodied, but old ideas are utilized and rearranged and a new and frequently much more satisfactory combination results. Im- provements in old ideas are the improvements which are the most substantial. Inventions which are radically new and strictly original are apt to be faulty and of little practical value. Fig. 6. Ancient Indian Water Wheel. (After Glynn.) Containing Fun- damental Suggestion of Both Turbine and Impulse Wheels. 6. Fundamental Ideas of the Turbine. The embryo turbine may be distinguished in the ancient Indian water mill (see Fig. 6). A similar early type of vertical wheel used in Europe in the six- teenth century, the illustration of which was taken from aft an- cient print (see Sci. Am. Sup. Feb. 17, '06) is shown m Fig. 7. Barker's mill in its original form or in the form improved by M. Mathon de Cour, embodied the principal idea of the pressure 6 Introduction. turbine, and was used to a considerable extent for mill purposes, In 1845 James Whitlaw suggested an improved form which was used in both England and Germany early in the nineteenth cen- tury. (See Fig. 8.) Many elements of the modern turbine were conceived by Benjamin Tyler, who received letters patent for what he termed the "Wry Fly" wheel in 1804. The description of this wheel as contained in the patent specifications is as follows : Fig. 7. Early Vertical Wheel. Containing fundamental suggestion of the Turbine. 'The Wry Fly is a wheel which, built upon the lower end of a perpendicular shaft in a circular form, resembles that of a tub. It is made fast by the insertion of two or more short cones, which, passing through the shaft, extend to the outer side of the wheel. The outside of the wheel is made of plank, jointed and fitted to each other, dow r eled at top and bottom, and hooped by three bands of iron, so as to make it water-tight; the top must be about one-fifth part larger than the bottom in order to drive Barker's Mill. the hoops, but this proportion may be varied, or even reversed, according to the situation of place, proportion of the wheel, and quantity of water. The buckets are made of winding timber, and placed inside of the wheel, made fast by strong wooden pins drove in an oblique direction ; they are fitted to the inside of the tub or wheel, in such a manner as to form an acute angle from the wheel, the inner edge of the bucket inclining towards the water, which is poured upon the top, or upper end of it about twelve and a half degrees ; instead of their standing perpendicular with the shaft of the wheel they are placed in the form of a screw, the lower ends inclining towards the water, and against the course of the stream, after the rate of forty-five degrees ; this, however, may be likewise varied, according to the circumstances of the place, quantity of water, and size of the wheel." Elevation. Plan and Partial Section. Pig. 7. Early Vertical Wheel. Containing Fundamental Suggestion of the' T (After Glynn.) Introduction, Fig. 9. Roue A' Curves (After Glynn). From the description it will be noted that, with the exception of the chutes, the principal features of the modern turbine were here anticipated. The "Wry Fly" wheel was an improvement on the "tub" wheel which was then in use to a considerable extent in the country. These various early efforts received their first practical con- summation and modern solution through various French in- ventors early in the nineteenth century. The "Roue a dives'* (Fig. 9) and the "Roue Volant" (Fig. 10) had long been used in France, and were the subject of extensive tests by MM. Pio- bert and Tardy at Toulouse. Those various wheels received the water tangentially through an opening or spout, being practically an improvement on the old Indian mill by the addition of a rim and the modification of the form of buckets. 7. The Modern Turbine. The next improvement in the United States consisted in the addition of a spiral or scroll case to the wheel, by means of which the water was applied equally to all parts of the circumference passing inward and downward through the wheel. To the. French inventors, Koechlin, Fourneyron and Jonval, is largely due the design of the turbine in a more modern and practical form. By the middle of the nineteenth century these wheels had met with wide application in France and been The Modern Turbine, Fig. 10. Roue Volant (After Glynn). adopted and considerably improved by American and German engineers, but were scarcely known in England. (See "Power of Water," by Jos. Glynn, 1852.) The turbine was introduced into the United States about 1843 by El wood Morris, of Penn- sylvania, but was developed and brought to public attention more largely through the inventions of Uriah A. Boyden, who in 1844 designed a seventy-five horse-power turbine for use at Lowell, Mass. (See Fig. , page .) The great advantage of the tur- bine over the old style water wheel may be summarized as fol- lowvS: (See Figs, n and 12.) I^irst : Turbines occupy a much smaller space. Second: On account of their comparatively high speed they can frequently be used for power purposes without gearing and with a consequent saving in power. Third : They will work submerged. Fourth : They may be utilized under any head or fall of water. (Turbines are in use under heads as low as sixteen inches and as high a? several hundred feet.) Fifth : Their efficiency, when the wheel is properly constructed, is comparatively high. Sixth : They permit a greater variation in velocity without ma- terial change in efficiency. IO Introduction. ,0 5_ & o ? I ? a 5 I g r-4 O II * I 8 S s a 1 6 73 S tn a The Francis Turbine. ir Seventh : They are more readily protected from ice interfer- ence. 8. The American or Francis Turbine. Through the efforts of Uriah A. Boyden and James B. Francis (1849), the Fourneyron turbine became the leading wheel in New England for many years. In 1838 Samuel B. Howd of Geneva, New York, patented the '''inward flow" wheel, in, which the action of the Fourneyron tur- bine was reversed. This seems to have been the origin of the American type of turbine, and the Howd wheel was followed by a large number of variations of the same general design on which American practice has been based for many years. About ^849, James B. Francis designed an inward flow turbine of the same general type as the Howd wheel. Two of these wheels / c Fig. 13. Inward Flow Wheel by S. B. Howd (After Francis). were constructed by the Lowell Machine Shop for the Boott Cotton Mills. In the Lowell hydraulic experiments (page 61) Mr. Francis refers to the previous patent of Howd and says: "Under this patent a large number of wheels have been con- structed and a great many of them are now running in different ;i2 Introduction. parts of the country. They are known in some places as the Howd wheel, in others as the United States wheel. They have uniformly been constructed in a very simple and cheap manner in order to meet the demands of the numerous classes of millers and manufacturers who must have cheap wheels if they have any." Fig. 13 shows a plan and vertical section of the Howd wheels as constructed by the owners of the patent rights for a portion of the New England states. In this cut g indicates the wooden Fig. 14. Original Francis Turbine. guides by which the water is directed on to the buckets ; W in- dicates the wheel which is composed of buckets of cast iron fastened to the upper and lower crowns of the wheel by bolts. The upright crown is connected with the vertical shaft S by arms. The regulating gate is placed outside of the guides and is made -of wood. The upright shaft S runs on a step at the bottom (not shown in the cut). The projections on one side of the buckets, it was claimed, increased the efficiency of the wheel by diminish- ing the waste of the water. The wheel designed by Francis was on more scientific lines, of better mechanical construction (see Fig. 14) and is regarded by Modern Changes in Turbine Practice. 13 many as the origin of the American turbine. The credit of this design is freely awarded to Francis by German engineers, this type of wheel being known in Germany as the Francis Turbine. The Francis wheel was followed by other inward flow wheels of a more or less similar type. The Swain wheel was designed by A. M. Swain in 1855. The American turbine of Stout, Mills and Temple (1859), the Leffel wheel, designed by James Leffel in 1860, and the Hercules wheel, designed by John B. McCormick in 1876, are among the best known and earliest of the wheels of this class. g. Modern Changes in Turbine Practice. A radical change has taken place in later years in the design of turbines by the adop- tion of deeper, wider and fewer buckets which has resulted in a great increase of power as shown by the following table from a paper by Samuel Webber (Transactions of Am. Soc. M. E. Vol. XVII) : TABLE I. Showing Size, Capacity and Power of Various Turbines Under a 26-foot Head. Inches Diameter. Cubic Feet ' Water per Second. Horse Power. Boyden-Fourneyron 36 22.95 55 Ripdon 36 35.45 89 Risdon "L C." 36 48.27 121 Risdon "L 1) " 36 80. 199 Leffel, Standard 36 40.45 96 Leffel, Special 35 60. 148 Tyler 36 40.7 95.8 Swain 36 58.2 140 Hunt "Swain bucket" 36 48.8 121 Hunt New Style 36 98. 239.74 Leffel "Samson" 3,5 109.1 264 "Hercules" 36 107.6 253.5 "Victor" 25 108.8 266 New Swain 36 89.5 215 By 1870 the turbine had largely superseded the water wheel for manufacturing purposes at the principal water power plants in this country. The old time water wheel has since become of comparatively small importance, but it is still used in many iso- lated places where it is constructed by local talent, and adapted to local conditions and necessities. 14 Introduction. The current wheel is still widely used for irrigation purposes and in many instances is a useful and valuable machine. 10. Historical Notes on Water Power Development. Water mills were introduced at Rome about seventy years B. C. (see Strabo Lib. XII), and were first erected on the Tiber. Vitruvius describes their construction as similar in principle to the Egyp- tian Tympanum. To their circumference were fixed floats or paddles which when acted upon by the current of the stream drove the wheel around. Attached to this axis was another ver- tical wheel provided with cogs or teeth. A large horizontal wheel toothed to correspond with it worked on an axis, the upper head of which was attached to the mill stone. The use of such water wheels became very common in Italy and in other countries sub- ject to Roman rule. Some of the early applications of water power are of interest. In 1581 a pump operated by a float wheel was established at London Bridge to supply the city of London with water. In 1675 an elaborate pumping plant driven by water wheels was established on the Seine river near Saint Germain. For this plant a dam was constructed across the river and chutes were arranged to conduct the water to the undershot water wheels. These were twelve or more in number, each operating a pump that raised the waters of the Seine into certain reservoirs and aqueducts for distribution. The pumping of water for agricultural irrigation and drainage, domestic supplies and mine drainage, was undoubtedly the first application of water power, and still constitutes an important application of water. Fig. 15, from an article by W. F. Dupfee, published in Cassier's Magazine of March, 1899, illustrates a primitive application of the water wheel to the pumping of water from mines. The frontispiece also shows the great Laxy over- shot water wheel in the Isle of Man which is still used for mine drainage. The wheel is about seventy feet in diameter and the water is brought from the hills a considerable distance for power purposes. 11. Development of Water Power in the United States. In this country one of the first applications of water power was the old tidal mill on Mill Creek near Boston, constructed in 1631, which was followed by the extensive developments of small powers wherever settlements were made and water power was Development of Water Power. available. Often availability of water power determined the location of the early settlement. About 1725 the first power plant was established along the Niagara River. This was a water-driven saw-mill constructed Chronological Development of Water Power of the United States to 1898. Year. Fall Ft. Minimum Horse Power. Drainage Area Sq. Miles. Lowell Mass 1822 35 1 1 , 845 4 083 Nashua, N H 1823 36 1,200 516 Oohoes, N. Y 1826 104 9,450 3,490 Norwich, Conn 1828 16 700 1,240 Augusta. Me 1834 17 3,5(JO 5 907 Manchester N H 1835 52 12,000 2, 839 Hooksett N H 184L 14 1,8(0 2,791 Lawrence Mass 1845 30 11,000 4,625 A uo'usta Ga 1847 50 8,500 8,830 Holyoke, Mass .... 1848 50 14,000 8,000 Lewiston, Me 1849 50 11,900 3,200 Columbus, Ga 1850 25 10,000 14,900 Rochester, N. Y . 1856 236 8,000 2,474 St. Anthony Falls, Minn 1857 50 15,500 19,736 Niagara, N. Y. (Hy. canal) Turner's Falls Conn 1861 1866 90 35 15,000 10,000 271,000 6,000 Fox River Wis 1866 185 6,449 Birmingham Conn 1870 22 1,000 2,000 Bangor, Me ... 1876 9 1,767 7,200 Augusta, Ga. . . . 1876 50 8,500 6,830 Palmer's Falls, N Y 1882 30 1,125 2,650 Mechanicsville, N Y 1882 20 3, 636 4,476 St. Cloud, Minn 1885 14 4,500 13,250 Little Falls, Minn 1887 14 4,000 11,084 Spokane \Vash 1888 70 18,000 4,180 Howland Me 1888 22 6,000 Great Falls, Mont 1890 42 16,000 22,000 Austin Texas 1891 ne 10,000 40, 000 Sault Ste Marie Out . 1891 18 10, 000 51,600 In'olsom Cal 1891 55 6,200 Concord, N H 1894 13 5,000 2,350 Niagara, N. Y. (tunnel) O^den Utah 1894 1896 170 446 50, 000 2, U40 271,000 30 Helena Mont ' 1897 32 10,000 14,900 Minneapolis Minn ... 1897 18 6,000 19,737 Mechanicsville NY 1898 18 3,270 4,478 by the French to furnish lumber for Fort Niagara. Mr. J. T. Fanning gives the following list of the dates of establishing some of the principal water powers of the United States : The last few years have witnessed a still more rapid develop- ment. The increase in manufacturing industries and other de- i6 Introduction mands for power and energy, the increased cost of coal, and the improvement in electrical methods of generation and transmis- sion have all united to accelerate the development of water power plants. Water powers once valueless on account of their dis- tance from centers of manufacturing and population are now accessible and such powers are rapidly being developed and their energy brought into the market. Fig. 15. Early Application of Undershot Water Wheel to Mine Drainage, Date Unknown (from Cassiers Mag. March, 1899). LITERATURE. 1. Appleton's Cyclopedia of Applied Mechanics. Modern Mechanis'm, Vol. 3, pp. 891-901. Description of the development of the turbine. 2. Spon's Dictionary of Engineering. Barker's Mill, pp. 230-235. do. Float Water Wheels (including undershot wheels), pp. 1511-1524. do. Overshot Water Wheels, p. 2557. do. Poncelet's Water Wheels, p. 26GO. do. Turbine Water Wheels, pp. 3014-3022. 3. Knight's Mechanical Dictionary, Vol. 3, Water Wheels, p. 2746; Tur bines, pp. 2G5G-2G58. Literature. 17 4. Emerson, James. Hydrodynamics. Published by author. Willimansett, Mass. 1892. Describes several types of American turbines. 5. Matthews, William. Hydraulia. London, 1835. (Description of London Bridge Water Wheels, p. 28.) 6. Fairbairn, William. Machinery and Millwork. Description of undershot water wheel, pp. 145-150; description of earlier types of tur- bines, pp. 151-173. 7. Francis, James B. Lowell Hydraulic Experiments, pp. 1-70. Descrip- tion and tests of Boyden-Fourneyron Tremond Turbines; also the Boyden-Francis "Center-Vent" Turbine, in which the Flow was Radially Inward. New York, D. Van Nostrand, 1883. 8. Weisbach, P. J. Mechanics of Engineering, vol. II. Hydraulics and Hydraulic Motors 1 . Translated by A. J. DuBois. New York, J. Wiley & Sons. 9. Morin, Arthur. Experiments on Water Wheels having a Vertical Axis, Called Turbines, 1838. Translated by Ellwood Morris in Jour. Franklin Inst, 3d ser., vol. 6, 1843, pp. 234-246, 289-302, 370-377. 370-377. 10. Morris, Ellwood. Remarks on Reaction Water Wheels Used in the United States and on the Turbine of M. Fourneyron. Jour. Franklin Inst, 3d ser., Vol. 4, 1842, pp. 219-227, 289-304. 11. Morris, Ellwood. Experiments on the Useful Effect of Turbines in the United States. Jour. Franklin Inst, 3d ser., Vol. 6, 1843, pp. 377-384. 12. Whitelaw, James. Observations of Mr. Ellwood Morris's Remarks on Water Wheels. Jour. Franklin Inst, 3d ser., Vol. 8, 1844, pp. 73-80. 13. Franklin Institute. The Koechlin Turbine. Jour. Franklin Inst, 3d ser., Vol. 20, 1850, pp. 189-191. (Report of experiments made by members of the institute at the request of Emile Geyelin, who introduced the Koechlin turbine at Dupont's powder mill.) 14. Ewbank, Thos 1 . Hydraulic and Other Machines for Raising Water. New York, 1847. 15. Geyelin, Emile. Experiments on Two Hydraulic Motors, Showing the Comparative Power Between an Overshot Wheel and a Jonval Turbine made for Troy, N. Y. Jour. Franklin Inst., 3d ser., Vol. 22, 1851, pp. 418, 419. 16. Glynn, Joseph. Power of Water. London, 1850. pp. 39-97. Weales Scientific Series. 17. Webber, Samuel. Ancient and Modern Water Wheels. Eng. Mag., Vol. 1, 1891, pp. 324-331. 18. Frizell, J. P. The Old-Time Water Wheels of America. Trans. Am. Soc. C. E., Vol. 28, 1893, pp. 237-249. 19. Aldrich, H. L. Water Wheels. Description of Various Types of Ameri- can Wheels. Power, Vol. 19, No. 11, 1894. 20. Francis, James. Water Power in New England. Eng. Rec., Vol. 33, 1896, pp. 418, 419. 2 iS Introduction. 21. Geyelin, Emile. First Pair of Horizontal Turbines ever Built Working on a Common Axis. Proc. Eng. Club, Philadelphia, Vol. 12, 1895, pp. 213, 214. 22. Francis, James. Water Power in New England. Eng. Rec. Vol. 33, 1896, pp. 418, 419. 23. Webber, Samuel. Water Power, its Generation and Transmission. Trans. Am. Soc. Mech. Eng., Vol. 17, 189G, pp. 41-57. 24. Tyler, W. W. The Evolution of the American Type of Water Wheel. Jour. West. Soc. Eng., Chicago, Vol. 3, 1898, pp. 879-901. 25. Johnson, W. C. Power Development at Niagara. Jour. Asso. Eng. Soc., July, 1899, pp. 78-90. Hist, of early development of power at Niagara. 26. Christie W. W. Some Old-Time Water Wheels. Description of Various old wheels in Eastern U. S. Eng. News, Vol. 42, 1899, pp. 394-395. 27. Ruchel, E. Turbines at the World's Fair, Paris, 1900. Review of Tur- bine development in various countries. Zeitschr. d ver Deutsch, Ing. p. 657, 1900. 28. Foster, H. A. The Water Power at Holyoke. Jour. Asso. Eng. Soc., Vol. 25, 1900, pp. 67-84. 29. Thomas, R. Development of Turbine Construction. Zeitschr. d ver Deutsch. Ing. p. 409, 1901. 30. Rice, A. C. Notes on the History of Turbine Development in America. Eng. News, Vol. 48, 1902, pp. 208-209. 31. Fanning, J. T. History of the Development of American Water Powers. Rept. 22d Ann. Meeting, Am. Paper and Pulp Asso., 1898, pp. 16-24. Progress 1 in Hydraulic Power Development. Eng. Rec- ord, Vol. 47, 1903, pp. 24-25. 32. Fanning, J. T. Progress in Hydraulic Power Development. Eng. Rec- ord, Jan. 3d, 1903. 33. Sickman, A. F. The Water Power at Holyoke. Jour. N. E. W. W. Asso., Vol. 18, 1904, pp. 337-351. Historical. CHAPTER II. POWER. 12. The Development of Potential Energy. The development of natural sources of potential energy, the transformation of such energy into forms which can be utilized for power, and its trans- mission to points where it can be utilized for commercial pur- poses, constitutes a large portion of the work of the engineer. The water power engineer primarily deals with energy in the form of flowing or falling water, but his knowledge must extend much further for he encounters other forms of energy at every turn. Much of the energy available from the potential source will be lost by friction in bringing the water to and taking it from the wheel. Much is lost in hydraulic and mechanical fric- tion in the wheel ; additional losses are sustained in every trans- formation, and, if electric or other forms -of transmission are used or auxiliary power is necessary for maintaining continuous operation, the engineer will be brought in contact with energy in many other forms. 13. Definition of Energy. Energy is the active principle of nature. It is the basis of all life, all action, and all physical phenomena. It is the ability to exert force, to overcome resist- ance, to do work. All physical and chemical phenomena are but manifestations of energy transformations, and all nature would be rendered inactive and inanimate without these changes. 14. Solar Energy the Ultimate Source. A brief consideration of the various sources of potential energy makes the fact mani- fest that solar energy is the ultimate source from which all other forms are directly or indirectly derived. The variations in solar heat on the earth's surface produces atmospheric currents often of tremendous power. This form of energy may be utilized, in its more moderate form, to drive the sailing vessel and the wind- mill, and in other ways to be of service to man. The energy of fuel is directly traceable to solar action. Through present and past ages it has been the active cause of chemical and organic 2O Power change and growth. From this has resulted fuel supplies avail- able in the original form of wood, or in the altered forms, from ancient vegetation to the forms of coal, oil and gas, and from which a large portion of the energy utilized commercially is derived. A brief study of meteorological conditions shows that through the agency of solar heat, and the resulting atmospheric move- ment, a constant circulation of water is produced on and near the earth's surface. Hundreds of tons of water are daily evapor- ated from the seas, lakes, rivers and moist land surface, rise as vapor into the atmosphere, circulate with the winds, and, under favorable conditions, are dropped again upon the earth's surface in the rainfall. Those portions of the rain that fall upon the land tend to flow toward the lower places in the earth's crust, where lie the seas and oceans, and such portions of these waters as are not absorbed by the strata, evaporated from the surface or utilized in plant growth, ultimately find their way to these bodies of water to again pass through this cycle of changes which is' constantly in progress. Thus we find water always in motion, and always an active agent in nature's processes. Due to its peculiar physical properties and chemical relations, it is one of the essential requisites of life, and is also of great importance in nature's processes through the energy of which it is the vehicle. 15. No Waste of Energy in Nature. Active continuous en- ergy transformation is a most important natural phenomenon. Changes from one form to another are constantly in progress. In nature's transformations energy is always fully utilized. As the running stream plunges over the fall, the potential energy, due to its superior elevation, is transformed into the kinetic en- ergy of matter in motion, and through the shock or impact the kinetic energy is transformed into thermal energy due to a higher temperature, which again may be partially changed in form by radiation or vaporization. Thus the quantity of energy is con- tinually maintained, while its quality or conditions constantly vary. There is, and can be, no waste or loss of energy as far as nature itself is concerned. Wasted or lost energy are terms that apply only to energy as utilized in the service of man. Nature itself never seems to utilize the entire quantity of energy from one source for the development of energy of a single form, but always differentiates from one form into a number of other forms. When the engineer therefore attempts to utilize any source of Laws of Energy Conservation. 21 potential energy for a single purpose, he at once encounters this natural law of differentiation and finds it impossible to utilize more than a portion of the energy used in the manner in which he desires to utilize it. Much of this loss may be due to the form of energy available, much to the medium of transformation and transmission, and much to physical difficulties which it is im- possible to overcome. 1 6. Laws of Energy Conservation. Primarily it should be fully understood and clearly appreciated that matter and energy can neither be created nor destroyed. Both may be changed in form or they may be dissipated or lost so far as their utilization for commercial needs is concerned. But in one form or another they exist, and their total amount in universal existence is al- ways the same. In any development for the utilization, trans- formation or transmission of energy, the following fundamental axioms must be thoroughly understood and appreciated: First : That the amount of energy which can be actually utilized in any machine or system can never be greater than the amount available from the potential source. Second: That the amount of energy which can be utilized in any such system can never be greater than the difference be- tween the amount entering the system and the amount passing from the system as waste in the working medium. 17. Efficiency. Efficiency is the ratio or percentage of energy utilized to energy applied in any system, part of a system, ma- chine or in any combination of machines. The efficiency of a given machine or mechanism, or the per- centage of available energy which can be obtained from a given system of generation and transmission therefore can never be greater than represented by the equation : pi -pi i Efficiency or amount of available energy = = in which jii E equals the energy in the working medium entering the machine E' equals the energy in the working medium passing from the machine. 1 8. Natural limit to efficiency. The total energy in a working medium such as water, steam, air, etc., is the energy measured from the basis of the absolute zero for the medium which is being considered. For example, the average surface of Lake Michigan is 580 feet above sea level ; each pound of water, there- fore, at lake level contains 580 foot pounds of potential energy. This amount of energy must therefore be expended in some man- 22 . Power. ner by each pound of water passing from the lake level to the ocean level, which may be regarded as the absolute zero refer- ence plane for water power. This energy cannot be utilized at Chicago for there no fall is available. A small portion of this energy is now utilized in the power plants at the falls of Niagara. Some energy will be ultimately utilized on the Chicago Drainage Canal, where a fall of some thirty-four feet is available from the controlling works to Joliet. Perhaps ultimately in its entire course one hundred and seventy feet of fall may be utilized by the waters of the drainage canal, in which case the absolute avail- able energy of each pound of water cannot be greater than shown by the following equation : Available energy = ^^ = = .2931, or 29.31 per cent. OoU OoU With any other form of energy the same conditions also pre- vail. Consider a pound of air at 760 degrees absolute tempera- ture Fahr., and at 75 pounds absolute pressure. The number of heat units contained will be given by the equation : Heat units temperature X weight X specific heat. B. T. U. = 760 degrees X 1 X .169 = 128. To utilize all of the energy in this air, it would be necessary to expand it down to a temperature of absolute zero and exhaust it against zero pressure. In any machine for utilizing com- pressed air, it will be necessary to exhaust it against atmospheric pressure. This will expand the air 3.10 times, and if expanded adiabatically it will have a final temperature of 474 degrees. The heat units in the exhaust will therefore be as follows : B. T. U. = 474 degrees X 1 X .169 = 80, and the available energy will be as follows : 1 OO QA AQ Available energy = ^ - = -^- = .375, or 37.5 per cent. IZo iZo In this case also the temperatures vary directly as the heat units, and are therefore a measure of available energy: ygQ 474 Available energy = = .375 or 37.5 per cent. In the ideally perfect furnace the efficiency is somewhat higher. The fuel may be consumed at a temperature of about 4,000 Fahr. absolute, and the gas may be cooled before escaping to about 600 Fahr. In this case the possible efficiency or available energy is : Practical Limits to Efficiency. 23 4QOO _ QQQ Available energy = -- -- - = .832 or 83.2 per cent. The above examples show, therefore, the limits which nature itself places on the proportion of energy which it is theoretically possible to utilize. For such losses the engineer is not account- able except for the selection of the best methods for utilizing such energy. The problem for his solution is, what amount of this available energy can be utilized by efficient machines and scientific methods. 19. Practical Limits to Efficiency. The preceding equations are the equations of ideally perfect machines. Of this available energy only a portion can be made actually available. In practice we are met with losses at every turn. Some energy will be lost in friction, as radiated heat, some in the slip by pistons, or as leakage from defective joints. In many other ways the energy applied may be dissipated and lost. From this it follows : The amount of energy 'which can be utilized can never be greater than the difference between the amount supplied to any given machine or mechanism, and the amount lost or consumed in such machines by friction, radiation or in other ways. Hence it follows that the efficiency of a given machine, or the percent- age of energy available, or which can be obtained from the ma- chine, can never be greater than the following: E CE ; +E" + E"' +E""etc.) . Efficiency - - - ^ -- ! - - in which E = total energy available E' E" E"' etc. the energy lost in friction and in various other ways, in the machine or system, and rejected in the exhaust from the same. Every transmission or transformation of energy entails a loss, hence, starting with a given quantity of energy, it gradually dis- appears by the various losses involved in the mechanism or ma- chines used. Other things being equal, the simpler the trans- mission or transformation, the greater the quantity of the orig- inal amount of energy that can be utilized. The term efficiency as here applied represents always the ratio between the energy obtainable from the mechanism or machine and the actual energy applied to it. Therefore the efficiency of a pumping engine is the ratio be- tween the energy of the water leaving the pump and the energy of the steam applied to the engine. 2 4 Power. The efficiency of a hydro-electric plant is the ratio between the energy in the electric current delivered at the switch board and the energy in the water entering the water wheel. The efficiency of the dynamo in the same plant is the ratio be- tween the energy furnished by the dynamo and the energy ap- plied to it. If a shaft receives from an engine 100 horse power and de- livers 90, ten horse power being lost in friction, etc., the efficiency of the shaft transmission is 90 per cent. If a steam engine receives 1,000,000 heat units from the steam it uses, and is able to deliver only the equivalent of 10,000 heat units ; i. e., 7,780,000 foot pounds of work, the efficiency of the engine is only one per cent. 20. Efficiency of a Combined Plant. In any plant or connected arrangement of mechanisms and machines for the transforma- tion or transmission of energy the efficiency of the plant is the' product of the efficiency of each of its. parts. Hence, to estimate total efficiencies, the efficiency of each part may be estimated, and the combined efficiency then obtained. From the. same calculation, the necessary relations between the input and the output of energy can be obtained. Thus, if a boiler has an efficiency of 50 per cent., and an engine has an efficiency of 10 per cent, the combined efficiency will be .5oX.io =.05 or five per cent. In the following examples the loss and efficiency of the unit and the combined efficiency of the various units in the system are shown. FIRST EXAMPLE. Example of Energy Loss in Well-Designed Steam Power Plant. Per Cent Lost. Per Cent Efficiency Net Effi- ciency from Potential Source. 20 80 80 Boiler . . 15 85 68 Steam Pipe 5 ,95 64.5 Engine 94 6 3.87 Belt 5 95 3 . 67 Shafting, Belts and Counter Shafts 40 60 2.2 Lathes or other Machine Tools 50 50 1.1 Percentage of original energy utilized in useful work 1 1 Efficiency of a Combined Plant. 25 SECOND EXAMPLE. Example of Energy Loss in Hydraulic Plant for Electric Lighting. Per Cent Lost. Per Cent Efficiency .Net Effi- ciency from Potential Source. Head and Tail Races 5 95 95 Turbine 20 80 76 Gearing 15 85 64 6 Shaft 5 95 60 37 Belt 5 95 57 35 8 92 52 76 10 90 47 48 Transformer 20 80 37 98 Lamp 80 20 7 60 Percentage of original energy utilized in useful work 7 60 THIRD EXAMPLE. Example of Energy Lost in Steam and Electric Pumping Plant. Per Cent Lost. Per Cent Efficiency Net Effi- ciency from Potential Source. 30 70 70 Steam Pipe 5 95 66.6 90 10 6.65 Belt 5 95 6.32 Generator 20 80 5.05 Line 10 90 4.55 Motor 10 90 4'. 09 25 75 3.06 Suction and Discharge Pipe 20 80 2.45 Percentage of original energy utilized in 2.45 21. Capacity of Each Part of a System Not Identical. In each of . the transmission systems outlined above a much larger amount of energy enters the first unit of the system than is de- livered by the last. Each unit in the system receives a decreas- ing amount of energy. In consequence, the first units in the system must be of greater proportional capacity, and in practice each unit must be selected of a size or capacity suited for its position in the system. Thus in the first example, for each 100 units of energy received by the furnace, the engine receives but 64.5, and the shafting but 4. 26 Power. 22. The Analysis of Losses. In estimating power losses the loss in each step from the generation to the utilization of the power should be carefully examined. Four steps may ordinarily be considered in any system : 1. Generation of power from potential source. 2. Conversion of power into form for transmission. 3. Transmission of power. 4. Utilization of power. An analysis of the first three items is shown in Table II. In Table III is shown the ordinary maximum and minimum ef- ficiencies obtained from various motors and machines in prac- tical work. Higher efficiencies are sometimes obtained under test conditions where great attention is given to secure favorable conditions, and, in many places where careless work is permitted, neglect and unsatisfactory conditions will result in much lower efficiencies than the minimum shown. 23. The Losses in a Hydro-electric Plant. To emphasize and point out in greater detail the various losses encountered in the generation and transmission of energy, especially as applied to hydro-electric plants, attention is called to Fig. 16. In this diagram is traced the losses from the potential energy of the water in the head race of the power plant to the power avail- able at the point where it is used. In each case considered it is assumed that 1,000 horse-power of energy is applied to the par- ticular work considered. First, consider the transmission of power for traction pur- poses. If a certain head is available when no water is flowing in the raceways, that head becomes reduced at once when the wheels begin to operate. A certain amount of head is also lost in order to overcome the friction of flow through raceways, racks and gateways. In the problem here considered it is assumed that the above losses are five per cent, of the total energy avail- able in the head-race, and that this loss occurs before the water reaches the turbines: hence, 95 per cent, of the potential energy is available at the turbine. The turbine loss is here assumed to be about 20 per cent. First-class turbines under three-quarter to full load conditions, will commonly give 80 per cent, efficiency, or a little better. Professor Unwin, in his "Development and Transmission of Power," page 104, gives the following percentage of loss in tur- bines: The Losses in a Hydro-Electric Plant. 27 Shafting, friction and leakage 3 to 5 per cent. Unutilized energy 3 to 7 per cent. Friction in shaft, guides and passages ' 10 to 15 per cent. Total loss of energy 16 to 27 per cent. TABLE II. Method of Generation. Losses. ( r Internal Combustion Engine ^ Gas Oil Engine losses. Fuel (Direct (Vacuum Pump) ( Furnace. Steam j \ Boiler. Fn ( Indirect ( Piping. f Direct (Ram) Ram losses. S g j Water ! g<2 Power.. 1 indirect (Wheels) a f Electric (Primary Batteries) . . . [ Various mechani- Minor j Wind (Mills) I cal and other O Sources . j Waves (Motors) ] losses due to [ Sun Heat (Solar Engines) [ method used. g f Internal Combustion Engine Included in engine losses. rv, * rM Q g| Steam Engine' and con- g g nection losses. Electrical Dynamos and wire i H losses. ^ rv* x g Hydraulic Pump losses. I Pneumatic Compressor losses . , f Di rect connected, Shaft f Mechan- j Cables, Ropes, Chains ) Various losses due ical Electric ] to method used. ^ [Combination I o I f Entrance head. j Pipe friction. g Hydraulic *j Motor losses. ^ L Connections. H . fTranformer losses, j Wire losses. g Electrical 1 Motor losses. [Connections. [Pipe friction. J Air cooling. Pneumatic "j Motor losses. I 1 Connections. Power. The Losses in a Hydro-electric Plant. 29. The next loss shown on the diagram is the loss in transmitting the energy through the bevel gear and the shafting to the gen- erator. The loss in gearing, shafting, etc., is shown as 10 per cent., which is probably much less than actually takes place in- most plants of this kind, but may be considered as representing the results of good practice. The loss in the transformation of power in the generator is- given as 8 per cent. The generator is an alternator, and the cur- rent generated would be at about 2,300 volts. This current must be raised to a higher voltage, by means of transformers, for long distance transmission. These transformers would give an efficiency of about 96 per cent. The line loss is dependent on the size of the copper used, but would probably not exceed 10 per cent. At the distributing point, where the energy is to be used,, the high voltage current must be transformed again into suit- able voltage for distribution. The same energy loss is estimated for these transformers. If the current is to be used for traction purposes, it will be necessary to convert it into direct current by means of a rotary converter, the efficiency of which is esti- mated at 92 per cent. The voltage from the general distribution system would probably be too high for direct use in the rotary converter, and would have to be transformed to a lower voltage before passing into the converter. A loss of about 6 per cent., therefore, should be allowed for this transformation. The current from the rotary converter is subject to a line loss- which may be again assumed at 10 per cent. The loss in the car motor may be estimated at 7 per cent. The percentage of loss and the percentage of efficiency for each unit in this generation and transmission system is based, of course, on the actual energy supplied and the unit next previous to it in the system, so that the percentages mentioned are not based on the total potential power available in the head-race but on the power actually reach- ing the machine. In the solution of any actual problems of this character it is necessary to determine the efficiencies of the various units of the plant under the condition of actual service. The efficiency will be found to vary under various conditions of load. It may therefore be desirable to determine the probable losses under various working conditions. In the selection of the various machines which are to form a. part -of such a system of transmission, the choice should be Power. based on an effort to establish a plant which will give the maxi- mum economy when all conditions of loading are considered. The losses in the transmission of power for traction purposes, as shown on the diagram, may be traced through in tabular form as follows : TOTAL ENERGY AVAILABLE. 1,000 HORSE POWER. Per Cent Loss. Per Cent Efficiency. Loss in horsepower 5 20 10 8 4 10 4 6 8 10 7 . 95 80 90 92 96 90 96 94 92 90 93 50 190 76 54.7 25.2 60.4 21. 7 31.3 39.3. 45.1 28.4 Shaft and 2T69.ri.nsr . Generator Transformers Transmission line Step-down Transformers Secondary Transformers -Rotary Converters Line .... . . . Traction Motor - Power utilized for operating the cars, or 37 per cent of the original energy 374.5 Horse Power. In the generation and transmission of power for lighting pur- poses, the losses will be similar to those above mentioned, up to and including the step-down transformers at the point of dis- tribution. In this case, however, no secondary transformers or rotary converters would be necessary. The only loss between the step-down transformers and the light will be the line loss assumed at 5 per cent. The loss in the individual transformer for the light will be about 8 per cent., leaving the available en- ergy for actual use in the lamp at about 456.2 horse power, or a little less than 46 per cent., of the total energy in the head-race. In the case of the utilization of this energy for manufacturing purposes, the loss would be the same up to and including the step-down transformers at the point of distribution. The line loss in the distribution from the transformer house to the manu- facturing establishment may be assumed at 5 per cent. The motor, if properly selected, may be run at the line voltage, and no transformer losses need be considered. The motor efficiency is here shown at 92 per cent., although in most cases the per- centage of efficiency would be considerably less. The belt loss in transmitting the power from the motor to the line shafting is estimated at 5 per cent. Efficiency of Generators and Motors. TABLE III. Ordinary Efficiency of Generators and Motors. CLASS OF MACHINERY. EFFICIENCY PER CENT AT FULL LOAD. Maxi- mum. Mini- mum. Water Wheels f Overshot Wheels 75 05 40 85 85 75 95 18 15 12 12 12 9 9 7 7 ' 20 30 12 9 6 4.5 3 50 70 92 90 85 95 95 97 95 99 95 85 75 97 98 95 65 60 25 60 75 50 75 15 12 10 10 10 7 7 6 5 16 25 10 7 5 3 2 30 60 80 80 75 50 85 90 75 95 70 50 50 92 90 85 Breast Wheels ^ Undershot Wheels Turbines (. Impulse Wheels Boilers Steam Generators. , Condensing ) Steam Engines . \ " Non-Condensing ) Steam Engines. . ) f Triple Expansion Corliss i Compound Corliss Simple Corliss ... i. Compound High Speed f Compound Corliss Simple Corliss \ Compound High Speed Simple Hi^h Speed [.Simple Slide Valve . . ( Gas or Oil Engines Steam Air Compression . . / Diesel Motor f Compound Con Corliss Simple Con Corliss { Simple Corliss High Pressure [^ Small Straight Line j Air, cold Electrical Machinery Transmitting Mechan- isms Air reheated f Dymimos ' Motor large 1 Motor small I Transformer CBelt Rope Cable j Direct connection Transmission Methods.. Shafting Gearing 1 Bevel Gearing ( Pneumatic per mile ] Hydraulic per mile ( Electric usual 32 Power. The shafting necessary for the general distribution of power through the factory is estimated at 75 per cent, efficiency. The belt loss from the shaft to the individual machine is esti- mated at an additional 5 per cent., leaving the total energy avail- able for use in the machine at 308.8 horse power, or about 31 per cent, of the original energy in the head-race. It should be noted that in each of the three transmission sys- tems mentioned above, the actual power utilized at the point of application is less than half of the energy available in the head- race. It is the function of the engineer to see that these losses are reduced to the greatest practicable extent. These losses must be limited in both directions. They must not be too great, nor too small. They must be adjusted at the point where true economy would dictate. This limit is the point where the cap- italized value of the annual power lost is equal to the capitalized cost of effecting further saving. In other words, true economy means the construction of a plant that will save all the power or energy which it is financially desirable to save, and will per- mit such waste of energy as true economy directs. 24. Units of Energy. Energy is known by many names and exists in many forms which seem more or less independent. The principal forms of energy are measured by various units. Those most commonly considered in power development and trans- mission are as follows: Work is energy applied to particular purposes. In general it is energy overcoming resistance, mechanically it is the exertion of force through space. Power is the rate of work, or the relative amount of work done in a given space of time. The unit of work is the foot pound, or the amount of worx: .required to raise one pound one foot. One pound raised one foot, one-tenth pound raised ten feet, ten pounds raised one- tenth of a foot, or any other sub-division of pounds and feet whose product will equal one requires one foot-pound of work to perform it. The unit of power is based on the unit of work, and is called "horse power." It is work performed at the rate of 550 foot pounds per second, or 33,000 foot pounds per minute. Units of Heat. The unit of heat is the amount of heat which will raise one pound of water from 39 degrees Fahr. to 40 degrees Fahr. at atmospheric pressure. It is called the British Thermal Unit, and is indicated by the initials B. T. U. Conversion of Energy Units. 33 Electric Unit. The unit of quantity of electricity is the coulomb. One coulomb per second is called an ampere, and one ampere un- der a volt pressure is equal to a watt, the unit of electric power. Water Power. Water power is the power obtained from a weight of water moving through a certain space. In water power the unit of quantity may be the gallon or the cubic foot ; the unit of head may be the foot ; and the unit of time may be the second or minute. The weight of water, unless highly mineralized, at ordi- nary temperature, varies from 62.3 to 62.5 pounds per cubic foot. As these weights vary from each other less than one-third of one per cent., the difference is insignificant in practical problems where the errors and uncertainties are often large. In the further discus- sion of this subject, therefore, the weight of 62.5 pounds is used as the most convenient in calculation. Steam Pozver. The unit of steam power in ordinary use is the pound of steam, its pressure, and rate of use. It is, however, based on the heat unit, and must be so considered for detailed examina- tion. Definite quantities of work are also designated by the "horse power hour," equivalent to 1,980,000 foot pounds, and the "kilowatt hour," equivalent to 2,654,150 foot pounds. The pound of steam may be considered as containing an aver- age of 1,000 British thermal units, which may be utilized for power. This is equivalent to 778,000 foot pounds. 25. Conversion of Energy Units, The various forms of energy as expressed by the units named are convertible one into another in certain definite ratios which have been determined by the most careful laboratory methods. In considering these ratios, however, it must be remembered that, as shown in the preceding examples, in the transformation from one form of energy into another the ratios given cannot be attained in practice on account of losses which can not be practically obviated. Such losses must be, in good practice, reduced to a minimum, and the ratios given are, therefore, the end or aim toward which good practice strives to at- tain as nearly as practicable when all conditions and facts are duly considered. Energy must be considered in two conditions as well as in the above named forms, viz. : passive and active or potential and kinetic. Potential energy is energy stored and does not necessarily in- volve the idea of work. Kinetic energy is energy in action and 8 34 .Power. involves the idea of work done or power exerted and for its meas- urement must be considered in relation to time. The most common units of potential energy and their equiva- lents are as follows : The footpound (one pound raised one foot). =1/62.5 or .016 foot cubic foot (of water). =1/8.34 or .12 foot gallon (of water). =1/2655.4 or .0003766 volt coulombs. =1/778 or .001285 British thermal units. The foot cubic foot (one cubic foot of water raised one foot) . =62.5 foot pounds. =7.48 foot gallons. =.08 British thermal units. =.02353 volt coulombs. The foot gallon (one gallon of water raised one foot) =8.34 foot pounds. =.01072 British thermal units =.00314 volt coulombs. =.1334 foot cubic feet. The volt coulomb =2655.4 foot pounds. =42.486 foot cubic feet. =318.39 foot gallons. =3.414 British thermal units. The British thermal unit =778 foot pounds. =12.448 foot cubic feet. =93.28 foot gallons. =.2929 volt coulombs. Quantities of energy available, used or to be used, and either potential or kinetic may be measured in the above units. When the rate of expenditure is also stated these units express units of power. Some of the equivalent values of power are as fol- lows, those most commonly used being printed in black-face type: The horse power =1980000 foot pounds per hour. =33000 foot pounds per minute. =550 foot pounds per second. =31680 foot cubic feet per hour. =528 foot cubic feet per minute. Conversion of Energy Units. 35 =8.8 foot cubic feet per second. =237600 foot gallons per hour. =3960 foot gallons per minute. =66 foot gallons per second. =746 watts. =2545 British thermal units per hour. =42.41 British thermal units per minute. ^=.707 British thermal units per second. The foot pound per minute =1/33000 or .0000303 horse power. =1/778 or .00129 British thermal units per minute. =.0226 watts. =i/8.34=.i2 foot gallons per minute. =i/62.5=.oi6 foot cubic feet per second. The foot cubic foot per minute =62.5 foot Ibs. per minute. =i/528=.ooi89 horse power. =1.412 watts. =7.48 foot gallons per minute. =.0803 British thermal units per minute. The foot cubic foot per second =375 f ot ft> s - P er minute. =62.5 foot Ibs. per second. =i/8.8=. 1 1 36 horse power. =448.8 foot gallons per minute. =7.48 foot gallons per second. =4.820 British thermal units per minute. =.0803 British thermal units per second. The watt =44.24 ft. Ibs. per minute/ =.00134 horse power. =.0568 British thermal units per minute. =5.308 gallons feet per minute. =.7089 ft. cu. ft. per minute. The British thermal units~pef" rrrrirute =778 ft. Ibs. per minute. =.02357 horse power. =17.58 watts. =93.28 ft. gal. per minute. =12.48 ft. cu. ft. per minute. 36 Power. 26. Motion in General. In moving a body against a given force or resistance the work done in foot pounds is the product of the space passed through (in feet) and the resistance (in pounds). Thus in raising a ten-pound weight 100 feet high, 1,000 foot-pounds of work is performed. But this is not the only work performed. To pro- duce motion in a body or to bring a body to a state of rest neces- sitates a transfer of energy. For all moving bodies are endowed with kinetic energy the energy of motion and this energy must be given to them to produce motion, and must be taken from them to produce a state of rest. Hence, Newton's laws of motion: 1. "Every body continues in a state of rest, or of uniform mo- tion in a straight line except in so far as it may be com- pelled by impressed forces to change that state." 2. "Change of motion is proportional to the impressed" force and takes place in the direction of the straight line in which the force acts." 3. "To every action there is always an equal and contrary reac- tion." The acceleration of gravity is the acceleration due to the weight of a body acting on its mass. The weight of a body W (on account of centrifugal effect of the earth's revolution) varies, being least at the equator and greatest at the poles. From Newton's second law it follows that the accel- eration in motion designated by g and caused by the weight of any body acting on its mass will be proportional to its weight, i. e., g^= constant X W, and hence the weight of a body divided by the ac- celeration will always be constant. This constant quotent desig- nated by the letter M is termed the mass of the body. (:)M=|- LetW=The weight of a body. g=Acceleration due to gravity=velocity of a falling body at end of first second, and is ordinarily taken as 32.2 ft. per sec. per sec. A=Acceleration of moving body=velocity of body at end of first second. W'=Weight acting. W"=Weight acted on. Kinetic Energy. 37 V= Velocity at end of time t. V a Average velocity. t=Time force has acted. S=Space passed through. h=Height passed through by falling body. V'=Initial velocity. S'=Initial space passed through. 27. Uniform Motion. In uniform motion the moving body passes through equal spaces in any equal divisions of time. Hence by definition : The space passed through (S) equals the product of the velocity (V) and the time (t). (2) S=Vt. (3) VA 28. Uniformly Varied Motion. If the velocity of a body is in- creased or diminished uniformly, the motion is termed uniformly varied motion and is termed uniformly accelerated motion in the first case and uniformly retarded motion in the latter case. In all such cases the following relations hold: ' (5) V=At=g t. (6) V a =Al (8) V=VTA~S. ith falling bodies : S=h, A=g. From which equation (8) becomes (9) V=V 2 gh, tne we ^ known basis of hydraulic calcu- lations. (10) Worfc=W h=W VV2ff=M V/2. 29. Compound Motion. When bodies are already in motion and additional force is applied, the following relations hold : (i i) V=V'+At. (12) S= Power. 30. Graphical Representation of the Laws of Motion. In each case The vertical ordinates represent velocity Abscissas represent time. Areas represent space passed through. TIME UNIFORM MOTION UNIFORM ACCELERATED MOTION V = constant S = Vt V = At = gt v f At 2 V sV t:= T : 2A V = T/2AS" V = V + At S- S' + V t COMPOUND MOTION - WITH INITIAL. ACCELERATED. VELOCITY Fig. 17. Graphical Representation of the Laws of Motive. 31. Transformation. The transformation of potential to kinetic energy is well illustrated by water acting upon a water wheel. The energy in a body is always constant whatever its form, except' as said energy be given up to other bodies or lost and wasted in vari- ous ways. Consequently the sum of the potential and kinetic en- ergies in any body is a constant quantity unless the difference be accounted for by energy loss or transfer as above noted. Water that has fallen to sea level has lost all the energy it may have once possessed, its energy having been expended in perform- ing some kind of work. If, in a hydraulic plant, we have an available fall of 8.8 ft. every cubic foot of water passing through this distance each second pro- duced 33,000 ft. Ibs. of work, or one horse power. After the water has passed through a well-designed turbine it flows sluggishly away, having used up nearly all its energy in the turbine to which Literature. 39 it has transferred its energy. If, however, on account of bad de- sign the water flows away at a rapid rate, say at 10 feet per second, the head lost, h=v 2 /2g i. e. h=io 2 /6"44=i.55 ft. of vertical fall. Under these conditions the energy due to this fall still remains in the water, after it has left the wheel, and is lost, the loss being 17.8 per cent, of the original energy. LITERATURE. 1. Thurston, Robert H. Conversion Tables of Weights and Measures. New York. J. Wiley & Sons. 1883. 2. Oldberg, Oscar. A Manual of Weights and Measures. Chicago. C. J. Johnson. 1887. 3. Everett, J. D. Illustrations of the C. G. S. System of Units. New York. MacMillan & Co. 1891. 4. Anderson, William. On the Conversion of Heat into Work. Discussion of energy conversion. London. Whittaker & Co. 1893. 5. Unwin, W. C. On the Development and Transmission of Power. Long- man & Co. London. 1894. G. Oswald, Wilhelm. Manual of Physics, Chemical Measurements. New York. The MacMillan Co. 1894. 7. Peabody, Cecil H. Tables of the Properties of Saturated Steam. New York. J. Wiley & Sons. 1895. 8. Richards, Frank. Compressed Air. New York. J. Wiley & Sons. 1895. 9. Bolton, Reginald. Motive Powers and Their Practical Selection. New York. Longmans, Green & Co. 1895. LO. Holman, Silas W. Matter, Energy, Force and Work. New York. The MacMillan Co. 1898. 11. Kent, Wm. Notes of the Definition of Some Mechanical Units. Am. Asso. Adv. of Sci. 1898. See also Eng. News, Vol. 40, p. 348. 12. Mead, Daniel W. Commercial Transformation of Energy. Trans. 111. Soc. Eng. 14th report, 1899. 13. Reeve, Sidney A. The Steam Table. New York. The MacMillan Co. 1903. 14. Kohlrausch, F. An Introduction to Physical Measurements. New York. D. Appleton & Co. 1903. 15. Carpenter, R. C. Experimental Engineering. New York. John Wiley & Sons. 1903. 16. Herwig, Carl. Conversion Factors. New York. J. Wiley & Sons. 19u4. 17. Smithsonian Institution. Physical Tables. 3d Edition. 1904. 18. American Institute of Electrical Engineering. Report of Committee en Standardization. 1907. Proc. Am. Inst. E. E. Vol. 26, pp. 1076- HOG. CHAPTER III. HYDRAULICS. 32. Basis of Hydraulics. The science of hydraulics is an empir- ical, not an exact science, but is based on the exact sciences of hydrostatics and dynamics. Its principal laws are therefore founded on theory, but on account of the multitude of modifying influences and of our necessarily imperfect theoretical knowledge of their varying characters and extent, the formulas used must' be derived from or at least modified by observation and experience and can- not be founded solely on theoretical considerations. The condi- tions under which hydraulic laws must be applied are so varied in both number and kind that the application of the laws must be modified to suit those various conditions and for this reason their successful application depends largely on the practical experience of the engineer. In the following discussion the letters used will have the signifi- cance shown below : E=Energy (abstract). P=Horse power. W=Total weight of water. h=The total available head in feet. h x =The velocity head. h 2 =The entrance head or influx head. h 3 =The friction head. q=The quantity of water (in cubic feet per second). w The weight of each unit of water (cu. ft.=62.5 Ibs.). a=Area (in square inches) against which pressure is ex- erted. s=The space (in lineal feet) through which the area moves under pressure. v=The velocity of flow (in feet per second). ^^Acceleration due to gravity (32.2 feet per second per sec- ond.) t=The time in seconds. 33. Mathematical Expression for Energy. Mechanically, energy is the exertion of force through space. The amount of available Mathematical Expression for Energy. 41 energy of water that may be theoretically utilized is measured by its weight (the force available) multiplied by the available head (the space through which the force is to be exerted), i. e., (i) E= Wh. From this it will be noted that the energy of water is in direct proportion to both the head and quantity. This energy may be. exerted in three ways which may be regarded as more or less distinct but which are usually exercised, to some extent at least. in common. The exertion of this energy in the three ways men- tioned, expressed in terms of horse power, are as follows : First: By its weight which is exerted when a definite quantity of water passes from a higher to a lower position essentially with- out velocity. This method of utilization is represented by the equation Second: By the pressure of the water column on a given area exerted through a definite space. This method of utilization is rep- resented by the equation 434h as Third : By the momentum of the water exerted under the full velocity due to the head. The energy of a moving body is repre- sented by the formula : Wv 2 (4) E = -^~ *g The equation for the horse power of water under motion is there- fore represented by the equation : ~ 550 x 2g An analysis of these formulas will show that under any given conditions the theoretical power exerted will be the same in each case. 34. Velocity Head (hj). It has already been pointed out (chap- ter IT) that energy must be expended in order to produce motion in any body and that the head (h x ) necessary to produce a ve- locity (v) is This proportion (h x /h) of the available head h has to be ex- pended to produce and keep in motion the flow of water. This head (h x ) is not necessarily lost (it has simply been converted into 42 Hydraulics. kinetic energy, and it may be re-converted into potential energy by correct design or it may be utilized in some other way, as, for example, by pressure or impact in hydraulic motors). Whatever head (h x ) is necessary to maintain the velocity (v), with which the water leaves the plant, will be lost to the plant. It is, therefore, desirable to keep v at this point as low as may be found practicable when other conditions are considered. Sudden enlargements or contractions in pipes or passages may wholly or partially destroy the velocity and cause the permanent loss of the corresponding head (h ). In this case an additional amount of the available head (r^) must be used to again generate the velocity (v) required to convey the water through the remainder of its course. Gradual change in the cross-section of all channel conduits or passages is, therefore, de- sirable in order that the transformation from kinetic to potential energy, and the reverse, shall be made without material loss. Not only the head (hj) but still other portions of the total avail- able head (h) may be lost in the channels and passages of a ma- chine or plant by improper design. 35. Entrance Head. The loss of head (h 2 ) which occurs at en- trance into 1 a raceway, pipe or passage may be called the "influx head." The amount of this loss differs considerably with the shape and arrangement of the end of the pipe or passage. In general, the influx head may be determined by the formula: (7) h a = (r -(Merriman's Hydraulics, Art. 53) In this formula the coefficient can be obtained from table VI, in which the variations of the constant under various conditions, with reference to a pipe inlet, are shown, and from which it will be noted that its magnitude depends on the shape and arrangement of the inlet. TABLE IV. Arrangements of a pipe inlet with corresponding coefficients. Arrangement of Pipe. c c 8 l A. Projecting into reservoir ,715 956 B. Mouth flush with side of reservoir .825 .469 (from 950 108 C. Bell shaped mouth (to 990 020 Submerged Orifices. To find the value of h 2 , the value of -\- 1 corresponding to the c given conditions, is to be selected from Table IV and substituted in formula (7). The ordinary arrangement of suction pipes is for a square ended pipe to project di- rectly into the suction pit. In res- ervoirs the pipe may be flush with the masonry or project as in the flcase of suction pipes. With condi- tion (A) formula (7) becomes (8) h a = .956-^ 2g The value of h 2 can be readily obtained from equation (8), as it will be 95.6 per cent, of the veloc- ity head. With the mouth of the pipe flush with the side of the reservoir the loss would be 46.9 per cent, of the velpcity head, and with a bell mouth pipe the loss would be de- creased to from two per cent, to 10.8 per cent, according to the de- sign of the bell mouth entrance. The arrangements of inlet pipes as referred to in Table IV are Fi z- 18. shown in Fig> Ig> 36. Submerged Orifices. A similar loss is sustained in the flow- through gates or submerged openings or in the flow past any form of obstruction which may be encountered by the water in its flow through channels, pipes or other forms of passages. Openings or obstructions with square edges may cause a serious loss of head which may, however, be reduced. First: By increasing the opening, thus causing a reduction ini velocity and consequently a saving in head, or Second : By rounding the corners of the opening or obstruction, thus causing a gradual change in velocity and a partial recovery of any head necessarily used for creating greater velocity through- such passage or past such obstruction. But few experiments have been made on submerged orifices and" tubes. These indicate a coefficient of about .62 for complete con- traction which increases to .98 or even .99 with the contraction* 44 Hydraulics. completely suppressed. Certain experiments have recently been made at the hydraulic laboratory of the University of Wisconsin, on the discharge through orifices and tubes four feet square and of various thicknesses or lengths and with various conditions of con- traction. The values of the coefficients as determined in these ex- periments with various losses of head and various conditions of entrance, are shown in Table V.* The Forms of Entrance and Outlet Used for the Tubes in the experiment were as follows: 7 A. Entrance; all corners 90. Outlet; tube projecting into water on down stream side of bulkhead. a Entrance; contraction suppressed on bottom. Outlet; tube projecting into water on down stream side of bulkhead. b Entrance; contraction suppressed on botton and one side. Outlet; tube projecting into water on down stream side of bulkhead. c Entrance; contraction suppressed on bottom and two sides. Outlet; tube projecting into water on down stream side of bulkhead. c' Entrance; contraction suppressed on bottom and two sides. Outlet: square corners with bulkhead to sides of channel preventing the return current along the sides of the tube. d Entrance; contraction suppressed on bottom, two sides and top. Outlet; tube projecting into water on down stream side of bulkhead. From this table it will be noted that a partial suppression of con- traction does not always improve results, and that by complete sup- pression, the coefficient is greatly increased with a corresponding decrease in head lost. 37. Friction Head (h 3 ) In raceways and short pipes the velocity head (hi) and the influx head (h 2 ) are frequently the sources of the greatest losses of head. In canals and pipes of considerable length the friction of flow may become the most serious sources of energy loss. The principles of flow in such channels may be considered as follows : First Principle : In any frictionless pipe, conduit, channel or pas- sage of unit length the flow may be expressed by the formula : (9) h = Y~ or v = i/2gh~ In practice, however, we find friction is always present and a friction factor must be introduced in the above formula in order to *From experiments by Mr. C. B. Stewart at the Hydraulic Laboratory of the University of Wisconsin. Friction Head. 45 represent the actual conditions of practice. (9) therefore becomes : (10) TABLE V. Value of the Coefficient of Discharge for flow through horizontal submerged tube, 4 feet square, for various lengths, losses of head and forms of entrance and outlet. Loss of head, h 2 in feet. Forms of En- trance and Outlet Length of tube, in feet. i 0.31 0.62 1.25 2.50 5.00 10.0 14.0 Value of the coefficient, c. 05 A .631 .650 .672 .769 .807 .824 .838 a .762 .742 .810 .848 b .740 .769 .832 .862 c .834 .769 .875 .890 c' .875 d .948 .943 .940 .927 .931 10 A .611 .631 .647 .718 .763 .780 .795 a .636 .698 .771 .801 b .685 .718 .791 .813 c .772 .718 .828 .841 c' .830 d .932 .911 .899 .892 .893 15 A .609 .628 .644 .708 .758 .779 .794 a .630 .689 .767 .803 b .677 .708 .787 ,814 c .765 .708 .828 .839 c' .829 d .936 .910 .899 .893 .894 20 A .609 .630 .647 .711 .768 .794 .809 a .63;! .694 .777 .819 b .678 .711 .796 .833 c .771 .711 .838 .856 c' .846 d .948 .923 .911 .906 .905 .25 A .610 .634 .652 .720 .782 .812 .828 a .634 .705 .790 b .683 .720 .809 c .779 .720 .854 c' d .965 .938 .928 30 A .614 .639 .660 .731 .796 .832 .850 -fi. a .639 b .689 c .788 c' d .984 4 6 Hydraulics. The formulas (9) and (10) represent one of the important funda- mental principles from which many hydraulic formulas are de- veloped. Second Principle: In any pipe, conduit, channel or passage we may fairly assume: Frst: From axiomatic considerations the resistance to the flow of water may be regarded as directly proportional to the area of the surface in contact with the water. Second: From observed conditions the resistance is found to be directly proportional to the square of the velocity of flow. Third : Experience leads to the conclusion that the resistance to flow is inversely proportional to the cross-section of the stream. These conclusions may be expressed by the following equation: (Velocity) 2 X area of contact Resistance = y ' , : area ot section Fig. 19. The area of the surface of a channel is the product of the wetted -section or wetted perimeter (p) tirnes the length of the section, or, to p x 1. (See Fig. 19.) The velocity is represented by v and the cross-section by a. Hence, from the above considerations, we may write for the friction head: (11) h s = and by ; transposition v a = p That is to say, the square of the velocity is in direct proportion to the area of the section and to the friction head and inversely proportional to the wetted perimeter and to the length of the sec- tion. In practice it is found that there are numerous factors which Kutter's Formula. 47 affect the theoretical conditions, as above set forth, which must therefore be modified in accordance with the conditions which ob- tain. In formula (n) therefore it is necessary to apply a coeffi- cient (c') which represents the summation of such other influences. The form in which this last equation is ordinarily written is /ON , v 2 pl /ah, h "= C a 0rV = C Afe- Ordinarily this form is somewhat abbreviated by substituting- for a/p the hydraulic radius which represents this ratio. That is to say, area of cross section _ a wetted perimeter " ^p~ " I The "hydraulic radius" is also sometimes termed the "mean dfepth" or the "mean radius." For the ratio of the resistance head to the length of section the equivalent slope s is substituted. That is to say: Resistance head h 3 _ Length of section ~ 1 With these substitutions the formula (12) assumes the final fprm of: (13) v = In the use of this formula three factors must be determined by measurement or estimate in order to derive the fourth, v, r and s can be determined experimentally or measured directly. The factor c is the most difficult to ascertain as it depends upon a very great variety of conditions which can only be known and apprie- ciated by a thorough knowledge of the conditions under considera- tion, and by comparison of such conditions with similar observed conditions. Various attempts have been made to derive a formula which would give the value of c in accordance with the varying conditions. The principal formulas for the values of c are those of Ganguillet and Kutter and of Bazin. Ganguillet and Kutter's form- ula for the value of c is as follows : | 38. Kutter's Formula. 41 fl i 1 ' 811 _, 0-00281 >'...,.".. ..... 4-L.p -| -- -- 1- ;" . , , . , , (14) c = From this formula it will be seen that Ganguillet and Kutter as- sume c to vary with the slope, with the square root of the hydraulic radius and with a new factor "n" which is termed the coefficient Hydraulics. HYPRAUL'IC RADIUS "r"- rf. ,k 1.0 2.0 VELOCITY V- IN FEET PER SECOND Fig. 20. Kutter's Formula. 49 Fig. 21. 50 Hydraulics. of roughness. The value of this coefficient as determined by these experiments is as follows: For large pipe with the following characteristics: Exceptionally smooth cast iron pipe n = .on Ordinary new cast iron or wooden pipe .0125 New riveted pipes and pipes in use .014 Pipes in long use .019 For open channels of uniform sections : For planed timber sides and bottom 11= .009 For neat cement or glazed pipe .01 For unplaned timber '. .012 For brick work .013 For rubble masonry .017 For irregular channels of fine gravel .02 For canals and rivers of good section .025 For canals and rivers with stones and weeds . . . .030 For canals and rivers in bad order 0.35 The relation of the above factors may be determined by the dia- grams, Figs. 20 and 21. If with a known slope and a known value of n (for example, let n=o.i5 and s=.ooo2, as at A, Fig. 20), a straight line be drawn on this diagram to the scales of the hydraulic radius (at B) it will show at the intersection with the scale for the coefficient (c) the relative value of this coefficient for these condi- tions, or with a known c and the known hydraulic radius and the given slope the value of n of a channel may be likewise determined. After a line has once been drawn connecting these four known values the velocity can be determined by drawing a line from the hydraulic radius scale (B) to the proper point on the scale of slope or hydraulic gradient at x, and then from the point of intersection of the line A B with the coefficient scale at x' drawing a line par-, allel with xB which will intersect the velocity scale at the point B', giving the velocity (in this case equal to 1.34 ft. per second). These formulas only apply with accuracy where the channels or passages are uniform and if applied to channels or passages which are not uniform the sections selected must be fairly representative. If the sections selected are not fairly representative the value of c or n determined from observations and experiments may vary consid- erably from the values which would otherwise be anticipated. That is to say, the* calculations based on c and n will take into account irregularities in channels and other unknown or unrecognized con- ditions, including curves, bends and obstructions which may not Bazin's Formula. Bazin's Form value of c in th ula fc e for i En 7 >r the niuk glisl J L L I I I i / i /i / / / 1 / / fl / / / V n n n n n n n cv rs is, n leasure, s / / / / / / M/ / c i-O 552 + OGforsni( matchec 10 for p "ick. 40 for ma 85 for reg ?ds. 30 for ( >od order. 75 in \ der. m 3tjL m nt l/r )oth plant boards, anks anc sonry. ular eartt canals in ery bad n I / 1 /N / 01 1=0. bi / / / / / r i / / 1 i O. i=0 / / H \ \ \ b< 1=1, gc i I . j ir / / / JLLLA IE it / / / / or / / I / / / L ji j n i /i i/i 1 1 1 / 1 i / on U Ice L CO CO (M los ios | 311 IcS - I . V ^ ^ C^ C^ 1 CO GO CO i I CC r-5 O < i O Tf GO CD 1C Tf CO U los S 8 lea Ics loj I 5r <^> 1C O C5 O r-i I I 1 Ij, 2 So 9) CO 57 58 Hydraulics. (32) b = -| d cot a (33) B = b + 2dcoto: (34) p = b+-^ sin a In the above, a=cross-section area; d=depth of water in channel; b bottom width ; B=width at water level ; p=wetted perimeter ; c=the length of slope which is equal to sin a: In Table VI the relation of these functions, for the slopes ordi- narily used in practice have been calculated as well as for the semi- circular section. The use of the table may be illustrated as fol- lows : The quantity of water which it is desired to deliver is de- termined by the conditions of the problem or by measurement. The velocity to be maintained in the channel is determined by the ex- isting slope, the nature of material encountered, or the friction head which it is found desirable to maintain. The area of the cross-section required to carry the quantity q with velocity v is a=-^- After the slope angle has been selected, for the material in which the channel is to be constructed, the corresponding values may be taken out of the table from their respective columns and multiplied by the square root of a. The result thus obtained gives the desired dimensions. If, for example, we desire to carry 100 cu. ft. of water per second in a canal at a velocity of 2~ 1/2 ft. per second at which velocity small pebbles are unaffected, and with a side slope of 1.5 to I, which is suitable for loose earth, has been decided upon, the required area of cross-section will be 100/2.5 =40 sq. ft. The square root of 40 is 6.33. The required dimensions of canal as taken from the table are Depth d= 689 x 6.33=4.36 ft. Bottom width b 418 x 6.33=2.65 ft. Top width 6=2.485 x 6.33=15.73 ft. and The wetted perimeter p=2.9O4 x 6.33=18.38 ft. Computation of the area from the above dimensions gives 40 sq. ft. Hence the work has been checked. 42. The Back Water Curve. One of the problems which be- comes very important in many water power installations is the effect on the elevations of the stream produced by the erection of a dam or other obstruction therein. The back water curve can best be determined by the use of the simple formula of flow, equa- tion (13). Flow of Water in Pipes. 50 (13) v = Cv/riT From this, as shown in equation (15) (15) q* = v'a* = 2f5j!l From this equation can be derived *> ". = = X i With L constant, h 3 : h' 3 ::-- : --, therefore 3 3 That is to say, with the quantity of water and length of section constant, if the coefficient remains constant the head due to any obstruction will vary in accordance with equation (36). Where the water is greatly deepened in proportion to its orig- inal depth the value of c will not remain constant but will vary. Where such is the case and where q 2 ! is constant, under which condition h 3 n'a 3 p 2 ha 2 rp z /Q7\ -L.t v/ *^ W'J n 3 ^/ 3 ^ A -7T , , , o The difficulties in the determination of the value of c are, of course, obvious, but it is believed that the back water curve can be closely calculated by this simple formula in which the new value of c is the only factor to be estimated, and where the other elements of the problem can be determined by actual measure- ments. In using this formula the original value of c under exist- ing condition of flow can be determined by calculation based on actual observation of flow under different conditions of water and the conditions of the channel under the new regimen can be closely estimated. New values of c can be very closely estimated on the basis of the values known to exist under other similar cir- cumstances. This method will permit of a more practical solution of the problem than by the use of formulas based on entirely the- oretical consideration of conditions which can never be approxi- mated in practice. 43. Flow of Water in Pipes. Mathematical expressions for the flow of water in pipes may be derived from either of the funda- mental hydraulic formulas v = CI/TS~ or v = c-/2gh, Starting with the former equation, in the case of a pipe flowing 60 Hydraulics. full the hydraulic radius r - -where d is the diameter of the pipe and for s we may substitute -^ We then have (38) '= In a pipe of unit length and unit diameter without friction the flow would be expressed by the formula v 3 v = i/2gh or h = -JT To modify this for friction a friction factor f is introduced and the' equation then reads : The friction varies . directly as the length and is assumed to vary inversely as the diameter. Hence, for any pipe of length 1 and diameter d the complete equation is : (39) h 3 = f JL -Xl or v : Placing (38) and (39) equal it will be found that 16.04 iso that the equations can be made equivalent by the proper modi- fications of friction factors. An extensively used formula for the determination of c in equation (38) is that of Darcy. It reads : (40) C = 7^ = ^ = For new pipe a = .00007726 and ft .00009647. For old pipe a = .0001543 and ft = .00001291. These coefficients were determined from experiments on small pipes and therefore in the case of large pipes with high velocities the velocities computed by this formula are too small. Various modifications of the Chezy formula, having the general form (41) v = cr n s m have been proposed or derived from experiments. Lampes and Flamant's are the best known of this type. Lampes reads (42) V = 77.68dO.694 S 0.555 and Flamant's (43) v = cd* s* in which c 76.28 for old cast iron pipe and 86.3 for new pipe. Flow of Water in Pipes. LOSS OF HEAD IN FEET PER 100 FEET 61 62 Hydraulics. The value of c in the formula v=c\/rs may vary from 75 to 150- for large cast iron pipe. For riveted steel pipe the coefficient varies but little with velocity and diameter and at ordinary velocities ranges from 100 to 115. A. L. Adams gives values of c for wood stave pipe ranging from 100 to 170. Experiments on the Ogden pipe line showed average values of about 120. An examination of the various formulas proposed for calculating the flow of water in pipes will show a very wide range of results For example, for calculating the head lost in a four-foot new cast iron pipe, some of the principal formulas offered and the graphical solution of the same are shown by Fig. 25. From these results it will be seen that the data from which the formulas were derived are evidently obtained under widely varying conditions and that in the relation of such formulas for use on important work, they must be chosen after a careful consideration of all the elements of the problem, and that it is usually much better, when possible, to utilize the original data and observation along similar lines when such can be obtained, and derive the formula to be used instead of accepting one whose basis may be obscure or unknown. In construction where pipes are short and comparatively unim- portant, a formula may be selected' which seems to agree with the ASPHALT COATED CAST IRON PIPE BY TUTTON'S FORMULA s 0.00" 6.0 Fig. 26. Flow of Water in Pipes. LAP-RIVETED i BY TUTTON'S FORMULA * Fig. 27. 0.15 0.14 0.13 0.12 0.11 0.10 0.09 O.OB 0.07 006 O.OS 0.04 0.03 0.02 0.01 0.00 WOOD-STAVE PIPE BY TUTTONS FORMULA V =IS5R 6B S b ' 4 / / 1.4 1.3 1.2 I.I 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 O.I o.o. ? / / / / v / / x / / / X fr ^ X ^ ^ - y / f X X _ / x' x & ':> ^ X ^ ^ x X s S f -X* <"** . X ^ Ix '. ^ ,.x ^' x /I x / r.. i ^ < X r i -^ r " Lx ^ ^ ^ ;:; ^ ^ 5 ^Z- . 1 2.0 3.0 4.0 SO 6.C VELOCITY IN FEET PER SECOND Fig. 28. 64 Hydraulics. elements of the problem. The formulas offered by Tutton seem to agree well with the actual results of experiments and several diagrams based thereon are shown in the following pages. In two of these diagrams (Figs. 26 and 27) the limiting values are shown and the results obtained from any pipe of the character represented therein should lie between these limits depending on its condition. 44. The Flow of Water Through Orifices. It is found that water flowing through an orifice in the side of a vessel acquires a velocity practically equal to that which would be acquired by a falling body in passing through a space equal to the head above the center of the opening, i. e., (44) v= i/2gh = 8.025/E in which v=velocity of spouting jet. g=acceleration of gravity=32.2. h=head on opening. The discharge through the opening would therefore be (45) q= va=aV 2 gh or practically (46) q=ca\/2gh where c is a coefficient varying with the size and shape of the orifice and with various other factors. A more accurate determination of the theory of flow through a given orifice is derived as follows: If a thin opening is considered at a depth y be- low the surface the discharge through the ele- mentary section Idy would be I 1 (47) dq = Idy 1 /2gy Integrating this equation between the limits 2 and h i we obtain the following: Fig. 29. (48) q = |l(h a * h,^)v/2g~ or practically (49) q = mfl l /2^(hj-h 1 f ) m being the coefficient of practical modification due to condition of the orifice. 45. Flow Over Weirs. In a weir h 1 =o. Hence equation (49) becomes (50) q = m (Dl/gg h* in which h is the head on the crest of the weir. That is, the ver- tical distance from the water level above to the crest of the weir. Flow Over Weirs. For practical use the coefficient m together with the constants ~ and 2g are combined as follows: o c = m i/2g = M !/2g and equation (50) becomes (51) = c The value of m and consequently of c varies with the shape of the weir and with other factors and must be determined experi- mentally. This has been done with weirs of many forms, both by Bazin in France and by Rafter and Williams at the Cornell hydrau- lic laboratory. The results of these experimental determinations are given by Figs. 30 to 34, .inclusive. These figures are reduced directly from the diagrams of Mr. Rafter in the Report of the Board of Engineers of Deep Waterways, 1900. In practice many weir formulas are in use, based on various ex- periments and observations. The formula of Francis', equation (52), is probably the best known in this country. It is best adapted to long, sharp crested weirs without end contractions. (52) q = 3.32 111* oo Head on Crest of Weir in Fig. 30. Weir Coefficients for Weirs of Various Shapes. 66 Hydraulics. ad on Crest of Weir in Peer ZO 3.O 4.0 Head on Crest of Weir in Feet Fig. 31. Weir Coefficients for Weirs of Various shapes. Flow Over Weirs. Head on Crest of Weir in feet 9n 10 4 Head on Crest of Weir in Feet Fig. 32. Weir Coefficients for Weirs of Various Shapes. Bazin, Series Flat crested V 3M. (e.56 Feet) wic Ftefey and Stearns' Experiments E not crested MuHln's Formuk Fiat crested w Width of Crest, 3.O 40 50 60 7.O SO 9O IO.O HO 120 !3O Discharge in Cubic Feet per second Figu Francis' Formula for Merrimack Dam. rancfs' Formula. Sharp crested Weir. Muttirva Formula, "Sharp crested Wefr Bazin's Formula fbr a High sharp c res-ted Weir Feet U.S.BOARD OF ENGINEERS ON DEEP WATERWAYS WATER SUPPLY DIVISION. Dmparative Discharqe over Weirs, by different Formulae, For a Single Foot of Crest. Barirrs Formula, Q-mLHVSqR Crest, measured from trie of sf fi Water, in feet. of Discharge, derived by t fbr ach Form of Weir ' Francis' Formula fbr a Sharp Cnesfea Weir. Formufq fbr Oam on tfie Mern'mac f?iver, at Lawrence, Mass Q 3.01206 LH' FrizeilS Formula fora Flat Crested weir Q-309LH* Muiiin's Formula, used by Cast Indian Engineers Q-S.SSLCH^ For a Sharp Crest-eo Weir >Q654-O.OIH For a riot crested To accompany Report on Special Water Supply Investigation 'o TTO 155 lao" 5o5 5rS 555 eio 84-o 55 2&o ?r one linear Foot of Crest. .^-P-AK 7o Hydraulics. Head on Crest of Weir in Feet 00 Head on Crest of Weir in Feet. Fig. 33. Weir Coefficients for Weirs of Various Shapes. Flow Over Weirs. Head on Crest 19 20 of f- Weir in Feet . 45 i ^ ^f :f a si ;t4 I s EE:: 44 Sf 5 ^ i =1 t N 5 G ~J - J t: 4* -T~ i - -ir* I f> T 1 M Mii ii e K TH- i: s $z u 10 i. 4- '^ z: - ]f i n H ~ i i \ ? T -- -1 i -i r? fe r -r pitt fnie n IT P e ^ -r ~r~|" ^~ 4.5 f 4,1 t ~: h- - : ^ i_J :i +- if ii fc n p Ota i 3 C k ! q II Efc * I! a P 5 U r C3f 2^ ^ 2.-0 -i r r * i* m III c X S f1 ^ I 3! id ^ 3 ==i T ' i F 5 , 1 - = aa BM v ^ - -Q K w 19 fll 1 t 3^ -=i k. +* FT ^ a rr rfl (t "VI- ^^ - ii sj 3^. f>^ izz: --4 1 ^ I.O I i Heo d o n c > e ST 4 v\ 1 reiri n Fe< tf B Fig. 34. Weir Coefficients for Weirs of Various Shapes. To accompany Report on Specjai Water Supply Ir.v/esJiqation 1899 - MS BOARD OF ENGINEERS ON DEEP WATERWAYS WATER SUPPLY DIVISION Diaaram showing over Weirs with Ser :t- x a sharp cresied we,r me- Discharge in Cubic Feet per Sections cf experimental Weirs. Direction of now M 656 Series No. 1 17 162 173. 130. 170 Header Crest of Vetr in nisrhartge over Weir, for a lenqrth of one Foot, in Cubic Feet per Second.(Approx.mate, Series No 117 168 173 135 130. 170 Sharp gWMte- Off' 0.5 10 IS 2.0 25 30 3.5 098 295 555 856 teas 1583 MOO SA45 6.0 148 420 750 II 35 1568 2040 3545 0.0 ' 1.16 958 686 1085 15.40 2038 25.80 31 53 1.20 370 7.ZO 11.45 16.50 82.04- 28.15 34.75 i.se 396 7.6O I2.0O I7.OO SB. 56 2660 35.15 1.20 3.90 7.6* IE05 17 l 22.S5 29.10 3568 1 10 333 eie 942 13.16 17.30 2I9O 86.64 1 1 1 I J 1 1 , I L 1 1 iss 196 ao.o ?rb sso g3 br one linear Foot of Crest. o afar SB'O gfio 870 auo iiao AO.O *io -NIU ^^ ^* u JWU .,-- ire 36. 74 Hydraulics. A number of different tormtilas for the flow over weirs are given on Fig. 35 and the flow as calculated by these formulas is shown on the diagram. L in these formulas represents the length of the weir crest which. in the dimension above is represented by 1. Figure 26 shows graphically the results of the application of the value of c as given on Figs. 30 to 34 as compared with Francis* formula. In small weirs the effect of end contraction and of the velocity of approach becomes important and corrections to the formulas must be applied in order to allow for those influences. If n =the number of end contractions and the effect of each is to reduce the effective length of the weir by one-tenth the head on the weir, equation (51) will become (53) q = c (1 - n * The effect of the velocity of approach is to reduce the head on the weir by the velocity head. This reduction is given by the formula : (54) ht== lJF in which v'=velocity of approach and h'=velocity head. TABLE VII. Coefficient of discharge C for use with Hamilton Smith, Jr.' 's formula (56} for flow of water over sharp crested weirs having full contraction. 1 = length of weir. Effective head =h .66 1(?) 2.6 3 4 5 7 10 15 19 .1 .15 .2 .25 .3 .4 .5 .6 .7 g .632 .619 .611 .605 .601 .595 .590 .587 .585 .639 .625 .618 .612 .608 .601 .596 .593 .590 .646 .634 .626 .621 .616 .609 .605 .601 .598 595 .650 .637 .629 .623 .618 .612 .607 .604 .601 598 .052 .638 .630 .624 .619 .613 .608 .605 .603 600 .053 .639 .631 .625 .621 .614 .610 .607 .604 602 .653 .640 .631 .626 .621 .615 .611 .608 .606 604 .654 .640 .632 .627 .623 .617 .613 .611 .609 .607 .655 .641 .633 .628 .624 .618 .615 .613 .612 .611 .655 .642 .634 .628 .624 .619 .616 .614 .613 61? .656 .642 .634 .629 .625 .620 .617 .615 .614 618 9 592 596 598 600 .603 .606 .609 611 61? 1 590 593 595 .598 .601 .604 .608 610 11 1 i .587 .591 .593 .596 .599 .603 .606 609 610 1 2 .585 .589 .591 .594 .597 .601 .605 .608 .610 1 3 .582 .586 .589 .592 .596 .599 .604 .607 .609 1 4 .580 584 587 .590 .594 .598 .602 fiOfi 609 1 5 582 585 .589 .592 .596 .601 605 .608 1 6 .580 .582 .587 .591 .595 .600 .604 .607 1.7 .594 .599 .603 .607 2.0 i Literature. 75 To allow for the influence of velocity of approach h' must be added to h and equation (53) becomes (55) q = c(l-ni)(h + hi)* Experimental results at the hydraulic laboratory of the Uni- versity of AVisconsin show that for small sharp crested weirs, with end contraction, the formula (56) of Hamilton Smith, Jr., is prac- tically correct: (56) q = c /2 IbJ In this formula c=coefficient of discharge (to be taken from Table VII). h=observed head on crest (H) plus correction due to velocity of approach. Variations in the forms of the crest of weirs and in the arrange- o ment of sides and bottom of the channel of approach cause con- siderable variation in their discharging capacity. It is therefore apparent that unless the conditions closely agree with those on which experimental data is available that the error of calculation may be considerable. LITERATURE. REFERENCES ON GENERAL HYDRAULICS. 1. Francis, Jas. B. Lowell Hydraulic Experiments. New York. D. Van- Nostrand. 1883. 2. Fanning, J. T. Hydraulic and Water Supply Engineering. New York. D. Van Nostrand & Co. 1886. :3. Smith, Hamilton, Jr. The Flow of Water Through Orifices, over Weirs, and through Open Conduits and Pipes. New York. Wiley & Sons. 1886. 3a. Church, Irving P. A treatise on Hydraulics. New York, Wiley & Sons, 4. Weisbach, P. J. Hydraulics and Hydraulic Motors. Translated by A. Jay Dubois. New York, Wiley & Sons. 1891. 5. Carpenter, L. G. Measurement and Division of Water. Bulletin No. 27, Colo. Agri'c. Expt. Sta., Ft. Collins, Colo. 1894. 6. Bovey, Henry T. A Treatise on Hydraulics. New York. Wiley & Sons. 1895. 7. Merriman, Mansfield. Treatise on Hydraulics. New York. Wiley & Sons. 1903. 8. Hydrographic Manual, Water Supply and Irrigation Paper No. 94. U. S. G. S. 1904. 9. Hoskins, L. M. Hydraulics. New York, Henry Holt & Co. 1907. REFERENCES ON FLOW OF WATER IN CANALS. 10. Hill, A. Flow o^ Water in Rivers and Canals. Van. Nost. Eng. Mag. Vol. 3, p. 118. 1870. 76 Hydraulics. 11. Gangtiillet, E. Uniform Motion in Canals and Rivers. Van. Nost. Eng. Mag. Vol. 2, p. 211. 1870. 12. Searles, W. H. Slope of Water Surface in the Erie Canal. Trans. Am. Soc. C. E., Vol. G, pp. 290-296. 1877. 13. Ellis, Theo. G. Flow of Water. Eng. News, Nov. 26, 1881, Vol. 8, pp. 478-9. 14. Cunningham, Allan. General Discussion of Flow in Canals. Proc. Inst. Civ. Eng. 1882-83, pp. 1-95. 15. Fteley, A. and Stearns, F. P. Flow of Water in Conduits. Trans. Am. Soc. C. E., Vol. 12 (1883), p. 114. 16. Flynn, P. J. Irrigation Canals and Other Irrigation Works and Flow of Water in Irrigation Canals. Denver, Colo. 1892. 17. Adams, A. L. Diagram for Calculating Velocities, Grades and Mean Radii for Flumes and Ditche3. Eng. News, Feb. 13, 1892, p. 157. 18. Ganguillet, E. and Kutter, W. R. A General Formula for the Uniform Flow of Water in Rivers and Other Channels. Trans, by Ru- dolph Herring and John Trautwine. New York, Wiley & Sons. 1893. 19. Boussinesq, H. The Gradual Variations in the Flow of Water in Chan- nels of Large Section. Comptes Rendus^ May 31, 1897. 20. Boussinesq, J. Experimental Verification of the Theory of Gradually Varied Flow in Open Channels. Comptes Rendus. June 14,. 1897. 21. The New Formula of Bazin. Genie Civil, March 5, 1898. 22. A New Formula by Bazin for Computing Flow of Water in Open Chan- nels. Eng. News, July 14, 1898. 23. Bazin's New Formula for Flow in Open Channels. Eng. News, 1898, Vol. 2, p. 26. 24. A Study of a New Formula for Calculating the Discharge of Open Chan- nels. Annales des Fonts et Chaussees. 2 Trimestre, 1898. 25. Determination of Flow in Rivers and Canals. Zeitschr. d Oesterr. Ing. u> Arch. Ver., Vol. 50, pp. 533-534. 1898. 26. Swan, Chas. H. and Horton, Theo. M. Hydraulic Diagrams for the Dis- charge of Conduits 1 and Canals. New York, Eng. News Pub. Co. 1899. 27. Crosthwaite, Ponsby Moore. Two Graphic Methods Applied to Hydraulic Calculations. Engineering. London. July 15, 1898. 28. Concerning the Conception of a Hydraulic Moment of Conduit Cross Sec- tion. Zeitschr. fur Arch, u Ing. Vol. 46, 1900. Heft-Ausgabe. Col. 402-417. 29. Siedek, Richard. Studies of a New Formula for Estimating the Velocity of Water in Brooks and Small Channels. Zeitschr. d Oesterr. Ing. und Arch. Ver. Vol. 55, pp. 98-106. 1903. REFERENCES ON FLOW OF WATER THROUGH PIPES. 30. Francis, Jas. B. Flow Through Pipes. Trans. Am. Soc. C. E. Vol. 2, ff p. 45. 1872. 31. Daaach, C. G. Flow of Water in Pipes under Pressure. Trans. Am. Soc. C. E. Vol. 7, p. 114. 1878. 32. Wehage, H. Friction Resistance in Pipes. Dingler's Polytechnisches Journal, 1884, p. 89. Literature. 77 33. Stearns, P. P. Flow of Water Through a 48" Pipe. Trans. Am. Soc. C. E., Vol. 14, p. 1. 1885. 34. Mair, J. G. Flow Through Pipes at Different Temperatures. Proc. Inst. C. E. Vol. 84, p. 424. 1886. 35. Duane, James. Effect of Tuberculation on Delivery of a 48" Water Main. Trana Am. Soc. C. E. 1893, p. 26. 36. Tuttle, Geo. W. Economic Velocity of Transmission of Water Through Pipes. E'ng. Rec. Sept. 7, 1895. 37. Coffin, Freeman C. The Friction in Several Pumping Mains. Eng. News, Feb. 20, 1896. 38. Hawks, A. McL. Flowage Test of 14" Riveted Steel Main at New West- minster, B. C. Eng. News, July 30, 1896. 39. Flow of Water in Wrought and Cast Iron Pipe. Am. Soc. Mech. Eng. Dec. 1897. 40. Herschel, Clemens. 115 Experiments on the Carrying Capacity of Large Riveted Metal Conduits. New York. John Wiley & Sons. 1897. 41. Gould, E. Sherman. The Flow of Water in Pipes. Am. Mach. Mar. 3, 1898. 42. Hawks, A. McL. Friction Coefficient for Riveted Steel Pipes. Proc. Am. Soc. C. E. Aug. 1899. 43. Fulton, C. H. Flow of Water in Pipes. Jour. Ass'n Eng. Soc. Oct. 1899. 44. Marx, C. D., Wing, Chas. B., and Hoskins, L. M. Experiments on the Flow of Water in the Six Foot Steel and Wood Pipe Line of the Pioneer Electric Power Company. Proc. Am. Soc. C. E. Feb., 1900; April, 1900; May, 1900. 45. Gregory, John H. Diagram Giving Discharge of Pipes by Kutter's For- mula. E'ng. Rec. Nov. 3, 1900. 46. Formulas for Flow in Pipe. Eng. News, 1901. Vol. II, pp. 98, 118, 332, 476. 47. Noble, T. A. Flow of Water in Wood Pipes. Trans. Am. Soc. C. E. Vol. 49, 1902. 48. Saph, A. V. and Schoder, E. W. Experimental Study of the Resistance of the Flow of Water in Pipes. Proc. Am. Soc. C. E. May, 1903; Oct., 1903. BEFEEENCES ON FLOW OF WATER OVER WEIRS. 49. Fteley, A. and Stearns, F. P. Flow of Water over Weirs. Trans. Am. Soc. C. E. Vol. 12, p. 1. 1883. 50. Francis, J. B. Experiments on Submerged Weirs. Trans. Am. Soc. C. E. Vol. 13, p. 303. 1884. 51. Herschel, Clemens. Problem of the Submerged Weir. Trans. Am. Soc. C. E. Vol. 14, p. 189. 1885. 52. Investigations on the Flow over Submerged Weirs. Zeitschr. des Ver. Deutsch. Ing. 1886, p. 47. 53. Hind, R. H. Flow over Submerged Dams. Proc. Inst. C. E. Vol. 85, p. 307. 1886. 54. Kaberstroh, Chas. E. Epxeriments on the Flow of Water Through Large Gates and over a Wide Crest. Jour. Ass'n Eng. Soc. Jan., 1890, p. 1. 78 Hydraulics. 55. The Flow of Water over Dams and Spillways. Eng. Rec. June 2, 1900. 56. Flow of Water over Sharp Crested Weirs. Annales des Fonts et Chaus- sees. Jan. 1, 1890; Nov., 1891; Feb., 1894. Also Proc. Eng. Club of Philadelphia, Jan., 1890; July, 1892; Oct., 1892; Apr., 1893. 57. Flow over a Weir of Curved Profile. Zeitschr. d Oesterr. Ing. u Arch. Ver. June 2, 1905. 58. Flynn, A. D. and Dyer, C. W. D. The Cippoletti Trapezoidal Weir. Trans. Am. Soc. C. E. July, 1894. 59. Werenskiold, N. Flow of Water over Rounded Crest. Eng. News, Jan. 31, 1895. Yj^^, p. 75. 60. Frizzel, J. P. and HJ^^el, Clemens. Flow over Wide Horizontal Top Weirs. Eng. News, 1892, Vol. II, pp. 290, 440, 446; 1895, Vol. I, p. 75. 61. Johnson, T. T. and Cooley, E. S. New Experimental Data for Flow over a Broad Crest Dam. Jour. W. Soc. Engrs. Jan., 1896. 62. Wide Crest Weirs. Bazin's Formula. Eng. News, 1890. Vol. I, p. 162. Vol. II, p. 577; 1896, Vol. I, p. 26. 63. Experiments on Flow over Dams. Eng. News, 1900, p. 207. 64. Rafter, Geo. W. The Flow of Water over Dams. Proc. Am. Soc. C. E. Mar., 1900. 65. Heyne H. Study of Hydraulic Coefficients. Zeitschr. d Oesterr Ing. u Arch. Ver. Dec. 5 1900. 66. Dery, Victor A. E. D. Experiments on the Measurement of Water over Weirs. Proc. Inst. C. E. Vol. 114, p. 333. 1893. REFERENCES ON BACK WATER AND INTERFERENCE. 67. Wood, De Volson. Back Water in Streams as Produced by Dams. Trans. Am. Soc. C. E. Vol. 2, pp. 255-261. 1873. 68. Hutton, W. R. Back Water Caused by Contractions. Trans. Am. Soc. C. E. Vol. 11, pp. 212-240. 1882. 69. Gillmore, Q. A. Obstruction to River Discharge by Bridge Piers. Van. Nost. Eng. Mag. Vol. 26, p. 441. 1882. 70. Back Water from Dams. Eng. Rec. July 9, 1892. 71. Ferriday, Robert. Measurements of Back Water. Eng. News, 1895, Vol. II, p. 28. 72. Frescolm. S. W. Back Water Caused by Bridge Piers and other Obstruc- tions. Jour. Eng. Soc., Lehigh Univ. Feb., 1899. 73. The Estimation of Damages to Power Plants from Back Water. Eng. Rec. April 26, 1902. 74. Harris, E. G., Taylor, W. D., Ladshaw, Y. E. Back Water from Dams. The Effect on Meadow Lands. Eng. News, 1902, Vol. II, pp. 142 and 316. 75. Tables for Computation of Swell on Open Water Courses. Zeitschr. fur Arch, und Ing. Vol. 49, Cols. 258-274. 1903. 76. Fliegner, A. A New Method of Computing the Back Water Curve. Schweizerische Bauzeitung. Aug. 22, 1903. 77. Tolman, Breitslav. The Computation of Back Water Curves. Oesterr. Wochenschr. f d Oeffent Baudienst. July 1, 8, 1905. CHAPTER IV. WATER POWER. THE STUDY OF THE POWER OF A STREAMlJ^FFECTED BY FLOW. 46. Source of Water Power. Water power depends primarily on the flow of the stream that is being considered for power pur- poses, and on the head that can be developed and utilized at the site proposed for the power plant. Both head and flow are essen- tial for the development of water power, but both are variable quantities which are seldom constant for two consecutive days at any point in any stream. The variations in head and flow radically affect the power that can be generated by a plant installed folr power purposes. These variations also greatly affect the power that can be economically developed from a stream at any locality. The accurate determination of both head and flow therefore be- comes very important in considering water power installations and hence should receive the careful consideration of the engineer. The neglect of a proper consideration of either or both of these factors has frequently been fatal to the most complete success of water power projects. 47. Factors of Stream Flow. The quantity of water flowing in a stream at any time, which is more briefly termed "stream flow" or "run-off," depends primarily upon the rainfall. It is, however, influenced by many other elements and conditions. It depends not only upon the total quantity of the yearly rainfall on the drainage area, but also on the intensity and distribution of the rainfall throughout the year. In addition to these factors the geological structure of the drainage area, the topographical features, the sur- face area of the catchment basin, the temperature, the barometric condition, all influence and modify the run-off. Sufficient data is not available for a full understanding of this subject, but enough is available so that the general principles involved can be intelli- gently discussed and the problems considered in such a way as to give a fairly satisfactory basis for practical work. A. knowledge of the importance of the factors above mentioned and the extent to which they modify, influence or control stream flow, is essential 8o Water Power. to a broad knowledge of water power engineering. These factors are discussed in more detail in chapters VI, VII and VIII. 48. Broad Knowledge of Stream Flow Necessary. The flow of a stream is constantly changing and any single measurement of that flow will not furnish sufficient data on which to base an in- telligent estimate of the extent of its possible or even probable economical power development. A knowledge of the economical possibilities of such development must be based upon a much broader knowledge of the variations that take place in the flow of the stream. In order to fully appreciate the power value of a stream, the character and extent of its daily fluctuations must be known or estimated. Averages for the year, monthly averages, and estimates of average power have been ordinarily taken as a basis for water power estimates, but they are more or less misleading, unsatisfactory and uncertain for the reason that such averages in- clude extremes, the maximum of which are often unavailable for water power purposes without more extensive pondage than is usually practicable. These maximum and minimum flows which affect the power of a stream not only through the quantity flowing but also through the head as well, as will be hereafter discussed, are of the utmost importance for a broad consideration of water power. So also is a knowledge of the various stages of flow and the length of time that each will prevail. Such knowledge demands daily observations or estimates of daily flow which can be repre- sented in graphical form by the hydrograph. 49. The Hydrograph. The hydrograph, constructed for the study of stream flow and its influence on water power, may be drawn by representing the daily flow in cubic feet per second at the point of observation by the ordinates of the diagram and the element of time by the abscissas. (See Fig. 37.) The result is a graphical diagram which shows the character and extent of the daily fluctua- tions in the flow of a stream at the point of observation during the period for which the hydrograph has been prepared. A single observation of the flow of a stream represents a totally inadequate and unsatisfactory criterion for water power consid- eration. By reference to Fig. 37 it will be seen that, if the dis- charge of the Wisconsin River at Necedah had been measured only on August 5, 1904, the conclusion would have been reached that the discharge of the river was about 2,100 cubic feet per second. If the measurement had been taken only on August 15, 1904, the flow would have been determined at about 5,850 cubic feet per second, or almost three times as great as on the first date. The The Hydrograph. 81 ON033S H3d 133J 3IBf)3 a a a a a cu Nl 39HVH08IQ ONDa3S_U3d 133J_ 31803 Nl 39UVH3SIO 82 Water Power. difference between the dates might be even greater, and no single measurement nor any series of rneasurements for a single week or month would give a fair criterion from which the normal flow of the river could be judged. The hydrograph of the daily flow of a river for a single year gives a knowledge of the variation in flow for that year only, under the peculiar conditions of the rainfall, the evaporation, and the other physical factors that modify the same and that obtain for that particular year. Such information, while important, is not altogether sufficient for the purpose of a thorough understanding of the availability of the stream flow for power purposes. Observa- tions show that stream flow varies greatly from year to year, and, while, with a careful study of the influences of the various factors on stream flow, together with a knowledge of the past variations in such factors, the hydrograph for a single year may give a fairly clear knowledge of the variations to be expected in other years where conditions differ considerably, still it is desirable that the observations be extended for as long a period as possible. Such long time observations may remove the estimates of flow entirely irom the domains of speculation and place them on the solid ground of observed facts. Hydrographs of a river that cover the full range of conditions of rainfall, temperature, etc., which are liable to pre- vail on its drainage area,. give a very complete knowledge of the flow of the stream for the purpose of the consideration of water power. It is rare, however, that observations of stream flow for a long term of years are available at the immediate site of a proposed power plant. Such observations are ordinarily made only at loca- tions where power has been developed and where water power or similar interests have been centered for a long period of time. Oc- casionally, however, the future value of potential powers is recog- nized and appreciated, and local observations are maintained for a series of years by interested parties, having a sufficient knowledge of the subject to recognize the value and importance of such in- formation. The variation of flow for some considerable time pre- vious to construction is thus available upon which to base the design. In .considering new installations, one of four conditions obtains : First : Hydrographs are available at the immediate site proposed. Second: Hydrographs are available at some other point on the river above or below the proposed installation. The Use of Local Hydrographs. 83 Third : Hydrographs are not available on the river in question but are available on other rivers where essentially similar condi- tions of rainfall and stream flow prevail. Fourth : No hydrographs, either on the river in question or on other rivers of a similar character and in the immediate vicinity, are available. 50. The Use of Local Hydrographs. When hydrographs, con- structed from observations taken at the immediate site of the pro- posed water power installation, are obtainable, for a considerable number of years, the most satisfactory -character of information is available for the consideration of a water power project. Under such conditions the engineer is not obliged to consider the rela- tion of rainfall to run-off or to speculate as to the relative value of the stream in question compared with other adjacent streams, or as to the effects of the physical conditions of drainage area, evap- oration, temperature and other factors on stream flow. The actual daily flow of the stream from day to day, perhaps through all ranges of rainfall, temperature, evaporation and other physical con- ditions, is known and the principal points which must be consid- ered are : First, the head available ; Second, the effects of the varia- tions of flow on the variations in head ; and Third, the extent to which the flow can be economically develo'ped or utilized. Gen- erally, however, even where local hydrographs are available, they are not sufficiently extended to cover all the variations in river flow which must be anticipated, and it is ordinarily desirable to com- pare the available data with the flow at other points on the stream in question or with other streams in the immediate vicinity. 51. Use of Comparative Hydrographs. Hydrographs taken at other points on the same river, or on other adjacent rivers where conditions are reasonably similar, are of great value in considering the local stream flow, provided all modifying conditions are under- stood and carefully considered. Hydrographs are ordinarily pre- pared to show the cubic feet per second of actual flow at the point at which observations are made. If the observations (and the hydrographs based thereon) made at some other point on a stream, of on some other streams, are to be used for jthe considera- tion of the flow at a point where a water power plant is to be installed or considered, the relation of the flows at the several points must be determined. As a basis for such comparison of stream flow, it may be as- sumed that the flow per unit of area at different points on the same Water Power. Fig. 38. Drainage Area of Wisconsin River Above Kilbourn, Wis. Use of Comparative Hydrographs. 85 % stream, or at points on different streams under similar circum- stances, is essentially the same. This is not strictly true, or per- haps it may be more truly said that the apparent similarity of condi- tions is only approximate and hence differences in results must necessarily follow. For a satisfactory consideration of the subject of comparative hydrographs, the variations from this assumption, as discussed in another chapter, must be understood and appre- ciated. For practical purposes, however, the assumption is often essentially correct and forms a basis for an intelligent considera- tion of stream flow where local hydrographs are not available. Fig. 37 is a hydrograph constructed from observations made on the Wisconsin River at Necedah, Wisconsin, by the U. S. Geological Survey for the water year, 1904, and shows the daily rate of dis- charge of the Wisconsin River at that point for the year named. The area of the Wisconsin River (see Fig. 38) above Necedah is 5,800 square miles. If, therefore, we draw a horizontal line from the point representing 5,800 cubic feet per second on the discharge scale (see Fig. 37), the line so drawn will represent a discharge at Necedah of one cubic foot per second per square mile of drainage area, and a similar line drawn from the 11,600 cubic foot point on the vertical scale will represent a discharge of two cubic feet per second per square mile, and so on. These lines may be fairly regarded not only as indicating the flow per unit of area of the - river at Necedah, but also the relative flow per unit of area of the Wisconsin River at points not greatly distant therefrom. At Kil- bourn, (see Fig. 38) located on the same river about forty miles below Necedah, the flow may be assumed to be similar and pro- portionate to the flow at Necedah. Above Kilbourn the drainage area is 7,900 square miles, and with similar flow the discharge would be proportionately greater. The fact must be recognized, and acknowledged, that the hydrograph is strictly applicable only to the point at which it is taken, and that certain errors will arise in considering its application to other points, yet observations and comparisons show that, while such errors exist, they are not nearly so important as the errors which arise from the consideration of averages, either annually or monthly. Consider, therefore, on this basis the Necedah hydrograph as shown in Fig. 37. On this diagram a flow of one cubic foot per second per square mile at Necedah, representing an actual flow of 5,800 cubic feet per second at that point, would, by proportion, represent a flow of 7,900 cubic feet per second at Kilbourn and, 86 Water Power. ' ON003S 3d I33J DIBflD 31UN Nl 39UVH3SIQ QN033S Ud 133J 318(13 Nl 33UVH3SIO Reliability of Comparative Hydrographs. 87 with a suitable change in scale, the diagram may be redrawn to rep- resent the flow at Kilbourn as shown in Fig. 39. This same method can be applied to any point on the same river or to comparative points on different rivers. 52. Reliability of Comparative Hydrographs. It must be clearly understood that comparisons as above described hold good only as the conditions are essentially similar at the various points com- pared. Stream flow at the best is very irregular and varies greatly from year to year. The actual departure from the truth can best be understood and appreciated from an actual comparison of flows on adjacent drainage areas where observations have actually been made for a term of years. From such an investigation, which can be made as extended as desirable, the true weight to be given to the comparative hydrograph can best be judged. It is not believed that the actual variations from the truth, as shown by carefully selected comparative hydrographs, will be any greater than the flow variations which actually take place from a drainage area from year to year under the varying conditions of rainfall and climate. This method, therefore, is believed to be a scientific and systematic one for the consideration and discussion of probable variations in stream flow at any given point, if its limitations and the modifying in- fluences known to exist on different drainage areas and under different geographical, geological and meteorological conditions are know r n and appreciated. 53. When no Hydrographs are Available. In a new country where no observations are available either on the drainage area under consideration or on other areas adjacent thereto, the study of comparative hydrographs is impossible and a different method of consideration must be used. If no data are available, time must be taken to acquire a reasonable amount of local information which should include not less than one year's observation. In addition to such observation a study as thorough as practicable should be made of the geology, topography, and other physical conditions that prevail on the water shed. Rainfall data is commonly avail- able for a much greater range of time than the observations of stream flow. The relations of rainfall to run-off are hereafter dis- cussed and approximate fixed relations are shown to exist between them. From such relations, and from a single year's observations,, conclusions may be drawn as to the probable variations from the observed flow which will occur during the years where the rainfall Water Power. B3A\Qd 3SUOH lVGI13dQ3Hl o en f c j in ' 31IJN ^ n V3S ] SbdQH 17 a a CD ID K OJ SbflOH b3MOd 3SUQH if in a fi a en in aj [ e 31VGS ] AVO b3d SHHQH 21 UQJ SnonNllNOD b3/V\Od 3SUQH 5J CO U CO O IB ^ n U3 CU < TJ- tv n eo ^ m r^ ^ nj ^ | s % & g U 'O M 3UVOBS U3d ON033S U3d 133J Nl 33bVH3SIO V 31V3S ] b3MOd 3SbOH SnOnNllN03 1VH13V The Hydrograph as a Power Curve. 91 AVO U3d SUnOH Qi UOJ SnOflNUNQO U3MOd 3SUOH 3 5 in ^ n 3TUN 3HVnDS H3d ON033S 3d 133J 3I8RD Nl 33UVHOSIO 92 Water Power. horse power of the river at Kilbourn with the wheels working with the efficiency and under the head named. Such a hydrograph is shown by Fig. 41, referred to by the left-hand scale (A). Power, however, is not always used continuously for twenty-four hours. If pondage is available the night flow may be stored and utilized during the day. If the flow of twelve hours at night is impounded and used during the day under the seventeen foot head, the power will be double that shown on scale A, and can be represented by another change in scale as shown by Fig. 41, referred to scale B. If the flow for the fourteen hours of night is stored and utilized in the ten hours of day, then the hydrograph can be made by another change in scale to represent the ten hours power as shown by Fig. 42. The total horse power hours which are available from a stream for each day may be represented (either theoretically or actually) by multiplying the scale of continuous power by 24. The actual horse power available at Kilbourn under the conditions named is represented by scale C in Fig. 41. It will be noted that by pointing off one place in the figures of scale C, Fig. 41, the hydrograph will represent the same condition as shown in Fig. 42. CHAPTER V. WATER POWER (Continued.) THE STUDY OF THE POWER OF A STREAM AS AFFECTED BY HEAD. 55. Variations in Head. In the previous chapter the graphical representation of stream flow has been considered. A method for the expression of the power resulting from the fluctuations of stream flow and under a constant head has also been shown. Ex- perience shows, however, that such a condition seldom if ever occurs. In some cases where the available head is a very large element of the possible power, the fluctuations may be so small as to be of little or no importance. In many other cases where the available heads are considerable, the importance of the fluctuation in head is comparatively small, under which condition the diagrams already discussed are essentially correct and are satisfactory for the consideration of the varying power of the stream. In power developments under the low heads available in many rivers, the fluctuation in head is almost or quite as influential on the con- tinuous power that may be economically developed from a stream as the minimum flow of the stream itself. The hydraulic gradient of a stream varies with the quantity of water flowing. At times of low water the fall available in almost every portion of its course is greater than is necessary to assure the flow between given points and frequent rapids result (see R. R. Fig. 43) which are commonly the basis for water power develop- Flood flow. Medium Water Low Water Stream Bed- Fi g . 43. Hydraulic Gradients of a Stream Under Various Conditions of Flow. 94 Water Power. ments. As the flow increases, however, a higher gradient and greater stream section is necessary in order to pass the greater quantity of water, and the rapids and small falls gradually become obscured (as shown by the medium water lines, Fig. 43) or dis- appear entirely under the larger flows (as shown by the higher water line, Fig. 43). Water power dams concentrate the fall of the Hood Mow Medium Wafer Low Water. Stream Bed. Fig. 44. Hydraulic Gradients of the Same Stream After the Construction of Dam and Under Various Conditions of Flow. river that is unnecessary to produce flow during conditions of low and moderate water (as shown in Fig. 44), and when the gradient of the water surface and the cross section of the stream are in- creased to accommodate the larger flow, the fall at such dams is frequently greatly reduced (as shown by the medium water line in Fig. 44) or, during high water, the fall is largely or completely de- stroyed (as shown by the high water lines in the Figure), or at least is so reduced as to be of little or no avail under practical water power conditions. The cross section of the river bed, its physical character and longitudinal slope, are the factors which determine the hydraulic gradient of a stream under different flows. They are so variable in character and their detail condition is so difficult of determina- tion that sufficient knowledge is seldom available, except possibly in the case of some artificial channels, to determine, with reason- able accuracy, the change of the surface gradient and cross section of the water under various conditions of flow. Where a power plant is to be installed, it is important to ascertain the relation of flow to head in order that the available power may be accurately deter- mined. Where a river is in such condition as to make the de- termination of a discharge rating curve possible, either by direct river measurement at the point in question or by a comparison with the flow over weirs at some other point, such determination should be carefully made, as such knowledge is of the utmost importance in considering the problem of continuous power. The Rating Curve. 95 56. The Rating or Discharge Curve. The rating curve, which will be discussed in some detail in a later chapter, is a hydrograph that represents the relation of the elevation of the water surface in a channel to the quantity of water passing a given cross section. The form of this curve varies with the various conditions of the cross section both at the immediate point and for a considerable distance above and below the location considered and can usually be de- termined only by detail observations. The rating curve is a uni- form curve only for channels in which no radical change in form of cross section occurs with the increase of flow. (See A Fig. 45.) If, on account of overflow conditions, or sudden enlargements of the cross section, that cross section varies radically in form at a given height, then at this elevation a radical change in the slope of the rating curve is likely to occur. (See B and C Fig. 45.) B Fig. 45. The Influence of the Stream Cross Section on the Rating Curve. Any change in the bed of the stream may, and frequently does, modify to a considerable extent the rating curve, which must be expected to vary under such conditions to an extent that depends on the variations that take place in the cross section and elevation of the stream bed. Such variations, however, are not, as a rule, of great magnitude and consequently will not usually affect the head materially at a given point. 9 6 Water Power. In Fig. 46, which shows the rating curve of the Wisconsin River at Necedah, Wis., as determined at different times during the years 1903 and 1904, an extreme change of head of about six inches will be noted for ordinary flows. When the change in head is of suf- fcJC Sfcrf * '<- EC 3 , 130* Discharge in Cu. Ft. Per Second. Fig. 46. Rating Curves, Wisconsin River at Necedah, Wis., Showing Changes in Head Due to Changes in Cross Section, ficient importance to warrant the expense, the river channel may be so dredged out as to restore the original head when the reduction in head is occasioned by the filling of the section. 57. The Tail Water Curve. It will be readily seen that while the rating curve shows the relation between stream flow and river height prior to the construction of a dam, it will still represent the condition of flow below the dam after construction is completed. The water flowing over the dam will create a disturbed condition immediately below. If the velocity of the flow is partially checked or entirely destroyed, a heading-up of the water may result below the dam sufficient to give the velocity required to produce the flow in the river below, but it will soon reach a normal condition similar to that which existed previous to the construction of the dam. 58. The Head Water Curve. In Chapter III is shown (see Figs. 35 and 36) the discharge curves over weirs of various forms and the formulas representing them are also quite fully discussed. From The Graphic Representation of Head. 97 these formulas or diagrams a discharge curve can be readily cal- culated, with reasonable exactness, for a dam with a certain form and length of crest. Such a curve will show the height of the head waters above the dam and under any assumed conditions of flow. From the rating curve of the river at the point considered, and the discharge curve of the weir proposed, the relative positions of head and tail waters under varying conditions of discharge can be readily and accurately determined, and if a weir is to be built to a certain fixed height, it will be seen that the head under any given conditions of flow may be thus determined. 59. Graphic Representation of Head. Fig. 47 shows the rating curve of the Wisconsin River (see lower curve marked "Tail Water DISCHARGE IN CUBIC FEET PCQ SECOND Fi g> 47. Showing Head at the Kilbourn Dam Under Various Conditions of Flow. 98 Water Power. Curve") at Kilbourn. On this diagram has also been platted sev- eral discharge curves, two being for a weir of 300 feet in length and two for a weir of 350 feet in length. Both weir curves in the upper set are based on the assumption that the entire flow of water is passing over the weir. The crest of the dam is shown as raised to gauge 19, and the distance between the rating curve, which now represents the height of the tail water, and the weir discharge curves, which represent the height of the head water (with two dif- ferent lengths of weir) under different conditions of flow, will show the heads that obtain at all times under these assumptions. The entire discharge of the stream, however, will not pass over the dam except when the plant is entirely shut down, which would seldom be the case. The essential information which is desired therefore is the available head when the plant is in active operation. At the Kilbourn plant the discharge of the turbines to be installed under full head will be 7,000 cubic feet per second, hence, with the plant in full operation, this quantity of water will be passing through the wheels. Therefore in determining the relation between head water and tail water it must be considered that with a flow of 7,000 cubic feet per second, the water surface above the dam will be at the elevation of its crest, no flow occurring over the spillway, and that only the flows greater than this amount will pass over the dam. Another curve for each weir has therefore been added to the diagram in which the zero of the weir curves is platted from the point where the line representing the height of the dam (elevation 19) intersects the line representing a discharge of 7,000 cubic feet per second. From this diagram (Fig. 47) it will be seen that other heads, shown in Table VIII, will obtain under various conditions of flow. It will readily be seen that the line representing the height of the dam is not essential and that the curves may be platted relative to each other, leaving the height of the dam out of the question entirely and indeterminate. A curve constructed on this basis but otherwise drawn in the same manner as in Fig. 47, is shown in Fig. 48. In Fig. 48, wherever the weir or head water curves pass above the tail water curve, it shows that an increase in the head will re- sult under the corresponding condition of flow and wherever they pass below such curve, it shows that a decrease in the head will result under the corresponding condition of flow, the amount of which is clearly shown by the scale of the diagram. Consequently, having given the height of the dam above tail water at the point The Graphic Representation of Head. 99 of no discharge, the head available under any other condition can be immediately determined from the diagram. From this diagram the changes in head (as shown in table IX) can be determined and these, with a 17 foot dam, will give the total TABLE VIII. Gauge heights and heads available at Kilboum Dam under various conditions of flow, with a length of spillway of 300 and 350 feet. HEAD^ WATER HEAE WITH Flow in cubic feet per second. 300 ft. dam. 350 ft. dam. Tail Water. 300 ft. dam. 350. ft. dam. 7000.... 19 19 1 7 14000 22 9 2 9 > *> 1 170 Ll 1 7 9 21000 25 2 24 6 Q 179 I/ ./ 1 K A 28000 27 26 9 mQ 1R 7 ID.O -ICQ 0*5000 28 5 27 7 I 9 2 ifi *i I C ft 42000 30.2 29 3 13 6 ifi fi i c 7 49000 31.5 30 4 14 7 Ifi 8 ic 7 56000 32 7 31 6 1 ^ fi 17 1 -ICQ 10. o heads available under various conditions of flow as shown in the last two columns. These heads will be seen to correspond with the heads given in table VIII. DISCHARGE OF WISCONSIN RIVER AT KILBOURN IN CUBIC FT. PER SEC. Fig. 48. Showing Change in Head at Kilbourn Dam Under Various Condi- tions of Flow. 100 Water Power. TABLE IX. Changes in head at Kilbourn Dam with lengths of crest of SOO and 350 feet and under various conditions of floiv with resulting total available head ivith 17 ft. dam. Flow in cubic feet . per second. CHANGES IN HEAD WITH TOTAL HEAD WITH 300 ft. dam. 350 ft. dam. 300 ft. dam. 350 ft. dam. 7000 ...... + .8 + .2 .3 .5 .4 .2 + .1 + .2 .4 1.1 1.5 1.3 1.3 1.2 17 17.8 17.2 16.7 16.5 16.6 16.8 17.1 17 17.2 16.6 15.9 15.5 15.7 15.7 15.8 14000 21000 28000 35000 42000 . . . 49000 56000 60. Effects of Design of Dam on Head. It should be noted in both of the last diagrams that the height of the water above the dam is readily controlled by a change in the form and length of the weir; that a contraction in the weir length produces a corre- sponding rise in the head waters as the flow increases, while the lengthening of the weir will reduce the height of the head water under all conditions of flow. The physical conditions relative to overflow above the dam will control the point to which the head waters may be permitted to rise and will modify the length and the construction of the dam. Where the overflow must be limited, the waters, during flood times, must be controlled either by a suffi- cient length of spillway or by a temporary or permanent reduction in the height of the dam such as the removal of flash boards, the opening of gates, or by some form of movable dam. Having determined the head available at all conditions of river flow, the hydrograph, as previously shown, may be modified to show the actual power of the river under the varying conditions of flow. The vertical scale, in this case, instead of being uniform must be variable as the head varies. Fig. 49 shows graphically the variation in the continuous theoretical power of the river taking into con- sideration the variation in head which will actually occur. Com- pare this hydrograph with Fig. 40 in which no variation in head is considered. 6 1. Effect of Head on the Power of the Plant. It is important at this point to take into consideration the effect of head and flow on the actual power of the plant. In most rivers, under flood condi- Effects of Design of Dam 'on Ke'ad. 101 m ^ n cu 31IW 3UVntlS U3d QND33S H3d 133J 318(13 Nl 39UVH3SIO IO2 Water Power. tions, 'the power theoretically * available is largely increased, for, while the head may diminish, the flow becomes so much greater that the effect of head on the theoretical power is more than off- set thereby. Practically, however, the conditions of head under which a given water wheel will operate satisfactorily (i. e. at a fixed speed) are limited, and, while the theoretical power of the river may radically increase, the power of the plant installed under such conditions will often seriously decrease, and under extreme conditions may cease entirely. The discharging capacity of any opening is directly proportional to the square root of the head, and the water wheel, or water wheels, simply offers a particular form of opening, or openings, and operates essentially under this general law. With a fixed efficiency, therefore, the power which may be developed by a water wheel is in direct proportion to its discharging capacity and to the available head. Hence, the power of the wheel decreases as the product of these two factors, and therefore the power available under conditions of high flow and small head are much less than where the head is large and the total flow of the river is less. The only way, therefore, to take advantage of the large increase in theoretical power during the high water condi- tions is to install a surplus of power for the condition of average water. This may sometimes be done to advantage, but its extent soon reaches a practical limitation on account of the expense. It often becomes desirable to take care of such extraordinary condition by the use of supplemental or auxiliary power. Such power can usually also be applied during conditions of low water flow when the power is limited by the other extreme of insufficient water under maximum head. In considering the effect of head on the power of a plant, it is necessary to understand that water wheels are almost invariably selected to run at a certain definite speed for a given power plant and cannot be used satisfactorily unless this speed can be main- tained. Also that any wheel will give its best efficiency at a fixed speed only under limited changes in head. If the head changes radically, the efficiency changes as well and this fact becomes more serious under a reduction in head. As the head is reduced, the discharging capacity of the wheel and its efficiency is also rapidly reduced so that the power of the wheel decreases more rapidly than the reduction in the discharging capacity would mdicate. When the reduction of head reaches a certain point the wheel is able to simply maintain its speed without developing Relations of Power, Head and Flow. 103 power, and when the head falls below that point, the speed can no longer be maintained. It is therefore plain that when the head of a stream varies greatly, it becomes an important and difficult matter to select wheels which will operate satisfactorily under such varia- tions, and, when the variations become too great, it may be prac- tically or -financially impossible to do so. This subject is discussed at length in a later chapter, but is called to the attention of the engineer as an important matter in connection with the study of head. 62. Graphical Investigation of the Relations of Power, Head and Flow. The relation of head and flow to the horse power of any stream on which a dam has been constructed, may be graphically investigated and determined by a diagram similar to Fig. 50. On this diagram are platted hyperbolic lines marked "horse power curves" which show the relation of horse power to head and flow within the probable limits of the conditions at Three Rivers, Mich. These lines are drawn to represent the actual horse power of a stream under limited variations in head and flow and on the basis of a plant efficiency of 75 per cent. These heads, which actually obtain at the Three Rivers dam, were observed under three condi- tions of flow, and these observations were platted on the diagram at e e e and a .curve was drawn through them. From the intersec- tion of this curve with the horse power curves, the actual power of the river available under the actual variations of head and flow, is determined. These measurements were taken with all of the water passing over the dam. Let- us assume that it is desired to investigate the effect of an installation of wheels, using 600 cubic feet per second, under a nine foot head. Under these conditions part of the water will pass through the turbines instead of over the crest of the dam, the available head will therefore be somewhat reduced, and the power curve of the river, under these new conditions, is shown on the diagram by the curve f f f . This curve was platted from the curve e e e by computing the amount the head on the crest of the dam would be lowered at different stages of the river by diverting through the wheels the quantity of water which they will pass under the reduced head. The actual power of the river at different heads and under these conditions is shown by the intersection of the line f f f with the horse power curve, and the actual power of the pro- posed plant under various conditions of flow is obtained by pro- 104 Water Power. 2200 - * I I I CURVE: SHOWING RELATIONS or POWER . DISCHARGE. MMD u B.5 9.0 9.5 ID.Q IQ.5 TOTAL FALL FROM ABOVE DAM TO MOUTH OF TAIL RACE Fig. 50. Graphical Study of Head. jecting the point of intersection of the discharge line with the line f f f on the turbine discharge line d d. Thus, with a flow of 600 cubic feet per second, the power of the plant would be about 470 horse power, while, with a flow of 2,100 feet per second, the power of the plant would decrease to about 420 horse power. At discharges below 600 cubic feet per second, the head would drop rapidly unless a portion of the installation was shut down. 63. Graphical Study of Power at Kilbourn. A more detailed Relations of Power, Head and Flow. 105 S3NiaH.ni ,,/:S-- INVld JO H3MOd 1VOI13a03Hl OJ 7 C*5 I CO I O 00 O o oo o CD f-*0 O co eocu ao 038010 S31V3 T1V AV/VmidS ,036 - B3AIU JO 'd'H ^fenmcucueu ^, cu 00 00 to cu z o> - a I * QN033S U3d 132J QIBRQ Nl 3SdVH3SIQ O T-H- IO 60. 5- r o6 Water Power. study of head in connection with the conditions at Kilbourn, Wis- consin, is illustrated by Figures 51 and 52. In Figure 51 the theo- retical horse power of any stream resulting from any variation be- tween the head and flow is shown by the hyperbolic curves drawn from the upper to the right hand side of the diagram. Figure 47, already considered, shows the relation of the head and tail water at Kilbourn, where a dam with a crest 350 feet in length is projected. The curve on Figure 51 marked "Height of crest of dam above tail water" was obtained by subtracting the height of tail water at the various river stages, as given by the rating curve of the river, from the height to w r hich the dam is to be constructed and platting the same in their correct position on the diagram. The dam here considered is 17 feet in height above average water or with its crest at elevation 19 on the gauge. The curve on the right marked "Fall over dam, all gates closed", is constructed in the same manner by laying off as abscissas the actual head as deter- mined from Fig. 47 under various conditions of flow when the whole discharge of the river is passing over the dam. The ab- scissas, therefore, between these two curves show the head on the crest of the dam when the whole discharge of the river is passing over the dam. For any given river discharge (as for in- stance 16,000 cubic feet per second) the total fall can be obtained (in this case 18.8) and the theoretical horse power of the river (in this case 34,000 horse power) can be determined by finding the intersection of the line for 16,000 cubic feet per second with the curve marked "Fall over dam, all gates closed", and determining the relation of this point to the power curves. This relation is more clearly indicated by the first scale to the right. 64. Power of the Kilbourn Wheels Under Variations in Flow. When the gates to the turbines are open a less quantity of water will flow over the dam and the head on the crest will therefore be diminished. The amount of water which will pass through the pro- posed installation under various heads, is shown by the curve marked "Discharge 24-57" turbines." The intersection of this curve, with the discharge lines, at all points to the left of the curve marked "Height of crest of dam above tail water" indicates that such flows will pass through the wheels at the head indicated by the point of intersection. The practical limit of the turbine capacity is the discharge indicated by the point of intersection of the turbine discharge curve with the "Height of crest of dam above tail water". It will be noted that this intersection shows a maximum discharge Effects of Low Water Flow, icy of 7,000 cubic feet per second under a head of 17 feet. A further increase in the discharge of the river up to 8,700 cubic feet per sec- ond, causes an increase in the head, which is found by following upward the curve marked "Head 24 turbines" to the point m where a maximum head is indicated. The discharge from the turbines under this condition increases but slightly and is indicated by the vertical projection of the point of greatest head (m) on the turbine discharge line (at n) which is so slightly above the 7,000 cubic feet line as to be hardly distinguishable on the diagram. The power of the plant depends upon the head and the discharge through the wheels, hence the theoretical power which might be developed by the 24 turbines with a flow of 8,700 cubic feet per second would be about 13,800 horse power, which can be deter- mined by calculation or is shown by the relation of the point n to the power curves. The actual value of these various points is more clearly shown on the second scale to the right, marked "Theoretical power of plant 24-57" turbines". A further increase in the dis- charge decreases the head until for the 24 turbines a minimum is reached at a discharge of 42,500 cubic feet per second. Under this condition of head the discharge through the wheels has also been somewhat reduced, and the corresponding rmrse power is reduced to 11,300 as shown by the intersection of the discharge curve and the line indicating the head existing under these conditions. 65. Effects of Low Water Flow. In the case of low water when the flow is not sufficient to maintain the flow over the dam, if the turbines are run at full capacity, the water level behind the dam will drop until a point of equilibrium is attained where the head is just sufficient to force the entire discharge through the turbines. As the water level is lowered below the crest, the power of the plant rapidly' diminishes owing to the great decrease in the head for a small decrease in the flow. When the head decreases beyond a certain point the power of the plant may be increased by closing some of the gates of the turbines until the discharge through the turbines is less than the discharge of the river, when the head will increase by the backing up of the water behind the dam. Thus it will be seen by the diagram that, with only 6,000 cubic feet per second flowing in the river, if all of the turbines are operated the head will drop to about 12.7 feet, and the power of the plant under this head and flow would be about 8,660 horse power. If, under these conditions, one unit of six turbines, amounting to one- fourth of the plant, is shut down, the water will rise until the head io8 Water Power. is increased to about 18 feet. Under these conditions about 800 cubic feet per second of this water will waste over the dam, and the power developed by the remaining portion of the plant will be 10,630 horse power, or, about 2,000 horse power more with one unit shut down and with the resulting head than with all units in operation and the consequent lower head. The above discussion simply illus- trates the point that it is rarely desirable to draw down the head of an operating plant, at least to any great extent, for the sake of operating a greater number of wheels, unless this is done for the purpose of impounding the night flow for use during the day or at times of maximum load. Even in this case too great a reduction in the head is undesirable and uneconomical. 66. Effects of Number of Wheels on Head and Power. Fig. 52 is an enlarged section of that part of Fig. 51 shown by the dotted lines. This diagram shows how the head on the wheels may be maintained by shutting off some of the wheels in case the flow be- comes so small as to entirely pass the wheels and thus reduce the head, as described above. It will be noted that with a total instal- lation of 48 wheels, by closing the gates of two wheels at a time, the variation in the head would be only a fraction of a foot until as ma^y as 24 wheels ahe closed. Hence it will be seen that when the power has been decreased by a rduction of head, the wheels should be closed off until the same power can be secured by the less num- ber of wheels operating with the highest head that is available with the given discharge of the river. As the lower flows of the river are reached great fluctuation in the head will occur with the opera- tion of the turbine gates. This diagram shows the actual delivered power of the plant and is based on a plant efficiency of 75 per cent. The power obtained for a given discharge is therefore less than shown by Fig. 51. In order to secure more accurate results a small correction for the variations in efficiency under the variations in head may some- times be desirable. ' In the problem under consideration this is unnecessary on account of the small variation which takes place. However, when the variations in head are considerable, this correc- tion is essential if a close estimate of power at different heads is desired. Figure 53 is a power hydrograph similar to those already discussed but with such changes in the scale as to show the con- tinuous power that could have been developed by these four groups of turbines at Kilbourn, Wisconsin, during the year 1904, under Effects of Number of Wheels on Head and Power 109 10000 14000 12000 ^^ 10000 8000 6COO 4000 2000 14 15 .16 19 17 18 Head in Feet Note H. P. Curves are based on 75$ efficiency Fig. 52. Relation of Number of Wheels to Power and Head. the variations in head which would actually have occurred with the dam it is proposed to construct. From the previous discussion of the conditions at Kilbourn it is seen that with a dam with fixed crest the variations in head, due to variations in flow, are comparatively small. Consequently the power of the wheel to be installed will not decrease with an in- crease in flow to as great an extent as usually occurs in water power plants. If a system of flash boards or an adjustable crest is found desirable in order to prevent overflow at times of flood, the power of the plant when these are lowered will be still further reduced. The hydrograph may be utilized for more detailed analysis of water power questions and will be further discussed in a future chapter. no Water Power. 93Miaani o ivDii3U03H n CHAPTER VI. RAINFALL. 67. Importance of Rainfall Study. The influence of rainfall on the flow of streams is so direct that those unfamiliar with the sub- ject are apt to assume that the relation may be represented by some simple expression and that, therefore, if the rainfall for a period of years be known, the corresponding stream flow may be directly and readily calculated therefrom. With only a brief famil- iarity with the subject it is evident that no such simple relation ex- ists. The relationship is, in fact, complicated by a multiplicity of other physical conditions which have an important if not an equal influence. Observations of stream flow are quite limited both in time and geographical extent while the observations of rainfall have extended over a long period of time and the points of observation are geo- graphically widely distributed. If, therefore, it is possible to trace such relationship between the flow of streams and the rainfall and other physical conditions on the drainage areas as will enable the engineer to calculate the flow even approximately, such relation- ships become of great value to the water-power engineer, on ac- count of the lack of other more definite information. It^is there- fore important that the engineer inform himself as fully as pos- sible on the relations that exist between rainfall and stream flow and the modifications of those relations by other physical factors. By such means the information regarding rainfall, already recorded for long terms of years, may be applied to the problem of stream flow in which the engineer is more directly concerned. For this reason the subject of rainfall is here discussed in as much detail as the space will permit. 68. Distribution of Rainfall. A continuous circulation of water is in progress on the earth's surface. The evaporation from the water and moist earth surfaces rises into the atmosphere in the 129- 127' 125" 123' 121 119 117 115 113 111 109 7 105 103 101' 90' 95 119 117 US' H3- lir 109 107 Jtf 03 91 89 87 85 83" OP THE UNITED^STATES ix 4 Rainfall. 1895 1896 1897 1898 IQ99 1900 E3 25 TO 30M 30 TO 35^33 TO 40^0VrB 40 llNCHES I! HI INCHES Y//A INCHES . E 3 INCHES . gra.NCHES . CINCHES . ^ INCHES . Fig. 55. Distribution of Total Annual Rainfall in Wisconsin. Distribution of Annual Rainfall in Wisconsin. 115 1901 1902 1903 1904 1905 UNDERI5 Ijij ISTOaok%//320T025 INCHES. I |j INCHES. Y///A INCHES 23 TO 30 INCHES 30 TO 35 INCHES AVERAGE J35 TO 40 | ilNCHES | OVER 40 llNCHES Fig. 56. Distribution of Total Annual Rainfall in Wisconsin. 1. 1 6 Rainfall. form of vapor, partially visible as clouds, mist and fog, and is afterwards precipitated as rain and dew. The distribution of rain- fall on the earth's surface is by no means uniform. An examina- tion of Fig. 54, which is a map showing the average distribution of the annual rainfall in the United States, will show how greatly the average annual rainfall differs in various parts of the United States. The local variation in the average annual rainfall in the United States is from a minimum of no rainfall, during some years in the desert regions, to an occasional maximum of more than one hun- dred inches in the extreme northwest. From this map it will be noted that from the Mississippi westward the lines of equal rain- fall are approximately north and south and parallel with the moun- tain ranges. In the Southern states, east of Texas, they are ap- proximately parallel with the Gulf of Mexico, and on both the At- lantic and Pacific coasts they are approximately parallel with the coast lines. At various points in the United States other influences come into play and greatly modify the general distribution as above outlined. In a general way the rainfall may be said to be in- fluenced by the topography of the continent and, to a considerable extent, by its altitude. In general, the rainfall decreases as the elevation above sea level increases, although in some cases the op- posite effect holds. This general law seems to be substantiated by reference to the annual rainfall map. In passing along the parallel of 40 as we ascend from the Mississippi River to the western mountains the annual rainfall decreases from about 35 inches an- nually to 10 inches or less. On the other hand, a reference to our Western coast will show that some of the heaviest rainfalls that occur are due to precipitation caused by the moist winds from the Pacific striking the higher mountain ranges. This is a local condi- tion, however, and is quite different in its character from the gen- eral law above stated. The mountain ranges along the Pacific coast which intercept the moisture from the Pacific and cause the heavy rainfalls in the higher mountain areas are also the direct cause of the small rainfall in the arid regions lying east of these mountains. 69. The Rainfall Must be Studied in Detail. The map of average annual rainfall is of value only for a general view of the subject. For special purposes a detail study of the local variations from the average conditions is necessary. Great variations take place in the annual rainfall of every locality. Sometimes the annual rainfall will be for a series of years considerably below the average, and Distribution of Weekly Rainfall in Wisconsin. 117 MAY 13 TO MAY 20 MAY 20 TO MAY 27 MAY 27 TO JUNE 3 JUNE 3 TO JUNE 10 JUNE 10 TO JUNE 17 JUNE 17 TO JUNE 24 INCHES IN DEPTH OT0.25" .25T0.50 .SO"TO.7S" .75"TO \". Fig. 57. Distribution of Weekly Rainfall in Wisconsin u8 Rainfall. Fig. 58. Rainfall Conditions in the United States at 8 A. M., July 10th, 1907. Fig. 59. Rainfall Conditions in the United States at 8 A. M., July 17th, 1907. Local Variations in Annual Rainfall. 119 then for a number of years the average may be considerably ex- ceeded. No general law seems to hold, however, in regard to this distribution and the variation seems to occur either without law or by reason of laws so complicated as to defy determination. The variations in the distribution of the annual rainfall in the State of Wisconsin for eleven years are shown by Figs. 55 and 56. From these maps can be clearly seen how greatly the distribution of rain- fall throughout the state differs in different years from the average annual rainfall as shown on the last map of the series. It should also be noted that in the same manner these annual rainfall maps are the results of the summation of an irregular distribution of numerous rainstorms, the irregularities of which can perhaps be more clearly shown by the maps on Fig. 57 which show the weekly distribution of rainfall in Wisconsin for six consecutive weeks in May and June, 1907. All such maps are but the result or sum- mation of individual rainstorms which occur during the period considered. Individual rainstorms never occur twice over exactly the same geographical extent of territory nor with equal intensity at any points within the territory covered. They are not only irregular in their distribution but progressive in both their dis- tribution and intensity, changing from hour to hour during their occurrence. The extent of a somewhat general rainstorm in pro- gress at 8 : oo A. M. (Washington time) over the Northwest on July i6th, 1907, is shown by Fig. 58. On the area over which this storm extended, the actual precipitation varied widely and the extent of the storm rapidly changed from hour to hour. At 8 : oo A. M. on July I7th the general rainfall had ceased and the storm -had be- come localized as shown by Fig. 59. The varying character and extent of the rainfall as illustrated by those two maps show the extremes of one storm which affected the Northwest, and illustrates, in a general way, the irregularity and lack of uniformity in rainfall occurrence and distribution. 70. Local Variation in Annual Rainfall. By reference to Fig. 60, the variations which have occurred in the annual rainfall at various localities in the United States will be seen, and from this data the lack of uniformity in the annual rainfall will be more fully appre- ciated. By an examination of the records of a sufficient number of years the limiting conditions may be determined and an ap- proximate determination of the relation between the extremely dry and extremely wet periods made. 120 Rainfall. No. Atlantic, So Atlantic, St. Lawrence, Ohio River, New Haven, Conn. Augusta, Ga. Detroit, Mich. Cincinnati, O. ^ ^ n ^ ^ % r> f/ / f 7* ^7^ ? ^ ^ 7j r/ 6 / / / / 7 s 7/ - & 40 ^ HpN l~t ~~R rt~?i ^-^^P-%^ 30 ^ 20 ^ 10 ^ y/S(%%sffik%%%/%> P_J | ^ a Hig^ ', /. '//, ? ^ y\ Kv 7 ! t ^p^p^^^ ' ', ) { i J' ^ rzi -' 1 ' i ] r f { J r ;/^ i i?x ?X2 i|%& Y y '' 'W '' r/// '" o Eastern Gulf, Western Gulf. Montgomery, Ala. San Antonio, Tex. Upper Misissippi, Lower Mississippi, Des Moiues, la. Little Kock, Ark. n ^ ^ %-* 2 2 111^^ ^ &\ ^ F 2 2i {22 \ \TvJ^^ fet, p^llp 80 \ \ty\'t'ti$i$t III'? ^^ =plll|ln! \^\^Yi ^^ ^ ^^i KE Mi Topeka, Kar ssouri River, is. Helena, Mont. Red Riv Moorehead, er. Minn. Tac S T o. Pacific, :oma, Wash. m _f^ K Pj p7] ^ ^ ^ ^^/ ^ ^ ^ 2 ^2 Z ^ ^ ' ^l^ii^^^l y // / // / / / 7 / ^ P71 r-rv-H ^ '^W////////////''/ ^ 1 1 1 1 ; ; L "^ 1 2 1 1 1 ^^^^^^ -P^P^-P^ / ^ ' 7 ^ %.%%% / /'t!'/.'t. ^i^l^^^i^i^i :/ 6 ^ ^ %' ^- ? 3^?^M>M? '-': ^ ^ t,y~0L$w)0$0W, Columbia, Pacific, Colorado, Great Basin, Spokane, Wash. Sacramento, Cal. Phoenix, Ariz. Winnemucca, Nev. Fig. 60. Variation in Annual Rainfall at Various Points in the United States. Local Variations in Annual Rainfall. 121 Figure 61 i a diagram showing the fluctuations that have occurred in the annual rainfall at Madison, Wisconsin, from 1869 to 1905. The variation at Madison has been from a maximum of about 52 inches in 1881 to a minimum of about 13 inches in 1895 which represents a greater range (4 to i) than ordinarily obtains. As a general rule the maximum may be stated to be about double the minimum annual rainfall. FLUCTUATION OF ANNUAL RAINFALL AT MADISON, WIS. Fig. 61 71. Local Variations in Periodical Distribution of Annual Rain- fall. The amount of the annual rainfall is only one of the elements that influence the run-off. The time of occurrence or the periodical distribution of the rainfall is even of greater importance. The general character of the periodic distribution of the annual rain- fall is similar each year in each locality, for the maximum and minimum monthly rainfalls occur in each locality at fairly definite periods. As the cycle of the seasons changes, conditions favorable or unfavorable to precipitation obtain, and, while these differ very largely from year to year and are subject to such wide variations as to render the character somewhat obscure, unless a number of seasons are considered, yet the same general character ordinarily prevails. Figure 62 shows the extreme and the average variation of the monthly rainfall at Madison. The monthly rainfall in the various months differs widely in amount and is by no means proportional to the total annual rainfall for the year. It is especially observable that during the year of maximum rainfall, viz: for 1881, the rain- fall for April was almost as low as for the April of the year 1895 when the total annual rainfall was at a minimum. It is also observ- INCHES OF RAINFALL. E _ . - to o rouJikCncnNicacaa - i i ii Rainfall. \ 1 1 ./ \ II \ / I \ 1 / ?\ i/ \ y \ / !\ \\ 1 \ i \ / / > \ / -^ /. i !\ / \ \ / / / Y L AVERAt E 1884 -I904P l \ s / - 5 /I TAL AN 4UAL 30 .18 lN' r 1 i l> 1 1 \ A ,\ --"' ^ \ '/ \ \ 3 l'\ "S^ \ (^ \ /" ^ ^ ^l '' FLUCTUATION OF MONTHLY RAINFALL AT MADISON, WIS, Fig. 62 able that the rainfall for August, 1881, was less than the rainfall for August of 1895. Figure 63 shows the typical average monthly dis- tribution of precipitation at various points within the United States, and the general law to which even the variations mentioned par- tially conform. The character of the monthly distribution varies widely at different locations, but will be seen to have a similar character wherever similar conditions prevail. Thus the New Eng- land States present a similarity in the distribution of the monthly rainfall. A similarity in the monthly distribution is also found, throughout the lake region and the Ohio Valley. The monthly dis- tribution throughout the Great Plains is also similar, and a marked similarity exists at points along the Pacific coast. 72. Accuracy of Rainfall Maps and Records. It must be under- stood that the rainfall maps, showing lines or belts of equal rain- fall, are only approximately correct, and that it would be impossible to show by such lines small differences in annual rainfall of less- Monthly Distribution of Rainfall. "Types of Monthly Distribution of Precipitation in the United States. Rainfall Distribution in the U. S. (Percentage of fall in each month represented by heavy lines.) 123 Fig. 63 124 Rainfall. than two or three inches. As a matter of fact, the rainfall actually differs considerably within comparatively small limits, but within such limits the average remains fairly constant for the year or sea- son. Frequently, however, the rainfall variations even within narrow limits differ widely. Many questions of importance in con- nection with the consideration of rainfall are still open to debate and are frequently answered in a diametrically opposite manner by data secured from different localities. 73. Rainfall and Altitude. The relation of the rainfall to al- titude has been a subject of frequent discussion and perhaps the majority of data secured tends to show that there is a material decrease in the fall of rain as the altitude increases, and this both within a broad area and with great changes of altitude and within a limited area and where the differences in altitude are compara- tively small. Mr. Rafter, in the Hydrology of New York, points out the fact that in the State of New York the rainfall records show both increase and diminution of precipitation with increase of altitude. The Hudson River catchment area shows a higher precipi- tation at the mouth of the river than it does at its source in the Adirondack mountains, while the Genesee River shows the op- posite : that is, a higher precipitation at its source than at its mouth. In this case the influence of altitude, if such influence can be said to obtain on such limited areas, is overshadowed by other predomin- ating influences. In this connection Fig. 64 is of interest. This diagram shows the variation in the annual and monthly rainfall at three stations within the City of Chicago. Curve No. I shows the rainfall at the Auditorium Tower, at an elevation of 233 feet above the level of the city. Curve No. 2 shows the rainfall at the Chicago Opera House Building, at an elevation of 132 feet. Curve No. 3 shows the rainfall at the Major Block, elevation 93 feet. The relative monthly rainfall at these three stations varies greatly, and, while the annual variations at these three points, all of which are within a square mile in the business center of Chicago, differ- considerably from each other, still the difference is insignificant in comparison with the monthly variation. While the influence of alti- tude may possibly be seen in the annual results and possibly in the monthly results as shown at stations one and three, the monthly results at station two show no such effect, or, at least, the effect is greatly obscured by other influences. 74. Value of Extended Rainfall Records. One of the points that becomes important in the consideration of rainfall records is the Value of Extended Rainfall Records. 125 ANNUAL JAM. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC. I B 3 30 ^ ' / ; . / / 1 1 ' .' 4.0 ! i /' ^*-L | ^ * ^-| * -v \ "X 1 \ i , i ' "N. 1 \ f-- ^ xf" 1 j y ^ ! s 4 V _^ | / -Nr x ^- s 1 i\ r i S ^x* ./ \ / \ "> 3 .-' ' SZ \, 3 ', / -\ /' 2 N ^ 3 \ / \ / =fe / ^ -7^ < ^~ -/ ~T~ -7^ ^N^ 2 \ i \ / "V \ i/HU. d / \ j i * V s 10 Fig. 4$. Monthly. and Annual Precipitation of Three Exposures in Chicago, 111. 1. Auditorium Tower, Elevation 238 feet. 2. Chicago Opera House Building, Elevation 132 feet. 3. Major Block, Elevation 93 feet.* length of time required to make such records safe as a basis for future estimates. This subject is well considered in a paper by Alexander A. Binnie, member of The Institute of Civil Engineers, published in the Proceedings, Vol. 109, 'pages 89 to 172. Mr. Binnie's conclusions are that: "Dependence can be placed on any good record of 25 years' dura- tion to give a mean rainfall correctly within 2 per cent of the truth." Mr. Rafter, after reviewing this paper, concluded, that: "For records from 20 to 35 years in length the error may be expected to. vary from 3.25 per cent down to 2 per cent, and that for shorter periods of 5 to 10 and 10 to 15 years the probable ex- treme deviation from the mean would be 15 per cent to 4.75 per cent respectively." Mr. Henry from his examination of this question in reference to various localities has drawn the following conclusion: For a ten year period the following variations from normal have occurred : New Bedford + 16 per cent. 11 per cent. Cincinnati +20 " 17 " St. Louis +17 " 13 " Fort Leavenworth +16 " 18 San Francisco.. + 9 10 " Reproduced from original slide published by Geographical Society of Chicago. 126 Rainfall. For a 25-year period Mr. Henry found that the extreme variation was 10 per cent both at St. Louis and New Bedford, and reached the conclusion that at least 35 to 40 years' variations are required to obtain a result that will not depart more than -j- or 5 per cent from true normal. The average variation of the 35-year period Mr. Henry found to be -f- or 5 per cent and for a total 4O-year period + or 3 per cent. 75. Accuracy in Rainfall Observation. It must also be under- stood that on account of the marked variations which actually occur in rainfall within limited areas and by reason of limited difference of elevation, the observation of actual rainfall is not without its difficulties. In order to secure great accuracy great care must be exercised in the placing of rain gauges so that they may receive and record the rain received in an accurate manner. Subject, as they are, to considerable variations, it would seem unwise to use great refinement in the calculations of rainfall, and in recording rainfall one decimal place is probably all that is warranted and two places is the ultimate limit of possible accuracy. 76. District Rainfall. In determining the average rainfall on a drainage area an extended series of observations over the entire district considered become essential and conclusions drawn from more limited observations are subject to considerable inaccuracies. Rainfall stations, distributed as uniformly as possible over the drainage area, should be selected, and the average result of the ob- servations of these stations should be used as the basis of calcula- tion. Possibly a still more accurate method of considering this subject would be the selection of rainfall observations on each particular branch of the stream considered. The value to be given to each set of observations used should be in proportion to the ter- ritory drained by the tributaries. 77. Study of Rainfall as Affecting Run-off. In considering the rainfall on a district in relation to the run-off of streams, it is desirable to study the rainfall records on the basis of what is termed "water year". The water year for most of the area of the United States, instead of coinciding with the calendar year may be best divided into periods beginning, approximately, with De- cember and ending, approximately, with the following November. The first six months of this period, December to May inclusive, is termed the "storage" period. June, July and August constitute the "growing" period ; September, October and November, the "re- plenishing" period. For the purpose of discussing rainfall in its Mean Monthly Rainfall 127 Northern Atlantic, New Haven, Conn, Southern Atlantic, Augusta, Ga, St. Lawrence, Detroit, Mich. Ohio River, Cincinnati, O. Eastern Gulf, Montgomery, Ala. Western Gnlf, San Antonio, Tex. Upper Mississippi, Des Moines, Iowa. Lower Mississippi, Little Rack, Ark. Fig. G5. Mean Monthly Rainfall at Various Points in the United States. 128 Rainfall. Topeka, Kas. Missouri River Helena, Mont. 40 30 Hudson Bay, Moorehead, Minn. Xo. Pacific, Tacoma, Wash. Columbia River, Spokane, Wash. Pacific, Sacramento, Cal. 10 10 Colorado River, Tucson, Ariz. Great Basin. Winnemucca, Nev. Fig. 66. Mean Monthly Rainfall at Various Points in the United States. Rainfall on the Drainage Area of the Wisconsin River. 129 T3S.3 IAGE OF STORAGE^ GROWING^ AND TOTAL ANNUAL. STORAGE PERIOD GROWING PERIOD . '(REPLENISHING JJPERIOO. Fig. G7. Rainfall on the Drainage Area of the Wisconsin River. 130 Rainfall. relation to run-off it is desirable to divide the annual rainfall in accordance with these periods. Figures 65 and 66 show the average monthly rainfall at various points in the United States, the average rainfall for each of the periods above mentioned and an additional diagram for each location showing the summation of the total rain- fall for each period of the water year. Here again attention is called to the fact that for most purposes of the engineer the extreme conditions and the varying conditions from year to year are of much greater importance than the average conditions as shown on these diagrams. Figure 67 shows the annual and periodic rainfall on the valley of the AVisconsin River at three different points, the relative location of which will be seen by ref- erence to the map on page 84. The upper diagram shows the rain- fall on the drainage area above Merrill, the center diagram the rain- fall above Necedah, and the lower diagram, the rainfall above Kil- bourn. In these three diagrams it is important to note the variation in the rainfall condition above the different points on the water- shed. For example, considering the entire area above Kilbourn and above Necedah, it will be noted that the annual rainfall for 1895 was the lowest within the period shown, while for the area above Merrill the rainfall for 1892 was the lowest for the period dis- cussed. This diagram will illustrate the fact, which is manifest on the investigation of most large streams, namely, that frequently the intensity of the rainfall upon part of the drainage area is radi- cally different from that on other parts, and that, consequently, the various quantities of rain falling on a large watershed tend to balance each other and keep the total more constant than observa- tion at any one point would seem to indicate, so that the minimum rainfall at any one point on the area is not necessarily coincident with the minimum rainfall that may occur at any other point or on the stream as a whole. From this it is evident that in an area of any magnitude it is necessary to consider the rainfall at a large number of stations well distributed over the area. LITERATURE. GENERAL SUBJECT OF RAINFALL. 1. U. S. Weather Bureau. Annual Reports and Monthly Weather Reviews. 2. Meteorologische Zeitschrift. 3. Zeitschrift des Osterreichen Gesellschaft fur Meteorologle. 4. Symon's Meteorological Magazine. 5. Annucine d3 la Societe Meteorogique de France, Paris. Literature. 131 6. The Royal Meteorological Society of Great Britain. Quarterly Journal. 7. Hawksley, Thomas. Laws of Rainfall and Its Utilization. Proc. Inst. C. E. Vol. 31, pp. 53-59. 1871. 8. Binnie, Alex. R. Tables of Mean Annual Rainfall in Various Parts of the World, Proc. Inst. C. E. Vol. 39, pp. 27-31. 1874. 9. Schott, C. A. Tables and Results of the Precipitation of Rain and Snow in the U. S. Smithsonian Contribution to Knowledge, No. 222, 1874. 10. Charts and Tables Showing Geological Distribution of Rainfall in the U. S. U. S. Signal Service Professional Paper No. 9. 1883. 11. Rainfall Observations at Philadelphia. Reports Phila. Water Bureau, 1890-92. Eng. Record, 1891, p. 246. 1892, p. 360. 12. Binnie, Alex. R. Mean or Average Rainfall and the Fluctuations to which It is Subject. Proc. Inst. C. E. Vol. 119 (1892), pp. 172-189. 13. Waldo, Frank. Modern Meteorology. New York, Scribner's Sons. 1893. 14. Davis, W. M. Elementary Meteorology. Boston, Ginn & Co., 1894. 15. Harrington, M. W. Rainfall and Snow of the United States. Bulletin C., U. S. Weather Bureau, 1894. 16. Russell, Thomas. Meteorology. New York, MacMillan Co. 1895. 17. Henry, A. J. Rainfall of the United States. Bulletin D., U. S. Weather Bureau. 1897. 18. Turneaure & Russell. Public Water Supplies. Chapter 4. New York, Wiley & Sons. 1901. 19. Hann, Julius. Handbook of Climatology.' New York, MacMillan Co. 1903. 20. Handbook der Ingenieur Wissenschaften. Part 3, der Wasserbau; sec. 1, Gewasserkunde. Leipzig, E. Engelmann, 1904. 21. Hann, Julius. Lehrbuch der Meteorologie. Leipzig. 1906. EXCESSIVE RAINFALL. 22. Francis, Jas. B. Distribution of Rainfall during a Great Storm in New England in 1869. Trans. Am. Soc. C. E. Vol. 77, p. 224. 23. The New England Rain Storm of Feb. 10-14, 1886. Eng. News, 1886, Vol. 15, p. 216. 24. Hoxie, R. L. Excessive Rainfalls Considered with Special Reference to Their Appearance in Populous! Districts. Trans. Am. Soc. C. E., p. 70. June, 1891. 25. Talbot, Arthur N. Rates of Maximum Rainfall. Technograph, Univ. of Illinois. 1891-1892. 26. Duryea, Edwin, Jr. Table of Excessive Precipitation of Rain at Chi- cago, Illinois, from 1889 to 1897, inclusive. Jour. W. Soc. of Engrs. Feb., 1899. CAUSES OF RAINFALL. 27. Henry, D. F. Rainfall with Different Winds. Rept. Chf. Engr. U. S. A. 1867, p. 598. 28. Blanford, H. F. How Rain is Formed. Smithsonian Report. 1889, pt. 1, p. 287. 132 Rainfall. 29 Belschow, Frantz A. The Causes of Rain and the Structure of the At- mosphere. Trans. Am. Soc. C. E. Vol. 23, p. 303. 1890. 30. Davis, W. M. The Causes of Rainfall. Journal of N. E. W. Wks. Ass'n. 1901. 31. Curtis, G-. E. The Effect of Wind Currents on the Rainfall. Signal Serv- ice Notes No. 16. THE EFFECT OF ALTITUDE ON RAINFALL. 32. Homersham, S. C. Variations of the Rainfall with the Elevation. Proc. Inst. C. E., Vol. 7, pp. 276, 282 & 284. 1848. MEASUREMENT OF RAINFALL. 33. Clutterbuck, J. C. Dalton's Rain-gage. Proc. Inst. C. E., Vol. 9, p. 157. 1850. 34. Fitzgerald, Desmond. Does the Wind Cause the Diminished Amount of Rain Collected in Elevated Rain Gages? Jour. As so. of Eng. Soc. 1884. 35. Weston, E. B. The Practical Value of Self-recording Rain-gages. Eng. News, 1889, Vol. 21, p. 399. 36. Self-Registering Rain-gages and Their Use for Recording Excessive Rain- falls. Eng. Rec. 1891, Vol. 23, p. 74. 37. Duryea, Edwin, Jr. Effect of Wind Currents on Rainfall and on the Gage Record. Signal Service Notes No. 16. CHAPTER VII. THE DISPOSAL OF THE RAINFALL. 78. Factors of Disposal. The portion of the rainfall in which the water power engineer is most directly interested is that which runs off in the surface flow or flow of streams. In order to form some idea of the amount of this run-off and the factors that control it, it is necessary, however, to investigate and consider the various ways in which the rainfall is distributed, for the ways in which the distribution occurs are mutually inter-dependent and of necessity modify and control each other. The rainfall disposal depends on a large number of factors or conditions among the most important of which may be named : (1) The amount of the rainfall. (2) The rate of rainfall. (3) The condition of the surface on which the rainfall takes place. (4) The condition of the underlying geological strata. (5) The atmospheric temperature. (6) The direction and velocity of the wind. (7) The nature and extent of vegetation. (8) The surface topography. (9) The evaporation. It will be noted that some of the factors mentioned above tres- pass more or less on others and are not clearly separable. 79. The Rate or Intensity of Rainfall. It will readily be recog- nized that with very heavy or intense rainfall a larger percentage of the water will run directly into the streams and a smaller per- centage will be taken up by the strata than would be the case were the rainfall very light. In very light rainfalls there is no run-off, the water being either taken directly into the strata or re-evaporated from the surface. 134 Disposal of the Rainfall. 80. Condition of Receiving Surfaces and Geological Strata. Next in importance in modifying the disposal of rainfall is the condition of the surface on which the rain falls and of the under- lying geological strata. If the geological strata are porus in na- ture and comparatively free from water they will readily receive and transmit the rainfall if the surface is in proper condition to re- ceive it. The condition of the surface itself modifies the reception of the rainfall in a very marked manner. With high surface slopes the rainfall may be large, even with somewhat porous strata, and yet very little water will be taken up by the strata. With low slopes and porus strata a large amount of water will be received directly by the surface and passed into the ground water and deep waters of underlying geological strata. The temperature has an important influence on the condition of the strata, and consequently the disposal of the rainfall. Strata otherwise porous but with saturated and frozen surface will re- ceive and retain practically no water and the consequence is that under these conditions even a low rainfall may produce a consider- able run-off that under other temperature conditions would not occur. 81. Effects of Wind. The wind has a marked effect on evapora- tion and consequently on the quantity of rainfall that passes away in the atmosphere. The average velocity of the wind will vary in different parts of the United States from three to seventeen miles per hour and, other things being equal, will increase evaporation as such average velocity increases. 82. Effects of Vegetation. The nature and extent of the vege- tation on a surface has a marked effect on the disposal of the rain- fall. Experiments at the Wisconsin Agricultural Experimental Station show that barley, oats and corn require 15.2, 19.6 and 26.4 inches of rainfall, respectively, to produce a crop. This includes the transpiration and evaporation from the cultivated surface as well as the actual quantity used by vegetation. The amount act- ually retained as a part of the vegetable growth is, of course, very small. The water simply serves to convey the soluble. foods of the soil to the various fibres of the plant. The actual amount of water used in irrigation is not a fair criterion of the amount needed for the development of plant life as in most cases crops are over-irrigated. The actual depth and the rainfall and irri- gation water used on crops vary from as low as 12 inches to sometimes as high as 16 feet, frequently running into quantities Effects of Vegetation. 135 much in excess of any ordinary rainfall in moist climates where irrigation is found to be unnecessary. In the Report of the Kansas State Board of Agriculture for De- cember 31, 1889, Mr. W. Tweeddale, C. E., gives the following ta- ble containing the results of investigations by M. E. Risler, a Swiss observer, upon the daily consumption of water by different kinds of crops: TABLE. X Daily Consumption of Water by Crops. INCHES 01 p WATER. Minimum. Maximum. Lucern grass 134 267 IVIeadovv 2rras c 1" ''87 Oats 0.140 193 Indian Corn 110 1 570 Clover 140 Vinevard. ... 035 031 Wheat 106 110 Rye . . . . . . 091 Potatoes 038 055 Oak trees . . 030 0.038 Fir Trees 0.020 0.043 Mr. Tweeddale finds that this table agrees with careful experi- ments made in France and elsewhere, and calculates from it that from seed time to harvest cereals will take up 15 inches of water and grass may absorb as much as 37 inches. This table shows also one of the important reasons why a de- crease of stream flow follows the destruction of forests and their replacement by meadows and cultivated fields. It is quite evident also that if the watersheds were covered by grasses or cereals there would be comparatively little water left for the flow of streams. From this it will be seen that the character of the vegetation on a watershed exerts a considerable influence on the ultimate distribu- tion of the rainfall. The presence or absence of forests has also, as shown by a series of observations in Germany, a marked effect on evaporation. Prof. M. W. Harrington (see Bulletin No. 7, U. S. Dept. of Agriculture, p. 97) has compiled the accompanying diagram (Fig. 68), which illustrates clearly the effect of forests upon the monthly evapora- tion. The upper curve represents the evaporation from water sur- 136 Disposal of the Rainfall. faces in the open country, while the lower curve shows the evap- oration from water surfaces in the woods. The shaded area thus illustrates the saving due to the cover and protection of forests. 83. Percolation. On pervious and unsaturated strata a portion of the rainfall sinks below the surface until it reaches a saturated Fig. 68. Reduction in Evaporation Due to the Presence of Forests. or a relatively impervious stratum. The water then follows the dip of the stratum until it reaches an outlet along some stream or ap- pears in the form of springs, frequently in an entirely different drainage area or possibly below the level of the sea itself. It is this ground water that gives rise to the dry weather flow of streams, and frequently is the only source from which stream flow is maintained during the dry seasons of the year. The same sources irequently maintain the winter flow at times when the rainfall is stored on the watershed in the form of snow and ice. Percolation is an important factor in the storage- of water and in the construction of raceways and canals and needs most careful attention when such works are under contemplation. A large amount of valuable data concerning the losses due both to evaporation and seepage has been collected by Mr. E. Kuichling in connection with the study of the water supply for the New York Barge Canal and is reproduced in the Appendix. A small portion of the ground water is taken up by the roots of plants and frequently feeds vegetation during dry periods. Water drawn from the soil for such purposes, after fulfilling its functions in vegetation, is transpired from the vegetable surfaces into the atmosphere. Streams fed from areas where large deposits of fine grained but porous material are developed, are usually more constant in flow and less subject to fluctuations either from flood or drought. The flows of the deeper strata usually pass far from the watershed on which the rainfall occurs and modify to a limited extent the stream flow in other valleys frequently far from the original rainfall source. Evaporation. 137 84. Evaporation. Evaporation takes place from moist surfaces and from the water surfaces of swamps, lakes, streams and the oceans, whenever such surfaces are in contact with unsaturated atmosphere. The absorption of the rainfall by the strata effectively limits the amount of evaporation from a given area by reducing the area of contact of wet surface with the atmosphere, thus con- fining the evaporation largely to free water surfaces. Fig. 69 shows a map of the approximate annual evaporation which takes place from water surfaces at various points within the United States. It will be noted that this map shows, in the greater por- tion of the United States, evaporations equal to or greater than the annual rainfall at such localities. The total annual evaporation, as shown in the map, is based, however, on free water surfaces only, and evaporation from ground surfaces only takes place from occasional moist surfaces which occur after rains and when the humidity is high. The total amount of water evaporated, there- fore, is very much less than that which the map would seem to in- dicate. This map and the table of monthly evaporation in the appendix are taken from data given in the Monthly Weather Review of September, 1888. The Weather Review observations are not based on absolute evaporation tests but are deduced from readings of dry and wet bulb thermometers as observed at various Signal Service Stations in 1887 and 1888. These deductions are supplemented by observations at several stations by means of the Piche evaprometer. While evaporation, like rainfall, varies from year to year in accordance with the variation in the controlling factors, yet in lieu of more extended observations this map and table indicate relative conditions at the various stations and ap- proximately the evaporation from free water surfaces. The com- parative monthly evaporation at sixteen stations distributed throughout the United States is shown graphically by Fig. 70. At a number of Eastern points, namely, Boston, Rochester and New York, evaporation observations have been made for a number of years and from the data thus collected a knowledge of the local variations that occur in evaporation at these points can be obtained. Evaporation is greatly promoted by atmospheric currents which have perhaps the most marked effect of any single influence. The temperature of the water and the humidity of the atmosphere also have a marked effect. Mr. Desmond Fitzgerald in a paper on evaporation (see Trans. Am. Soc. C. E., Vol. XV, page 581) offers the following formula for evaporation : izr las* 123' icr no* nriM* nr nr 100* lor wy toy ior 99 ii9 c lit" 115 H3' nr 109 loT 5 ios 5 103 101 ANNUAL EVAPORATION' IN THE UNITED STATES 140 Disposal of the Rainfall, No. Atlantic, So. .Atlantic, Gt. Lawrence, Ohio River, New Haven, Conn. Augusta, Ga. Detroit, Mich. Cincinnati, O. -B Eastern Gulf, Western Gulf, Montgomerj*, Ala. Palestine, Tex. Upper Mississippi, Lower Mississippi, Des Moines, la. Little Rock, Ark. Missouri River, Topeka, Kans. Helena, Mont. Red River, Moorehead, Minn. No. Pacific. Olympia, Wash. Columbia, Spokane, Wash. Pacific, Sacramento, Cal. Colorado, Yuma, Ariz. Great Basin, Winnemucca, Nev, Fig. 70. Monthly Evaporation From Free Water Surfaces at Various Points in the United States. Evaporation. 141 E=(V-v)( 1 --r) 60 In this formula V equals the maximum force of vapor in inches of mercury corresponding to the temperature of the water; v, the force of the vapor present in the air; W, velocity of the wind in miles per hour; and E the evaporation in inches of depth per hour. The value of v depends on certain relations between the tempera- ture of the air and the water. From a careful examination of the formula it will be seen that evaporation as represented thereby does not depend largely on temperature. Table XI is taken from a paper on "Rainfall, Flow of Stream, and Storage" by Mr. Desmond Fitzgerald (Trans. Am. Soc. C. E., Vol. XXVII, No. 3), and shows the monthly evaporation from water surface at Boston, Massachusetts, for sixteen years. The table is partially made up from a diagram of mean monthly evaporation but only when the observation practically agreed with the same. 85. Evaporation Relations. Professor Cleveland Abbe gives the following relations of evaporation, as established' by Professor Thomas Tate : (a) Other things being the same, the. rate of evaporation is nearly proportional to the difference of the temperature indicated by the wet-bulb and dry-bulb thermometers. (b) Other things being the same, the augmentation of evapora- tion due to air in motion is nearly proportional to the velocity of the wind. (c) Other things being the same, the evaporation is nearly in- versely proportional tt> the pressure of the atmosphere. (d) The rate of evaporation of moisture from damp, porous sub- stances of the same material is proportional to the extent of the surface presented to the air, without regard to the relative thickness of the substances. (e) The rate of evaporation from different substances mainly depends upon the roughness of, or inequalities on, their surfaces, the evaporation going on most rapidly from the roughest or most uneven surfaces ; in fact, the best radiators are the best evaporizers of moisture. (f) The evaporation from equal surfaces composed of the same material is the same, or very nearly the same, in a quiescent at- mosphere, whatever may be the inclination of the surfaces ; thus a 1 4 2 Disposal of the Rainfall. ".COO?"-C- C: C GC CO GC i O r- ( * * * c: O c- i^ co Ci c cc c: c^i t^ io o I-H i :M co 10 xc ic co co :M r- 1 C! ^C O 1^ CC 1C "-C O t^ ^ O i C^Ol^OCOOC^^liCCOOiO :ClCOCCiOlCOOOOr-ICO^H O -r-i ' ' CC>COGC3<|--C Or- l^-iCOOO * * * * >i< * * -X- 1C O CO Tt^ CC -* TC -t -M Ct O l^ Ct i I (M O rt O ^C Cvl o c3. a 2 Evaporative Relations. 143 horizontal plate with its damp face upward evaporates as much as one with its damp face downward. (g) The rate of evaporation from a damp surface (namely, a horizontal surface facing upward) is very much affected by the elevation at which the surface is placed above the ground. (h) The rate of evaporation is affected by the radiation of sur- rounding bodies. (i) The diffusion of vapor from a damp surface through a variable column of air varies (approximately) in the inverse ratio of the depth of the column, the temperature being constant. (j) The amount of vapor diffused varies directly as the tension of the vapor at a given temperature, and inversely as the depth of the column of air through which the vapor has to pass. (k) The time in which a given volume of dry air becomes satu- rated with vapor, or saturated within a given percentage, is nearly independent of the temperature if the source of vapor is constant. (i) The times in which different volumes of dry air becon e saturated with watery vapor, or saturated within a given per cent, are nearly proportional to the volumes. (m) The vapor already formed diffuses itself in the atmosphere much more rapidly than it is formed from .the surface of the water. (This assumes, of course, that there are no convection currents of air to affect the evaporation or the diffusion.) 86. Practical Consideration of Losses. From the previous dis- cussion it will be readily realized that it would be impossible to dif- ferentiate all of the methods of the disposal of rainfall upon a drain- age area. Evaporation differs widely from different classes of vege- tation and from different classes of land surfaces ; also on account of the slope and exposure. No two square miles upon a drainage area offer the same conditions as affecting evaporation which differs very widely with such conditions. Evaporation and seepage from any surface varies with the temperature, with the moisture in the air, and with the velocity of the wind. It is therefore impossible to compute, with any degree of accuracy, evaporation over an ex- tended surface of a watershed or drainage area, or to ascertain with any degree of accuracy the probable losses that will take place in the same area. For water power purposes, the rainfall can, therefore, be divided into two quantities in which the water power engineer is interested : First : The run-off on which the power developed directly depends, OF THE 144 Disposal of the Rainfall. and, Second : The losses, by whatever means they occur, which are not available for such purposes. Evaporation is usually but not always the source of greatest loss on a drainage area and commonly other sources of loss are insignificant when compared with it. It is therefore a common practice to deduct the run-off from the rainfall on a given drainage area and to classify the difference as evapora- tion, including under this term all losses of this same general character, whether through seepage, evaporation or otherwise. LITERATURE. 1. Vermeule, C. C. Report on Water Supply. Geol. Survey of New Jersey. Vol. III. 1894. 2. Vermeule, C. C. Report on Forests. Geol. Survey of New Jersey. 1899. 3. Turneaure and Russell. Public Water Supplies, Chap. V. New York,. Wiley & Sons. 1901. 4. Rafter, George. Hydrology of the State of New York. pp. 4G-197. Al- bany, N. Y. New York State Education Dept. Bui. 85, 1905. PERCOLATION. 5. Lawes, J. B. The amount and Composition of the Rain and Drainage Waters Collected at Rothamsted. Jour. Royal Agric. Soc. of England, Vol. 17, p. 241, 1881; Vol. 18, p. 1, 1882. . Fortier, Samuel. Preliminary Report on Seepage Wiater, and The Un- derflow of Rivers. Bulletin No. 38, Agric. Expt. Station, Logan, Utah. 1895. 7. Seepage or Return Waters from Irrigation, Bulletin No. 33. Colo. Agric. Expt. Sta., Fort Collins, Colorado. 1896. 8. Fortier, Samuel. Seepage Water of Northern Utah. Water Supply and Irrigation Paper No. 7. 1897. 9. The Loss of Water from Reservoirs by Seepage and. Evaporation. Bul- letin No. 45. Colo. Agric. Expt. Sta., Fort Collins, Colorado. May, 1898. 10. Loss from Canals from Filtration or Seepage. Bulletin No. 48. Colo. Agric. Expt. Sta., Fort Collins, Colorado. 1898. 11. Kuichling, Emil. Loss of Water from Various Canals by Seepage. (See paper on Water Supply for New York State Canals, Report of State Engineer on Barge Canal, 1901). 12. Wilson, H. M. Irrigation Engineering. New York, Wiley & Sons. 1903. 13. Wilson, H. M. Irrigation in India. Water Supply and Irrigation Paper No. 87. 1903. 14. Mead, D. W. Report on Water Power of the Rock River. Chicago. Pub. by the author. 1904. EVAPORATION. 15. Greaves, Charles. On Evaporation and on Percolation. Proc. Inst. C. E. 1875-76. Vol. 45, p. 19. Literature. 145 16. Fitzgerald. Desmond. Evaporation. Trans. Am. Soc. C. E., Vol. 15, p. 581. Sept., 188G. 17. Loss of Water from Reservoirs by Seepage and Evaporation, Bulletin No. 45, Colo. Agric. Expt, Sta., Fort Collins, Colo. May, 1898. 18. Depth of Evaporation in the United States. Monthly Weather Review. September, 1888. 19. Depth of Evaporation in the United States, Engineering News, Decem- ber 30th, 1888; January 5th, 1889. 20. Harrison, J. T. On the Subterranean Water in the Chalk Formation of the Upper Thames and its Relation to the Supply of London. Proc. Inst. C. E. 1890-91. Vol. 105, p. 2. 21. Fernow, B. E. Relation of Evaporation to Forests. Bulletin No. 7, For- estry Div., U. S. Dept. Asric. and Engineering News, 1893, Vol. 30, p. 239. 22. Kimball, H. H. Evaporation Observations in the United States. Read before the Twelfth National Irrigation Congress, 1904; Engi- neering News, April 6, 1905. USE OF WATER IN AGRICULTURE. The Publications of the United States Experiment Stations on Irriga- tion and of the Experiment Stations of the various States contain much information on this subject. The following are of especial importance: 23. Hill, W. H. Report of State Engineer to Legislature of California, 2 Vols. Sacramento, 1880. 24. Carpenter, L. G. Duty of Water. Bui. 22, 'Agric. Expt. Sta., Fort Col- lins, Colorado. 1893. 25. Fortier, Samuel. Water for Irrigation. Bui. 26, Utah Agric. Expt. Sta., Logan, Utah. 1893. 26. Report of Irrigation Investigations, U. S. Dept. Agriculture, Irrigation Inquiry. Bui. 86 for the year 1899. 27. King, F. H. Irrigation and Drainage. New York. MacMillan Co., 1902. The amount of Water Used by Plants, pp. 16-46. Duty of Water, pp. 196-221. 28. Mead, Elwood, Irrigation Institutions, Chap. VII, The Duty of Water. New York. MacMillan Co. 1903. 29. Wilson, H. M. Irrigation Engineering, Chap. V., Quantity of Water Re- .quired. New York, Wiley & Sons. 1903. CHAPTER VIII. RUN-OFF. 87. Run-Off. That portion of the rainfall that is not absorbed by the strata, utilized by vegetation or lost by evaporation, finds its way into streams as surface flow or run-off. The demands of the first named factors are always first supplied and the run-off is therefore the overflow or excess not needed to supply the other demands on the rainfall. The run-off, therefore, while a direct func- tion of the rainfall, is not found to increase in direct proportion thereto, except perhaps in seasons such as early spring when from seasonal conditions the demands of vegetation, percolation and evaporation are not active and all or most all of the rainfall flows away on the surface. The remainder of the year the run-off may be said to increase with the rainfall but usually at a much less rapid rate and in many cases the rainfall is entirely absorbed by the strata or vegetation, and does not influence or affect the run-off. In this case the run-off is supplied from the ground water, stored from previous rainfalls, and is entirely or largely independent of the immediate rainfall conditions. An examination of the observed run-off of streams, and the rain- fall on their respective drainage areas, for annual, monthly and sea- sonal periods, will show that there is a relation more or less direct between the rainfall and run-off (see Fig. 71, et seq.). The relations are shown by various diagrams and mean curves from which many departures will be noted. The departure of individual observations from the mean curve expressing these relations shows the relative importance and influence of other factors in affecting such relations. The relations of the numerous factors which are known to influence the results are quite complex and are not well established and much more meteorological information in much greater detail and a care- ful consideration and study of the same will be necessary before such relations can be even approximately established. Run-Off. 147 148 Run-Off. 88. Influence of Various Factors. The influence of various factors of disposal was discussed in the last chapter. Evaporation is known to vary with temperature, the direction and velocity of the winds, barometric pressure, and various other meteorological influences, and yet no clearly defined relation has yet been shown to exist between these factors, by means of which their actual in- fluence on the run-off can be approximately calculated. Mr. C. C. Vermeule (see Vol. Ill, Geol. Survey of New Jersey) considers that annual evaporation depends largely on the mean annual tem- perature #nd offers a formula for the calculation of the same, which,, in many cases, gives results which seem to agree closely with the facts and data collected from a number of Eastern drainage areas. Mr. Vermeule'' s formula for the relation between annual evaporation and precipitation on the Passaic River, and some other Eastern drainage areas where conditions are similar, is : E= 15-50+0.16 R in which E=The annual evaporation (including all losses on drainage area: except from run-off) and R=the annual rainfall. For general application to all streams he suggests the formula =(15.50+0.16 R) (0.05 T 1.48) in which T= mean annual temperature. Mr. Vermeule also offers a formula for the evaporation for each month and discusses at length the influence of ground storage on the flow of streams. Mr. Geo. W. Rafter (see Water Supply and Irrigation Paper No. 80) has made a careful analysis of available data which indicates that no such intimate relation can be found to exist. In general, the information available does not seem to show that other factors have a sufficiently definite relation to run-off or to each other to make such relation clearly manifest and yet such factors are known to have an unmistakable and constant influence. This fact is quite clearly demonstrated by a number of diagrams prepared by Mr. Rafter, which are here reproduced. Figure 72 shows graphically the relation between precipitation, evaporation, run-off and temperature on the Lake Cochituate basin for thirty-three years. In this diagram the years are arranged in accordance with the precipitation. In a general way the evapora- tion and run-off for these years may be said to vary with the pre- Influence of Various Factors. 149 co O> * 15 4J 50 *53 c 4P 450 ^7 Years Years arranged in order of dryness. Fig. 72. Relation Between Precipitation, Evaporation, Run-off and Tempera- ture on Lake Cochituate Basin. 9 Run-Off. cipitation. Evaporation, which, it must be remembered, here in- cludes all losses except that due to run-off, increases in general as the rainfall on the area increases and decreases with the rainfall, For limited periods, however, this general law does not hold. Other factors affect the relations and cause material departures from the general law. This is particularly marked in the years 1891 and 1872. For these two years the rainfall was almost identical in amount. The evaporation for the same years, however, differed materially, being about 16 inches greater in 1891 than in 1872. As a consequence the run-off for the year 1891 was about 15% inches greater than in 1872. In order to demonstrate the mutual relation between evaporation and temperature the data illustrated in the previous figure has been 60 49 48 47 46 44 50 40 30 1G i/ Years Fig. 73. Relation Between Evaporation and Temperature on Lake Cochituate Basin. Years being arranged according to amount of evaporation. Influence of Various Factors. . 74 -Relations between reen- tat,on, Run . 0ff , Evaporation and Temperatnre on Sudbllry ^ss&sas*** ration respectively. ' g eVap - 129" lay 125" i23 r 119 nr us* 113 ur 109* lor 105 103* ior 99' 47 05 93 91* 89 flr ' 85" 83 81 79' 11' IS* cy er 65 OP THE UNITfcDJSTATES 154 Run-Off. 60 40 30 20 JO 44 - 40 20 10 Vo/irc Years 30 20 10 44 439 42 41 40 YEAXS* Fis 75Relations Between Precipitation, Run-Off, Evaporation and Tempera- ture on Upper Hudson River. Years arranged according to regular order and decreasing evaporation. rearranged by Mr. Rafter, and in Figure 73 the relation for the years has been arranged in the order of their evaporation, and com- pared with the mean temperature for the year. This figure serves to show that while temperature may, and unquestionably docs, influence evaporation, yet the mean annual temperature has no controlling effect on the annual evaporation. It will be noted that for the year 1878, when the mean temperature was a maximum, the evaporation was considerably below the average for this drainage Relations of Annual Rainfall and Run-Off. 155 area. Similar relations for the Sudbury River basin are shown in Fig. 74 and for the Upper Hudson River basin in Fig. 75. 89. Relations of Annual Rainfall and Run-Off. Figure 76 is a mean run-off map of the United States and should be compared with the map of average rainfall. The run-off as shown by this map is expressed in inches on the drainage area and similarly to the com- mon expression for the amount of rainfall. The value of this map is comparative only. In this case, as in the cases of rainfall and evaporation, the mean conditions are subject to wide variations. A detailed study of local conditions is always necessary in order to fully understand and appreciate the influence of extreme condi- tions and of local factors. The relation between the annual rainfall and run-off on various drainage areas is shown in Figures 71 to 75, inclusive, as previously described. The mean relations between these two factors on four selected drainage areas are, however, more clearly shown by the graphical diagrams Figs. 77, 78 and 79. From these diagrams a Pig. 77. RUN-OFF DIAGRAM OF HUDSON MD GENESEE RIKRS . HUDSON RIVER, teaa-iooi INCHES ON CATCHMENT AREA PERIOD HAXIMUM YEAR HINIHUM YEAR HEAR I *..-<./. fMw tahfalt. -/. ttatef J 5j 2.45 li.7 11. SI 4.11 20.1 16.1 4.5 19.12 C.S7 12.2S 10.37 2.33 .> 12.7 3.S S.iO 3.71 S.09 10 Jt 3.4} 7.0i 10.} 3.7 S3.S7 33.08 10.79 31.17 17.4* IHJ1 4tJ S3J of Hudson River Indicate* ikut & iii INCHES ON CATCHIKNT AREA YEAR H/fHMUH YEAR 0CM 27.71 75.73 71. m 13.20 S.S3 7.57 11.4 li.S J cn*taf 7.95 ;. e.iiii.n b.seto.77 11.9 1.7 *J *,i*.i,u.g. li.it lit .4 jtCT M ii ^1 * Id Total. 47.7* I.U 1S.41 31.00 C.tf H.33 10.3 lit , MLI Prvipltatlon In tatefti eateluntirt *na \ \ Fig 78. 156 Run-Off. mean relation can be traced for each area from which, however, there are considerable departures in individual years. The study, therefore, of this subject on this basis will demonstrate the mean relation and the departure therefrom which must be expected on the area considered and other areas where physical conditions are similar. KUK-OFf DIAGRAM OF MUSK/NGUM RIVER 1888-1895 INCHES OH CATCHMENT AREA HAXIMUM YEAH HIHIHUH YEAR HEAM Of. CM**. /tatnfaJl. frn.of. I3.S4 4.04 g.OO S.14 0.4 f.SS 7.6t OJ7 7.tt 2S.4 4JO i rr~-(r i 44 45 SO SS 60 SS Fig. 79 Table 'X.ll.Muskingum River, 1888-1895, inclusive. [Catchment area=5,828 square miles.] 1888. 1889. - 1890. Period. Rain- fall. Run- off. Evapo" ration- Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Storage 17.16 5.17 11.99 13.52 6/02 7 50 27.77 ]8 07 9 70 Growing Replenishing ........... 14.31 11.14 1.77 3.39 12.54 7.75 12.12 10.24 1.24 96 10.88 9 28 13.68 15 52 2.64 6 13 11.04 9 39 Year 42 61 10 33 32 28 35 88 8 22 27 66 56 97 26 84 30 13 1891. 1892. 1893. Storage 16 72 12 42 4 30 20 39 9 06 11 33 25 04 14 13 10 91 Growing 13 56 1 77 11 79 16 54 3 65 12 89 8 31 1 22 7 00 Replenishing 1 7 08 1 37 5 71 4 81 67 4 14 9 01 85 8 16 Year 37.36 15.56 21.80 41.74 13.38 28.36 42.36 16.20 26.16 1894. J895. Storage 16 93 7 63 9 30 13 04 4 04 fi 00 Growing 4 56 OC 3 90 9 14 49 8 6 Replenish ing 9 02 .41 8 61 7 6<> 37 *729 Year 30.51 8.70 21. el 29.84 4.90 24.94 . J The Water Year. 157 90. The Water Year. The relation of annual rainfall and annual run-off is more or less obscured by variations in the periodic dis- tribution of the annual rainfall. A study of the relation of the periodic rainfall and the periodic run-off is therefore necessary. For a comprehensive understanding of the relation of rainfall to run-off it is more convenient to refer to the water year instead of the calendar year. The water year is the annual division of time that represents the full annual cycle of change in hydrological conditions. It does not, as a rule, conform very closely to the calen- dar year, neither is the water year constant for each annual period in its beginning or end, but varies as meteorological conditions vary. As previously stated, in the greater portion of the United States, the water year naturally divides itself into periods, beginning, ap- proximately, with December, and ending, approximately, with the following November. The period from December to and including May is termed the "Storage" period ; June, July and August con- stitute the "Growing" period, and September, October and Novem- ber are termed the "Replenishing" period. Not only the year but these periods as well vary each year, and are not necessarily limited by our artificial division of calendar months and years. During the storage period, the snows of winter and the rains of spring saturate the ground, and a large amount of water is held in storage in lakes, swamps, and forests, and in pervious soils, sands and gravels. The portions of this stored water tributary to a drain- age area but not necessarily within the boundaries thereof, and at elevations above the level of the stream, are, when conditions de- mand, available to supply the stream flow, and are also available for the purpose of sustaining plant life. Such waters will feed a stream to an extent depending on their character and magnitude, regardless of the amount of the immediate rainfall, and will cause a stream to flow for several months, even without rain, if the per- vious deposits and other storage resources are well developed upon the area. These relations vary widely with each individual area, and in areas not well provided with such deposits the streams often run dry through the warm days of summer. Whenever the surface of the stream falls below the ground water gradient the ground water is affected and begins to supply the stream flow. This sometimes occurs early in May, and seldom later than the beginning of June. During June, July and August the rainfall is rarely sufficient to take care of the evaporation and Run-Off. growth of vegetation without something of a draft on the ground water, and the stream flow during this period is usually entirely dependent on the ground water, except during exceptionally heavy rainstorms. By the end of the growing period about August 3ist the ground water is often so reduced as to be capable of storing several inches of rainfall. During the replenishing and storage periods of winter and spring the ground begins to receive its store of water, and, with favorable rainfalls, the ground becomes fully saturated by the end of April or May. Ta,ble XIII. Hudson River, 1888-1901, inclusive. [Catchment area=4,500 square miles.] 1888. 1889. 1890. Period. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Storage .......... 20.40 17.06 3.34 17.10 14.04 3.06 24.75 19.28 6.47 GrAwipg - - . ... 10.25 2.05 8.20 15.05 4.28 10.79 13.50 2.85 10.65 Replenishing - 13.27 4.53 8.74 10.81 3.41 7.40 12.10 6.81 5.29 Year. 43; 92 a 23. 64 20.28 a42.96 21.71 21.25 50.35 28.94 21.41 1891. 1892. 1893. Storage 20 69 IS 59 4 10 24 95 22 50 2 45 19 83 15 20 4 63 13 49 2 07 11 42 19 12 6 87 12 25 13 37 3 12 10 25 Replenishing 8.78 1.90 - 6.88 9.80 3.71- 6.09 8.98 3.59 5.39 Year...., 42.96 20.56 22.40 '53.87 33.08 20.79 42.18 21.91 20.27 1894. 1895. 1896. Storage 21.37 13.18 8.19 15.79 11.68 4.11 22 17 18.52 5 65 Growing 8.73 3.20 6.53 10.37 2.36 8.01 10 25 2 53 7 72 Replenishing 11 87 2 99 8.88 10.51 3.42 7.09 12 79 4 58 8 21 Year 41.97 19 37 22 60 36 67 17 46 19 21 45 21 23 62 21 58 1897 1898. 1899. Storage 19.77 14.60 5.17 22.80 18.61 4.19 19.48 15.15 4.3S Growing...... 15.80 7.79 8.01 13.52 8.24 10.28 7.40 1.63 6.77 Replenishing 10 94 3.80 7.14 12.19 5.27 6.92 8.91 2.76 6.15 Year 46 51 26 19 20.32 48.51 27.12 21.39 35.79 19 54 16.25 1900. 1901. Storage...... 21.13 16.12 5.01 18.47 14 84 3 63 Growing 12.11 2.30 9.81v 15.09 4.02 11 07 ReptentflhiTi g 12.17 2.25 9.92 9.02 3 6 02 Year 45 41 20.67 24.74 42.58 21.86 20.72. i Approximate. Relations of Periodic Rainfall to Run-Off. Table XIV. Connecticut River, 1872-1885, inclusive. [Catchment area =10,334 square miles, j 159 1872. 1873. a 1874. Period. Rain- fall. Run-- off. Evapo- ration. Rain- fall. Run- fall. Evapo- ration. Rain- fall. Run- off. Evapo- ration. 14.92 13.30 1.62 18.18 21.80 3.64 23.08 23.04 0.04 18.96 6.29 12.67 10.11 2.71 7.40 14.37 6.62' . 7 75 12.42 6.64 5.78 15.04 5.22 9.82 7.76 2.15 5 61 Year 48.30 26.23 20.07 43.31 29.73 13.58 45.21 81 81 13 40 Period 1875. 1876. a 1877. Storage 17.51 15.-47 2.04 22.50 24.74 - 2.24 18.09 12.68 5 41 14.55 3.80 10.75 12.51 3.35 9.16 14.00 2 91 11 09 Replenishing 11 38 3.60 7.76 10.57 2.28 8.29 13 08 5 27 ' 7 81 Year 43 42 22.87 20.55 45.58 30.37 15.21 45 17 20 86 24 81 Period. 1878. 1879. 1880; Storage 21.88 13.59 10.58 18.02 3.45 3.06 3.86 10.14 7.50 23.19 18.07 9.48 21.49 2.92 2.93 1.70 13.15 6.55 18.29 11.82 11.58 14.78 2.45 2.62 3.51 9. S7 8.96 Replenishing Year 46.03 24.53 21.50 ' 48.74 27.34 21.40 41.69 19.85 21.84 Period. 1881. 1882. 1883. Storage 20.83 11.30 11.38 16.02 2.93 3.39 4.81 8.37 7.99 &20.50 611.45 b6. 50 12.14 3.35 2.17 8.38 8.10 4.33 ft 12. 65 &13.50 &6.20 8.73 2.51 1.37 4.12 10.99 4.88 Growing Replenishing Year 43.51 22.34 21.17 38.45 17.66 20.79 32.55 12.61 19.94 Period. 1884. 1885. Storage 21.42 12.14- 8.51 20.20 2.79 2.61 1.22 9.35 5.90 18.58 14.82 11.76 13.63 3.20 5.61 4.85 11.62 6.15 Growing Replenishing Year 42.07 25.60 16.47 45.16 22.44 22.72 "Not included in mean. b Rainfall computed, approximate. 91. Relation of Periodic Rainfall to Run-Off. For streams where the observations of flow have been made for a number of years, comparisons can readily be made of the relation of annual and periodic rainfall and run-off. Such investigations should be made by the water power engineer when considering a river relative to its availability for water power purposes. An analysis of such data for the Muskingum, Hudson, and Connecticut Rivers as made by Mr. Rafter, is shown in Tables XII, XIII and XIV (for ad- i6o Run-Off. ditional tabular data see Appendix). Graphical representations of the periodic relations of the rainfall and run-off on the Upper Hudson River basin are shown in Fig. 80, and the same relations for the Sudbury River basin are shown in Fig. 81. 9 , '0 tf ^ Storage period 25, SO, 40 80 15 20 Precipitation in inches 25 JO 15 20 Precipitation in inches 25 30 25 30 5 10 15 ?0 Precioitatfon in Inches Fig. 80. Rainfall and Run-Off of Upper Hudson River for Each Period of the Water Year. [From W. S. and I. Paper No. 80 "Relation of Rainfall to Run-Off.' ] Relations of Periodic Rainfall and Run-Off. 161 40 20-= Qc 10 10 Storage period 30 25 JO 15 20 25 Precipitation in inches 10 15 20 25 40 30 35 30 S5 10 Crowing period 10 15 Precipitation in Incites 10 15 20 25 30 20 20 Replenishing period 10 $ 70 w 15 20 Precipitation in inches 10 15 20 30 30 Fig. 81. Rainfall and Run-Off of Sudbury River for Each Period of the Water Year. [From W. S. and I. Papar No. 80 "Relation of Rainfall to Run-Off. "J 1 62 Run-Off, 92. Monthly Relation of Rainfall and Run-Off. The relations of rainfall to run-off from month to month on a given drainage area are not usually as direct and definite as the annual and periodic re- lations. The mean and extreme relations can, however, often be established within somewhat wider limits, and such relations will permit of the formation of at least a general idea of the probable limits of the monthly run-off, under other rainfall conditions. The wide range of the possible error of such estimates will be shown by the divergence of independent observations from the normal. To establish accurately the maximum and minimum limits, it is probable that observations, at least as extended as those needed for accurate rainfall estimates, will be needed. The observed relations between the monthly rainfall and the monthly run-off in various drainage areas are shown by Figs. 82, 83, 84 and 85. On Fig. 82 are shown the relations of monthly rainfall and run-off for several Northern river basins, and on Fig. 83 are shown the same relations for several Southern river basins. An examination of these diagrams will show the marked effect of seasonal tempera- tures and conditions upon the quantity of run-off. The high per- centage of run-off in the spring should be noted ; also how the per- centages of run-off in these rivers drop with the advance of the season and rise again in the fall. On Fig. 84 are given the monthly relations of rainfall and run-off for thirty years on three small river basins in the immediate vicinity of Philadelphia. These drainage areas, being small, are more readily and directly affected by rainfall, hence the relations are much more marked and uniform than those that exist on larger rivers. The marked variation from normal due to the influence of other varying conditions on the drainage area, especially during the summer months, should be noted. Figure 85 shows a set of monthly diagrams prepared by Emil Kuichling, C. E., for his discussion of the relation of rainfall to run-off in certain rivers in the Eastern part of the United States. On these diagrams the figures not enclosed are numbers of ob- servations from drainage basins Nos. I to 8 inclusive, of the fol- lowing list. The figures enclosed in circles are the numbers of observations from drainage basins Nos. I to 28, inclusive. Relations of Monthly Rainfall and Run-Off. 163. I A 4 JANUARY ' * ^ /, / ^x ^ /s '.- ^ pgfc * /\ \ FEBRUARY \^ ?^- J *. K z ..^ ^ ? //, ^ X* ^ A JUNE JULY ^ <^ in PTEMBER i al. - ^ D X, x ^^ /^ ,^ ^ ^ 2 X A k ^ #! 4 jX ^ t OCTOBER ; ^/ X X ^ -^ ^ >-^ ^ /^ -CJ^I X A 7 * ^ ^ ^ NOVEMBER < g ^" X, _/ ^x '* J > $ ^ v x* >! ^^ ^ A V X ^ <5 n DECEMBER Sv ^^ Z / ^ 79 2 s -'"A x 5 > s^ H n *l ' 123456789 10 0123456789 10 Horizontal Ordinates Rainfall in Inches. Wisconsin River at Necedah. D Chippewa River at Eau Claire. A Grand River at Grand Rapids. V Grand River at Lansing. X Thunder Bay River. Rock River at Rocktoiu Fig. 82. Monthly Rainfall and Run- Off Northern Rivers. 164 Run-Off. & 1 u '___ ^ x JANUARY t /* / *r X" // iff* S s '.^ x' K ~ ^ ^ FEBRUARY y V x X ^ K ,-' x ' // > -^q A & '' / / .4 x AP RIL /^ / ' J ^ /x ^ ^ 58 / '^ ^ ^ ^ ^ 1 ^ x ,x" ,4 X MAY 2 / ^x ,-<3 ^ /^ ^ Ix & ^ .' V o X t ^ JU NE y X X r^" ^ ^ 7 / V^ "' J ^ ^ o ^ u AUGUST OCTOBER DECEMBER ^^1 1 2 3 4 5 6 7 9 10 11 12 13 1 2 3 4 5 6 Horizontal Ordinates Rainfall in Inches. Talladega Creek, Watershed Area 156 Square Miles. V Upadachee River, " "440 " Alcovy River " " 228 " " Fig. 83. Monthly Rainfall and Run-OffSouthern Rivers. Relations of Monthly Rainfall and Run-Off. 165 / D 5 4 3 2 1 7 e 5 4 3 2 1 7 B 5 Z i,. B ?5 2 1 7 B 5 4 3 2 1 D 7 B 5 4 3 2 I n % JANUARY B * 3 I c w 1 x J* FEBRUARY i k XX, 3x , <; p< ^ ft a s b x V ^< * J| A C x MARCH ^ * * a ^ A X 4 ^^ ^0 O A A %* APRIL *A < X < { A f^ ycf ^ A/ g ^0 * O MAY 1 ' O r x^ V * A & ^A i ^ Wl ^c JUNE A x< 3 & AX 2 A^ ft ft ^ ** i 2 JULY x AUGUST A i k A X *>, A ' ' (4 ^A Ax O *L ^ ftf ^ D 4 a n OCTOBER X A ^ x x a? x3^ Jo * 5 x ojp x a a^ ai & i NOVEMBER x K Ox r^ sS A< 3 ^ " * I 2 3 4 5 B 7 B 3 ID II 121314 RAINFALL IN INCHES I 2 3 4 5 B 7 B 3 ID II 121314 RAINFALL IN INCHES WATERSHED AREA 102.2 SQUARE MILES O B S E RVAT IONS XTOHICKON CREEK ANESHAMINY " 139.3 OPERKIOMEN " 152. Ffg. 84. Relation between Kainfall and Run-Off on Tohickon, Neshaminy, and Perkiomen Creeks near Philadelphia, Pennsylvania. 1 66 Run-Off. ui -I ,\ \- V \ *. a a; 9 I fc ni Relation of Monthly Rainfall and Run-Off. 167 Watersheds from which Observations were platted on Diagram 85. No. Name of Basin. Area in Sq. Miles. No. of Years Record. 1 Crotoii River, N. Y 338 Qrt 2 Perkiomen Creek Pa 152 i q g Neshaminy Creek Pa . 139 3 1 '\ 4 Tohickon Creek Pa ... 10'' 2 14 5 Sudbury River Mass 75 2 25 5 Hemlock Lake NY . . 43 i 12 Mystic Lake Mass . . 27 7 18 8 Cochituate Lake Mass 19 QQ 9 Cayadutta Creek N Y , 40 2 10 Saquoit Creek N. Y 51 5 2 11 Oneida Creek, N Y 59 2 12 Nine-Mile Creek, N. Y 63 1 13 80 8 1 14 E. Branch Fish Creek, N. Y 104 1 la Oriskany Creek, N. Y 144.0 2 ](> Mohawk River N Y at Ridge Mills 153 2 17 W Branch Fish Creek N Y 187 3 18 Salmon River N Y 191 1 19 East Canada Creek N. Y 256 n 2 20 West Canada Creek N Y . 518 2 21 Schroon River N Y. . 563 4 22 Passaic River, N J 822 17 23 Raritan River, N. J 879 3 24 Genesee River, N. Y 1070 25 Mohawk River, N. Y., at Little Falls . . 1306 2 26 Black River, N. Y 1889 4 27 28 Hudson River N. Y., at Mechanic vi lie, N. Y . . . . Muskingum River, Ohio 4500.0 5828 12 8 A continuous graphical record for ten years, showing the rela- tions of rainfall to run-off on the Illinois River basin, based on ob- servations of stream flow made at Peoria, 111., is shown by Fig. 71. 93. Maximum Stream Flow. In the construction of spillways, dams, and reservoirs, and the study of their effect on the overflow -of embankments, levees, and lands, the question of maximum run- off becomes important. Many formulas have been suggested by engineers for determin- ing flood flows, each of which is based on more or less extended observations, and are applicable only when used under conditions similar to those on which they are founded. Very few of these formulas take into account the great number of conditions that modify the results. For this reason most of such formulas are of little use except for the purpose of rough approximation. None of these should be used without a knowledge of the conditions under i68 Run-Off. Max. rate of Discharge in Cu. Ft. per Sec. per Sq. Mile, (q) Maximum Stream Flow. 169 which they are applicable. Such calculations should, wherever pos- sible, be based on the known ratio of actual maximum and mini- mum flows on the drainage areas, or on drainage areas adjacent and similar thereto, and the use of a factor of safety as great as the importance of the local condition will warrant. Such data serves as the best and most conservative guide for all calculations of this class. A record of the maximum and minimum flows of various Ameri- can and foreign streams from the report of Mr. Kuichling, to which reference has already been made, is contained in the Appendix. Figure 86 shows a graphical representation of the actual rate of maximum flood discharge of these rivers and on this diagram is given the formulas, both graphically and analytically, for ordinary %nd occasional maximum floods as proposed by Mr. Kuichling. It is evident that Mr. Kuichling has endeavored to represent the maximum flood conditions that may occur on any river. In many localities, the results given are much larger than the actual condi- tions of flow will warrant. In some cases the overflow of lands and property by floods, caused by back water or otherwise, may be prevented by the con- struction of levees and the installation of .pumping plants for drain- age purposes. Under such conditions both the extreme height pf the flood and the length of its occurrence become important and can be determined only by gauge observation. A graphical study of such data affords the best means for its consideration. Figure 87 shows hydrographs of the high water conditions on the Fraser River at Mission Bridge, British Columbia. This stream is fed by the melting snows of the foot-hills, and the floods occur at essen- tially the same time each year within certain limits, as a rule reach- ing a maximum during May, June or July. The differences that occur from year to year are shown by the different hydrographs which represent, however, gauge heights in feet and not discharges. The highest record is that of the flood of June 5, 1894, of which, however, no hydrograph was obtained. 94. Estimate of Stream Flow. For the purpose of estimating water power no safe deduction can be made from average run-off conditions, although a knowledge of such conditions is desirable. The information that is needed for the consideration of water power ic a clear knowledge of the maximum and minimum conditions, the variations which occur between these limits and a knowledge of the length of time during which each stage is likely to occur 10 i7o Run Off. -{- &i i* O 00 Gauge Height in Feet. Estimate of Stream Flow. 71 throughout the year or throughout a period of years. As pointed out in the previous section, the extreme conditions are important in considering the height of flood as influenced by spillways and other obstructions in the river. The extrejn^jmd^average low water conditions commonly control or limit theexTelirr^i^tlie~pTant which should be installed. [y~~tne illustrations already shown it is fully demonstrated that the run-off of any stream, either for the year, period or month, cannot be approximately expressed either as an average amount or as a fixed percentage of the rainfall. An expression showing the relation between rainfall and run-off necessarily assumes quite a complex form, from which large variations must be expected. Where average amounts of run-off are considered, care must be used to base the deduction on correct principles. In considering the variation in the monthly flow of a stream, the flows of such stream should be considered in the order of their monthly discharge rather than, in their chronological order. For example : in Table XV, the mean monthly flows, of various streams, in cubic feet per second per square mile of drainage area are given. These flows are arranged in the chronological order of the months. The aver- age monthly discharges of the streams' are calculated therefrom, and are shown in the last column. An examination of this table will show that the minimum monthly flow of a stream does not always occur during the same month for each year. For the consideration of these streams for water power purposes, the better arrangement of the recorded flow is not in the sequence of the months, but by the monthly periods arranged in the relative order of the quantities of flow. In Table XVI this data has been rearranged. In this arrange- ment the least flow for any month in a given year is placed in the first line and the flows for other months are arranged progres- sively from minimum to maximum. The average for each month will, by this arrangement, give a much better criterion of the average water power to be expected from each drainage area dur- ing each year than the average monthly flow as determined in Table XV. 172 Run-Off. TABLE XV. Mean Monthly Flows of Various Eastern Streams Arranged in Chronological Order. (In Cubic Feel per Second per Square Mile. ) Kennebec Kiver at Waterville, Me. Drainage Area 4380 sq miles. Year. '9:) '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 Ave. January . . .60 .53 .95 2.64 6.92 3 47 .37 .40 .91 3.33 2.17 .46 .41 .45 5.43 2.17 1.46 .80 .61 .40 .28 1.27 1.37 1.27 .98 .64 2.98 6.21 3.87 1.25 1.21 .71 .77 .83 2.07 .62 1.84 .81 .84 .86 5.75 6.10 2.94 2.96 1.65 1.04 .60 1.29 1.21 2.17 .',3 2!56 6.76 5.70 2.26 .89 .71 .59 .92 1.77 .59 1.97 .53 .54 .73 5.31 1.81 2.00 1.14 .73 .43 .28 .40 .51 1.46 .54 2.05 2.07 6.45 6.41 2.28 1.31 .95 .63 .<;9 1.44 .93 2.14 .73 .57 1.10 9.39 3.46 1.8S 1.17 .95 .64 .67 .55 1 72 1.9U .88 .87 6.57 5.07 3.85 i.4H 1.79 1.15 .96 1.20 1.03 .99 2.32 .9i .88 4.42 3.74 1.66 1.52 1.19 .88 .57 .44 .33 .32 1.41 2.22 .20 .86 3.41 4.71 1.89 1.22 1.07 .98 1.07 .77 .60 1.58 .70 .60 1.20 3.08 2.40 1.53 1.07 .73 .68 .40 .52 .47 1.12 .FC .72 1.97 5.13 4.17 2.14 1.34 .87 ,68 >J9 .78 February March April . . , May July 1.81 .51 .46 .53 .51 .36 1.65 1.30 .67 .62 .85 .85 .44 1.12 August .... September October November .... . . Average . . . .. Merrimac River at Lawrence, Mass. Drainage Area 4553 sq. mi. Tsar. '90 '91 '92 '93 '94 '95 '96 '97 '98? '99 '00 '01 '02 '03 '04 'o:> Ave. January 1.53 1 70 2.92 2.96 5.19 4.73 1.61 1.00 .64 .54 .56 .47 .54 90 1.84 1.87 .94 1.61 1.79 2.25 1.28 1.05 1.06 .87 .47 1.43 .86 1.29 .65 1.10 2.36 3.42 4.28 .97 .52 .57 .61 .79 .74 1.17 1.43 .66 .94 3.16 2.43 1.54 1.33 .50 .37 .40 .50 .78 .67 1.11 .63 .51 1.28 4.35 1.37 .67 .57 .48 .37 .88 2.10 2.06 1.27 1.44 2.00 4.62 4.00 .98 .77 .45 .44 .67 1 14 1.46 .96 1.58 .75 1.01 2.32 3.87 2.22 2.79 2.37 1.12 .61 .48 1.2$ 2.2K 1.76 1.62 1.71 4.09 3.34 2.42 1.42 .58 .83 .64 1.41 2.17 1.93 1.85 1.73 1.07 2. 6-> 5.81 2.09 .65 .54 .46 .44 .39 .61 .61 1 42 .74 3.62 3.56 4.06 2.21 .87 .40 .41 .33 .55 1.28 1.4.) 1.63 72 .53 2.04 3.94 4.04 1.61 .62 .6 .57 .86 .65 2.09 1.53 2.24 1.20 6.06 3.72 2.18 1.13 ".93 .81 .74 1.54 1.23 1.74 1.96 .86 1.99 5.66 3.34 0.94 2.21 1.00 .72 .51 .79 .64 .80 1.62 ,57 .63 2.64 4.45 3.74 1.00 .60 .55 .6^ .78 .58 .39 138 .83 .49 2.2(i 3.47 1.12 .89 .57 .58 1.64 .70 .73 1.82 ,. 1.24 1.40 3 30 3.7S 2 26 1.27 .75 .67 1 38 .90 1.14 1.29 March 3.44 3.79 3.14 1.73 .69 .75 1.84 2.70 1.95 1.44 2.06 April May .. June July August September October November December Average Hudson River at Mechanicville, N. Y. Drainage Area 4500 sq. mi. Year. '88 '89 '90 '91 '92 '93 '94 ,'95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 Ave. January .... February... March April May June . . 1.41 .82 1.52 4.73 4.76 1.09 .34 .38 .63 1.02 2 36 2.22 1.77 2.44 .84 1.84 3.04 1.97 1.52 1.28 .95 .41 .83 1.77 2.93 1.65 2.50 1.74 2.47 3.35 3.98 1.64 .43 .45 1 97 2.05 2.03 .72 1.94 1.84 2.59 3.94 4.45 1.23 .71 .52 .59 .45 .33 .91 1.91 1.62 4.19 2.06 2.41 4.79 4.37 2.80 2.06 1.22 .99 .63 1.69 .93 2.34 .71 1.02 1.97 3.98 4.95 1.07 .56 1.11 1.53 .86 .81 1.60 1.68 1.50 1.07 3.28 2.47 1.68 1.58 .70 .55 .42 .81 1.42 .97 1.37 .86 .79 .93 5.29 1.52 .63 .57 .87 .58 .58 1.87 2.42 1.41 1.51 1.04 3.02 5.55 1.02 1.05 .62 .54 .64 .91 2.52 1.54 1.66 .89 .87 2.71 4.24 2.70 2.63 2.47 1.83 .61 .56 2.22 3.20 2.08 1.72 1.50 4.49 3.05 2.46 1.17 .57 1.14 .86 1.75 2.05 1.25 1.83 1.49 1.17 2.14 5.25 2.17 .58 .54 .31 .46 .58 1 49 1.30 2.77 1.72 5 02 2.00 .91 .52 .60 .42 .47 1 11 .69 .54 1 80 6.28 2.60 1.73 .79 1.03 .89 .94 83 l"53 5.53 2.38 1.76 1.40 1.98 1.40 .81 1.53 1 41 1.56 2.19 6.87 3.11 .78 1.8S l.OF 1.31 .91 2.25 1 ^ 1.2J* 1.52 2.46 4.61 2.96 1.50 .58 1.39 1.4H 2.62 1.03 .87 1.86 1.35 .79 2.09 5.06 1.82 2.12 1.54 1.25 2.67 1.35 1.60 1.38 2.84 4.15 2.48 1.45 .96 .94 .93 1.12 1.57 1.6.' July August September . October November. . December. . Average 1.02 1 43 1.13 1 50 1.88 1.67 1.83 .... 1.18 2.03 Estimate of Stream Flow. 173 TABLE XV. Continued. Potomac River at Point of Rocks, Md. 9654 sq. mi. Year. '98 '99 '00 '01 '0^ '03 '01 '05 Ave. January 2.40 1.95 .&3 . 57 1.81 1.78 .76 .89 1.38 February 85 3 00 1.38 .37 3.37 2 .10 1.81 ' .58 1.71 March 1 59 3 72 1.93 1 45 5.64 2.77 1 16 2 43 2 58 Vpril 1 b7 1 22 96 4 07 2 99 2 99 77 68 1 92 .May 1 89 1 20 45 2 85 .02 .64 97 .46 1 13 June 42 54 .86 2 01 .33 1 86 1 05 .68 97 July 26 27 31 1 11 32 1 32 47 1 06 64 Vugust 2 34 25 20 .87 .26 .50 .25 .60 .66 September 2 44 2 50 2 59 4.19 1 97 1.68 1,87 2.52 2.71 246 2 14 200 1 88 1 t.8 2.:>5 2 6;' 2 12 2.35 4.73 2.93 3.35 3.94 4.87 3.98 2.47 2.42 3.02 3.20 3.05 2.17 2.77 J.60 >.3f- 3.11 2.96 2.67 3.12 Maximum.. 4.76 3.04 3.98 4.45 4.79 4.95 3.28 5.29 5.55 4.24 4.49 5.25 5.02 6.28 5.5t 6.87 4.61 5.06 4.85 Merrimac River at Lawrence, Mass. 4553 sq. mi. Year. '90 '91 '92 '93| '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 Ave. "Mini mil in .69 47 47 .52 37 37 .44 .48 .58 .39 .33 .53 74 .51 .39 .49 48 .75 .54 .86 .57 .40 .48 .45 .61 .64 .44 .40 .57 '.81 .64 .55 .57 .59 .44 .54 .87 .61 .44 .57 .67 .75 .83 .46 .41 .62 .93 .72 .57 .58 .60 .53 .59 .94 .65 .50 .57 .77 1.01 1.41 .54 .55 .65 1.13 .79 .58 .70 .88 .70 .64 1.05 .74 .50 .63 ^96 1.12 1.42 .61 .74 .72 1.20 .fO .60 73 .87 .73 .90 1.06 .79 .66 .67 .98 1.S8 1.62 .61 .87 .86 1.23 .86 .62 .83 .96 .84 1.00 1.28 .97 .67 .88 1.14 2 22 1.71 .65 1.28 .96 1.54 .94 .63 .89 1.12 .95 1.61 1.43 1.10 .78 1.28 1.44 2.28 1.93 1.07 1.49 1.61 1.74 1.00 .78 1.12 1.42 .7.) 2.92 1 61 1.17 .94 1.37 1.46 2 32 2.17 1.73 2.21 2.04 2.18 1.99 1.00 1.22 1.88 .14 2.96 1.79 2.36 1.33 2.06 2.00 2.37 2.42 2.09 3.56 2.09 2.24 2.21 2.64 1.64 2.30 .44 4.73 1.87 3.42 2.43 2.10 4.00 2.79 3.34 2.62 3.62 3.94 3.72 3.34 3.74 2.26 3.20 Maximum .79 5.19 2.25 4.28 3.16 4.35 4.62 3.87 4.09 5.81 4.06 4.04 6.06 5.66 4.45 3.47 4.32 Potomac River at Point of Rocks, Md. 9654 sq. mi. Year. '98 '99 '00 '01 '0> '03 "04 '05 Ave. 26 18 14 37 15 .22 .12 .24 .21 .26 .25 .14 .40 .26 .30 .14 .80 .26 .42 .25 .20 .48 .29 .33 .17 .33 .31 .85 .*7 .31 .57 .29 .48 .23 .46 .43 .87 .33 .45 .77 .32 .50 .25 .58 .51 1 45 .42 .48 .87 .33 .64 .47 .60 .66 1.59 .54 .64 1.11 .62 1.32 .76 .68 .91 1.60 1.20 .83 1.49 1.81 1.78 .77 .68 1.27 1.67 1.22 .86 2.01 1.96 1.86 .97 .89 1.43 1.89 1.95 .9ti 2.62 2.99 2.30 1.05 1.06 1.85 2.34 3. CO 1.38 2.85 3.37 2.77 1.16 1.10 225 Maximum 2 40 3 72 1 93 4 07 5 64 2.79 1.81 2.43 3.01 fact is more fully demonstrated by the tables on maximum and min- imum run-off given in the Appendix. From the data in the Appen- dix it will be noted that the recorded minimum of some of the Southern streams is between .5 and .6 cubic feet per second per square mile, while numerous other streams will vary from .2 to .4; nevertheless a large oortion of the streams shown have minimum flows of .1 and less. CHAPTER IX. RUN-OFF (Continued). 95. Relation of Run-Off to Topographical Conditions. The rel- ative run-off from a drainage area depends largely on its topo- graphical condition. This is due to the fact that climatic condition depends on the elevation and slope of the drainage area, and also to the fact that the rapid removal of the water from steep slopes assures less activity in the other factors of rainfall disposal and consequently a greater run-off. Mr. F. H. Newell in a paper before the Engineering Club of Philadelphia (see Proceedings Engineer- ing Club of Philadelphia, vol. 12, page 144, 1895) presents a dia- gram (see Fig. 88) which shows in a broad way, the influence of such conditions. In describing this diagram Mr. Newell says : "The diagonal line represents the limit or the condition when all of the rain falling upon the surface, as upon a steep roof, runs off; the horizontal base, the conditions when none of the water DEPTH OF MEAN 'ANNUAL RUN-OFF IN INCHES _ M ro a _ in a cn^a m c 7 z / / i 7 * / // ^S / / / / -^ / / /- / / / / / / / 2 ] j _S *S 2 i ANNU/ 5 2 i D A D 1. EPTH C Fig. 88 176 Run-Off. flows away. Between these are the two curved lines, the lower rep- resenting the assumed condition prevailing in a catchment basin of broad valleys and gentle slopes, from which as a consequence there is relatively little flow, and the upper curve, an average condition of mountain topography, from which large quantities of water are discharged. For example, with a rainfall of 40 inches on an un- dulating catcl ment basin, about 15 inches is discharged by the stream, while from steep slopes 30 inches runs off. With less mean annual rainfall the relative run-off is far less, as for example, with 20 inches, about 7 inches of run-off is found in steep catchment basins, and about 3 inches on the rolling plains and broad valleys of less rugged topography. Following these curves down, it would appear that as the average yearly rainfall decreases the run-off diminishes rapidly, so that with from 10 to 15 inches no run-off may be expected on many areas, and from 2 to 4 inches from the mountains. There is an apparent exception to this, in that with very small annual rainfall the precipitation often occurs in what is known as cloudbursts, large quantities of water falling at a sur- prisingly great rate. Under these conditions the proportion of run- off to rainfall increases, as the water does not have time to sat- urate the ground." "These curves should not be regarded as exact expressions, but as indicating general relationships and as showing graphically de- ductions based upon long series of observations of quantities not determined with exactness. Computations of this relation made in various parts of the country have, when platted graphically, fallen near or between these curves, according to the character of the country from which the water was discharged. On the figure are shown three average determinations, numbered i, 2 and 3, rep- resenting respectively the relation of run-off to rainfall, for the Connecticut, Potomac and Savannah Rivers. The horizontal lines indicate determinations made for western streams coming from areas of small precipitation. The exact amount of rainfall is not known, as the observations are not representative of the conditions prevailing upon the mountains, and therefore the horizontal line has been used instead of a dot, as indicating the probable range of rainfall, as, for example, being from 10 to 15, or from 15 to 20 inches. The height of these short lines above the base indicates the average annual run-off of the basin, a quantity which has been determined with considerable accuracy according to the method just described." Effects of Geological Conditions on the Run-Off. 177 Figure 88 is presented on account of the .general principles illustrated thereby and should be used for such purpose only. While the limits given by Mr. Newell are sufficiently broad to include many of the conditions in the United States, they are too broad to give a sufficiently definite relation for most local conditions and too narrow to include all conditions which may occur in the United States. The latter fact is perhaps best illustrated by Fig, 89, reproduced from a paper by Messrs. J. B. Lippincott and S. G. Bennett on "The Relation of Rainfall to Run-Off in California", published in the Engineering News, vol. 47, page 467. This figure shows the annual and mean run-off from various California drain- age areas based on several years' observations. The diagram shows both the Newell curves, illustrated in Fig. 88, and three mean curves for California conditions, also several mean and numerous annual run-off observations which can be studied in detail in the article above referred to. The general curve for large drainage areas is for areas of 100 square miles or over. S 10 IS 20 25 ANNUAL RAINFALL IN INCHES Fig. 89 96. Effects of Geological Condition on the Run-Off. The geo- logical condition of a drainage area has a marked effect on the run-off. The determination of the exact geological conditions of any drainage area, which control or modify the resulting run-off, is difficult or even impossible and can seldom be done with suf- ficient accuracy so that the results may be even approximated with- out actual observations on the drainage areas. The effects of these conditions, however, are important and they are here pointed out Run-Off. so that such effects may be realized and the fact appreciated that the run-off of streams otherwise similarly located may be materially different on account of difference in these conditions. A good ex- ample of the geological influence on run-off may be seen by compar- ing the stream flow of any of the Northern Wisconsin streams with that of the Rock River in the Southern portion of the state. Most of the Northern Wisconsin streams flow, in part, over pervious beds of sand-stone and a considerable amount of the water falling on their drainage areas is undoubtedly lost through absorption by the underlying strata. These losses undoubtedly affect the flow of the stream to a considerable extent. These streams, however, have no large under-flow through loose material which can absorb and transmit any considerable portion of the rainfall that would other- wise appear as surface run-off. The Rock River, on the other hand, follows for a considerable portion of its course through Wisconsin, its pre-glacial drainage valley which is filled to a depth of 300 feet or more with drift material consisting largely of sands and gravels through which a large amount of water doubtlessly escapes. The TABLE XVII. Comparative Mean Monthly Run-Off of ihe Wisconsin River at Necedah, Wis- consin, and the Rock River at Rock! on, Illinois, in Cubic Feet Per Second Per Square Mile. 19O3. g H-5 & r EH jj 1 h Cu << >, c3 g s 3 1-5 j>> 3 H-5 M % a CD OQ +3 o o > ft 6 a> P Wisconsin river 45 44 04 1 48 9 50 1 IP 1 56 1 15 9 73 1 83 86 1 34 Rock river 91 6i 91 78 44 45 1904. Wisconsin river Rock river 45 77 2 80 2.21 1 76 2.63 88 1.96 39 1.02 ?6 .66 ?4 .90 38 2.34 50 .98 30 41 1905. Wisconsin river 1.56 2.10 2.72 1.63 1.91 1.10 4.02 1.06 1.50 .64 1.05 .4] 1.28 .41 .99 .39 .81 .40 1.53 .44 Rock river .60 .53 19O6. ^Wisconsin river 3 90 1 81 1 86 1 13 90 89 83 1.17 1 41 Rock river 1 56 1 59 1 9? 1.49 58 37 38 10 ?1 ?8 Effects of Area on the Run-Off. 179 deposits of this old river bed have been quite extensively explored for water supply purposes and yield very large quantities of water for domestic and manufacturing supplies. Most of the under-flow, however, undoubtedly passes away to an unknown outlet as the modern river leaves the old valley near Rockford, 111. A comparison between mean monthly flows of the Wisconsin and Rock Rivers, as shown in Table XVII, will give an idea of the effect of these different conditions as shown by the run-off of these two- rivers. 97. The Influence of Storage on the Distribution of Run-Off. Favorable pondage conditions on a watershed have an important* effect on the distribution of the run-off, and this effect is readily discernible in the records of flow from such areas. Figure 90 is a hydrograph of the discharge of the various rivers draining the Great Lakes for the years .1882 to 1902. A general similarity is seen in the annual variations in these hydrographs and yet there is a considerable variation from the maximum to the minimum discharge in accordance with the rainfall and other condi- tions prevalent on the watershed. In every case, however, the minimum of the year is found to occur at about the same time, and the time of maximum height is also fairly constant. The ratios between maximum and minimum flow are very much less than those that obtain on other watersheds where the pondage area is much less. In the St. Lawrence River the maximum mean monthly discharge is about 320,000 second feet, and the minimum is about 185,000 second feet, the maximum being not quite double the minimum. In the discharge of the Niagara River the maximum mean monthly discharge is about 260,000 cubic feet, and the minimum about 175,000, the fluctuation being still more moderate. The mean monthly discharge of the St. Marys River shows a maximum of about 110,000 second feet, and a minimum of about 50,000. The ratio here is somewhat higher, because, in this case, Lake Superior and its drainage area being the source of supply, the relation of pondage to drainage area is less than in the com- bined lakes, and the effect is seen in the variation in the discharge of this river. 98. Effects of Area on the Run-Off. The size of the drainage area of any stream has a marked effect on the distribution of the run-off. The hydrographs of small areas show the effects of heavy rains by an immediate and marked increase in the flow. i So Run-Off. The Study of a Stream from its Hydrographs. 181 This is well shown by a comparison of the hydrographs of Per- kiomen Creek and the Kennebec River (Fig. 96), and of the Hood and Spokane Rivers (Fig. 99). On small streams where per- vious deposits are largely developed, the rainfall is rapidly absorbed and does not so radically affect the run-off. Large streams do not feel the immediate effect of rainfall, on account of the time required for the run-off to reach the main stream. The flow of large streams is also modified by the fact that uniform conditions of rainfall seldom obtain on the entire area. On large drainage areas, condi- tions of rainfall may prevail on one or more of the tributaries only, while on other portions of the drainage area the conditions may be quite different. Such conditions may frequently be reversed, with the result that the larger the stream the less becomes the extremes of flow and the greater the uniformity of flow. 99. The Study of a Stream From Its Hydrographs. The influ- ences of various factors on the run-off, as above discussed, can be clearly seen from an analysis of the stream flow data, but they can best be appreciated by noting their effect on the hydrograph. The hydrograph of the actual flow of a stream is the best means of studying its manifold variations, but to fully comprehend the wide limit of such variations, hydrographs must be available for a long term of years. When the hydrographs are sufficiently ex- tended to cover all of the usual variations in rainfall and other meteorological conditions, they afford a comprehensive view of the entire subject of the run-off of the stream. Figures 91 and 92 show hydrographs of the Passaic River for seventeen years. From these hydrographs the actual variations in flow as they have occurred on this drainage area during this period can be seen. The average monthly rainfall on the drainage area has also been shown on these diagrams and the effects of such rainfall on the run-off should be noted. It is important to note especially the marked effect of a limited rainfall during the months of the storage period, when the ground has previously become saturated, as compared with the effects of the same or greater rainfalls during the growing period, when the ground water has been partially ex- hausted by the demands of vegetation and the draft of the low water flow. In these diagrams, and those following, the flows are shown in cubic feet per second per square mile, in order that their value for comparative purposes may be increased. The absolute discharge of a river in cubic feet per second gives no comparative 182 Run-Off. 2.40 I 2^2 I 4.12 -89 I 0.61 U4 | 7.69 Figures near top of each diagram show total monthly rainfall. Fig. 91. Daily flow of Passaic River, Little Falls, N. J. The Study of a Stream from its Hydrographs. 183 ^ 8 2 6 JT I ^ 12 10 I 3 i G O) ? 12 I 10 tn 8 S 6 4 2 Figures near top of each diagram show total monthly rainfall. F i g 92. Daily flow of Passaic River, Little Falls, N. J. 184 Run-Off. measure of discharge values, but when the corresponding area is also shown, the diagram becomes more or less applicable for com- parative purposes to other areas. Hence, for general or compara- tive discussion, the discharge per unit of area should be the basis of consideration. 100. Comparative Run-Off and Comparative Hydrographs. In studying and comparing all run-off data and the hydrographs based thereon it is important to note that a uniformity of conditions pro- duces a uniformity of results. Such data is not only of value in the study of the river from which it is obtained, but also furnishes information regarding other streams that exist under the same or similar conditions, both physical and meteorological. Table XVIII, which shows the monthly run-off for a term of years of certain Michigan streams, gives a comparison of the flow of streams under such conditions, as expressed by their comparative monthly run-off. The relative geographical locations of these streams are shown in figure 93. The run-off from each drainage area is given in cubic feet per second per square mile, so that the results are strictly comparable, the question of size of area being eliminated. A general resemblance can be traced between most of these streams. The Manistee and Au Sable Rivers, in the Northern portion of the state, have sand and othef pervious deposits largely developed on their drainage areas, and show, in consequence, greater uniformity of flow and a greater mean flow than that of the other streams. Comparative hydrographs of some of these streams for the year 1904 are shown in Fig. 94. The vertical scale for each of the hydrographs shown on the diagram is the same, and represents the discharge in cubic feet per second per square mile. The relative flows of the different streams are thus easily compared. On these diagrams has also been shown the average rainfall which occurred on each drainage area for each month. A study of the rainfall record in connection with the flow lines of the hydrograph, will show that the difference in flow is not entirely attributable to the prevailing rainfall conditions on the drainage area, but that other physical influences have a material effect. These hydrographs were originally prepared in order to form a basis for an estimate of the probable horse power on the White River, on which no gauge readings had been taken. On the right of the diagram is shown a horse power scale from which the probable power of the White River, with a given fall and drainage area, and on the basis Comparative Hydrographs. 185 Fig. 93. Map showing location of various Michigan drainage areas. 11 i86 Run-Off. 3*6 BRAND RIVER AT NORTH 3.86 2.18 3.64 2.74 1.91 LANS 3.60 20000 a a ' GRAND RIVER AT CRAN 2.48 I 3.62 I IJ9 RAPID 2.89 80000 40000 299 AJ SABLE: RIVER 3.14 344 Fig. 94. Comparative Hydrographs of Various Michigan Rivers for the year 1904. Comparative Hydrographs. 33VONOd HUM SHOOK H3MDd 16UOK I8 7 .1 2 o s 311ft 3HVnl)S 3d ON033S U3d 133J Nl 33dVH3Sia i88 Run-Off. TABLE XVIII. Discharge in cubic feet per second per square mile of drainage area of various Michigan rivers. Ihunder Bay river at Alpena At Grand Rapids. f-b river &b -u.3 <1 Kalamazoo river at Allegan. St. Joseph river at Buchanan. Muskegon river at Newayga. Manistee river at Sherman. Au Sable river at Bamfield. White river at Moran's Bridge. 1901 March 3.25 2 73 April 1.49 1.39 1 06 64 1 29 May 1.18 .66 48 .53 76 June ... .63 49 34 57 53 45 July .74 .92 78 51 45 45 August .51 .38 58 52 38 40 September 1.31 .39 .44 .50 54 37 October .70 .47 .51 50 71 50 November . . .' .41 .42 .35 57 .70 38 December .32 .65 .66 .54 .82 .38 1902 January 40 .46 .55 .46 69 30 29 .40 43 .46 .62 .33 March 1.31 1.41 1 26 .58 1 32 57 April .91 1.03 1.02 .55 90 1.03 Alay 78 1.15 1 09 55 98 1 34 June .74 .70 .88 .56 .92 .77 July 40 1.57 1 78 .62 1 10 .64 August 46 .53 57 54 60 .47 71 September . . . .21 .57 50 .52 .58 .46 71 October 48 .79 84 .61 .84 67 .75 November 77 .95 .66 .63 79 57 95 December .34 .96 .62 .64 1.00 .54 .91 Yearly mean .59 .88 .85 .56 .86 .68 1903 January .44 1.53 83 93 1.13 1 48 February .... , 55 2.26 1.36 1 20 1.52 .67 1.18 March 1.67 2.13 2.69 1.84 2.05 1.58 1.43 April 1 16 2.04 2 45 1 63 1 76 1.38 1 38 May 62 .68 52 .76 .91 .97 June 44 .53 46 .69 .78 July. 48 .45 53 .62 22 .79 August .83 52 .79 .69 40 1.03 September .79 1 06 1,04 .92 40 1.01 October .68 1 15 62 81 35 .86 November 43 54 43 68 41 28 78 December. . . .38 62 33 .72 .66 41 1.13 Yearly mean 1904 January . .71 .38 1.05 1.00 48 .93 .82 1 49 1 28 1.07 1.94 February 46 1 07 98 1 48 1 18 2 35 March 64 3 05 3.44 3 07 1 29 1.79 April 3.48 2.90 2.22 2.08 2.24 2.35 1.89 May 1 79 1.00 69 1.03 95 2 00 1.49 June . . 1.17 .52 .33 .73 .68 1.42 1,05 Comparative Hydrographs. 189 TABLE XVIII. Continued. ~ S3 y ? I-| 2 ^ H3 At Grand J Rapids, g 0. river 51 Kalamazoo river at Allegan. St. Joseph river at Buchanan. Muskegon river at Newayga. Manistee river at Sherman. 3^2 -*i 5> "J'CPQ O> 02 "& *H CS . So ^3 ^c5 July 36 35 25 66 67 1 22 90 46 August 36 29 24 .55 45 1 18 85 66 September October .34 38 .35 .59 .21 .32 .61 71 .33 .47 .33 .45 l.ll 1 19 .77 82 .68 93 November December .35 .35 .37 .24 .26 .55 .56 .47 .40 .42 .39 1.09 1 08 .76 1.37 .79 .94 Yearly mean .84 .78 1.06 1.36 1.33 Mean for last 5 or 6 months .35 41 25 61 47 41 1 14 91 74 1905 January "fi3 1 20 1.31 1 34 February 67 1 31 1.97 1 51 March 1 94 1 52 1 19 1 55 April 1 47 1 81 1 07 1 55 Mav 1 40 1 51 1.14 1 47 June 2 76 1 29 .98 1.84 Mean for 6 mos. . . 1.49 1.61 1.11 1.54 of the comparative flows of various Michigan rivers, could be es- timated. In Fig. 95 these hydrographs have been re-drawn, the daily flows being platted in the order of their magnitude. This form of diagram represents the best basis for the comparative study of stream flow for power purposes where storage is not considered, and where the continuous power of the passing stream is to be investigated. A careful study of Figs. 94 and 95 will show that the run-off is similar in streams situated under similar geographical, topograph- ical, and geological conditions, and having equal, or similar, rain- falls on the drainage area. The departure of the various streams here considered, from the average of all, gives a very clear idea of the errors which may be expected in estimating the flow of any par- ticular stream from the hydrographs of other adjacent streams, or from the flow of streams more remote, and which are located under different physical conditions. 10 1. Comparative Hydrographs From Different Hydrological Divisions of the United States. The hydrographs oif streams differ widely in character, both in accordance with their geographical location and the diverse physical character of their drainage areas. Their geographical location affects their climatic, geological and ipo Run-Off. Kennebec River, Waterville, Me.: Drainage Area, 4410 Sq. Mi. Perkiomen Creek, Frederick, Pa.: Drainage Area, 152 Sq. Mi. Yadkin River, Salisbury, N. C.: Drainage Area, 3399 Sq. Mi. 1903 1904 Alcovy River, Covington, Ga.: Drainage Area, 228 Sq. Mi. Coosa River, Riverside, Ala.: Drainage Area, 70G5 Sq. Mi. I 1903 Creek, Nottingham, Ala.: Drainage Area, 156 Sq. Mi. Fig. 96. Hydrographs of Atlantic and Eastern Gulf Drainage. Comparative Hydrographs. 191 12 10 8 6 4 8 U s a CJ fl a> ^ I 1903 1904 1 - 1 fli m j m 1 . $\ H i i 3 frwxh E2 1-4. f d -rrTs ^ t 03 ^ M 4 I* Q) > ! ft - Licking River, Pleasant Valley, O., Drainage Area 690 Sq. Mi. 1903 ^^ 1904 >9^ ^xN r^' ^fa ^ J &2 kW, ^ y ///, ^ 'T^^C /: >?>/; N^V '///< y//4. ^/; ^k^, -0 a S 10 - 8 - 6 4 .S 2 Seneca River, Baldwinsville, N. Y., Drainage Area, 3103 Sq. Mi. 1303 1904 1 i i 1 1 1 BJ 8 ii yiA Ji i IffArtt B M W/ffl/M 1 . Y\ rv^33k i \ ^A TM/tyPx/^ i ^ r, ^ ^ ft ^ ^ =^A 08 1 s Q 6 4 2 8 6 4 2 Chittenango Creek, Chittenango, N. Y., Drainage Area, 79 Sq. Mi. 1903 1904 I I S ^ \ A ^\ A r /x ML *\i ^^J ^2 A. ^_i if^ ^^ / ^^/ Gr an d Riv< ''rrrtkf? 3r, Gr 2^ anc i^J 1 R ap fazz ids L^ M Ld ich ^^ | Salt River, McDowell, Ariz., Drainage Area, 6260 Sq. Mi. Fig. 98. Hydrographs of Mississippi Valley and Gulf Drainage. Comparative Hydrographs. 193 Spokane River, Spokane, Wash., Drainage Area, 4005 Sq. Mi. Hood River, Tucker, Ore., Drainage Area, 350 Sq. Mi. Kalawa River, Forks, Wash., Drainage Area, 213 Sq. Mi. 1903 1904 ^Tr y&r. Kern River, Bakersfield, Cal., Drainage Area, 2345 Sq. Mi. oS i : >Q Pacific E jjr^ 1903 1904 fYt ^k San Gabriel River, Azusa, Cal., Drainage Area, 222 Sq. Mi. Bear River. Collinston, Utah, Drainage Area, 6000 Sq. Mi. Walker River, Coleville, Cal., Drainage Area, 306 Sq. Mi. Fig. 99. Hydrographs of Western Drainage. 194 Run-Off. topographical conditions, and results in a material difference in the distribution and quantity of run-off. Hydrographs from the various hydrological divisions of the United States are shown by Figs. 96 to 99, inclusive. For each drainage area hydrographs for two years are shown in order to eliminate, partially at least, the effect of any peculiar conditions which might have obtained during a single year, and to show that the hydrographs are characteristic. 102. General Conclusions. A complete discussion of run-off is impossible in the space available in this volume. Attention has been called to the general laws upon which the amount of run-off depends, and to the similarity in flow that obtains on watersheds which are physically similar, also to the variations in run-off that occur on different watersheds due to differences in physical condi- tions. Each stream presents peculiarities of its own, and in investigating stream flow the data available is seldom the same and is always found to be much too limited for a complete understanding. Only general suggestions can be offered for the study and investigation of these subjects. Attention has been directed, as clearly as pos- sible, to the errors which are likely to arise in the investigation of water power conditions by comparative study. From a knowledge of such errors the engineer will realize the limiting values of his conclusions, and hence 'should so shape his design as to effect as safe a construction as the condition will permit, and also a construc- tion which will bear out fairly well his conclusions at the time of its inception. It is evident that no exact conclusions are possible in these matters, and that an element of uncertainty is always pres- ent. A knowledge of the extent of these uncertainties and the probable limits of exact knowledge are as important to the engineer as his ability to draw correct conclusions from data which is known to be correct. LITERATURE. RESULTS OF STREAM FLOW MEASUREMENTS. 1. Annual Reports of the Water Bureau of Philadelphia. Contain com- plete data relating to the Perkiomen, Tohickon and Neshaminy. 2. Monthly Data Relating to the Sudbury, Cochituate, and Mystic. Reports of the Boston Water Board, and of the Metropolitan Water Board, Boston. Publications of the U. S. Geological Survey contain data for the years indicated below : Literature. 3. 1888. Tenth Annual Report. Part I. 4. 1889. Eleventh Annual Report. Part II. 5. 1890. . Twelfth Annual Report. Part II. 6. 1891. Thirteenth Annual Report. Part III. 7. 1892. Fourteenth Annual Report. Part II. 8. 1893. Bulletin No. 131. 9. 1894. Sixteenth Annual Report. Part II. 10. 1894. Bulletin No. 131. 11. 1895. Seventeenth Annual Report. Part II. 12. 1895. Bulletin No. 140. 13. 1896. Eighteenth Annual Report. Part IV. 14. 1896. Water Supply and Irrigation Paper, No. 11. 15. 1897. Nineteenth Annual Report. Part IV. 16. 1897. Water Supply and Irrigation Papers, Nos. 15 and 16. 17. 1898. Twentieth Annual Report. Part IV. 18. 1898. Water Supply and Irrigation Papers, Nos. 27 and 28. 19. 1899. Twenty-first Annual Report. Part IV. 20. 1899. Water Supply and Irrigation Papers, Nos. 35 to 39, inclusive. 21. 1900. Twenty-second Annual Report. Part IV. 22. 1900. Water Supply and Irrigation Papers, Nos. 47 to 52, inclusive. 23. 1901. Water Supply and Irrigation Papers, Nos. 65, 66 and 75. 24. 1902. Water Supply and Irrigation Papers, Nos. 81 to 85, inclusive. 25. 1903. Water Supply and Irrigation Papers, Nos>. 97 to 100, inclusive. 26. 1904. Water Supply and Irrigation Papers, Nos. 124 to 135, inclusive. 27. 1905. Water Supply and Irrigation Papers, Nos. 165 to 178, inclusive. RELATIONS OF RAINFALL AND STREAM FLOW. 28. Fteley, A. The Flow of the Sudbury River, Mass. Trans. Am. Soc. C. E. Vol. 10, p. 225, 1881. 29. Lawe, J. B. On the Amount and Composition of Rain and Drainage Waters, collected at Rothamsted. Jour. Royal Agric. Soc. Eng. Vol. 17, p. 241, 1881, and Vol. 18, p. 1, 1882. 30. Coghlan, T. A. Discharge of Streams in Relation to Rainfall, New South Wales. Proc. Inst. C. E., Vol. 75, p. 176, 1884. 31. Croes, J. J. R. Flow of the West Branch of the Croton River. Trans. Am. Soc. C. E., Vol. 3, p. 76. May, 1884. 32. Brackett, Dexter. Rainfall Received and Collected on the Water-sheds of Sudbury River and Cochituate and Mystic Lakes. Jour. Asso. Eng. Soc., Vol. 5, p. 395, 1886. 33. McElroy, Samuel. The Croton Valley Storage. Jour. Asso. Eng. Soc. 1890. 34. Fitzgerald, Desmond. Rainfall, The Amount Available for Water Sup- ply. Jour. New Eng. W. Wks. Assn. 1891 35. Fitzgerald, Desmond. Yield of the Sudbury River Watershed in the Freshet of February 10-13, 1886. Trans. Am. Soc. C. E., Vol. 25, p. 253, 1891. 36. Talbot, A. N. The Determination of the Amount of Storm Water. Proc. 111. Soc. Eng. & Surveyors. 1892. 196 Run-Off. 37. Fitzgerald, Desmond. Flow of Streams and Storage in Massachusetts. Trans. Am. Soc. C. E., Vol. 27, p. 253. 1892. 38. Fitzgerald, Desmond. Rainfall, Flow of Streams, and Storage. Trans. Am. Soc. C. E., Vol. 27, p. 304, 1892. 39. Babb, C. C. Hydrography of the Potomac Basin. Trans. Am. Soc. C. E., Vol. 27, p. 21, 1892. 40. Babb, C. C. Rainfall and Flow of Streams. Trans. Am. Soc. C. E., Vol. 28, p. 323, 1893. 41. Mead, D. W. The Hydrogeology of the Upper Mississippi Valley, and of Some of the Adjoining Territory. Jour. Ass'n Eng. Soc., Vol. 13, p. 329, 1894. 42. Report on Water Supply of New Jersey. Geol. Survey of N. J., Vol. 3. 1894. 43. Starling, Wm. Measurements of Stream Flow Discharge of the Missis- sippi River. Trans. Am. Soc. C. E., Vol. 34, pp. 347-492, 1895. 44. McLeod, C. H. Stream Measurements. The Discharge of St. Lawrence River. Trans. Can. Soc. C. E. June, 1896. 45. Data Relating to the Upper Mississippi. Report, Chief of Engineers, U. S. A., 1896, p. 1843. 46. Wegmann, Edward. The Water Supply of the City of New York. Data Relating to the Croton. Wiley & Sons. 1896. 47. Johnson, T. T. Data Pertaining to Rainfall and Stream Flow. Jour. Wes. Soc. Eng., Vol. 1, p. 297, June, 1896. 48. Chamier, Geo. Capacities Required for Culverts and Flood Openings. Proc. Inst. C. E., Vol. 134, p. 313. 1898. 49. Pannalee, W. C. The Rainfall and Run-off in Relation to Sewage Prob- lems. Jour. Asso. Eng. Soc., Vol. 20, p. 204, Mch., 1898. 50. Seddon, J. A. A Mathematical Analysis of the Influence of Reservoirs upon Stream Flow. Trans. Am. Soc. C. E., Vol. 40, p. 401. 1898. 51. Sherman, C. W. Run-off of the Sudbury River Drainage Area, 1875-1899, inclusive. Eng. News, 1901. 52. Clark, E. W. Storm Flow from City Areas, and Their Calculation. Eng. News, Vol. 48, p. 386, Nov. 6th, 1902. 53. Pence, W. D. Waterways! for Culverts. Proc. Purdue Soc. C. E., 1903. 54. Weber, W. O. Rainfall and Run-off of New England Atlantic Coast and Southwestern Colorado Streams, with Discussion. Jour. Asso. Eng. Soc. Nov., 1903. 55. Abbott, H. L. -Disposition of Rainfall in the Basjn of the Chagres. Monthly Weather Review, Feb., 1904. 56. Mead, D. W. Report on the Water Power of the Rock River. Chicago, 1904. Published by the Author. FLOODS. 57. The Flood in the Chemung River. Report State Engineer, N. Y., 1894, p. 387. 58. The Floods of February 6th, 1896. Geol. Survey of N. J. 1896, p. 257. 59. Morrill, Park. Floods of the Mississippi River. Bui. E., U. S. Dept. of Agric. 1897. Literature. 197 60. Starling, Wm. The Floods of the Mississippi River. Eng. News, Vol. 37, p. 242. Apr. 22nd, 1897. 61. Starling, Wm. The Mississippi Flood of 1897. Eng News, Vol. 38, p. 2, July 1st, 1897. 62. McGee, W. J. The Lessons of Galveston. Nat. Geo. Mag. Oct., 1900. 63. Study of the Southern River Floods of May and June, 1901. Eng. News, Vol. 48, p. 102. Aug. 7th, 1902. 64. Brown, L. W. The Increased Elevation of Floods in the Lower Missis- sippi River. Jour. Asso. Eng. Soc., Vol. 26, p. 345, 1901. 65. Holister, G. B. and Leighton, M. O. The Passaic Flood of 1902. Water Supply and Irrigation Paper No. 88, U. S. G. S, 66. Leighton, M. O. The Passaic Flood of 1903. Water Supply and Irriga- tion Paper No. 92, U. S. G. S. 67. Murphy, E. C. Destructive Floods in the United States in 1903. Water Supply and Irrigation Paper No. 96, U. S. G. S. 68. Frankenfield, H. C. The Floods of the Spring of 1903 in the Mississippi Watershed. Bui. M., U. S. Dept. of Agric. 1903. 69. Flood Damages to Bridges at Paterson, N. J. Eng. News, Vol. 50, p. 377, Oct. 29th, 1903. 70. Kansas City Flood of 1903. Eng. News, Vol. 50, p. 233, Sept. 17th, 1903. 71. Engineering Aspect of the Kansas City Floods. Eng. Rec., Vol. 48, p. 300, Sept. 12th, 1903. 72. Murphy, E. C. Destructive Floods in the United States in 1904. Water Supply and Irrigation Paper No. 147, U. S. G. S, FORESTS IN RELATION TO RAINFALL AND STREAM FLOW. 73. Swain, Geo. F. The Influence of Forests Upon Me Rainfall and Upon the Flow of Streams. Jour. New Eng. W. Wks. Ass'n. 74. Rafter, Geo. W. Data of Stream Flow in Relation to Forests. Ass'n C. E., Cornell Univ., Vol. 7, p. 22, 1899. 75. Thompson, D. D. Influence of Forests on Water Courses. Scientific American Sup. No. 807. 76. Vermeule, C. C. New Jersey Forests and Their Relation to Water Sup- ply. Abstract of Paper Before Meeting of The American For- estry Ass'n. New Jersey, June 25th, 1900; Eng. News, July 26th, 1900; Eng. Record, Vol. 42, p. 8, July 7th, 1900. 77. Bremner. Water Ways for Culverts and Bridges. Jour. West. Soc. Engrs., Vol. 11, p. 137. April, 1906. CHAPTER X. STREAM FLOW. 103. Flow in Open Channels. The discussion of the flow of water in open channels in Chapter III includes only such channels as have uniform cross sections, alignment, and gradient and a bed of uniform character throughout the length considered. Such condi- tions are closely approximated in artificial channels in which the quantity of water flowing is under control. In such channels, and with a steady flow, that is with the same quantity of water passing every cross section in the same time, it is shown that: / (1) v = c A /ah = c T/rs" and that (2) q = av = ac A = ac l/rs" v In natural water courses no two cross sections are the same but may differ in area, a, and wetted perimeter, p ; and the fall, h, in any length, 1, usually differs considerably from reach to reach. The quantity, q, of water flowing in any such stream is also constantly changing. There every condition of uniform flow is lacking and can only be approximated for selected reaches of such streams and during periods when stream flow is fairly steady. 104. Changes in Value of Factors with Changes in Flow. From an examination of equation (2) it is evident that in any channel as the quantity of water flowing, q, changes, there must be a corre- sponding change in some or all of the factors on the other side of the equation. For steady flow in a uniform channel, s remains constant and all changes are confined to the values of a, c and r. The laws of change in the values of c are given by Kutter's and Bazin's formu- las, but are best illustrated and understood by reference to Fig. 22, which is a graphic expression of the formula of Bazin. In variable flow a change in all of the factors usually accompa- nies a chang:e in the value of q, each factor changing in accordance with the physical conditions of the channel. The changes in the value of c, in an irregular channel, do not al- ways seem to follow Bazin's law. In some cases c is even found to Flow in Open Channels. 199 decrease as r increases. The law of simultaneous increase in c and r presupposes a channel of uniform character and condition. If an increase in the hydraulic radius, r, in any channel is accompanied by a radical change in the character of its bed the law will not hold. It is evident that under such conditions the values of c for different values of r are not fairly comparative. No more uniform law of change can be expected under such conditions than would occur in the comparison of the relation of c and r for entirely different chan- nel sections. In Fig. .TOO are shown the observed values of c and r for certain reaches of the Wisconsin River above Kilbourn, Wis. It will be 10 20 30 40 SO 6O 70 80 90 100 110 120 Pig. 100. Relations of Coefficient to Hydraulic Radius in Certain Reaches of the Wisconsin River. 200 Stream Flow. noted that the value for readies A, D and E follow in general the law as established by Bazin. These are fairly uniform. On the other hand the values of c and r for reaches b and c seem to follow an entirely different law, a condition due to irregularities in the cross section of the reach. Where the values of a, p and r vary radically from section to sec- tion and differ materially from the values in the sections considered and on which calculations are based, the value of c will be found to differ radically from that which the character of the bed and the en- tire section would indicate. Absurd values of c are a clear indica- tion that the sections selected are not representative. The calcu- lated value of c is modified by all unknown or unconsidered factors of the reach. The influences of irregularities in bed or section, the presence of unconsidered bends or changes in the gradient, and all other irregularities in the channels, modify the values of c. 105. Effects of Variable Flow on the Hydraulic Gradient. In order to understand the effect of variable flow on the surface gradi- ent of a stream, and in order to realize how conclusions drawn from the laws of uniform flow must be modified to meet conditions found in natural streams, it is necessary to consider the cause of variable flow in a stream, the variation in channel conditions, and both the effect of flow on such conditions and the effect of such conditions on the flow of a stream. Tnic^t by Time Fti REPRODUCTION OF RECORD OF U. S.L.S. GAUGE. No. 5 FOR MAY 17, 1609. He AD OF K> nf g 13 Transverse Curve of Mean Velocities 'Section 'Dry Dock' Mean Hbter'ttyi-5766 Fig. 109. I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 IB 19 20 2> 5FT 10- 15" 20- 25- 30- 35- \/ Fig. 110. Vertical Velocity Curves, Section Dry Dock. 212 Stream Flow. of the bed and banks is clearly shown. The friction between the stream sur- face and the atmosphere is also shown by the fact that the maximum velocity is not at the surface but is a short distance below the surface. The surface velocity may be modified radically by the direction and velocity of the wind. Fig. 109 shows the transverse curve of mean velocities in this sec- tion. The distribution of velocities in each vertical section is shown in Fig. no. The velocities here shown are relative only as compared with each vertical. The velocity at the bottom of each curve is that shown by figures in Fig. 108. The distribution of velocities in any section is not the same under all conditions of flow but differs mater- ially with the stage of the river. This is illustrated by Fig. in in which is shown three sections of the same stream illustrating conditions of low, medium and high water. Above each section is shown a corresponding transverse curve of mean velocities of flow. The change in the distribu- tion of velocities as the stream in- creases should be noted. The distribution of velocity is also affected by bends in the stream above the point of observation which tends to throw the current of the stream toward the concave side, and to cause a transverse slope in the section of the stream at the curve. Such a condition (see Fig. 112) creates cross currents and eddies and produces conditions of variable flow. From Fig. 108 it will be seen that in any vertical line in a given section, the velocities will vary with the condition of the bed, and Variation in Velocity in the Cross-Section of a Stream. 213 Fig. 112. CALM WIND DOWN STREAM WIND, UP STREAM ICE COVERED 20 : ^r 60 u 80 or a 100 ) 1 \ / 1 \ / / J ) z / y / ^ _^ 100 PER CENT OF MEAN VELOCITY Fig. 113. Ideal Vertical Velocity Curves. 100 u 10 20 X. 30 o jt*. K u 50 60 U u it 70 bl a do 90 100^ \ MEAN OF 31 CURVES- VARIOUS STREAMS. \ MEAN OF 7 CURVES- WEST CANADA. MEAN OF 4 CURVES- MOHAWK RIVER UTlCA, N.Y. / MEAN OF 12 CURVES- MOHAWK RIVER LITTLE FALLS. 1 / MEAN OF 8 CURVES -MOHAWK RIVER SCHENECTADY. 1 / t i ' / 'I 1 I i / J y/ il / /// 7 X '/> X/i /// ~2L //,\ s ^ ^/ "/ .,. ^^^ + ~ ^ &*' -- 10 5 6 ^Zf** 7 PER 5 a CENT 9 OF ~ M XEAN )0 1 VELOC 10 li ITY >o i: 30 14 Fig. 114. Mean Vertical Velocity Curves. Stream Flow. the influence of air current or ice at the surface. These conditions have an influence on the velocities in each section considered. Vari- ations in the vertical velocities can be better studied by means of the vertical velocity curve, which can be obtained by means of velocity observations taken in a vertical line from the surface to the bed of the stream. Ideal curves under various conditions are illustrated by Fig. 113. Figs. 114, 115 and 116 are reproduced from the report of the State Engineer of New York for the year 1902. These diagrams show comparisons between the mean vertical velocities of streams having different classes of beds. From these illustrations it will be noted that there is a general similarity between the various velocity curves which aids materially in the measurement of stream flow. It will be noted, for example, that the mean velocity, in any vertical velocity curve from an open channel, lies near the point of .6 total depth but that with varying conditions this position may vary from 55 per cent, to about 75 per cent, of the depth. The velocity at .6 depth is found to average nearly 100 per cent of the mean velocity, but may actually vary from 95 per cent, to 105 per cent, of the mean \ \ in MEAN OF 52 CURVES- GENERAL CONDITIONS. - 20 I 1- u 30 < 40 * so o l_ z bl O a 70 hi a 80 90 100 -MEAN OF 31 CURVES-SMOOTH BED. 'MEAN OF 15 CURVES -ROUGH BED. 1 1 / / ft / 1 I/ ~J\ //I /'/ ^ ' / 5 ' x XX / x X X x/ x ^ ^x^ x" ^ ^J>-^ ^^' ^* ^^' """ 10 SO GO 70 80 90 100 110 120 130 \A PER CENT OF MEAN VELOCITY Fig. 115. Mean Vertical Velocity Curves. Effects of Ice-Covering on the Distribution of Velocites. 215 u 10 20 X 1- 30 <40 1- t 50 o Is 60 o tt 70 u a 80 90 100 4 1 ^_ < ,' . ^*^> S^ ^-^^ ^ (_ G 50 60 7O 80 90 IOO 110 120 130 U PER CENT OF MEAN VELOCITY Fig. 116. Mean Vertical Velocity Curves. velocity. The velocity at the surface is subject to the external influ- ence of atmospheric currents and is not so constant in its relation to the mean velocity. The surface velocity will average about no per cent of the mean velocity of the vertical curve, but is found to vary with the variations in conditions from 105 per cent, to 130 per cent. of such velocity. in. Effects of Ice-Covering on the Distribution of Velocities. The effect of the formation of an ice sheet over a stream is to ma- terially increase the surface friction and results in a rearrangement of velocities in the cross section. As the ice sheets form in winter, the conditions will vary from that of an open stream to that of a closed channel. The velocities are gradually affected as the ice be- gins to form, until the entire surface is affected where the stream becomes entirely covered. As the ice sheet thickens more of the cross section of the stream is occupied by the ice sheet, and greater friction results. Fig. 117 shows two vertical velocity curves, one for an open and one for an ice-covered channel. These may be regarded 2l6 Stream Flow. 10 20 30 60 Id O a 70 u a 80 90 MEAN OF 4 CURVES -OPEN SECTION. --- MEAN OF 1 3 CURVES - UNDER ICE. 40 50 120 130 140- 60 70 80 90 100 NO PER CENT OF MEAN VELOCITY Fig. 117. Comparative Mean Vertical Velocity Curves for Open and Ice Covered Section. as typical of open and closed conditions between which the actual velocities wall vary with the conditions of the ice. The change in the distribution of velocities results in an entire change in the relation between gauge height and flow so that the rating curve for an open section will not apply to the river under ice conditions. If therefore the stream flow is to be accurately determined during such condition, it becomes necessary to establish the new relation between gauge height and flow. As before noted, such relations vary somewhat with the condi- tions of the ice sheet but may be regarded as fairly constant when! the section is fairly clear and deep. The relations between the rat- ing curves for this open channel and for ice conditions as deter- mined by the United States Geological Survey for the Wallkill River at Neupaltz, N. Y. is shown in Fig. 118. Table XXI, from an article by F. A. Tillinghast (sec Engineer- ing News, May nth, 1905), shows the relations of maximum and Effects of Ice-Covering on Velocities. 217 o> 14 1 iu 1 12 Ul o 2 10 8 EOQO 4000 6000 8000 DISCKAB3E IN CUBIC FEET PER SECOND. 10000 Fig. 118. Rating Curve for Wallkill River at Newpaltz, N. Y. mean velocities in the verticals. It should! be noted that there are two points of mean velocity under ice conditions that average n per cent, and 71 per cent, of the total depth below the Surface. The point of maximum velocity is at an average depth of 36 per cent, of the total depth of the stream and averages IIQ per cent, of the mean velocity; TABLE XXI. Position o/ Mean and Maximum Velocities in a Vertical Plane Under Ice. Coeffi- Depth Stream and Place Depth from Under Sur- face of Ice Feet Num- ber of curves Depth of Mean Velocity of Maxi- mum Veloc- to re- duce Max. tn ity Mean Wallkill at Neupaltz, N. Y. . . . (a) Wallkill at Neupaltz, N. Y. . . . (b) Esopus at Kingston, N. Y (a) Esopus at Kingston, N. Y (b) Rondout at Rosendale, N. Y. . . (a) Rondout at Rosendale, N. Y. . . (b) Connecticut at Urford, N. H. . .(c) 4 to 12 4 to 19 2.3 to 7.4 5 to 8 4 to 8 5to7 2.5 to7.7 20 26 16 8 5 8 18 0.12 0.13 0.08 0.11 0.08 0.13 0.11 0.11 0.71 0.74 0.68 0.73 0.68 0.21 0.69 0.71 0.38 0.38 0.36 0.37 0.35 0.35 0.35 0.36 0.85 0.86 0.80 0.85 0.82 0.86 0.85 0.84 Notes: a. By F. H. Tillinghast. b. By W. W. Schlecht. c. By C. A. Holden. 13 CHAPTER XI. THE MEASUREMENT OF STREAM FLOW. 112. Necessity for Stream Flow Measurements. In order to ascertain the value of a stream for water power purposes, it is neces- sary to determine the amount and variations in its continuous flow either by comparison with the flow of other streams or by the direct observation of the flow of the stream itself. As has already been shown, the latter method is by far the most satisfactory as the de- termination of the actual flow of the stream eliminates all errors of comparison, and the necessity for any allowances or modifications on account of differences in geological, geographical, topographical or meteorological conditions on the drainage area. The Hydrographic Division of the United States Geological Sur- vey has undertaken the gauging of a large number of streams in the United States and has established numerous gauging stations at which observations have been made for a number of years. This data, references to which are given in the list of literature appended to Chapter IX, is of great value for comparative purposes. It is seldom, however, that, when a stream is to be investigated for water power purposes, flow data, at the particular point under consider- ation, is available. One of the first duties of the engineer, there- fore, usually consists in making measurements of the stream flow and establishing stations at which the daily flow can be observed and recorded. The methods in use by the United States Geological Survey are the result of much study and investigation and probably represent the most practical methods for making such observations with a fair degree of accuracy. Many of the methods and suggestions in this chapter are based on the methods and conclusions of the Survey as modified by the experience and practice of the writer.* * These methods are described in detail in Water Supply and Irrigation Papers No 94, entitled, "Hydrographic Manual of the United States Geologi- cal Survey," and No. 95, entitled "Accuracy of Stream Measurements." See also "River Discharge" by J. C. Hoyt and N. C. Grover, John Wiley and Sons, 1907. Methods for the Determination of Flow. 219 113. Methods for the Estimate or Determination of Flow in Open Channels. There are three general methods of estimating or determining the flow of water in streams with open channels. First By the measurement of the cross section and slope and the calculation of flow by Chezy's formula, together with Kutter's or Bazin's formulas for estimating the values o l.2 10 t x X / x^ x X 1 x 4.0 X 3 1 - i i 3 1 i, ! VELOCITY. IN FEET PER SECOND Fig. 122. Current Meter Rating Curve. tion, the flow through any unit of area may vary more or less from the flow through other similar areas. On this account it is desir- able, in order to systematically survey the velocities in a cross-sec- tion, as well as for ease in calculation, to divide the cross-section area into parts, both horizontally and vertically, and determine the actual velocity of each of said parts. As a basis for the work, the cross- section of the stream should first be obtained by sounding. The vertical sections, chosen for the purpose of water observation, are usually five feet or more apart but the horizontal divisions are usually somewhat less as the variations in the vertical velocities are usually much greater than in horizontal velocities. The size of both horizontal and vertical division depends on the irregularity of the distribution of velocity in the cross-section as well as on the ac- curacy required in the determination af flow. The greater the care used in the determination of the velocities in the unit areas and the greater the number of such sub-divisions of the cross-section, the more accurate will be the work. UNIVERSITY CF Current Meter Computations. 225 The meter readings may be made in one of four ways : First By determining the velocity at frequent, definite intervals of depth and then ascertaining the point and amount of average velo- city in each vertical section. Second By what is known as the integration method, which consists in lowering and raising the meter with uniform motion from the surface to the bottom of the vertical section and noting the average velocity determined by this method. Third By making a point measurement at the depth correspond- ing to the thread of mean velocity as determined in the first method. Fourth By determining the velocity at some other point of observation and deducting the mean velocity from the known rela- tion of the point measured to the point of mean velocity. The last two methods can be safely used where the vertical velocity curve lias been determined with sufficient accuracy, and are fairly approxi- mate at other sections where the conditions are not of an unusual nature. Distance from inftial point ,/\5|0 I 610 Fig. 123. Cross-section of Saline River at Guaging Station near Salina, Kans. "Fig. 123 shows the cross section of the Saline River near Salina, Kan., on September 3 !>. |l| &b ^^ Q O 3 O Computed by E. C. Murphy. Checked by E. C. Murphy. if- 1| ^ % t^ ri co o tO CO 1 M o o o OrH t^ 3 i !M to OD C5 1 Computa- tions of qidap o oq co j r^- ci rH CO J^O O 00 rH O OO puooas jad o ,2~.88 O O O rH O O i I i I O O O O puooas jad suorj -Aai jo iaq -ranu [raioj, ^M. : a-o Obervations. SUO1 1 ) -n{OAa[ CC 1>- 'N OO O ^ CO IO CC O O rH OS rH OOiOiOCiOOO jo qidaa t-t-OCrHlCOOCOt-t-^ O^CO^COCOCO^^r.0 ^a Ci rH LO CO CO Ci O O ^ 1C CC CO O rH^*iO00^^00 ."Sill O O^COiOOiOOiOO>OOC X X. % "H 8 X X E ^ ^ "^ ^ ^~ \ H x -o ' \ \ ^x !S \ "V o 10.000 20,000 30,000 40,000 50.000 60.000 70,000 80.000 90.000 100.000 110 Discharge in second-feet Fig, 126, Discharge, Velocity and Area Curved for the Potomac River at Poin , - . V , i 5 ^s \ ^ ^^ ^ . 15 \ ** *+< . ^ y ^ ?^ ^ ^ ^ ^N L \ * \ JO l rt \ \ \ i \ x, CU o \ * ^o 1 o ^\ 4 . ^\ n o\ x \ MEASUREMENTS IN /9O^ NO. 1 - 1903 NO. 2 TO 7 g 33 0) J iii * S \ h . \ \ | \ > \ \ S V ' ^ g K o w * w oo>o>N>r>*r> the Poncelet wheel but with a sharper curve inward. The discharge of the water is inward. D is an internally driven tangent wheel similar to the preceding but with an outward discharge. E is the so-called hurdy-gurdy or tangential wheel. The water is delivered through a nozzle and the wheel is practically an ex- ternally driven tangent wheel of larger diameter and with a smaller number of buckets. Diagrams F, G and H illustrate three types of impulse wheels with inclined delivery. (See also Figs. 6, 7, 9 and 10.) Diagram F shows a crude form of vertical wheel similar in form to the Indian wheel, Fig. 6. It is used on rapid mountain streams and is probably the original conception from which the turbine has been developed. Diagram G is the Borda turbine and consists of a series of spiral buckets in a barrel-shaped vessel. Diagram H is a Danaide turbine which has spiral buckets enclosed in a conical tube. This is an old form of wheel formerly used in France. 125. Use of Water Wheels. Almost all water wheels in prac- tical use are modifications of some of the above forms and by a study of these forms a wheel may be classified and a clearer under- standing obtained of the principles of its operation. Many of the forms of wheels shown in Figs. 127, 128 and 129 are practically ob- solete or are used onlv in minor plants or for special conditions 2 4 2 Water Wheels. B H Fig. 129. Diagrams of Impulse Wheels Use of Water Wheels. 243 that make them of only general interest in the study of water power. While gravity wheels are still occasionally used their application is entirely to the smaller water power plants. In many cases the turbines purchased for such installations are of cheaper make, poorly designed, constructed and selected, and often improperly set and, consequently, inefficient. In such cases, and where the ques- tion of back water and the interference of ice is not important, the Fig. 130. "Overshot" Water Wheel. Manufactured by Fitz Water Wheel Co. gravity wheel may be more efficient and quite satisfactory. Well designed and well constructed gravity wheels are said to give effi- ciencies of 85 per cent, and above. (See Frontispiece and Fig. 130). With such plants the engineer has usually little to do and consequently they will not be further considered here. The types of wheels now most largely used for moderate and large water power developments are the reaction and impulse turbines. 126. Classification of Turbines. All moder turbines consist of a wheel to which buckets are attached and whicn is arranged to re- volved in a fixed case having attached to it a nozzle, guide or 244 Water Wheels. series of guides. The guide passages or nozzles direct the water at a suitable angle onto the buckets of the wheel. The revolving wheel contains curved buckets or passages whose functions are to receive the water, utilize its energy and discharge or waste it as nearly devoid of energy as possible. Turbines may be classified in various ways: First. In accordance with the action of the water on the same. (A) Reaction or pressure turbines, such as the Fourneyron, Jon- val, Francis, etc. (See Fig. 128, G, H, I and J.) (B) Action or impulse turbines, such as the Girard and tangen- tial wheels. (See Fig. 129, diagrams D and E.) (C) Limit turbines, which may act either by reaction or impulse. Second. In accordance with the direction of flow in reference to the wheel. (A) Radial flow turbines. In these turbines the water flows through the wheel in a radial direction. These may be subdivided into (a) Outward radial flozv turbines, such as the Fourneyron and Cadiat. ,(See Fig. 128, diagrams F and D.) (b) Inward radial flow turbines, or wheels in which the water flows inward in a radial direction such as the Francis and Scheile turbines. (See Fig. 128, J and K.) (B) A. vial flow turbines in which the general direction of the water is parallel to the axis of the wheel such as the Jonval and Girard wheels of similar design. (See Fig. 128, H.) (G) Mixed flow turbines, or turbines in which the flow is par- tially radial and partially axial as in turbines of the American type. (See Fig. 128, diagram I; also Figs. 143 to 158 inclusive). Third. In accordance with the position of the wheel shaft. (A) Vertical (See Figs. 132, 134, 135, 151, etc.). (B) Horizontal (See Figs. 140, 152.) Fourth. In accordance with the arrangement of nozzles or guides. (A) Complete turbines with guides surrounding the entire wheel. (B) Partial turbines with guides partially surrounding the wheel in one or more groups. The re-action turbine is a turbine with restricted discharge which acts through the reactive pressure of the water. Under some con- ditions the energy of the water may be exerted, at least in part, by its impact or momentum. The impulse turbine acts princip- Condition of Operation. 245 ally through the momentum of the moving mass of water although, when the current reverses, some reactive pressure may be recog- nized. The limit turbine may act entirely as a reaction or as an impulse turbine according to the conditions under which it oper- ates. 127. Condition of Operation. These wheels operate under the fol- lowing conditions : REACTION OE PRESSURE TURBINES. Guides complete. Buckets with restricted outlets. Buckets or wheel passages completely filled. Energy most largely developed through reactive pressure. Discharge usually below tail water or into a draft tube. ACTION OR IMPULSE TURBINES. Guides partial or complete. Buckets with outlets free and unrestricted. Wheel passage never filled. Energy entirely due to velocity. Discharge must be above tail water. No draft tube possible, except with special arrangement which will prevent contact of tail water with wheels. LIMIT TURBINES. (A) Buckets so designed that the discharge is unrestricted when above tail water. Buckets in this case are just filled. Act without reactive effect. Discharge above tail water. (B) If tail water rises to buckets, the discharge is restricted and reaction results. In this case the full bucket admits reaction and discharge may be below tail water. 128. Relative Advantage of Reaction and Impulse Turbines. The reaction wheel is better adapted for low and moderate heads, especially when the height of the tail water varies and where the amplitude of such variation is a considerable percentage of the total head. Such a wheel, which is designed to operate with the buckets filled, can be set low enough to utilize the entire head at 246 Water Wheels. all times and will operate efficiently when fully submerged. The reaction wheel can therefore be set to utilize the full head at time of low tail water and when the quantity of flow is limited. For low head developments this is an important factor. The impulse turbine, on the other hand, must have a free discharge and must therefore be set far enough above the tail water to be free from back water if it is to be operated at such times. Another difference between the reaction and the impulse turbine is the higher speed with which the former operates. This is often a distinct advantage, for direct connection with high speed ma- chinery, and with low and moderate heads. On the other hand, with high heads the slower speed of the impulse wheels is frequently of great advantage, especially in the form of the tangential wheel when the diameter can be greatly increased and very high heads utilized with moderate revolutions. In such cases the height of the back water is usually but a small percentage of the total head, and the loss due to the higher position of the wheel is compara- tively small. The speed of a wheel for efficient service is a function of the ratio of the peripheral velocity of the wheel to the spouting velocity of water under the working head. This ratio will vary from .65 to .95 in reaction turbines, according to the design of 1 the wheel. In im- pulse turbines this ratio varies from .40 to .50. 129. Relative Turbine Efficiencies. The impulse turbine has the further advantage of greater efficiency under part gate, that is, at less than its full capacity. When, as is usually the case, a wheel must operate under a variable load it becomes necessary to reduce the discharge of the wheel in order to maintain a constant speed with the reduced power required. (See Fig. 131). This is ac- complished by a reduction in the gate opening which commonly greatly affects the economy of operation. The comparative efficiencies of various types of the turbines are shown in Fig. 131. The maximum efficiency of turbines when operated at the most satisfactory speed and gate will be about the same for every type, if the wheel is properly designed and con- structed and the conditions of operation are suitable for the type used. This maximum efficiency may vary from 75 to 85 per cent., or even between wider limits, but, with suitable conditions, should not be less than 80 per cent. In order to make the curves on the diagram truly comparative, the percentage of maximum efficiency Relative Turbine Efficiencies. 247 20 30 40 50 60 70 PER CENT OF MAXIMUM DISCHARGE 80 90 100 Fig. 131 Comparative Efficiencies of Various Types of Turbines. -and of maximum discharge are plotted instead of the actual effi- ciencies and actual discharge. The Fourneyron turbine usually shows very poor efficiencies at part gate as shown in Fig. 131. The curve for this turbine is drawn from Francis' test of the Tremont (Fourneyron) turbine {see Fig. 132, also Table LXI) and is substantiated by efficiency curves shown by various tests by James Emerson.* The Janval turbines usually show better part gate efficiencies than the Fourneyron but are not as efficient, under such conditions, as turbines of the inward flow or Francis type. The Jonval curve, shown in Fig. 131, is plotted from the test made in 1884 at the See "Hydrodynamics" by James Emerson. 248 Water Wheels. Holyoke testing flume * of a 3O-inch regular Chase-Jonval turbine. (See Table LXXVI). The American-Francis turbine varies greatly in part gate effi- ciency according to the details of design and the relation of speed and head under which it operates. The curve shown in Fig. 131,. representing this type, is from the test of a wheel manufactured by J. & W. Jolly of Holyoke, Massachusetts, similar but not the same- as that illustrated by the characteristic curve Fig. 249. The impulse wheels when properly designed and operated show a higher part gate efficiency than any other type of w r heel. The curve shown in Fig. 131 is from a test o.f a 12" Doble tangential wheel in the laboratory of the University of Wisconsin.! As already indicated, the design of the wheel has a great in- fluence on its efficiency at part gate. Individual wheels or series of wheels of any type may therefore depart widely from the curves- above shown, which are intended only to show as fairly as possible the usual results obtained from well made w r heels of each type. It should be noted also that efficiency is only one of the factors- influencing the choice of a wheel and that many other factors, must be weighed and carefully considered before a type of wheel is se- lected as the best for any particular set of conditions. 130. Turbine Development in the United States. The develop- ment of the turbine in the United States has been the outgrowth of some seventy years of practical experience. In the early settle- ment of the country the great hydraulic resources afforded facili- ties for cheap power and numerous water powers were developed under low and moderate heads. These developments created a corresponding great demand for water wheels and stimulated in- vention and manufacturing in this line. American inventors have devised many different forms of wheels which were patented, con- structed, tested and improved to meet the prevailing conditions. When a successful wheel was designed, it was duplicated in its original form and its proportions increased or diminished, to con- form to the desired capacity. As wheels of greater capacity or of higher speed have been required, modifications have been made and improved systems have resulted. * See page 44 of 1897 catalogue of Chase Turbine Manufacturing Co.. Orange, Mass. tFrom "Test of a 12" Doble Tangential Water Wheel," an unpublished) thesis by H. J. Hunt and F. M. Johnson. Turbine Development in the United States. 249 The best American water wheel construction began with the Boyden-Fourneyron and Geylin-Jonval turbines of improved French design, but modern American practice began to assume its characteristic development with the construction of the Howd-Fran- cis turbines, already described. Moderate changes in the form and arrangement of buckets and other details gave rise' to the earlier forms' of ''Swain/' "Leffel" and "American" wheels each of which consisted of an inward flow turbine modified from the earlieY de- signs of Howd and of Francis as the experience of the inventor seemed to warrant. In all of these cases the wheels discharged inward and essentially in a radial direction and had to be built af sufficient diameter to provide an ample space for receiving the dis- charging waters. This necessitated slow speed wheels of com- paratively low capacity (see Table I, page 13). In order to secure higher speed, the diameters of the wheels were reduced thus re- ducing the power. This reduction was, however, more than coun- terbalanced, in the later wheels, by an increase in the width of the bucket in an axial direction.' It was found also that the cap- acity of the wheels could also be materially increased, with only small losses in efficiency, by decreasing the number of buckets. Wheels were gradually reduced in diameter and the buckets in- creased in breadth until, in many cases, they reached very nearly to the center of the wheel. This necessitated a downward dis- charge in the turbine and resulted in the prolongation of the buck- ets in an axial direction in many cases to almost double the width of the gate. From this development has resulted the construction of a series of wheels known as the "American turbines" having higher speed and greater power than has been reached in Euro- pean practice. The entire line of development has, until within the last fifteen years, been toward the increase of speed and power for low and moderate head conditions. It is only within this period that a con- siderable demand has been felt in this country for turbines having other characteristics and adapted for higher heads. The American type of turbine, in its modern form is not designed or suitable for high heads its origin being the result of entirely different conditions. About 1890 came a demand for turbine wheels under comparatively high heads which manufacturers of wheels of the American type were therefore poorly equipped to meet. The first of such wheels supplied were therefore of European types, 15 250 Water Wheels. which apparently better suited such conditions. Recognizing, however, the importance of meeting such demands, the American manufacturer found that the wheels of essentially the original Francis type were well suited for this purpose. The narrow wheel and numerous buckets of the earlier types reduced the discharge of water, and, increasing the diameter, reduced the number of revo- lutions. Such types of wheels of high efficiency can now be obtained from the leading manufacturers in the United States, and, while many manufacturers still prefer to furnish simply their stock designs, which are only suited for the particular conditions for which they were designed, still, other manufacturers are prepared to furnish special wheels which are designed and built for the particu- lar conditions under which they are to be used. The systems of wheels offered by American manufacturers, which can be readily and quickly duplicated at a much less expense than would result from the design of special wheels for each particular customer, has resulted in the ability of American manufacturers to furnish water wheels of a fairly satisfactory grade and at a cost which would have been possible in no other way. In the United States the cost of labor has been comparatively high and special work is particularly expensive, much more so than in Europe where skilled mechanics receive a compensation for labor which is but a small fraction of that of their American competitors. Average American practice, at the present time, leaves undoubtedly much to be desired and considerable advance may be expected from the correction of designs, resulting from practical experience and by the application of scientific analysis. 131. The American Fourneyron Turbine. As noted in Chapter I, one of the first reaction turbines developed in the United States was the Bo)^den wheel of the Fourneyron type. In these wheels (see Fig. 132) the water entered from the center, guided by fixed curve guides, g, (Fig. 133) and discharged outward through the buckets, B. The use of these wheels gradually spread and they rapidly replaced many of the old overshot and breast wheels used up to that time, and soon became the foremost wheel in New England. The manufacture of the Fourneyron turbine has, for common use, been discontinued on account of the competition of other cheaper wheels which were found to be more efficient at part gate The American Fourneyron Turbine. 251 Fig. 132. Tremont (Boyden-Fourneyron) Turbine (after Francis). Fig. 133. Guides and Buckets of Tremont (Boyden-Fourneyron) Turbine. 252 Water Wheels. and more generally satisfactory under ordinary conditions of serv- ice. The Fourneyron turbine, when well designed and constructed, is a turbine of high full gate efficiency. This wheel is adapted for high heads where a comparatively slow speed is desired, and it is now frequently used for high grade and special work where its peculiarities seem best suited to such conditions. One of the modern applications of the Fourneyron turbine is that in the power plant of The Niagara Falls Water Power Com- pany. Fig. 134 shows vertical and horzontal sections of one of the double Fourneyron units used by this company in their first plant. These wheels discharge 430 cubic feet per second and make 250 revolutions per minute ; at 75 per cent, efficiency each wheel will develop 5,000 horse power. The buckets of these wheels are di- vided vertically into three sections or stories in order to increase their part gate efficiencies. These wheels are of Swiss design by the firm of Faesch and Picard and were built by The I. P. Morris Company of Philadelphia. [The wheels are vertical and connected by vertical shafts, each with one of the dynamos in the station above. The shaft is built of three-quarter inch steel, rolled into tubes 38 inches in diameter. At intervals the shafts pass through journal bearings, or guides, at which points the shafts are reduced to ii inches in diameter and are solid. The speed gates of these wheels are plain cylindrical rims which throttle the discharges on the outside of the wheels and which, with the co-operation of the governor, keeps the speed constant within two per cent under ordinary conditions of operation. Another wheel of this type is that manufactured and installed at Trenton, Falls, N. Y., by the same firm. (See Fig. 311.) 132. The American Jonval Turbine. The Jonval turbine, orig- inally of French design, was introduced into this country about 1850 and became one of the most important forms of turbine of early American manufacture. In the tests of turbines at Phila- delphia in 1859-60 (see page 360) a Jonval turbine developed the highest efficiency and the type was adopted by the city for use in the Fairmount Pumping Station. Like the Fourneyron turbine, these wheels, while highly efficient at full gate, have largely been superceded by other cheaper and more efficient part gate types, except for special conditions. The American Jonval Turbine. 253 Pig. 134. Double Fourneyron Turbine of The Niagara Falls Water Power Company. (Designed by Faesch & Picard; built by I. P. Morris & Co.) 2 54 Water Wheels. Fig. 135 shows the Geylin-Jonval turbine as manufactured by the R. D. Wood Company of Philadelphia. W represents the run- ner, B the buckets which receive the water through the guides, g. The wheel shown has double inlets that are closed by the double cylinder gates, GG. This gate closes up against the hood, C, by means of the rod r, r, which connect with the governor mech- anism. The general de- sign of the ordinary wheel of this type is perhaps best shown by Fig. 136.* In this figure A is the fixed or guide wheel and B is the movable or tur- bine runner. In the later hydraulic developments the use of this -wheel has been con- fined, largely at least, to locations that require special designs. One of the later develop- ments of the Jonval tur- bine has been that for The Niagara Falls Paper Company. The first in- stallation consisted of three upward discharge Jonval turbines of 1,100 horse power each, under a head of 140 feet. The installation provided, however, for a total installation of six turbines. The ver- tical shafts are 10 inches in diameter and 140 feet in length and weigh about 19 tons each. These shafts, in addition to the weight of the wheels, which are 4' 8" in diameter, are supported by marine thrust bearings, under the beveled wheels, together with a step bearing under the turbine. When the turbine is in use, however, the weight of the wheel and the shaft is balanced by the upward pressure of the water which at two-thirds gate is designed to ex- actly balance this weight. At full gate there is an unbalanced up- Fig. 135. Vertical Geylin-Jonval Turbine (Manufactured by R. D. Wood & Co.). * See page 7, 1877 catalogue, J. L. & S. B. Dix, Glen Falls, N. Y. The American Jonval Turbine. 255 ward pressure, and, at less than two-thirds gate, an unbalanced downward pressure; these pressures are, however, only the differ- ence between the weights and the water pressure and are easily cared for by the bearings above described. These wheels have thirty open- ings and operate at 260 revolu- tions per minute. The gates are provided with sleeves (cylinder gates) each weighing 2,800 pounds and slide outside the guide wheels to the hood. These sleeves are guided by four rods which extend above the turbine casing about 10 feet to a yoke which is counter- balanced. A sectional view of one of these turbines is shown in Fig. 137 and the general arrange- ment of the plant is shown in Fig. 138. A still more recent type of the Jonval turbine is the double, hor- izontal wheel, built for The Niag- ara Falls Hydraulic Power and Manufacturing Company and in- stalled in 1898. (See Figs. 139, 140). These wheels have a common, central intake and quarter- turned draft tube which turns down to and is sealed in the tail race below the floor. The speed control is effected by a register gate through which the water passes before it reaches the guide ring. This is said to give a somewhat lower efficiency at part gate than does a gate interposed between the guide tubes and runner bucket. Economy of water at part gate is said to be no particular object in this plant and reduced efficiency is, in fact, an advantage in that it reduces the gate movement and retains a velocity in the penstock, with a given change of load, and consequently reduces the inertia action and aids the speed regulation. This turbine is rated at 2,500 H. P. at 250 revolutions per minute, under the normal head of 210 feet.* Fig. 13G. Jonval Turbine as Manu- factured by J. L. & S. B. Dix. * See "The Electrical World," January 14, 1899. 256 Water Wheels. Fig. 137. Geylin-Jonval Turbine of Niagara Falls Paper Mill Co. Manufac- tured by R. D. Wood & Co. (From Eng. News, Apr. 5, 1894.) 133. The American Type of Reaction Turbine. The Howd Wheel (Fig. 13) from which the idea of the Francis inward flow wheel (Fig. 12) was derived, was invented in 1838 and acquired a considerable market throughout New England. From these wheels originated the American inward and downward or mixed flow tur- bines. The early wheels of American manufacture were designed very much after the style of the Francis wheel with changes, more or less radical, in the shape and details of the buckets. The demand for wheels of greater power, and -higher speed, has resulted in a gradual development of other and quite different forms. The development of the turbine in the United States is well illustrated by that of the "American" turbine of Stout, Mills & Temple, now The Dayton Globe Iron Works Co. This wheel was The American Jonval Turbine. 257 Fig. 138. Plant of the Niagara Falls Paper Co. Showing Installation of Jonval Turbines. (From Gassier' s Magazine, Nov., 1904. designed in 1859 and was called '' the American Turbine. The general form of the original tur- bine wheel is shown in Fig. 141. This was followed (1884) by the design of what is known as the "New American" turbine, illustrated by Fig. 142. In this wheel the buckets are length- ened downward and have a partially downward as well as inward discharge. This wheel was followed in 1900 by the "Special New American" illustrated in Fig. * 143, having a great increase in capacity and power. The fourth and most recent type (1903) is the "Improved New American" illustrated in Fig. 144. The comparative power and speed of these vari- ous wheels is shown in the tables on pages 258 and 259. Table XXIII is misleading to the extent that while the diam- eter of each wheel is given as 48" such diameters are not strictly comparative. Part of the additional capacity and power of the "Special New American" and of the "Im- proved New American" is due to the cutting back of the buck- ets (see Figs. 141 to 144) which, while it reduces the diameter at the point of measurement, gives a discharge which would be fairly comparative with wheels of the older type of per- haps three or four inches larger diameters. (See Sec. 140.) 258 Water Wheels. TABLE XXIII Development of "American" Turbines. Capacity, Speed and Power of a Turbine under a 16-foot Head. Year brought out. Discharge in cu. ft. Eev. per min. Horse power. 1859 3271 102 79.1 Standard. New American 1884 5864 102 141.8 New American 1894 9679 107 234 Special New American Improved. New American .... 1900 1903 11061 13234 107 139 267.0 3^5.0 Fig. 139. Horizontal Geylin-Jonval Turbine of Niagara Falls Hydraulic- Power & Manufacturing Co. Showing Guide Chutes.* * Cuts 139 and 140 reproduced from Electrical World, Jan. 14, 1899. Tur- bines manufactured by R. D. Wood & Co. The American Type of Reaction Turbine. 259 The development of turbines may also be illustrated by a compar- ison of the size and speed of turbines of various series required to develop essentially the same power. (See Table XXIV.) TABLE XXIV Increase in Speed of "American" Turbines for Same Power (16-foot head). Size of wheel. Horse power. R. P. M. 48 79.1 102 New American 36 81.5 136 27^ 87.3 186 Imprcw6(l New American .... 25 87.5 267 Fig. 140. -Horizontal Geylin-Jonval Turbine Showing Bucket Ring* Figs. 145 and 146 show a vertical and a horizontal half plan, half section of a vertical Improved New American turbine. W is the crown and hub of the wheel; B, the buckets; G, G, are the wicket *See foot note r a S e 258 260 Water Wheels. gates that control the admission of water to the wheels and which are operated by means of the ring Gr, which is moved by an eccen- tric and rod, r, connected with the governor through the shaft, P. The inner edges of the bucket are spaced some distance from the shaft and the main discharge is inward and downward, though a portion of the bucket will admit of a slightly outward discharge. 134. The Double Leffel Turbine. Perhaps the greatest depar- ture of American inventors from the lines of the original Francis Fig. 142. New American Turbine Runner. Fig. 141. American Turbine Run- ner.* TABLE XXV. Development of "Leffel" Wheel. Capacity, Power and Speed of 40-inch Wheel Under 16-foot Head. Year brought out. Discharge. Kev. per minute. Horse power. Standard 1860 2547 138 Special 1870 3672 138 93 1890 6551 158 155 Improved Samson 1897 8446 163 207 * Manufactured by The Dayton Globe Iron Works Co. The American Type of Reaction Turbine. 261 Fig. 143. Special New American Turbine Runner.* Fig. 144. Improved New American Tur- bine Runner.* type of turbine was that of James Leffel. In this wheel was combined a double runner, the upper half being a radial inflow runner of the Francis type and the lower half con- sisting of a runner with inward radial admission and axial discharge, es- sentially on the line of the later development of tne American type of wheels. The wheel, as originally designed, had the narrow bucket, slow speed and low power of all early American wheels. In its later development the buckets have been extend- ed inward and downward and these wheels have found their best modern development in the Sam- son-Leffel wheel, illustrat- ed in Figs. 147 to 151. In Fig. 147, W repre- sents the hub and crown of the wheel which is se- curely keyed to the shaft, S. B' B' are the upper buckets that discharge inward and downward through the passage aa. The lower buckets, BB, it will be noted, have the same lines as other modern wheels of the American type. They receive the * Manufactured by The Dayton Globe Iron Works Co. 262 Water Wheels, Pigs. 145 and 146. Section and Plan of ImprovedNew American Turbine.* * Manufactured by The Dayton Globe Iron Works Co. The American Type of Reaction Wheels. 263 Figs. 147 and 148. Section and Plan of Samson Turbine.* Manufactured by The James Leffel & Co. 264 Water Wheels. Figs. 149, 150 and 151. Top View, Runner and Outside View of Samson Tur- bine.* * Manufactured by The James Leffel & Co. The Double Leffel Turbine. 265 water inward and discharge it downward, outward and inward with the general purpose of distributing it over the cross-section of the turbine tube. The gates, G, are of the wicket type and are con- nected by rods with an eccentric circle which is operated through the arm, A, and the gearing, Gr, by the governor shaft, P. The gate gearing is well shown by reference to the section-plan, Fig. 148, and the top view, Fig. 149. The Samson turbine runner is illustrated in Fig. 150, and Fig. 151 shows an outside view of one of the vertical, turbine units. Fig. 152. Double Horizontal Leffel Turbine of The Niagara Falls Hydraulic Power & Manufacturing Co. Manufactured by The James Leffel & Co. The development of this wheel is illustrated by Table XXV. This table is fairly representative of the growth of this turbine as the diameter is, in all cases, the maximum diameter of the wheel. (See Sec. 140.) The adaptability of the earlier turbine designs to the later mod- erate head developments is well illustrated in the design of the 16 266 Water Wheels. wheels for The Niagara Falls Hydraulic Power and Manufacturing Company, installed by The James Leffel Company about 1892. These turbines have the single narrower buckets, smaller discharge and relatively slower speed of the earlier designs. The runners are double discharge, horizontal, seventy-four inches in diameter and operate at a speed of 250 revolutions per minute under a head of 215 feet, and each wheel develops about 3,500 horse power. Fig. 153. Leffel Double Runner of The Niagara Falls Hydraulic Power & Manufacturing Co. Manufactured by The James Leffel & Co. Fig. 152 shows one of these units complete. Fig. 153 is a view of the runner. For a test of this wheel, made December 1903, see page 381. J 35- Other American Wheels. The development of modern American wheels could, perhaps, have been equally well illustrated by the growth of various other American turbines. The develop- ment of all American wheels up to the present time has been on the line of increasing both the speed and the power of the wheel for low head, with a return to the earlier type for wheels to be used under the moderate heads. Fig. 154 illustrates a runner of the well-known McCormick pat- tern. Mr. J. B. McCormick, who had previously become familiar Other American Wheels. 267 with certain wheels of large capacity designed and patented by Matthew and John Obenchain, re-designed and improved these wheels, about 1876, and secured high efficiencies together with increased power far beyond any other wheels of that period. Mc- Cormick wheels in their original or modified form are now made by a large If j|r& number of American man- | uTacturers and these wheels have had a marked effect on the design of almost all modern Ameri- can water wheels. The runner in the illustration is the Hunt-McCormick runner as manufactured by The Rodney Hunt Ma- chine Company, but is very similar to the Mc- Fig. 154. Hunt-McCormick Runner of The Rodney Hunt Machine Co. Cormick wheels of various other manufacturers. The Smith-McCormick runner is manufactured by The S. Morgan Smith Company. This company has also recently brought out a new wheel called the "Smith Turbine/' of greater power and higher speed, the runner of which is illustrated by Fig. 155. Fig. 156 repre- sents the Victor runner or "type A" runner of The Platt Iron Works Com- pany, designed for low heads. Fig. 157 is the "typeB" runner, of the same Corn- Fig. 155.-Smith Runner of S. Morgan pany, designed for medi- Smith Co. um heads. This runner 268 Water Wheels. again illustrates the tendency to return to the earlier forms of runner for medium head wheels. This latter type has also been adopted by other manufacturers of turbines, as may be seen by ref- erence to Fig. 158 which shows the Hunt runner manufactured for moderate heads by The Rodney Hunt Machine Company. Fig. 159 is from a shop photograph of the Shawin- igan Falls turbine manu- factured by the I. P. Mor- ris Company. This is one of the largest turbines ever constructed and develops 10,500 horse power under a head of 140 feet. It is a double mixed inflow type with spiral casing and a double draft tube through which the water discharges outward from the center. The diameter of the cas- ing at the intake is 10i feet and the sectional area gradually diminishes around the wheel in pro- portion to the amount of water flowing at each point. The wheel com- plete is 30 feet in height and weighs 182 tons. The runner, which is of bronze, is shown in Fig. 160. Figs. 161 and 162 show two sections of a single turbine of the Francis in- flow type built for the Snoqualmie-Falls plant of The Seattle & Tacoma Power Company by The Platt Iron Works Corn- Fig. 157. High Head or "Type B" Runner pany. The turbine has 9 of The Platt Iron Works Co. capacity of about 9.000 Fig. 156. Victor or "Type A" Runner of The Platt Iron Works Co. Other American Wheels. 269 H. P. under 270-foot head .at 300 R. P. M. The runner is 66 inches in diameter and has a width of 9i inches through the buckets.* This is believed to be the largest capacity single discharge wheel yet constructed. For further details see Figs. 183, 189 and 190. 136. Early Development of Impulse Wheels. As already pointed out (see Chapter I, Figs. 6 and 7), water wheels of the impulse type were among the earlier forms used. In the practical construc- tion of water wheels for commercial purposes in this country, the reaction turbine was, how- ever, the earliest form of development. This was because the reaction tur- bine was best suited for the low heads first devel- oped. As civilization ad- vanced from the more level country into the moun- tainous regions the condi- tions were found to radi- cally differ. In the form- er location large quanti- ties of water under low heads were available; in the latter, the streams diminished in quantity but the heads were enorm- ously increased. These conditions demanded an entirely different type of wheels for power purposes and the demand was met by the construction of the tan- gential wheel now so widely and successfully used in the high head plants of the West. The earliest scientific consideration of impluse wheels in this country was by Jearum Atkins who, apparently, anticipated the design of the wheels of the Girard type in Europe by his design of such a wheel in 1853. t (See Fig. 163.) Fig. 158. Hunt Runner of The Rodney Hunt Machine Co. * See "Engineering News," March 29, 1906. t See "Tangential Water Wheels" by John Richards, Cassier's Magazine, vol. v, p. 117. 270 Water Wheels. Fig. 159. Shawinigan Falls Turbine, Manufactured by I. P. Morris Co. Other American Wheels. 271 In Atkins' first application for a patent (in 1853) he shows a clear conception of the principles of the impulse wheel. After describing the mechanical construction of his wheel, Mr. Atkins says: "The important points to be observed in the con- struction of this wheel and appendages, are : First, that the gear- ing * * * should be so arranged as to allow the wheel's veloc- ity at the axis of the buckets to be equal to one-half the velocity of the water at the point of impact, * * * "As the power of water, * * * is measured by its velocity, * * * it is obvious that in order that the moving water may communicate its whole power to another moving body, the velocity of the former must be swallowed up in the latter. This object is Fig. 1GO. Shawinigan Falls Turbine Runner. effected by the before-described mode of applying water to a wheel in the following manner, the velocity of the wheel, as before stated, being one-half that of the water. "Let us suppose the velocity of the water to be twenty-four feet per second ; then the velocity of the wheel being twelve feet per second, the relative velocity of the water with respect to the wheel, or the velocity with which it overtakes the wheel, will be twelve feet per second. Now it is proved theoretically, and also demon- strated by experiment, that water will flow over the entire surface of the semi-circular buckets of the wheel with the same velocity with which it first impinged against them, or twelve feet per sec- ond. Then, as the water in passing over the face of the buckets 272 Water Wheels. has described a semi-circle, and as its return motion on leaving the wheel is in an opposite direction from that of the wheel, its velocity with respect to the wheel being twelve feet per second, and as the wheel has an absolute velocity of twelve feet per sec- Fig. 161. Section Snoqualmie Falls Reaction Turbine. The Platt Iron Works Company. ond, it is obvious that the absolute velocity of the water with re- spect to a fixed point is entirely suspended at the moment of leav- ing the inner point of the buckets, its whole velocity, and conse- quently its whole power, having been transmitted to the wheel." Early Development of Impulse WheeL 273 Pig. 162. Section-Elevation Snoqualmie Falls Reaction Turbine (The Platt Iron Works Co.). Fig. 163. Plan of Atkins Wheel and Wheel Case (1853). From Cassier's Magazine, Vol. v, p. 119. 274 Water Wheels. a. Moore bucket, 1874. 6. Knight buckets, 1870. c. Dodd bucket, 1889. d. Hug bucket, 1897. e. Doble Ellipsoidal bucket, 1889. /. Pelton bucket, 1880. Fig. 1C4. Buckets of Tangential or Impulse Water Wheels. (Trans. Am. Inst. Mining Eng. 1899. Mr. Atkins' first application for a patent was rejected. After a long illness, from which he finally recovered, he again applied for a patent which was finally granted in 1875. The Atkins' patents are simply of historical interest as his inventions have had little effect on the practical development of the impulse wheel. American Impulse Wheels. 275 137. American Impulse Wheels. The impulse wheel found its- earliest practical development in California where the conditions for the development of power made such a wheel necessary. The early tangential wheel, used on the Pacific Coast, was quite simple in construction and the development of the buckets, which began with the simpler flat and curved forms, was very largely based on the experimental method used for the development of the reaction, Fig. 1G5 . Telluride Double Tangential Wheels. 2000 H. P. 500 Foot Head. (Pel ton Water Wheel Co.) turbine in the East. Experiments were made at the University of California, by Mr. Ralph T. Brown, as early as 1883, and the bulletin, published by the department was the earliest literature on tangential wheels published in this country. With the early development of the tangential bucket are con- nected the names of Knight, Moore, Hesse, Pelton, Hug, Dodd and Doble, and many other inventors, whose wheels have become well-known and widely used. The most extensive early develop- 276 Water Wheels. ment of this wheel was by The Pelton Water Wheel Company whose work has been so widely known and used as to make the name "Pelton Wheel" a common title for all wheels of the tangen- tial type. Some of the many forms of American buckets used are shown in Fig. 164 with the approximate date of their invention or de- sign. The general arrangement of a double 2000 H. P. unit, run- ning at 200 R. P. M. under 500 foot head is shown in Fig. 165. This is one of three units in- stalled by The Pelton Water Wheel Company for The Tellu- ride Transmission Plant of Col- orado. The wheels are of cast steel fitted with steel buckets, held in position by turned steel bolts. They are connected by a flexible coupling to a 1,200 H. P. generator. Fig. 166 shows the runner of an impulse wheel made by the same company. This is 9' 10" in diameter, and is designed to develop 5,000 H. P. at 225 R. P. M. under an effective head of 865 feet. Fig. 167 shows the runner of an impulse wheel manufactured by the Abner Doble Company. This runner was from the Doble Wa- ter Wheel Exhibit at the St. Louis Fair and developed 170 H. P. at 170 R. P. M. under a head of 700 feet and generated direct cur- rent for use on the intramural railway. In addition to the tangential wheels already described, a few manufacturers have developed wheels of the Girard type. One such wheel, designed and built by The Platt Iron Works Company, is illustrated in Figs. 168 to 171, inclusive. Fig. 168 is a section- elevation showing the arrangement and design of the guides and Fig. 166. Pelton Tangential Water Wheel Runner. Designed for 5000 H. P. at 865 foot head and 225 E. P. M. (Pelton Water Wheel Co.) American Impulse Wheels. 277 buckets of the wheel. Fig. 169 shows a section through the wheel and on the line of the shaft. In these figures W represents the runner; BB the buckets; g, the inlet guides, and G, the gate by which all or a portion of the guide passages may be closed and the power of the wheels reduced. The gate, G, is connected by the gearings, Gr, with the rod, r, which is connected through the rocker Fig. 167. Doble Runner. (Abner-Doble Co.) arm with the governor mechanism. The wheel or runner of this turbine is shown by Fig. 170, and a general view of the wheel is shown by Fig. 171. 138. Turbine Development in Europe. Modern European tur- bine practice has been the development of the last twenty years. European manufacturers have approached the subject more on the Water Wheels. t>asis of theoretical analysis than has been done in America. The conditions of development have also been largely special and not under such uniform conditions as in America. The result has been the development of special designs for special locations and the rapid accumulation of a considerable experience under a wide range Fig. 168. End Section and Elevation, Girard Impulse Turbine with Draft Tube. (Platt Iron Works Co.) of conditions. While the radial flow turbines were the earlier type developed, European practice has been largely centered on the axial flow wheels of the Jonval type for complete turbines, and axial flow and radial flow wheels of the Girard type for partial turbines under high heads. * American Impulse Wheels. 279 The axial flow turbine while simple in construction and low in cost is difficult to regulate and hence the demands of electrical de- velopment for close regulation has given rise to a variety of mod- ern designs which are summarized by Mr. J. W. Thurso essentially as follows : * Fig. 169. Longitudinal Section Girard Impulse Turbine. (Platt Iron Works Company.) ist. For low heads to 20 feet. Radial inward flow, reaction tur- bines with vertical shafts and draft tubes. 2nd. For medium heads, 20 to 300 feet. Radial inward flow reac- tion turbines with horizontal shafts and concentric or spiral cases and draft tubes. 3rd. For high heads over 300 feet. Radial outward flow, full or partial action turbines (of the Girard type) with horizontal shafts, * See "Modern Turbine Practice" by J. W. Thurso. 280 Water Wheels. Fig. 170 Runner of Girard Turbine. Type High-Pressure Runner. (Platt Iron Works Co.) Fig. 171. General View of Girard Turbine with Cover Raised. (Platt Iron Works Co.) often with draft tubes; also, modified impulse wheels of a tangential type. The types of tur- bines for low and mod- erate heads are mod- ifications of the Fran- cis inward flow turbine. Earlier European practice is perhaps well; represented by Fig. 172 which represents one of eight turbines installed by Messrs. Escher, Wyss & Co. c > for the City of Geneva, Switzerland. These wheels are of the Jon- val type and operate under heads some- times as great as 12 feet but during high water the heads de- crease to about five and one-half feet. The turbines consist of three annular rings or buckets and are so de- signed that the water is admitted to as many buckets as may be re- quired for economical operation under ' the very great differences in the condition of supply. The width of the inner and interme- diate rings are each seventeen and three- Turbine Development in Europe. 281 quarters inches, and the outer ring is eleven inches, all meas- ured radially. The outside diameter of the wheel is thirteen feet, eleven inches. The outer ring of guides is not provided with means for excluding the water from the buckets but the intermedi- ate or inner rings can be entirely and independently closed. The Fig. 172. One of the seventeen 210 H. P. Jonval Turbines at the Geneva Water Works. Built by Eecher, Wyss & Co. gates for closing the intermediate and inner rings consist of a flat plate in the form of a half ring, which lies on the top of the crown and a vertical curtain which hangs from the end of the plate and completes the closure of the other half of the bucket the openings 17 282 Water Wheels. of which are on the side of the same, the water entering the buckets by a quarter-turn. These turbines are used to operate the pump that furnishes the water supply for the city of Geneva for domestic and manufactur- ing purposes. Fig. 173. The 1200 H. P. Double Turbine at Chivres near Geneva. Escher, Wyss & Co. ( Gassier' s Magazine, October, 1897.) Fig. 173 shows a pair of vertical turbines furnished by the same company for Chivres near Geneva. Here the fall in summer is 15 feet and in winter 28 feet. The lower turbine will develop 1,200 Turbine Development in Europe. 283 H. P. at 80 R. P. M. under the higher head, and under the lower head the turbine above works w r ith the lower one. Each turbine is cone shaped and divided into three compart- ments in order to maintain the efficiency of the wheels at the same revolutions under the wide range in heads. Rapid advancement is now being made in turbine design both in this country and in Europe and the progress can best be known and appreciated by reference to the current technical press. CHAPTER XIII. TURBINE DETAILS AND APPURTENANCES. 139. The Runner Its Material and Manufacture. The runners of most reaction turbines (see Figs. 136, 142 to 149, 151, 154 to 159, 161) consist of hubs, crowns and rings, to which the buckets are at- tached. The wheels are sometimes cast solid, and sometimes built up. In built-up wheels the buckets are first cast, or otherwise formed, after which they are placed in a form or moulded, and the crowns, hubs and rings are cast to them. Turbine water wheels for low heads are usually made of cast iron or of cast iron with steel buckets. Wheels for high heads are frequently made of cast bronze or of cast steel. (See Figs. 158 and 159.) Probably the majority of cast wheels manufactured at the pres- ent time are cast in one solid casting of buckets, rings, hubs, and crowns. The buckets are formed by carefully prepared cores and in such manner as to leave them uniform in spacing and thickness, and smoothly finished so as to admit of the passage of water through or between them without excessive friction. With wheels so cast, no material finishing or smoothing of the surfaces of the bucket is practicable, and the casting must come from the sand with a satis- factory surface. In wheels cast solid, great care is necessary in order to prevent serious shrinkage strains. This is partially over- come by the use of soft iron, which results, however, in increased wear of runners subject to the action of sand-bearing waters. With buckets cast separately, a higher surface finish of the bucket is possible ; but when separate buckets are made and after- wards united, the runner must be strongly banded in order to give it the necessary strength. Buckets of sheet steel, forged or bent to the desired shape, present a uniform and satisfactory surface, and when punched at the edges before casting, form a solid and substantial wheel. The runners of Girard impulse wheels (see Fig. 171) are made in the same manner as reaction runners. The runners of tangential wheels are usually made with separate buckets and body. (See Figs. 167 and 168.) The bodies are made, Diameter of Runner. 285 according to the severity of the service, of cast iron, semi-steel, forged steel, etc. The buckets, dependent on the conditions of service, may be of cast iron, cast steel, gun metal, bronze, etc. The buckets, in the best wheels, are cast, shaped and polished and care- fully fitted to the wheel body. The bolt holes are then carefully drilled and reamed and the buckets are bolted in position by care- fully turned and fitted bolts. 140. Diameter of the Runner. The diameters of reaction runners are measured at the inlet, and, when the buckets at the inlet are parallel and of one size, the determination of the turbine diameter is a simple matter. (See Fig. 174, diagram A.) In order to give the runner greater speed and capacity, the buckets are sometimes cut back at a point opposite the bottom of the gate opening (see diagram B), and the diameter of the runner opposite to the gates is reduced below that of the lower diameter. In such cases the edges of the buckets are sometimes made parallel with the shaft but are usually inclined upward. In the latter case, the diameter of the wheel at its top may be considerably reduced over its diameter at the offset. In such cases the cutting back of the runner may be one or more inches at the bottom line of the gate with an inch or more inclination to the top of the buckets, and the diameter of the wheel at D and D'", diagram B, may differ from two to six inches or even more. With wheels so constructed, there is considerable difference in the practice of different manufacturers in measuring and listing the diameter of the wheels made by them. In some cases, the inside diameter, from rjng to ring, D, diagram B, of the runner, is given as the list diameter. In other cases, the diameter is taken at the inner angle of the offset as D'. In a number of cases the diameter is measured at about the center of the gateway, D", and in other cases, the diameter is measured at the upper and smaller diameter of the runner, D"'. This variable practice leads to a considerable differ- ence in the nominal diameter of the various turbines as listed in the catalogues, and frequently a runner listed as of a certain diame- ter by one manufacturer may be two to six inches larger than the runner of another manufacturer which is listed as of the same di- ameter. This discrepancy in the method of measuring and listing the diameter of turbine runners accounts, in some degree, for the apparent greater capacity, higher speed or greater power of the wheels of one manufacturer over those of another. 286 Turbine Details and Appurtenances. The practice of some of the American manufacturers of turbines, in measuring and listing the diameters of their wheels, is shown in Table XXV. In this table, all runners which are not cut back and with edges parallel to the shaft, are classified as Style A, even where they differ widely from the form shown in diagram A, Fig. 174. All runners with buckets cut back are classified as Style B, even where the bucket edges are parallel with the shaft. The diameters of tangential runners are usually measured be- tween the centers of buckets or on the diameter of the circle on which the center of the jet impinges on the buckets. TABLE XXV. Practice of Various American Manufacturers i>i Measuring and Cataloging the Diameter of Turbine Water Wheels. Manufacturer. Name of Kunner. Style. Point of measure- ment. Dayton Globe Iron Works American A j) New American A D Rodney Hunt Machine Co . . Special New American Improved New American 1 . . McCormick 8 B B B \y D' j) Hunt A D The James Leffel & Co Standard Leffel A D Special Leffel A p Samson B D Platt Iron Works Co Improved Samson Type A B B D D" Tvpes B and C A D S Morgan Smith Co McCormick 3 B D' Smith B D' The Trump Manufacturing Co. Standard Trump 4 B jy, Hisrh Speed Trump B 5 P Wellman, Seaver, Morgan Co Jolly-McCormick B D" 1 Fillet at angle. Diameter measured just above. 2 Diameter of Hunt-McCormick runners as measured at the crown which pro- jects beyond the tips of the buckets and is essentially the same in diameter as at D' 3 Diameter of the Smith-McCormick runners is measured at the crown which projects beyond the tips of the buckets and is essentially the same in diameter as atD'. 4 Diameter at D is 20# greater than at D". 5 Bucket of of high speed runner has parallel edges but is cut back as shown in B. 141. The Details of the Runner. The reaction runner will vary in design with the conditions under which it is to operate and the experience and ideas of its designer. In American practice the Details of the Runner. 287 manufacturer usually constructs a series of runners of similar ho- mogeneous design ; that is to say, each wheel of the series has all of its dimensions proportional to that of every other wheel of the series, and is of similar design in all of its parts. On account of demands for considerable variations in speed or power, or on account of improvements which have been found de- sirable by reason of the demands of his trade, the manufacturer often designs and constructs several series of wheels, each of which is particularly adaptable to certain conditions which he has had to meet. (See Tables XXII and XXIV.) In such cases each series is best suited for the particular condition for which it was designed, and is not necessarily obsolete or superseded by the later series. Fig. 174. The curves of the runner buckets (see Figs. 13, 14, 133, 134, 136, 146-148, 175) must be such as to receive the jet of water from the nozzle or guides without shock, permit it to pass along the surface of the buckets or through the passages in the runner with mini- mum friction, and discharge it as nearly devoid of velocity as prac- ticable. To accomplish this, the relative position and relation of the curves of guides and buckets must be carefully arranged. As the jet of water, is always directed forward in the direction of the revo- lution of the wheel, the jet has an original velocity in that direc- tion, and, since the bucket must be so shaped as to give a continued contact, as the jet progresses and the wheel revolves, the portion of the bucket farthest away from the guides must be curved back- ward, and terminate at such an angle as shall permit the jet to pass away from the wheel with free discharge. (See Figs. 175 and 128.) 283 Turbine Details and Appurtenances. B Fig. 175. Curves of Buckets and Guides in Turbine Wheels. Vertical Turbine Bearings. 289 RIGHT HAND HAND Reaction runners are made either right or left handed as de- sired. When looking at the top of the runner, if the wheel is de- signed to move in the direction of the hands of a watch, it is called a right handed wheel, and if it moves in the other direction, it is called a left handed wheel. (See Fig. 176.) The buckets, hub, crown, and ring of the reaction runner must be of sufficient strength to receive the impact or pressure of the moving column of water under the working head, and to transmit the energy to the shaft through which it is to be transmitted to the machinery to be operated. A heavy ring is usually desirable, both to give strength and support to the outer edge of the buckets and also, under some cir- cumstances, to give the effect of a fly-wheel in order to materially assist in maintaining uniform speed. Floating blocks or other material, in spite of the use of trash racks, sometimes reach the turbine, and when caught between the buckets and the case are apt Pig. 176. "Hand" of Water Wheels. to cause ser ious injury to the buckets. The runner is attached to a shaft passing through the hub, to which it should be closely fitted and strongly keyed to prevent its becoming loosened by vibration and the strain of operation. This is^ especially necessary in vertical wheels, for if, under these con- ditions, the wheel becomes loosened and drops from the shaft, it is apt to be practically destroyed. Impulse runners acting under high heads are subject to heavy shocks and must be especially sub- stantial. 142. Vertical Turbine Bearings. In all turbines where the dis- charge is axial and only in one direction, there is a reaction in the other direction that tends to unbalance the wheel and to cause a thrust in the direction opposite to the discharge. The leakage into the space back of the runner frequently produces a thrust in the opposite direction which may be wholly or partially relieved by openings left in the runner, usually close to the axis. In large units an attempt is made to balance these various pressures with some form of thrust bearing to sustain the difference in pressure which will occur under different conditions of operation. 290 Turbine Details and Appurtenances. In most single vertical turbines a simple step bearing is used. The bearing itself in American turbines usually consists of a lig- num vitae block, turned to shape, and centered in a bearing block which is held firmly and centrally in place by the cross trees. The bearing block is shown by T, and the cross trees by t, in Figs. 146, 147 and 185. The bearing on the shaft" itself is usually a spherical sector, or some other symmetrical curve of similar form. In some cases this bearing is cut directly in the shaft itself. (See Fig. 147.) In others, a cast iron shoe is provided and attached to the shaft. (See M, Figs. 145 and 184.) Above the turbine a second bearing is also provided (see T', Figs. 145 and 147) to keep the shaft in vertical alignment. This bearing in American wheels is usually Fig. 177. Geylin (Patent) Glass Suspension Bearing (R. D. Wood & Co.). of the type shown in Fig.. 182, except that it is adapted to its ver- tical position. In the Geylin-Jonval turbine, manufactured by R. D. Wood Company, a patent glass suspension bearing is used. (Fig. 177.) This bearing is attached above the wheel (see T, Fig. 135) and has the advantage of being readily accessible. The turbine is here sus- pended on a circular disc composed of segments of glass, B. B. Fig. 177, arranged with depressed divisions which form a continu- ous space around each segment of which the disc is composed, al- lowing, while the turbine is in motion, a perfect, free circulation of the lubricating matter with which the space is filled.* The bear- ing is a true metallic ring, A, firmly secured to the turbine shaft which revolves on these stationary glass segments. In most European vertical turbines the step bearing is simply a guide, the main bearing being above the turbine and more readily accessible than in the American form. * Catalogue of R. D. Wood & Co., 1901, p. 107. Vertical Turbine Bearings. 291 Figs. 178 and 179 represent vertical bearings of this kind. In these bearings C is a spherical sector so arranged as to take up any slight error in the vertical alignment of the shaft. Fig. 178 is a ball bearing; the hardened steel balls, AA, revolve between the special bear- ing plate, B and Bi. In Fig. 179 oil is pumped under pressure through the inlet, pipe OE, into the space A. By its pressure the bearing plate, B, is raised from its companion plate, B, and the oil es- caping between the plates lubricates them and over- flows through the overflow pipe, OO. In both Figs. 178 and 179 the height of the shaft is adjusted by the nut,' N, which, after adjustment, is fastened securely in such position. At the power plant of The Niagara Falls Power Company a thrust or hang- ing bearing of this disc type, somewhat similar to Fig. 179, is used (See Fig. 180). In this bearing the shaft is suspended to a revolving disc carried on a stationary disc. The Fig 178. Vertical Suspension Ball Bear- discs are of close-grained i ng .* charcoal iron of 25,000 pounds tensile strength and of 14" inside, 34" outside diameter. The lower or fixed disk is dowelled to a third disk with a spherical (3' 4" radius) seat. This *Wasserkraftmaschinen von L. Quantz. 2 9 2 Turbine Details and Appurtenances. is to provide for an automatic adjustment for slight deviations from the vertical due to uneven wear of the discs and other causes. The bearing surfaces between the discs are grooved to allow a circulation and distribution of the oil over the surface. Three methods of lubri- cation, forced, self, and a combination system, were experimented with and the combination sys- tem finally adopted. In the system of forced lub- rication, the oil enters the fixed disc at two diamet- rically opposite points and is forced between the discs under 400 pounds pres- sure. Self-lubrication is accomplished by oil sup- plied at the inner circum- ference of the disc and thrown outward by cen- trifugal force. The disc bearings are enclosed in a case provided with sight holes through which the condition of the bearing as well as the temperature of the oil can be observed. A thermometer and an incandescent light are sus- pended in the casing for this purpose. The oil is cooled by water circulating pipes inside the casing. The shaft is provided with a balancing piston (see Fig. 181) supplied with water from a pipe entirely independent of the pen- stock and under a head of 136 feet. This piston carries the greater part of the load, less than 2 per cent, of the load being left to be carried by the oil-lubricated disc bearing described above. 143. Horizontal Turbine Bearings. In horizontal wheels vari- ous forms of bearing may be used according to the conditions and circumstances of their operation. When practicable the bearings should not be submerged and should otherwise be made as accessi- ble as possible. In such cases the forms of bearings may be the same as those used on other machines subject to similar strains. Fig. 179. Vertical Suspension sure Bearing.* Pres- * Wasserkraftmaschinen von L. Quantz. Horizontal Turbine Bearings. 293 In many horizontal American wheels, where submerged bearings are necessary, lignum vitae bearings are used similar in type to the upper vertical bearing before mentioned (see T', Figs. 145 and 147). Such a bearing is shown in detail in Fig. 182. In this bearing the shaft, S, is sustained in position by the blocks, TT, which fit the For Elecfr*. V/ires Thrust Girder Section through Ball Disk Oil Inlet OH Catcher Section through Oil Sight Hole. Fig. 180. Vertical Thrust or Hanging Bearing of the Ni- agara Falls Power Co. (See Eng. Record, Nov. 28, 1903.) recesses of the cast iron bearing block, K, which in turn is attached to a cross tie in the case or to a pedestal, P. The blocks, TT, are adjusted by means of the screws, BB, which, after adjustment are locked in position by the lock nuts, LL. Such submerged bearings are sometimes lubricated by water only, in which case op- 294 Turbine Details and Appurtenances. portunity must be given for the free circulation of the water. In other cases the boxes are made tight and flow into them along the shaft is prevented by stuffing boxes at each end of the main box, the boxes being lubricated by forced , grease lubrica- tion. Bronze boxes of the types used for other high grade machines are sometimes used for submerged bear- ings. In such cases great care is necessary to pre- vent the entrance of grit- bearing waters. Such bearings are lubricated by forced oil or. grease. In forced lubrication it is desirable that both a force and return pipe be used so as to give visible evidence that- the lubri- cant is actually reaching the bearing. In some Fig. 181. Section of Turbine used in new Power House of The Niagara Falls Power Company, showing Balancing Hydraulic Position used to sustain Turbine and Shaft. (Eng. Record, Nov. 28, 1903.) cases bearings that would be otherwise submerged are made accessible at all times by metallic tubes (see Fig. 322) used as manholes. Where the turbine is placed horizontally, gravity can no longer offset the thrust caused by the reaction of the turbine when the discharge is in one direction, and the thrust must therefore be over- come by the use of some form of thrust-bearing. Where other con- ditions permit, it is quite common practice to install two turbines on a single horizontal shaft, having their discharges in opposite di- rections, in which case the thrust of each turbine is overcome by the thrust of its companion (see Figs. 153, 160 and 316). In many cases, however, the arrangement, size and capacity of the wheels to be used are not such as will permit the use of twin turbines and thrust-bearing, and other means of taking up the thrust must be provided. Horizontal Turbine Bearings. 295 144. Thrust-Bearing in Snoqualmie Falls Turbine. In the Sno qualmie Falls Turbine, manufactured by The Platt Iron Works Company (see Figs. 161 and 162), the device for taking up the thrust is thus described by the designing engineer, Mr. A. Giesler:* "Single-wheel horizontal-shaft units are relatively infrequent in turbine practice, especially in large sizes, where the thrust of a sin- gle runner is large enough to require careful consideration. The thrust is made of two parts : (I) that due to the static pressure or effective head of water at the various points of the runner surface ; .and (2) that due to the deflection of the water from a purely radial B Fig. 182. Horizontal- Lignum Vitae Bearing as Used in American Turbines. path through the wheel. As concerns the first part, the front face of the wheel is pressed upon by a pressure varying from the supply head at the outer circumference to the discharge pressure (vacuum) at the inner edge of the vanes, which latter extends over the whole central area of the runner (and shaft extension). The rear face of the runner is subjected to the pressure of water leaking through the radial air-gap between casing and runner, substantially equal to the supply head. This greatly overbalances the pressure on the front face, and the resultant thrust is\to the right in Fig. 161 (to- ward the draft tube). The. discharge ends of the vanes, being :urved transversely, also havfe a pressure component directed to- * See "Engineering News" of March 29, 1906. 296 Turbine Details and Appurtenances. ward the right. The velocity effect produces a thrust directed to- ward the left, but this is very small and does not materially reduce the pressure thrust. "By far the larger part of the pressure thrust is eliminated by venting the space back of the runner into the discharge space. Six holes through the wheel near the shaft, indicated in Fig. 161, have this function. The water leaking in through the air-gap is continu- ously discharged through these vents into the draft-tube, and the accumulation of any large static pressure back of the wheel is thereby avoided. "The average pressure on the front of the runner, however, is always lower, and the resultant thrust is therefore toward the draft- f *- * Cross Section. Longitudinal Section* Fig. 183. Thrust-Bearing Snoqualmie Wheels. tube, though its amount varies considerably, being greatest for full gate opening. This thrust is taken up by the balancing piston im- mediately back of the rear head of the wheel case, and the ultimate balance and adjustment of position is accomplished by the collar thrust-bearing behind the balancing piston. "The balancing piston is a forged enlargement of the shaft, fin- ished to a diameter of 17 inches, which works in a brass sleeve set in a hub-like projection on the back of the wheel-housing. The in- side of the sleeve has six circumferential grooves, each one inch wide and one-quarter inch deep, as water packing. The chamber in front of the piston communicates by a pipe (containing a strainer) with the supply casing of the water-wheel, and therefore receives the full pressure of the supply head. The chamber back of the piston Thrust-Bearing in Snoqualmie Falls Turbine. 297 is drained to the draft-tube, so as to carry off any leakage past the piston. The device thus produces a constant thrust on the piston, directed toward the left. By throttling the pressure pipe this thrust can be adjusted as desired. "The thrust-bearing shown in Fig. 161 and in detail in Fig. 183 consists of a group of four collars on the shaft, working in a babbit- ted thrust-block which is bolted to the back of the wheel-housing. The collars are formed on a steel sleeve which fits over the shaft and is bolted to the rear face of the balancing piston ; this makes it possible, when the collars are worn out, to renew the bearing by dismounting the thrust-block and placing a new sleeve. The thrust-bearing is lubricated by oil immersion. An oil chamber is cored in the block and communicates by numerous oil holes with the bearing faces ; a constant flow of oil is maintained by means of oil-supply and drain-pipes. Concentric with the oil chamber and outside of it a water chamber is cored in the block. Cooling water is supplied to this chamber by a pipe from the pressure side of the turbine, and drains from the top of the bearing through a drain-pipe to the draft-tube. A U-pipe attached at one side of the bearing forms connection between the water chambers of the upper and lower halves of the block. This detail avoids making the connection by a hole through the joint face, which would allow leakage of water into the oil-space and into the bearing. "The balancing piston is so proportioned and the pressure supply pipe is throttled to such a point as to give exact balance (i. e., with zero thrust in the thrust-bearing) at about half to five-eighths the full output of the wheel. At larger power there will be an unbal- anced thrust to the right, and at smaller output to the left, which are taken by the thrust-bearings. The maximum thrust on the collars is about 25,000 Ibs. The collars are 2i/ 2 inches high (2% .inches effective) by 131/2 inches mean diameter, giving a total effec- tive bearing area on four collars of 418 sq. inches. The maximum collar pressure is thus about 60 Ibs. per sq. in." 145. The Chute Case. The chute case (see Figs. 146, 147 and .184) consists of the fixed portion of the turbine to which are attached the step and bearings of the wheel (T), the guide passages (g) which direct the passage of the water into the turbine bucket, and the gates (G) which control the entrance of the water, and also the case cover (C). The case cover keeps the wheel from contact 18 298 Turbine Details and Appurtenances. with the water except as it passes through the guide and gates. To the chute case is usually attached the apparatus and mechanism for manipulating or controlling the position and opening of the gate. (A. P, Gr., etc.) In vertical turbines a tube, d, is usually attached to the lower ring, forming a casing in which the lower portion of the turbine revolves and on which the bridge tree, t, holding the step bearing is attached. When this tube is no long- er than one diameter it is usually called the turbine tube; but when it is con- siderably extended, it is termed a draft tube. The design of the tur- bine tube depends largely on the character of the wheel. Some wheels dis- charge downward and in- ward, some almost entire- ly downward, some down- ward and outward, and in some cases, the wheel dis- charges in all three direc- tions. For the best re- sults the tube should be so designed that the water from the wheel shall be received by it with no radical change of velocity and so that the remaining velocity will be gradually reduced and the water discharged at the lowest practicable velocity. The chute case and its appurtenances should be so designed that the water will enter the bucket with the least possible shock or re- sistance at all stages of gate and with a gradual change in velocity, and will discharge from the buckets into the turbine tube with as little eddying as possible and be evenly distributed over the cross section of the tube so as to utilize the suction action of an unbroken column of water. The case must also be designed of sufficient Fis. 184. The Chute Case. 299 Fig. 185. Section Swain Turbine. strength to sustain the weight of the turbine wheel and so that the step bearings are accessible and can be readily replaced or adjusted. The arrangement of the case must also be such that the openings between the wheel and the case are as small as practicable and the line of possible leakage will be as indirect as pos- sible so as to avoid leak- age loss. Most chute cases are either cast or wrought iron. Cast iron usually lends itself to a more sat- isfactory design for receiv- ing and passing* the water without sudden enlarge- ment and opportunities for losses by sharp angles and irregular passageways. Wrought iron, while not always lending itself read- ily to designs which elim- inate all such losses, possesses much greater strength for a given weight which is a great advantage under some conditions. 146. Turbine Gates. Three forms of gates are in common use for controlling the admission of water into reaction turbines. The cylinder gate consists of a cylinder closely fitting the guide that by its position admits or restricts the flow of water into the buck- ets. Fig. 184 is a section of a turbine of the McCormick type, manufactured by the Wellman-Seaver-Morgan Company, having a gate of this type, GG, between the guides and runners, which is shown closed in the cut. The gate is operated by the gearing, Gr., which raises it into the dome, O, through connection with the gov- ernor shaft, P. This same type of gate is used over the discharge of the Niagara- Fourneyron turbine (see GG, Fig. 134), over the inlet of the Geylin-Jonval turbine, GG, Figs. 135 and 137, and be- tween the guides and buckets of the Niagara turbine, shown in Fig. 101. A modified form of the cylinder gate is that used by the Swain 'Turbine Company (see Fig. 185), which is lowered instead of being raised into the dome as in Fig. 184. 3 Turbine Details and Appurtenances. A similar modification, called a sleeve gate by its designer, J. W. Taylor, is shown in Fig. 186. When partially closed the cylinder gate causes a sudden contrac- tion in the vein of water which is again suddenly enlarged in enter- ing the runner after opening the gate. (See Fig. 188.) These con- ditions produce eddying which results in decreased efficiency at part gate. (See Figs. 185 and 186.) The wicket gate, when well made, is perhaps the most satisfac- tory gate, especially for moderate or high heads. It can be readily balanced and should be made with perhaps a tendency to drift shut, so that should the governor mech- anism break or become disabled, the gates will drift shut. These gates are illustrated by GG, Figs. 147 and 148, which illustrate the wicket gate of the Samson turbine of The James Leffel & Company, and Fig. 187 which shows the wicket gate of the Well- man-Seaver-Morgan Company. In both cases the wickets are con- nected by rods with the eccentric circle and through an arm and section with the gearing Gr. Figs. 145 and 146 show the wick- et gate of the Improved New American, and Figs. 161 and 162 show the wicket gates of the Sno- qualmie Falls turbine, manufact- ured by The Platt Iron Works. - In both the New American and Fig. 186. Section Taylor Sleeve Snoqualmie wheels, the gates are Gate - moved by a gate ring (see Gr. Fig. 145). Figs. 189 and 190 show the details of the wicket gates and connection of the same to the gate ring of the Snoqualmie Falls Turbine. The tendency to produce eddying is much reduced in well de- signed wicket gates, although the sudden enlargement of the re- Turbine Gates. 301 duced vein at part gate undoubtedly reduces the efficiency of the wheel. (See Fig. 191, A and B.) The register gate (see G, Fig. 192) consists of a cylinder case with apertures to correspond with the apertures in the guides, g, and is so arranged that, when in proper position, the apertures reg- ister and freely admit the water to the wheel, and is also so con- structed that when properly turned the gate cuts off the passage completely or partially as desired. Considerable eddying is produced by the partially closed reg- ister gate, with a consequent decrease in part gate efficiency. (See Fig. 193.) The cylinder gate is usually the cheapest and most simple form of gate, but the wicket gate, if properly designed and constructed seems to ad- mit of the entrance of water into the bucket with least possible resistance and eddying, and in the most efficient manner. This form of gate is the most widely used in high- grade turbine construc- tion at the present time, although the cylinder gate is 'largely in use and has given satisfactory results. In some cases the pas- sage of water is restricted or throttled by the use of a butterfly valve, either in the inlet or in the turbine tube. This throttles the inlet or discharge and regulates the head in a very inefficient manner, but may be reasonably satisfactory where econ- omy of water is unnecessary. In impulse wheels the gates are usually so arranged that the guide passages are opened one at a time instead of all opening par- tially, as in part gate conditions with the reaction wheel. This re- sults in less loss in the eddyings caused by part gate. Fig. 194 shows the type of gate used by The Platt Iron Works in their Gir- Fig. 187. Wicket Gate of the Wellman- Seaver Morgan Co. 302 Turbine Details and Appurtenances. ard turbines where the guide passages are arranged symmetrically in three groups about the wheel. In the tangential wheel, where a single nozzle is used, the most efficient method found for redu- cing the opening is with the needle as illustrated in Fig. 195. This figure shows a cross section of +he Doble needle nozzle, a form which gives a high velocity coefficient under a very wide range of opening. The character of the stream from a needle nozzle when greatly reduced is shown by Fig. 196 where the clear and solid stream gives evidence of high effi- ciency. If the flow of water through the nozzle is regulated by throttling the water with a valve before it reaches the nozzle, a very low efficiency results. 147. The Draft Tube. The re- action wheel is of particular ad- vantage under low heads on ac- count of the fact that it can run efficiently under water, and there- fore, under backwater conditions, can be made to utilize the full head available. It is not necessary, however, to set the reaction wheel low enough so that it will be below water at all times for the principle of the suction pipe can be utilized and the wheel set at any reason- able ^distance above the tail water and connected thereto by a draft tube which, if properly arranged, will permit the utilization of the full head by action of the draft or suction pull exerted on the* wheel by the water leaving the turbine through the tube from which all air has been exhausted. The water issuing from the turbine into a draft tube, which at the starting is full of air, takes up the air in passing and soon estab- lishes the vacuum necessary for the draft tube effects. The func- tion of the draft tube is not only to enable the turbine to utilize by suction that part of the fall from the wheel discharge to the tail water level, but it should also gradually increase in diameter so as Fig. 188. Showing Cylinder Gate Partially Open and Eddies Caused by Sudden Contraction and En- largement of Entering Vein of Water. Turbine Gates. 303 Section A-B. ;-*^jf it**? 3 -* Fig. 189. Showing Relations of Gate Guides and Buckets in Snoqualmie Falls Turbine (Platt Iron Works Co.). Gate Arm Cover Ring *_ f/r^/%^ '&zfe Operating Ring ^<&/%yy2r ' w fro.m Governor Ar/n> ''Operating Pin oj 2 Operating Pin Brackets 1 " ' Screwd to Gate Operating ffing; I80apart, Section A-B. ^ Fig. 190. Showing Rigging for the Operation of Wicket Gate in Snoqualmie Falls Turbine (Platt Iron Works Co.). 304 Turbine Details and Appurtenances. A. Gate wide open. B. Partial gate. Fig. 191. Showing Condition of Flow Through Open and Partially Closed Wicket Gates. to gradually decrease the velocity of the water after it is discharged from the turbine wheel, thus enab- ling the turbine to utilize as much as possible of the velocity head with which the water leaves the tur- bine. It should be noted that a partial vacuum is established in the draft tube and, therefore, the draft tube must be strong enough to stand the exte rior pressure due to the vacuum so created. In or- der to perform its functions Iron .. ,. e in a more satisfactory man- ner, it must also be made perfectly air tight. One of the great advantages in the use of the draft tube is the possibility, by its use, of setting the wheel at such an elevation Fig. 192. Register Gate Works Co.). (Platt Turbine Gates. 305 above the tail water that the wheel and its parts can be properly inspected, by draining the water from the wheel pit. Otherwise it would be necessary to install gates in the tail race and pumps for pumping out the pit in order to make the wheel accessible. The- oretically, the draft tube can be used of as great length as the suc- tion pipe of a pump, and this is probably true of draft tubes for very small wheels. Practically, the draft tube should seldom be as long as 20 feet, especially for large wheels, for its success in the util- ization of the head depends on the maintenance of an unbroken col- umn of solid water, which is diffi- cult to maintain in large tubes. As the size of the wheel increases the difficulties of maintaining a vac- uum increase and the length of the draft tube should correspondingly decrease. It is practically impos- sible to maintain a working head with large turbines through long draft tubes with the turbine set at great distances above the water. Long draft tubes should, as a rule, be avoided and in all cases where I ^jfij |H J^ draft tubes are used, they should be as straight and direct and as nearly vertical as possible. It is the prin- ciple of the draft tube that per- mits horizontal shaft wheels to be utilized, as otherwise, with this type of machinery, only a small portion of the head could be used to advantage under normal conditions, for such wheels being often direct connected to the machinery are, of necessity, placed above the tail water. The draft tube is commonly of iron or steel, but in plants where concrete construction is used the draft tube may be formed directly in the concrete of the station or wheel foundations. On the Fourneyron turbine Boyden used what he termed a diffu- ser. (See Fig. 197.) The main purpose of the diffuser, and of the conical tube as well, is to furnish a gradually enlarged passage through which the velocity of the water as it leaves the wheel is Fig. 193. Showing Eddying Caused by Partial Closure of Register Gate. 306 Turbine Details and Appurtenances. Fig. 194. Gates and Guides of Girard Impulse Turbine. (Turbine Design as Modified for Close Speed Regulation, G. A. Buvinger, Proc. Am, Soc. M. E., Vol. XXVII.) Fig. 195. Cross-section of Doble Needle Nozzle.* * From Bulletin No. 6, Abner Doble Co. The Draft Tube. 307 Fig. 196. Stream from Doble Needle Nozzle.* so gradually reduced as to enable the velocity head to be utilized in the wheel, thus saving head which would otherwise be lost. It has already been noted that impulse wheels of the Pelton and Girard types cannot operate satisfactor- ily submerged, and must be set at such positions that they will be above the tail water at all times. In many localities where the Fig. 197.-Boyden Diffuser. variation in the surface of tail waters is considerable, this means a large relative loss in the head utilized and that this type of wheel will therefore not be practicable except under high ' * From Bulletin No 6, Abner Doble Co. 308 Turbine Details and Appurtenances. head conditions and where the loss entailed by the rise and fall of the tail water will be inconsiderable. An attempt has been made, however, to so design a draft tube that a vacuum will be established and maintained below the wheel, in such a manner, however, that the water will not come in contact with the wheel. The vacuum is so maintained as to hold the water at an established point just below the wheel, thus permitting the wheel to utilize the full head except for the small clearance between the wheel and the water surface in the draft tube. This arrangement is shown in Figs. 168 and 171, as applied by The Platt Iron Works Company to a Girard turbine. CHAPTER XIV HYDRAULICS OF THE TURBINE. 148. Practical Hydraulics of the Turbine. It is not the purpose of this chapter to consider mathematically and at length the princi- ples of hydraulic flow in relation to the curves of guides and buckets and the effects of such curves on the power and efficiency of the tur- bine. These relations are expressed by long and involved equations of considerable interest to the engineer who is to design and con- struct the turbine but of little practical value to the engineer who is to select and install it in a water power plant. Few of the designers of American wheels have given much attention to the involved mathematics of hydraulic flow in the turbine and the designs of most American wheels are based on the results of experiment and broad practical experience. The designs of Swiss and German wheels are, to a much greater extent, based on mathematical analysis. It is an open question whether the best work of either American or foreign manufacture shows any marked superiority in comparison with the other. The results actually attained in the manufacture of wheels in this country seem to show that the American practice in wheel design will give equal and even more uniformly satisfactory results than the European methods, at least as carried out by foreign engineers under American condi- tions. Correct theory must be the basis of all successful work. The theory of the experienced man may be unformulated and unex- pressed, but correct design has always a correct theory as its basis even if unrecognized as such, and such a theory properly applied will lead to correct results. On the other hand, formulated theory will lead to correct results only as far as the theory is correct and takes into account all controlling or modifying factors and is properly ap- plied. A correct theory, carefully formulated and properly applied, cannot fail to be of great service to the engineer in extending his experience to wider fields. Scientific study and mathematical an- alysis of the turbine, based on wide experience and careful experi- ments, can but lead to the accomplishment of better results than have vet been attained. 3io Hydraulics of the Turbine. An understanding of certain laws of flow through turbines as con- firmed by both theory and practice is essential to a proper compre- hension of the principles which should govern the selection and installation of such wheels and these laws are considered in this chapter. 149. Nomenclature used in Chapter. In the discussion in this chapter the letters and symbols used have the following signifi- cance: a Area of gate orifice or orifices. a Angle of deflection of jet. ft = Supplement to angle of deflection = 180 a.. D = Diameter of wheel in inches. E = Energy in foot pounds per second. F = Force producing pressure or motion. g = Acceleration of gravity. h = Effective head at the wheel. n = Number of revolutions per minute. nj = Number of revolutions per minute for head h^. it Ratio of circumference to diameter = 3.1416 P = Horse powers of turbine at any given head. P! = Horse power of turbine at head hj. q = Discharge in cubic feet per second at any given head. q 1 = Discharge in cubic feet per second at head h x . r x = Internal radius of wheel. r 2 = External radius of wheel. S = Space passed through by force acting. ; iij Velocity of wheel at gate entrance. u 2 Velocity of wheel at point of discharge. v = Theoretical spouting velocity due to head = v' = Velocity of the periphery of the impeller, in feet per second. v, = Absolute velocity of water entering the wheel. v 2 = Absolute velocity of water leaving the wheel. v r = Relative velocity of water entering the wheel. V R = Relative velocity of water leaving the wheel. v a = Average velocity. W Total weight per second. w = Weight of unit of water = 62.5 Ibs. cp = Ratio peripheral velocity of wheel to spouting velocity of water = TURBINE CONSTANTS. C = Coefficient of discharge of gate orifice or orifices. A = Constant relation of turbine diameter and speed. K = Constant relation of turbine diameter to discharge. K 3 = Constant relation of turbine diameter to power. K a = Constant relation of peripheral velocity. K 4 = Coefficient of relation of turbine speed and discharge. K 6 = Coefficient of relation of turbine power and speed. (Specific speed.) First Principles. 311 150. First Principles. In the utilization of water for power pur- poses it is the first principle of design that the water should enter the wheel without shock and leave it without velocity. This should be interpreted to mean that the approaches of the water to the wheel must be such as to cause no loss by undue friction or by sudden con- tractions or enlargements (inducing eddies and other sources of lost energy), and that all shocks should be confined as far as possible to the action on the wheel buckets leaving the full amount of energy, and consequently the velocity, to be entirely converted to power therein. In gravity wheels, illustrated by the various overshot wheels for- merly so extensively used for water power purposes, the water sho'tild enter the wheel at the lowest practicable velocity and should be retained in the buckets until the buckets have made the greatest possible descent from the nearest practicable approach to the eleva- tion of head-water, to the nearest practicable approach to the eleva- tion of the tail water. Part of the velocity of approach to the wheel may be utilized by impact on the buckets but the entire energy re- maining in the water as it falls or flows away from the wheel is lost, and cannot be further utilized in the wheel. The greater the reduction in velocity, the greater the proportion of energy that can be utilized, but there comes a limit beyond which it is not practicable to go. This limit varies with different condi-> tions and may be the result of too great expense in the building of raceways or in the construction of the machine itself. A point will be reached where the friction expended in the large machine needed to reduce the velocity will consume more energy than would be lost in inducing a higher velocity. These losses must be equalized. In practice it is found that about two or three feet per second are satis- factory velocities at which to reject or discharge the water used by motors. These velocities represent heads of from .062 to ,14 feet, or from three-quarters to slightly less than two inches. The veloc- ity of discharge must, however, be fixed for each individual case and after all conditions are fully understood and considered. 151. Impulse and Reaction. A jet of water spouting freely from any orifice will acquire a velocity (see Eq. 9, Chap. II). (1) v = -/2JpT and will possess energy in foot pounds per second (see Eq. 10, Chap. II) as follows: Wv 8 3 I2 Hydraulics of the Turbine. The energy of the- jet leaving the orifice is the product of a force, F, which acting on the weight of water, qw, for one second gives it the velocity v. The space passed through by the force in one second, in raising the velocity from to v is (see Eq. 6, Chap. II) (3) S = v a t and the work done in foot pounds is therefore (4) E = FS = - From Equations 2 and 4 therefore Fv _ gwv 2 ( 5 ) - 9^r- (6) and therefore F _ qwv g The force, F, is exerted, by reaction on the vessel of which the orifice is a part and may produce motion in that vessel if it be free to move, or it may produce motion in another body by impulse through the extinction of the momentum of the jet in impinging against it. These equal and opposite forces are well shown: ist. By the force required to sustain a hose nozzle against the reaction of a fire stream, and 2nd. By the force of the jet, from the nozzle so sustained when exerted against any object in its course. These conditions are illustrated by Figs. 198 and 199. The force, F, which may be exerted by a jet impinging against a surface depends on the momentum of the moving stream of wa- ter and is directly proportional to its velocity. It is also a function Fig. 198. Fig. 199. The Impulse Wheel. 3i3 of the angle through which the jet is deflected. If friction be ig- nored, the stream will be deflected without change in velocity, and the force exerted against the surface in the original direction of the jet will be equal to the momentum of the original stream less Fig. 201. Fig. 202. Fig. 200. the component, in the original direction, of the momentum of the diverted jet. (See Fig. 200). (7) (1 cos a) If the jet impinges against a flat surface (see Fig. 201) a = 90, Cos a and If the jet is deflected 180 by means of a semi-circular bucket (see Fig. 202) Cos 180 = 1, and therefore >) - * = ^ 152. The Impulse Wheel. Impulse water wheels utilize the im- pulsive force of a jet impinging against buckets attached to the circumference of the wheel. The bucket must move under the impulse in order to transform the energy of impact into work and the ratio of v', the velocity of the periphery of wheel, to the velocity v of the jet is indicated by # 4f (10) tp = and v ' = q> v 19 314 Hydraulics of the Turbine. In determining the force, F, exerted upon the moving bucket, the relative instead of the actual velocity of the jet must be considered and it is readily seen that the value of the relative velocity v r will be as follows: (11) v r = v = .$ and a =180, in equation (13), there is ob- tained (14) E = q wv- That is, E equals the entire energy of the jet (see equation 2), and hence the theoretical efficiency when (=0.5 is 100 per cent. Another criterion for maximum efficiency is that the absolute velocity of the water in leaving the bucket must be zero. When a =180, the absolute velocity with which the water leaves the bucket is evidently the velocity relative to the bucket minus the velocity of the bucket or (15) v This gives = (1 ) v which gives (p = 0.5 as obtained by two other methods and here shown to be indepen- dent of the angle ft. The absolute path of the water in space is shown by ABCD Fig. 204, and the magnitude of this velocity is shown below in curve EF where ordinates are absolute velocities along the tangent lines to curve ABCD at the point directly above. These curves are based on the assumption that < 0.5 and the bucket is semi-circular in cross s'ection as shown. The theoretical considerations thus far discussed are modified by the frictional resistance which the bucket offers to the flow of wa- ter over its surface and by the spreading of the original jet from its semi-circular section to a wide thin layer in leaving the bucket. Hydraulics of the Turbine. Further loss no doubt takes place as a result of the fact that the bucket is in its assumed position at right angles to the direction of the jet only at one instant during its rotation. Upon entering D Fig. 204. and leaving the jet it is inclined considerably to this direction and doubtless operates less efficiently. These conditions result in a much greater drop in efficiency than the above analysis would seem to indicate. 154. Reaction Wheel The flow of water through the buckets of a reaction wheel is less easily analyzed than in the case of the im- pulse wheel. The chief difference in the two types of wheels arises Reaction Wheel. from the fact that the reaction wheel is "filled" and hence the ve- locity of the water relative to the buckets at any point does not remain constant but varies inversely as the cross sectional area of the passageway. The path described by a particle of water in passing through the Fig. 205. wheel has been investigated by Francis,* by a method based upon the assumption that "every particle of water contained in the wheel, situated at the same distance from the axis, moves in the same direction relative to the radius and with the same velocity." This assumption becomes more accurate as the number of buckets increases. Fig. 205 shows the path, resulting from the application of this assumption, of the water through the "Tremont" Fourneyron wheel and Fig. 206, through the center vent wheel a.t the Boott Cotton Mills. The former indicates, since the jet of water is carried for- ward in the direction of rotation, that the water resists the rota- Fig. 206. * See "Lowell Hydraulic Experiments," p. 39. Hydraulics of the Turbine. Fig. 207. tion of the wheel until nearly to the circumference when it is sud- denly deflected and leaves the wheel, as it should, in a direction nearly normal to the wheel. The jet of water in the Boott wheel (Fig. 206), on the other hand, shows a continual backward deflection of its path from the point where it leaves the guides, and hence a continual delivery of its energy to the wheel. This seems to indicate a more logical condition and . a better shaped bucket than that of the Fourneyron. It will be noted that the actual path of the water in this case is very similar to that in the impulse wheel shown in Fig. 204. For the economical operation of the reaction wheel the following principles must be observed: I St. In order that the jet of water may enter the wheel without shock the resultant of the velocity of the water as it leaves the guides and the velocity of the periphery of the runner must have a direction parallel to the bucket blades at this point, and a mag nitude equal to that which will produce the required discharge through the cross sectional area of the passageway. 2nd. The relative velocity of the bucket and of the water relative to the bucket at the point of discharge must be such that the water leaves the buckets with the minimum practicable absolute velocity. 3rd. Such residual velocity as may remain in the discharging wa- ter must be conserved and utilized as far as practicable by the proper arrangement of the draft tube. 4th. In all wheels it is also essential by proper design to reduce losses from friction, eddying, etc., as greatly as possible. The first requirement is illustrated in Fig. 207 where AB is one of the runner buckets of an outward flow wheel. The guides, AC, direct the water into the buckets with an absolute velocity, v 2 . The velocity of the runner at point A, where the water enters, is u 2 . The two velocities combined graphically give a resultant, v r , which must be tangent to the curve of the bucket and equal to (18) v 9.2 where * Q q 3 = required discharge through the passageway, and a 2 = area of cross section of the passageway at point of entrance, A. Reaction Wheel. 319 This requirement does not enter into the design of an impulse wheel since the jet impinges against the edge of the wedge-shaped partition in the bucket always in a direction tangent to the bucket curve at that point regardless of the relative speeds of runner and jet. Further, since the discharge is "free" and the buckets not "rilled," no sudden change of velocity occurs. The effect of part gate conditions upon the first requirement de- pends upon the type of speed gate and may best be studied from Figs. 188, 191, 193 and 207. A change in either direction or mag- nitude of v l will change v r unless the two effects tend to neutralize which may happen in some instances. In all reaction wheels the velocity of inflow, v 15 through the guides is increased by partly closing the gate, while the velocity, Ui, of the wheel remain un- changed. v r will therefore change, and a change in either its direc- tion or magnitude will produce an impact or sudden enlargement respectively- as the water enters the runner, and therefore a loss, unless the direction of the guides is changed to correspond. The wicket gate, when carefully designed, has given rise to part gate efficiencies more nearly approaching those of impulse wheels than with gates of any other type (see Figs. 131 and 236). The second requirement, that of minimum residual velocity of the water in leaving the buckets, is shown graphically in Fig. 207. VR is the velocity of discharge of the water relative to the bucket and is, of course, tangent to the curve of the bucket. u 2 is the peripheral velocity of the runner. The resultant of two velocities is the absolute velocity with which the water is discharged from the wheel, and is shown in magnitude and direction by line v 2 . Now, at part gate the quantity of water discharged is less than that at full gate and hence VR must also be less since the cross section of the passage must be filled. u 2 remains unchanged and hence the resul- tant v 2 will be increased with a corresponding waste of energy and loss in efficiency. This is an unavoidable loss in a wheel operating under part load and makes it impossible to maintain full efficiency of operation by any design whatever of the regulating gates. This loss does not appear in the impulse wheel since the velocity with which the water leaves the bucket is theoretically at least not in- fluenced by the quantity. The third requirement is partially satisfied by gradually expand- ing the draft tube from the wheel to the point of discharge. This will recover only the component of the residual velocity in the axial 320 Hydraulics of the Turbine. direction. The larger component of the residual velocity however tends to produce a rotation of the water column in. the draft tube, and is not recovered by any present design. The fourth requirement is evident. L.3 Figs. 208-209. Reaction Wheel with Concrete Draft Tube.* 100 TOTAL AVAILABLE ENERGY ENTRANCE .GATES Fig. 210. Graphical Relation of Velocity and Energy in the Flow Through a Reaction Turbine with Draft Tube. * Turbinen and Turbinenanlagen, Viktor Gelpke-, page 61. Energy Transformation, Reaction Turbine. 321 155. Graphical Relation of Energy and Velocity in Reaction Tur- bine. The relations of the changes in velocity and in energy in the passage of water through a reaction turbine and its draft tube are graphically shown in Fig. 210.. Fig. 208 shows the cross section of a radial inward flow reaction turbine with a concrete draft tube. The cross sections of the draft tubes at various points are shown in Fig. 209 from which it will be seen that the draft tube of this turbine gradually changes form and increases in cross section in order that the velocity of flow may be gradually decreased from the point of discharge of the turbine to the end of the draft tube. The changes in absolute velocity in the passage of water into and through the turbine and draft tube are shown by line V, V x , V 2 , V 4 , V 5 ; the height of the ordinates at these points shows the approxi- mate absolute velocities at such points in the flow. The absolute velocity is a maximum at or near the point where the water enters the runner and is decreased as greatly as possible at the point of its discharge into the draft tube. By gradually increasing the area of the draft tube, an additional reduction in velocity is obtained, the water finally issuing with a velocity V 5 . The maximum veloc- ity, measured by the ordinate V 2 , is, in reaction wheels, consider- ably below the spouting velocity (i/2gh) In its flow through the wheel, the velocity of the water relative to the bucket increases and becomes a maximum at the outlet of the wheel. This increase in relative velocity is shown by the line V,, V.. The energy transformation which takes place during the change in velocity is illustrated by the dotted line marked "Energy trans- formation" which begins at a maximum of 100 per cent, at the en- trance of the wheel ; is decreased by friction, leakage, shocks, etc., by about 16 per cent, under full gate conditions. The energy is transformed into useful work in the wheel by the reaction at the point of discharge and utilizes about 80 per cent, of such energy, the remaining 4 per cent, being rejected in the discharge from the draft tube with a slight recovery of velocity energy as before de- scribed. 156. Turbine Relations. In all water wheels the quantity of dis- charge, the power, speed, efficiency and effective head on the wheel are closely related and vary in accordance with certain definite laws modified by the design of the turbine and the conditions under 322 Hydraulics of the Turbine. which it is operated. The conditions of operation must be adapted to the type of machinery used, or the machinery must be selected in accordance with the conditions under which it must operate, in or- der that the best results may be attained. If a jet or stream of water, with a velocity, v, acts on the moving surface of a motor bucket, this bucket, if the friction of the wheel is negligible, may acquire a velocity essentially equal to that of the jet, i. e., to the theoretical velocity due to the head. In actual prac- tice the velocity of the bucket will always be less by the amount of velocity lost in overcoming the friction of the wheel. The velocity of the wheel here considered must be measured at the center of ap- plication of the forces, i. e., at the point of application of the result- ant of all the forces of all the filaments of water that act on the wheel. Under conditions where the resultant velocity of water and bucket are the same, it is evident that the water will produce no pressure o-n the bucket and the motor can deliver no power. As soon as resistance occurs, the speed of the wheel is reduced. Under reduced speed the momentum of the jet, or the reactive pressure of the water, according to the circumstances of design, is converted into power. This impact or pressure increases as the speed or ve- locity of the bucket decreases until the maximum impact or pres- sure results with the bucket at rest, in which case also no work is done. At some speed, therefore, between these extremes the maxi- 90 BP 30 80 80 100 REVOLUTIONS PER MINUTE 140 Fig. 211. Efficiency Speed Curves of a 48" "Victor Turbine." Turbine Relations. 323 & II IS , Ip 2 < , \ *-* \\ o or hU o $ > ft a: ^ P o 000000 ^ C4 O CD (O * QV2H 100J fJ331ti!HJ. d3QNR b3A\Od 3SUOH 324 Hydraulics of the Turbine. mum amount of work, from a given motor, will be obtained. That is to say, at a certain fixed speed the maximum work and the maxi- mum efficiency of a given wheel will be obtained, and at any speed below or above this speed, the power and efficiency of the wheel will be reduced. These conditions vary considerably according to the type and design of the wheel considered and also according to the gate opening at which the wheel may be operated. The efficiency curves of a 48" Victor turbine, under a thirteen foot head and under various conditions of gate, are shown in Fig. 211. Fig. 212 shows the <-power cttrve of the same wheel under the same conditions of head and gates. 157. Relation of Turbine Speed to Diameter and Head. The velocity of the periphery of the impeller or buckets of a wheel is not necessarily and in fact is not usually the same as the velocity of the point of application of the resultant of the forces applied to the wheel. This point may be at some considerable distance within the wheel and at a point not easily determined. This point of applica- tion of the resultant forces may vary in position with the gate open- ing. The peripheral diameter is fixed and is therefore more conve- nient for consideration than the point of application of the forces. The peripheral diameter, or the catalogued diameter, is therefore used in the discussion of the general subject. Many wheels vary in diameter at various points on the periphery (see Fig. 174), and there is no uniform practice among manufacturers in designating such di- ameters so that the diameters used in the following discussion and the functions based thereon are in accordance with the practice of each maker and are therefore not strictly comparative. In this dis- cussion the laws discussed are equally true if based on any actual diameter or any simple function of the same. The diameter chosen simply influences the magnitude of the derived function and not the character. The discussion holds therefore in each case regardless of the method of measurement except for the purpose of comparison between wheels of various makers in which case similar diameters must be used. In reaction wheels, the buckets extend from the periphery of the wheel to a point quite near the axis of revolution (see Fig. 128, Diagram I). In such wheels the resultant of the forces applied falls a considerable distance within the circumference of the wheel. In such wheels the peripheral velocity may exceed the velocity of the jet acting on the wheel. In impulse wheels (see Fig. 129, Diagram E) the buckets are small in comparison to the wheel diameter and Relation of Speed to Diameter and Head. 325 are located at the periphery; hence, in this class of wheels, the re- sultant of the forces applied lies at or near the periphery, and the peripheral velocity will be less than that of the jet acting on the wheel. Taking the velocity of the periphery of the wheel as a function of the velocity due to head, the relations may be expressed by the formula : (19) v' = is constant: D n (24) r=* 1841.6 cp = A is constant. v n If h I, this will reduce to: (25) D nj = 1841.6

for various makes of wheels, as expressed by the data in the manufacturers' catalogues, it is found that these values vary somewhat for different wheels of a series but are usually practically constant. It will be noted, however, from the efficiency speed curve, shown in Fig. 211, and the power curve, shown in Fig. 212, that the speed, and conse- quently the values of and A, may vary somewhat without materi- ally affecting the efficiency or power of the wheel. It should also be noted from Figs. 211 and 212 that if it is de- sired to secure the greatest efficiency and power at part gate, the values of and A for a given wheel must be reduced. Table XXVI gives the values of A and for various American wheels, calculated from the catalogues of the manufacturers. TABLE XXVI. Showing Relation of Diameter and Speed of Various American Turbines working under Catalogue Conditions. _ D n _ v^ = D n Vh v "Worno rf Whool L ^ c/ 3 Min. Max. Min. Max. Reaction Wheels. T. C. Alcott & Son... Alcott's Standard High Duty 1210 1254 .658 .682 Alcott's Special High Duty 1211 1253 .658 .682 Alexander, Bradley & Dunning Syracuse Turbine 1203 1226 .654 666 American Steel Dredge Works Little Giant 1235 1462 671 794 Camden Water Wheel Works. United States Turbine 1372 1588 745 864 Chase Turbine Mfg. Co. Christiana Machine Co *Chase-Jonval Tur- bine (regular) *Chase-Jonval Tur- bine (special) Balanced Gate Tur- 1612 1840 1997 2237 .876 .999 1.084 1.2H bine 1220 1298 .663 .706 *NOTE. Wide variation in constants due to the design being special for various sized wheels (series not exactly homogeneous). Relation of Speed to Diameter and Head. 327 TABLE XXVI Continued Showing Relation of Diameter and Speed of Various American Turbines working under Catalogue Conditions. D n v ' D n A = -/== q>= = .000543 7= V\\ v Vh t S <7 3 Manufacturer. Min. Max. Min. Max. Reaction Wheel Con. Craig Ridgway & Son Co Double Perfection 1186 1250 .614 .679 Craig Ridgway & Son Co Standard 1200 1275 652 693 Dayton Globe Iron Works Co American Turbine... 1218 1295 .662 .704 fNew American Tur- bine (high head type) 1064 1077 .578 .585 Improved New Amer- ican 1632 1738 .886 .944 J. L. &S. B. Dix Special New American Improved Jonval Tur- bine 1284 1474 1340 1617 .697 800 .727 880 Dubuque Turbine & Roller Mill Co Dubuque Turbine & Roller Mill Co Flenniken Turbine... McCormick'sHolyoke 1511 1533 .821 .833 Turbine 1196 1296 650 704 Humphrey Machine Co Hercules Turbine. . . . JIXL Turbine 1160 1198 1170 1209 .630 .652 .636 .657 JXLCR Turbine 1196 1206 .652 .656 Rodney Hunt Ma- chine Co McCormick Holyoke Turbine 1159 1278 .630 .694 Hunt McCormick Tur- bine 1158 1272 .629 .691 New Pattern Hunt Turbine 1163 1415 .632 .768 Standard Wheel, 1887 Pattern 1200 1291 .651 .701 E. D. Jones & Sons Co. James Leffel & Co . . . Crocker Wheel Samson W r ater Wheel Improved Samson Standard 1208 1543 1578 1330 1292 1554 1H32 1339 .657 . 838 . 856 . 7'2>2 .702 .84* .886 .727 Special 1380 1434 .750 . 779 Munson Bros. Co Phoenix "Little Giant".. 1001 1020 .544 .554 tCatalogue recommends a maximum and minimum age speed. ^Tables based on full theoretical power of the water, to 90 per cent efficiency, depending on location. speed. Constants given are for the aver- Wheels are said to give from 75 per cent 328 Hydraulics of the Turbine. TABLE XXVI. Continued. Showing Relation of Diameter and Speed of Various American Turbines working under Catalogue Conditions. A = Dn Vh = .000543 JL i/h 'I i. < p Manufacturer. ^ame 01 wneei. Min. Max. Min. Max. Reaction Wheel Con. Norrish, Burnham & Co 1213 1233 659 670 Platt Iron Works Co. . Victor Register Gate. Victor Standard Cyl- 1181 1380 1221 1410 .641 .749 .663 .765 Poole Engineering & Machine Co Poole-Leffel 1341 1380 " 728 749 T. H. Risdon & Co. ... Risdon Standard Risdon Turbine Type T C 1213 1213 1420 1420 .659 659 .772 772 Ris.don Turbine Type D. C 1213 1420 .659 .772 S. Morgan Smith Co . . Smith-McCormick . . . Smith 1180 1655 1344 1679 .641 898 .730 911 Trump Mfg. Co Standard Trump 1320 1380 .716 749 Wellman, Seaver, IMorgan Co McCormick 1212 1260 658 684 Impulse Wheels. DeRemer Water Wheel Co DeRemer Water Wheel 962 1001 .522 .545 Abner Doble Co Tangential \Vheel 841 848 456 460 Pelton Water Wheel Co Tangential Wheel 912 92] 495 500 Platt Iron Works Co.. The Risdon Iron Wks. Victor High Pressure Tangential Wheel 915 917 919 920 .497 .498 .499 .499 From equation (26) may be derived (27) = ^ff- From this equation the economical speed or correct number of revolutions n for any wheel of diameter D, at any head, i/F, can be obtained if the revolutions n of any other wheel of the series at head h, and of diameter D, is known. Relations of and Efficiency. 329 If in equation (27), D = D a , the equation reduces to (28) n- ^Eor^ = -^ T/hi Vh T/hi That is to say : The economical speed of any wheel will be in direct proportion to the square root of the head under which it acts. If in the equation (28), n 1, the equation reduces to (39) n n lV /K From which it follows that tLe revolutions of a wheel (n) for any head, h, is equal to the evolutions n x for one foot head multiplied by Vh. 158. Graphical Expression of Speed Relations. The relation expressed by equations 18 to 27, inclusive, between the values of v, <, D, n, and h, are graphically shown by Fig. 213. The theoretical relations between v' and h, and as expressed by equation (19) when 4>-i, are represented by the upper curved line in the diagram referred to ordinates and abcissas. The relation between , v and h, where has a fractional value or is less than 100 per cent., as is the case for all wheels working under practical conditions, is shown by reference to the curved lines below ; the fractional value of as rep- resented by each line is given thereon. The relations between v, D and n are shown by the relations of the straight lines originating near the lower right-hand corner of the diagram referred ta ordi- nates and abcissas, and the mutual relations of all lines on the dia- grams show the mutual relations between the various factors that are here considered. 159. Relations of < and Efficiency. In any turbine running under different heads but otherwise under the same physical condi- tions as to gate opening, setting, draft tubes, etc., the efficiency will remain constant provided the ratio of the velocity of rotation to the theoretical spouting velocity of the water under the given head remains the same. This is to say, the efficiency of a wheel will remain constant under various conditions of head as long as the value of < remains constant. This law is well demonstrated by ex- periments made on a 12" Morgan-Smith wheel at the Hydraulic Laboratory of the University of Wisconsin.* These experiments were made under seven different heads varying from about 7.10 feet to about 4.25 feet. The results of all these experiments have been * "Test of a Twelve-Inch McCormick Turbine," an unpublished thesis by O. W. Middleton and J. C. Whelan. 20 330 Hydraulics of the Turbine. REVOLUTIONS PER MINUTE Fig 213. Speed Relations of the Turbines. Relations of and Efficiency. 0.0 O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1. 1 VALUES OF $ Fig. 214. Efficiency^ Curve of a 12 "Smith-McCormick Turbine. 332 Hydraulics of the Turbine. platted in a single diagram (see Fig. 214) from which it will be noted that all experiments are fairly close to the mean curve ; that the variation therefrom is probably due to experimental errors (principally, it is believed, in the determination of the relative velocities) and that reduction in head shows no uniform decrease in efficiency. The experiments referred to, which are soon to be published in a University bulletin, show that this law is true under all conditions of gate as well as for the full gate conditions, illus- trated in Fig. 214. Hence the conclusion may be drawn that the efficiency of a wheel will remain essentially constant if < remains constant at least under moderate changes in head. 160. Discharge of a Turbine at Fixed Gate Opening. The dis- charge of a turbine with fixed gate opening, but at various speeds, is not always the same but varies within certain limits and as the speed varies. In some cases the discharge of a wheel increases as the speed increases. (See discharge of Tremont turbine, Fig. 215.) Sometimes the discharge decreases as the speed increases (see dis- charge of Victor and McCormick turbines, Fig. 215), and some- times the discharge increases with the speed to a certain point and then decreases with a further increase in the speed (see discharge of Samson ; and New American wheels, Fig. 215.) In reaction turbines the discharge takes place first through the guide from which it passes into and through the buckets of the wheel. The relations of these two sets of orifices change as the speed of the wheel changes and affects the total discharge. If dur- ing such changes of speed, the ratio, $- , remains constant, it is found by experiment that the conditions remain similar to thost; of any short tube or orifice. The discharge of a turbine may there- fore be determined by the formula : (30) q = Cat/2jh And it may be stated : In a given turbine with fixed gate opening, the discharge will be proportional to the square root of the head, i. e., the discharge divided by Vh is constant. The values of C and a vary with the opening of the gate or gates, but for any one position are essentially constant. Let the discharge of a wheel under fixed gate conditions and with a given head, h a , be given by the formula: C3i; q, = Discharge of a Turbine at Fixed Gate Opening. 333 The discharge of any other head will be proportional to i/h" and therefore T= hence (32) (33) (34) q = Therefore, it may be stated : In a given turbine with fixed gate opening the discharge at any head h will be equal to the discharge at one foot head multiplied by -\/h. That this law is essentially correct may be demonstrated by ex- periment. Fig. 216 shows the results from the series of tests on the McCormick turbine, before mentioned, at full gate. Three sets no 100 90 80 70 60 50 X i A- 48 ff VICTOR CYLINDRICAL GATE B- 99j"TURBINE LOWELL MASS C- 44"lMPROVED NEW AMERICAN D- 45 "SAMSON E- 5l"MCORMICK W-S-MORGAN 25 30 35 40 45 50 DISCHARGE IN CUBIC FEET PER SECOND UNDER ONE FOOT HEAD Fig. 215. Full Gate is the same lie close to the average line, and that the departures from this line are prob- ably due to experimental errors. The results are sufficiently close, however, to demonstrate that the discharge under practical condi- tions essentially follows the law above expressed. // la. 5 4 d < u 012345678 DISCHARGE IN CUBIC FEET PER SECOND Fig. 216. The Relations of Head to Discharge of a 12 "SmithrMcCormick Turbine. Discharge or a Turbine at Fixed Gate Opening. 335 161. Power of a Turbine. The power which may be generated by any wheel depends on the head a/ailable, the quantity of water which may be discharged through the wheel under the given head, the relative speed at which it may be run, and the efficiency of operation. Hence (35) q w h e _ q h e 550 8.8 Combining equations (30) and (35) there results (36 550 8.8 From equation (36) it is apparent that if C, e and a are constant for any given turbine and fixed gate opening, and if the value of remains constant, the power of the turbine will be in direct propor- tion to h^. consequently 1 0.9 P0.7 o 0.6 i 0.4 k. O gO.3 0.2 O.I 0.0 07.10 FOOT HEAD O6.80 6.40 ttS.70 AS. 20 4.70 . U4.25 k \ ^H- N 1 A xj t ^ V u \ & f o jt* \o. V w | 5 \ ^ u ^ jdi - Ni i o fe ^ "i L ^ .f \ I i A tit s A < l<> ^ u 5 o ; u ^ J 1 . VI c u u & 1 - k U >. ! J i <. ) i a ^ T - t I J3 " i E o / I h i. ". ft g h- 8 t- I uu -i JL Zi .5 1.0 1.5 2.0 _ 2. 5 2.9 DISCHARGE IN t CUMC FEET PEK.tCCONO UNDER ONE FOOT HEAD Fig, 217. Relations of Velocity to Discharge for a 12" "Smith-McCormick' Turbine at Various Gate Openings. 336 Hydraulics of the Turbine. U-.l Equation (37) may be reduced to (38) P = From which can be determined the power of a wheel at any given head, provided its power at any other head is known. In equation (38) if h =i, there results (39) P = P 1 h 2 ' From which it may be stated: In a given turbine with a fixed gate opening, the power that can be developed at any head will be equal- to the power at one foot head multiplied by h*. This law may also be demonstrated experimentally as will be seen by reference to Fig. 218, in which is shown the theoretical curve representing the relation between head and horse power of the 12" McCormick turbine before mentioned. The turbine on which these experiments were made was small and the heads were & 1.0 2.0 3.0 4.0 ACTUAL HOPSE POWER OF WHEEL Fig. 218. Relations of a Power to Head in a 12 "Smith-McCormick Turbine.' The Relation of Discharge to Diameter of a Turbine. 337 limited so that there is some variation from the theoretical curves but the fact expressed by the general law is quite clearly shown. 162. The Relation of Discharge to the Diameter of a Turbine. In any homogeneous system of water wheels, the diameter, height and corresponding openings and passages are proportional and it follows that in such similar wheels similar areas are proportional to each other and to the squares of any lineal dimension. In such wheels, therefore, the area a of the gate openings is proportional to the square of the diameter of the wheel, and the equation may there- fore be written : (40) Cal/ 2g~ = K D 8 In this equation K is a constant to be determined by experiment. Combining equations (40) and (30) there results (41) q = KDVF from which can be obtained, by transposition (42) Equation (41) is not only theoretically but is also practically cor- rect, as is shown by the data in Table XXVII, which is also graphi- cally represented in Fig. 219. These data are taken from a paper TABLE XXVII. Discharge of thirteen water wheels of the same manufacture but of different di- ameters, as determined by actual tests, compared with value computed by the formula: q = K D 2 t/h in which h = 13, K = .0172 DISCHARGE. No. Diam- eter in inches. Reduced from actual tests, Cu. ft. per Sec. Computed ( Mean Curve) Cu. ft. per Sec. Variation from Com- puted Dis- charge Cu. ft. per Sec. Per cent. Variation from Com- puted Dis- charge. 1 . 9 5.17 5.02 + 0.15 + 2.99 2... 12 8.79 8.92 0.13 1.46 3 15 13.85 13.93 0.08 0.57 4 18 18.85 20.07 1.22 6.08 5 12 29.07 27.32 + 1.75 + 6.41 6 24 35.31 35.68 0.37 1.04 7 . 27 47.81 45.16 + 2.65 + 5.87 8. 30 54.15 55.75 1.60 2.87 9. , 36 77.33 80.28 2.95 -3.67 10 39 93.51 94.22 0.71 -0.75 11 42 107.73 109.27 1.54 1.41 12. 45 128.53 125.44 + 3-09 + 3.10 13. - 51 161.07 161 . 12 0.05 0.03 338 Hydraulics of the Turbine. by A. W. Hunking, entitled "Notes on Water Power Equipment," in vol. 13, No. 4, of Jour. Asso. Eng. Soc., April, 1894. In this table are given the discharges of thirteen water wheels of various diam- eters, the discharges of which were determined from actual tests. DISCHARGE IN CUBIC FEET PER SECOND c r 3 C 3 i 3- i 5 S D ( 3 t I \ o . 3 ( & 1 3 C s i s i 3 R D C 2 - 1 n 3 " \ * a ^ u Vx 1 5SJ ^ ^~ 2 a i. to ^j ^> 5" en ** Fig. 219. Relations of Discharge to Diameter in Reaction Turbine of the same manufacture. These results have been reduced to the common basis of the dis- charge at 13 foot head. The computed discharges at 13 foot head on the basis of equation (41) are also given, as well as the percent- age of variations of the actual from the theoretical discharges. The wheels were of the same make with inward and downward dis- charge. The departures or variations from the mean values, as de- termined by calculation, are probably due both to imperfections in the construction of the wheel and to errors in making the tests. They may be seen, however, to practically conform to the theoreti- cal deductions. The values of the coefficient K, as calculated from the tables contained in the catalogues of various manufacturers of American wheels, are given in Table XXVIII. 163. The Relation of Power to the Diameter of a Turbine. By substituting the value of q from equation (41) in equation (35) there results (43) qhe " 8.8 The Relation of Power to the Diameter of a Turbine. 339 TABLE XXVIII. Showing Relation of Diameter and Discharge of Various American Turbines- working under Catalogue Conditions. K= WL Manufacturer. Name of Wheel. K Min. Max. Reaction Wheels. T. C. Alcott & Son , Alexander, Bradley & Dunn- ing American Steel Dredge Wks.. Camden Water Wheel Worki- Chase Turbine Mfg. Co Christiana Machine Co Craig, Ridgway & Son Co Craig, 'Ridgway & Son Co Dayton Globe Iron Works Co. J. L. &S. B. Dix Dubuque Turbine & Rollei Mill Co Dubuque Turbine & Roller Mill Co. . . Holyoke Machine Co Humphrey Machine Co Rodney Hunt Machine Co.. E. D. Jones & Sons Co . James Leffel & Co Munson Bros. Co Norrish, Burn ham & Co. Platt Iron Works Co Alcott' s Standard High Duty Alcott' s Special High Duty. *Syracuse Turbine * Little Giant United States Turbine *Chase-Jonval Turbine (reg- ular) *Chase-Jonval Turbine (special) Balanced Gate Turbine Double Perfection Standard *American Turbine New American (high head type) Improved New American.. Special New American Improved Jonval Turbine. . Flenniken Turbine. McCormick's Holyoke Tur bine Hercules Turbine flXL Turbine fXLCR Turbine McCormick's Holyoke Tur- bine *Hunt-McCormick Turbine. New Pattern Hunt Turbine. Standard Wheel, 1887 pat- tern Crocker Wheel Samson Improved Samson Standard Special J Phoenix "Little Giant" . . . Victor Register Gate ....'. Victor Standard Cylinder Gate .00654 .0157 .00538 .0205 .0214 .01086 .00902 .0116 .00586 .00543 .00509 .0233 .0175 .00454 .00652 .0184 .0162 .00351 .00645 .01877 .01913 .01297 .0123 .0175 .0170 .022 .00612 .00937 .00924 .00917 .0167 .0222 -00860 .0168 .00622 .0340 .0229 .00913, .01346 .00952: .0142 .00659- .00801 .00644- .0263 .0205 .00546- .0088 .0191 .0175 .00536 .00953 .01929 .02867 .01543 .0141 .0179 .0171 .022 .00640* .00965 .0172 .00955- .0186 .0227 340 Hydraulics of the Turbine. TABLE XXVIII. Continued. Showing Relation of Diameter and Discharge of Various American Turbines working under Catalogue Conditions. - q K Manufacturer. Name of Wheel. Min. Max. Reaction Wieels.CoTi. Poole Engineering and Ma- chine Co Poole-Leffel .... .00625 .00827 T. H Risdon & Co *Risdon Standard Turbine . . .00501 .00698 -'S. Morgan Smith Co *Risdon Type T. C. Turbine *Risdon Type D. C. Turbine *Smith-McCormick .00753 .0100 0187 .00948 .0132 0238 Smith . . ... 0247 .0256 Trump Mfg Co . . Standard Trump 0210 0263 Wellman, Seaver, Morgan Co. McCormick .0185 .0199 Impulse Wheels. DeRemer Water Wheel Co. . Abner Doble Co *DeRemer Water Wheel. . *Tangential Wheel .000135 000075 .000173 000119 Pelton Water Wheel Co. . ^Tangential Wheel. 00010 000135 Platt Iron Works Co Victor High Pressure ... . 0170 0''*47 Risdon Iron Works *Tangential Wheel 000134 000173 *Wide variation in constants due to the design being special for various sized wheels (series not exactly homogeneous). tTables in catalogue based on full theoretical power of the water. Wheels are said to give from 75 per cent to 90 per cent efficiency, depending on location. $Munson Bros. Co. make several types of "Litte Giant" turbines causing above wide variation in -constants. - is constant for a given wheel, as long as is constant, this expression may be represented by a constant K 2 which may 1^e derived independently for each make of wheel, or may be deter- mined from the equation (44) K - Ke K ~ With this substitution (43) becomes (45) p rr K 2 D 2 h* That is to say: With wheels of homogeneous design, the power of any wheel under the given head is in direct proportion to the square -of its diameter. This law is both theoretically and practically cor- rect, as demonstrated by Table XXIX, and Fig. 220, taken from the paper by Mr. Hunking to which reference has previously been Relation of Speed to Discharge of Turbine. 34* TABLE XXIX. Horse Power of thirteen water wheels of the same manufacture but of different diameters, as determined by actual tests, compared with values determined by the formula: P=K 2 D 2 h 1 K 2 =.00158 HORSE POWER h = 13 No. Diame- ter in inches. From Tests. Computed. Variation from Com- puted H. P. in H. P. Variation from Com- puted H. P. Percent. 1. 9 6 10 6 00 + 10 + 1.67 2 12 1041 1067 026 2.44 3 15 16 49 1667 018 1.08- 4 18 22 89 24 00 1.11 4.62- 5 21 33 71 32.67 + 1.04 + 3.18 6 24 41.53 42.67 1.14 2.67 7 27 56 67 54 07 + 2 60 + 4.81 8 30 63 69 66 68 299 -4.48 9 36 97 45 9600 + 1.45 + 1.50 10 39 10998 112 68 2.70 2.40 11 42 13309 13069 + 2.40 + 1.84 12 45 15382 150.02 + 3.80 + 2.53 13 51 196 28 192.69 + 3.59 + 1.86 Fig. 220. Relation of Power to Diameter in Reaction Turbines of the same manufacture. 34 2 Hydraulics of the Turbine. made. This table and figure illustrate the relation between the the- oretical power, as determined by equation (45), and the actual horse power of thirteen wheels of the same manufacture but different diameters, as determined by actual tests. The values of the constant K 2 for the most efficient relation of power to diameter in various American turbines, as calculated from the tables contained in the catalogues of various American manu- facturers of turbines, are given in Table XXX. The values of K 2 and other turbine constants will be found to vary widely in the various types of turbines, not only of different manufacturers but of the same manufacturer. The interpretation of this fact is not that one turbine is, in the abstract and according to the relative value of the constants, more valuable than another, but that each turbine is best fitted for a particular range of conditions for which it was presumably designed. TABLE XXX. Showing Halation of Power and Diameter of Various American Turbines Work ing under Catalogue Conditions. K = "~ Manufacturer. Name of Wheel. K. Min. Max. Reaction Wheels. T. C. Alcott & Son, Alexander, Bradley & Dunn- ing American Steel Dredge Wks. Camden Water Wheel Works Chase Turbine Mfg. Co Christiana Machine Co Craig, Ridgway & Son Co Craig, Ridgway & Son Co Dayton Globe Iron Works Co. J. L. &S. B. Dix Dubuque Turbine & Roller Mill Co Dubuque Turbine & Roller Mill Co.. Alcott' s Standard High Duty Alcott's Special High Duty. Syracuse Turbine Little Giant United States Turbine. . . . *Chase-Jonval Turbine (reg- ular) *Chase-Jonval Turbine (special) Balanced Gate Turbine Double Perfection Standard * American Turbine *New American (high head type) Improved New American. . . Special New American Improved Jonval Turbine. . Flenniken Turbine McCormick's Hoi yoke Tur- bine.. .000589 .00141 .000483 .00190 .00190 .000590 .000932 .000800 .00113 .000538 .000434 .000422 .00212 .00158 .000447 .000596 .00167 .000999 .00155 .000565 .00332 .00207 .000780 .001150 .000854 .00120 .000629 .000726 .000588 .00244 .00187 .000532 .000802 .00173 The Relation of Power to the Diameter of a Turbine. 343 TABLE XXX. Continued. Showing Relation of Power and Diameter of Various American Turbines Work- ing under Catalogue Conditions. * ^2 Manufacturer. JSame of Wheel. Min. Max. Reaction Wheel. Con. Holyoke Machine Co Hercules Turbine 00147 001 ^Q Humphrey Machine Co |IXL Turbine 0003Q7 OOfkrtOft fXLCR Turbine 000730 001 31 Rodney Hunt Machine Co. . . McCormick Holyoke Tur- bine 00169 00173 *Hunt McCormick Turbine. New Pattern Hunt Turbine Standard Wheel, 1887 Pat- tern . . : .00173 .00120 00101 .00260 .00146 00122 E. D. Jones & Sons Co Crocker Wheel 00159 00163 James Leffel & Co Samson . 00158 00159 Improved Samson 00201 00202 Standard 00056 00058 Special 000897 000920 JPhoenix "Little Giant" 000842 001 560 000852 000885 Platt Iron Works Co Victor Re^i^ter Gate 00158 00179 Victor Standard Cylinder Gate 00205 00205 Poole Engineering and Ma- chine Co. Poole-Leffel 000625 000650 T. H. Risdon & Co *Risdon Standard Turbine. 000485 000675 S. Morgan Smith Co. *Risdon Type T. C. Turbine *Risdon Type D. C. Turbine Sinith-McCormick .000672 .000781 00169 .000913 .00135 00217 Smith 00232 00236 The Trump Mfg. Co Standard Trump 00191 00241 Wellman, Seaver, Morgan Co. .00168 .00171 Impulse Wheels. DeRemer Water Wheel Co.. Abner Doble Co . . . *DeRemer Water Wheel . . . *Tan w ential Wheel .000124 0000055 .000186 0000107 Pelton Water Wheel Co Platt Iron Works Co ^Tangential Wheel .0000093 00154 .0000130 00^23 Risdon Iron Works Co *Tangential Wheel 0000128 0000165 *Wide variation in constants due to the design being special for various sized wheels (series not exactly homogeneous). tTables based on full theoretical power of the water. Wheels are said to give from 75 per cent to 90 per cent efficiency, depending on location. fcMunson Bros. Co. make several types of "Little Giant" turbines, causing above wide variation in constants. 344 Hydraulics of the Turbine. C"J CM c LJ H O 01 \ CD V VN X ^^ \ CO CNJ ^ "*-.. \ \\ CD 10 in a m CM S3HONI HI 133HM JO Relation of Speed to Discharge of Turbine. 345 As the power of a wheel varies directly with the value of K 2 , this constant is a direct measure of comparative power and indicates the relative power that can be developed by various types of wheels of the diameter and under a given head. The range of values for K 2 as found in American practice is shown graphically in Fig. 221 where the power of turbines of various diameter and types under one foot head is given. The power of a wheel varies under differ- ent heads as h^, and therefore the power at any head can be de- termined directly by multiplying the readings of the graphical table by h*. For example, from Fig. 221 it will be seen that various types of 40" American wheels, under one foot head, will give from .75 to 4 H. P. and at 16 foot head they will therefore develop 64 times the H. P. at one foot head or from 48 to 256 H. P. within which range a choice must be made. 164. Relations of Speed to Discharge of Turbines. As the speed of all wheels of the same series must be proportional to Vh> the equation may be written : (46) v' = K.T/F from which and from equations (19) and (21) (47) K 3 - _ - r ^ 12 x From equations (42) and (47) may be derived (48) n = H As the first term of the last expression is constant, there may be written : (49) K 4 = 12X60 K 3 K from which equation (48) may be re-written. K^W (50) n = - A 'For a head of one foot, h=i, equation (50) becomes (51) n -r-L Equation (50) may be rearranged to read: (52) K 4 = -lL|/^= = n 21 346 Hydraulics of the Turbine. TABLE XXXI. Showing Relation of Speed and Discharge of Various American Turbines Working under Catalogue Conditions. I ^4 Manufacturer. Name of Wheel. Min. Max. Reaction Wheels. T. C. Alcott & Son Alexander, Bradley & Dunn- ing. . Alcott's Standard High Duty Alcott' s Special High Duty. 98.8 154.5 114.7 159.2 American Steel Dredge Wrks. ^Syracuse Turbine *Littie Giant 89.8 172 108 . 2 9 43 8 Camden Water Wheel Works Chase Turbine Mfg. Co United .States Turbine 205.2 239.2 * Chase Jon val Turbine (reg- ular) . 140 174 *Chase-Jonval Turbine (special) 9 01 255 Christiana Machine Co Balanced Gate Turbine . . 115 8 126 2 Craig, Ridgway & Son Co Double Perfection 90 5 97 2 Craig, Ridgway & Son Co Standard 94 101 2 Dayton Globe Iron Works Co. ^American Turbine. . . . . 83.0- 109 fNevv American (high head type) . . 75 4 85 9 J. L. & S. B. Dix. . Improved New American. . . Special New American 265.0 170.5 ft_t A 268.0 190.0 i on n Dubuque Turbine & Roller Mill Co mn 1 C> A Dubuque Turbine & Roller Mill Co IVTnr^rkrmipb-'fi T^nlvrifca Tii r bine IP)'? 176 Holvoke Machine Co 148 154 Humphrey Macnine Co 1IXL Turbine 71 3 88 3 JXLCR Turbine. . 90 5 116 9 Rodney Hunt Machine Co. . . McCormick's Holvoke Tur- bine. 159 5 176.0 *Hunt McCormick Turbine. *New Pattern Hunt Turbine Standard Wheel, 1J87 Tat- tern 161.4 132.4 19(3 o 207.5 174.8 145 E. D. Jones & Sons Co Crocker Wheel 161 169 8 James Leffel & Co 9n i 7 9/VJ A Improved Sampson 240 241.5 Standard ]03 7 107 Special 134 7 139.8 Munson Bros. & Co Norrish, Burnham & Co. ... tJPhoenix -'Little Giant" 102.0 1 15 . 9 132.1 120.0 Platt Iron Works Co V T? ' f C" f 1 Y3 Wo Victor Standard Cylindei Gate . . 205.0 2:2.0 Relation of Speed to Power of Turbine. 347 TABLE XXXI. Continued Showing Relation of Speed and Discharge of Various American Turbines Working under Catalogue Conditions, L "-4 Manufacturer. JName of Wheel. Mm. Max. Reaction Wheels. Con. Poole Engineering and Ma- chine Co . . Poole-Leffel 1104 me T H Risdon & Co *Risdon Standard Turbine QQ 4 mo S. Morgan Smith Co *Risdon Type T. C. Turbine *Risdon Type D. C. Turbine Smith-McCormick 100.7 108.0 163 7 137.3 158.0 185 Smith 265 266 The Trump Mfg. Co Standard Trump 194 in o Well man, Seaver, Morgan Co. McCormick 168.5 179 Impulse Wheels. DeRemer Water Wheel Co. . DeRemer Water Wheel. . . . 11 10 13 20 Abner Doble Co ^Tangential Wheel 6 61 9 20 Pelton Water Wheel Co Tangential Wheel 9 21 10 92 Platt Iron Works Co Victor High Pressure 37 8 42 2 Risdon Iron Works Tangential Wheel 10 67 12 10 *Wide variation in constants due to the design being special for various sized wheels (series not exactly homogeneous). tUatalogue recommends a maximum and minimum speed. Constants given are for the average speed. ^Tables in catalogue based on full theoretical power of the water. Wheels are said to give from 75 per cent to 90 per cent efficiency, depending on location. $$Munson Bros. Co. make several types of "Little Giant" turbines causing above wide variation in constants. It is evident that K 4 is constant for all turbines with constant K and K 3 ; also, for all turbines where q, the discharge, is equal at the same speed, n, and under the same head, h, K 4 must be constant for different heads since n and q are proportional to V n - The values of the constant K 4 as calculated from the tables contained in the catalogues of various American manufacturers are given in Table XXXI. i64a. Relation of Speed to Power of Turbines. From equation (35) may be derived 8.8 P (53) eh 348 Hydraulics of the Turbine. From equation (48) may be derived (*) K, !/K = 12 X u X Vh * 7? Combining equations (53) and (54) (55) 12 X 60l/e By transposing K.T/K 12X60 nr = (56) As the first member of the equation is constant for any given wh el, there may be written (57) and hence (58) K < n"^ From equation (58) it will be noted that the value of K 5 under a given head is in direct proportion to the square of the velocity of the wheel and to its power. K 5 is termed the "specific speed" of the wheel. A high value of K 5 is an indication of high speed, and a low value, of low speed. The values of the constant K 5 as calculated from the tables con- tained in the catalogues of various manufacturers of American wheels are given in Table XXXII. Fig. 2-22 shows graphically the relation of power to speed under one foot head, as expressed by the constant K 5 within the range of practice of American turbine builders. The use of the diagram may be illustrated as follows : At 35 revolutions per minute various types of American wheels will develop from I to 5.8 horse power. For the best efficiency, that is for a constant value of <, the number of revolutions ot a wheel will vary as i/h, and the power will vary as h*. Thus for a 1 6 foot head these wheels will run four times as fast as for a one foot head or at 140 R. P. M., and will develop 64 times the power that will be developed at a one foot head, or from 64 to 371 H. P., between which limits the wheel must be chosen. Suppose a wheel is desired to develop 500 H. P. at 150 R. P. M. under 25 foot head. These conditions correspond to 4 H. P. at 30 Relation of Speed to Power of Turbine. 349 3 4 5 6~~ 8 8 10 II HORSE POWER UMDEfl ONE FOOT HEAD. Fig. 222. Speed Curves of Various Standard American Wheels. 350 Hydraulics of the Turbine. TABLE XXXII. Showing Relation of Speed and Power of Various American Turbines working under Catalogue Conditions. 1 ^5 Manufacturer. Name of Wheel. Min. Max. Reaction Wheels. T. C. Alcott & Son Alcott' s Standard High Duty 941 1216 Alexander, Bradley & Dunn- iner. . Alcott's Special High Duty. 2152 723 2300 830 American Steel Dredge \Vrks ^Little Giant 2880 5420 Camden Water Wheel Works Chase Turbine Mfg Co United States Turbine *Chase-Jonval Turbine ( reg- 3780 4570 ular ^ 1680 2580 *Chase-Jonval Turbine (special ) 3460 5530 Christiana Machine Co Balanced Gate Turbine 1220 1475 Craig, Ridgway & Son Co Double Perfection . 840 895 Craig, Ridgwav & Son Co Standard . ... 776 975 Dayton Globe Iron Works Co *American Turbine. . . 623 1140 fNew American (high head type) 520 " 674 J. L. &S. B. Dix . Improved New American . . Special New American Improved Jonval Turbine 6100 2490 965 . 6477 3293 1363 Dubuque Turbine & Roller Mill Co. . Flenniken Turbine 1350 1880 Dubuque Turbine & Rollei Mill Co McCormick's Holyoke Tur- bine . . 2380 2810 Holyoke Machine Co Hercules Turbine 2030 2155 Humphrey Machine Co . JIXL Turbine. 572 889 JXLCR Turbine 1052 1545 Rodney Hunt Machine Co. . McCormick's Holyoke Tur- bine 2310 2810 *Hunt McCormick Turbine. *New Pattern Hunt Turbine *>'tandaid Wheel, 1887 Pat- tern 2360 1624 1665 3910 2900 2160 E. D. Jones & Sons Co 2360 2680 James Leffel & Co Samson 3775 3833 Improved Samson Standard 5013 948 5400 1063 Special 1730 1858 Munson Bros. & Co JJPhoenix "Little Giant" 843 1600 Norrish, Burnharn & Co. . . 1130 1345 Platt Iron Works Co Victor Register Gate 2254 2712 Victor Standard Cylinder Gate 3733 4145 Victor High Pressure 129 10 169.50 Relation of Speed to Power of Turbine. TABLE XXXII. Continued. Showing Relation of Speed oni Power of Various American Turbines working under Catalogue Conditions. ] *. Manufacturer. Name of Wheel. Min. Max. Reaction Wheels. Con. TJ oole Engineering and Ma- chine Co Poole-Leffel 1170 1239 T H Risdon & Co *Risdon Standard Turbine 2351 3680 8 Morgan Smith Co *Ri.-don Type T. C. Turbine * Risdon Tvpe D. C. Turb.ne Smith McCormick 3520 46UO 2640 5070 7370 3013 Smith 6165 6640 The Trump Mfg Co Standard Trump ;# 07 4250 Wellman, Seaver, Morgan Co. 2380 2862 Impulse Wheels. DeRemer Water Wheel Co. . Abnei' Doble Co *DeRemer Water Wheel. . . . ^Tangential Wheel 12.34 4.00 18.01 7 62 Pelton Water Wheel Co ^Tangential Wheel 7.84 11.42 Risdon Iron Works *Tangential Wheel 8.24 11.22 *Wide variation in constants due to the design being special for various sized wheels (series not exactly homogeneous). tCatalogue recommends a maximum and minimum speed. Constants given are for the average speed. ^Tables in catalogue based on full theoretical power of the water. Wheels are said to give from 75 per cent to 90 per cent efficiency, depending on location. ft.Munsoti Bros. Co. make several types of "Little Giant" turbines causing above wide variation in constants. R. P. M. under one foot head, and would require a wheel having a constant K 5 = 36oo. 165. Value of Turbine Constants. The values of the constants discussed in this chapter have been determined fro-m the cata- logues of the manufacturers of American turbines and are the values which may be used for determining the manufacturer's standard re- lations of the wheel for particular and fixed conditions where < is constant, as, for example, the development of a certain power under a fixed head and with a given speed. When the head varies at dif- ferent times, the value of also varies and the value of the other co- efficients of the turbine, A, K, K 2 , K 4 , and K 5 , will also vary. In order to discuss such conditions the laws of the variations of these constants, for any series of wheels, must be known. These laws 352 Hydraulics of the Turbine. can be ascertained from a complete test of any one wheel of the series and the laws so determined will hold for the entire series if the series is actually constructed on homogeneous lines. Owing to imperfections in the processes of manufacture, there is actually more or less variation between different wheels of a series. It is therefore desirable, when the approximate size of the wheel needed is known, to secure a test of a wheel of that particular size and hand. Of the constants discussed, < and A express the standard rela- tion recommended by the manufacturer between diameter and speed in the series of wheels he offers. See equations (23) n (24) ii The coefficient K is the constant of discharge and shows the standard relation for various types of turbines between the quantity of water discharged and the diameter of the wheel. See equations (41) q = (42) D = K 2 is the constant of power and shows the standard relation be- tween the diameter of the wheel and the power. See equation (45) P = K 2 D 2 h* K 4 is the constant of discharge and shows the standard relation between speed and discharge. See equation (30) n - I q K 5 is the constant expressing the standard relation of power and speed for a particular series of wheels. See equation. (58) P = K 5 1^1 The catalogue tables of turbines from which the standard values of the constants in the preceding tables have been calculated are presumably based on the actual tests of certain wheels of the series. The actual results of a test of any individual wheel of the series is likely to depart to an extent from the tabular value. Differences Literature. 353 will often be found between wheels of different diameters, between wheels of the same diameter but of opposite hand, and even between wheels of the same size and hand which are supposed to be con- structed on identical lines. These differences in results are due to carelessness in construc- tion, or to unusually good construction in the effort to secure special results, where the conditions warrant special effort. Any change in the design of a wheel for the purpose of reducing or increasing the discharge, and hence reducing or increasing its power, will give rise to differences in these coefficients which must be taken into account in any calculations made thereon. A careful study of these coefficients as determined from the actual tests of any wheel, to- gether with a study of the design of the wheel itself, will form the basis of a complete and systematic knowledge of water wheel de- sign. LITERATURE. 1. Hermann, Gustav. Die graphische Theorie der Turbinen and Kreisel- pumpen. Verhaldung des Vereines zur Beforderung des Gewerb- feisses in Preussen. 1884, pp. 307-379; 521-580. 2. Arnot, C. Graphic Turbine Tables. Showing relation of head and dis- charge for various sizes of turbines. Zeitschr. d ver Deutsch. Ing. p. 980. 1890. 3. Ludewig, H. Allgemeine Theorie der Turbinen. Berlin. L. Simon, 1890. 4. Richards, John. Turbines Compared with Water Wheels. Eng. News. Vol. 1, p. 530. 1892. 5. Hunking, A. W. Notes on Water Power Equipment. Jour. Asso. Eng. Soc. Vol. 13, p. 197. 1894. 6. Moissner, G. Die Hydraulik und die hydraulischen Motoren. Jena. 1895. 7. Bodmer, G. R. Hydraulic Motors, Turbines and Pressure Engines. New York. Van Nostrand. 1895. 8. Elaine, R. G. Hydraulic Machinery. New York. Spon & Chamberlain. 1897. 9. Heines, Charles N. Centrifugal Pumps, Turbines and Water Motors. Manchester, Eng., Technical Pub. Co. 1898. 10. Fox, William. Graphics of Water Wheels. Stevens Indicator. Vol. 16, p. 30. 1899. 11. Brauer, Ernst A. Grundriss der Turbinen Theorie. Leipsig, S. Hirzel. 1899. 12. Zeuner, Gustav. Vorlesungen iiber Theorie der Turbinen mit vorbereiten- den untersuchungen aus der technischen hydraulik. Leipsig. Arthur Felix. 1899. 13. Rateau, A. Traite des turo-machines. Paris. Ch. Dunod. 1900. 354 Hydraulics of the Turbine. 14. Henrotte, J. Turbines-hydrauliques, pornpes et ventilateurs, centrifuges,. princeps theoriques, dispositions pratiques et calcul des dimen- sions. Liege, Imprimerie Liegeoise. 1900. 15. Marks, G. Croiden. Hydraulic Power and Engineering. New York. Van Nostrand. 1900. 16. Wood, DeVolson. Turbines, Theoretical and Practical. New York. Wiley & Sons. 1901. 17. Miiller, Wilhelm. Die Francis-Turbinen. Hanover, Janecke. 1901. 18. Kessler, Jos. Berechnung and Konstruktion der Turbinen. Leipsig. J. M. Gebhardt. 1902. 19. Camerer, R. Diagrams of Theory of Turbines. Graphic Representa- tion of Equation with Proof and Application. Dingler's Poly- tech. Jour. p. 693. 1902. 20. Thurso, John Wolf. Modern Turbine Practice and the Development of Water Power. Eng. News. Dec. 4, 1902. 21. Rea, Alex. Turbines and the Effective Utilization of Water-Power. Mech. Engr. March 22, 1902. 22. Osterlin, Hermann. Untersuchungen iiber den Energieverlust des Was- sers in Turbinenkanalen. Berlin. Julius Springer. 1903. 23. Thurso, John Wolf. Effect of Draft Tube. Eng. News. Vol. 1, p. 29. 1903. 24. de Graffigny, Henri. Les Turbo-moteurs et les Machines Rotatives. Paris E. Bernard. 1904. 25. Dickl, Ignaz. Die Berechnung der achsialen Actionsturbinen auf zeich- nerischem Wege. Vienna. Spielhagen & Schurich. 1904. 26. Danckwerts. Die Grundlagen der Turbinenberechung fur Pratiker and Studierende des Bauingenieurfaches. Wiesbaden. C. W. Krei- del. 1904. 27. Thurso, John Wolf. Modern Turbine Practice. New York. Van Nos- trand. 1905. 28. Church, Irving P. Hydraulic Motors. New York. Wiley & Sons. 1905. 29. Basshnus, N. Klassifikation von Turbinen. Zeitschritt der Verenier Deutschjer Ingenie for 1905, p. 922. 30. Graf, Otto. Theorie, Berechnung und Konstruktion der Turbinen und deren Regulatoren; ein Lehrbuch fur schule und praxis. Munich. August Lachner. 1904 and 1906. 31. Wagenbach, Wilhelm. Neuere Turbinenanlagen. Berlin. 1905. 32. Gelpke, Viktor. Turbinen und Turbinenanlagen. Berlin. Julius; Springer. 1906. 33. Pfarr, A. Die Turbinen fur Wasserkraftbetrieb. Berlin. Julius Springer. 1907. 34. Tangential Water Wheel Buckets. The Engr. May 1, 1904. 35. Kingsford, R. T. A Complete Theory of Impulse Water Wheels and Its- Application to Their Design. Eng. News. July 21, 1898. CHAPTER XV. TURBINE TESTING. 166. The Importance of Testing Machinery. A correct theory based on mathematical analysis forms a valuable foundation for machine design. In the construction of any machine, however, theoretical lines can seldom be followed in all details, and, even if this were possible, the truth of the theory must be demonstrated by actual trial for there are usually many factors involved which cannot be theoretically considered and yet affect practical results. In any machine much depends upon the character of the workman- ship, on the class of material used, and on all the details of manu- facture, installation and operation as well as on design. All of these matters can hardly be included in a theoretical consideration of the subject, and it therefore becomes necessary to determine the actual results attained by a trial of the machinery under work- ing conditions. General observations or even a detailed examination of any machine and its operation can rarely be made sufficiently com- plete to give any accurate knowledge of the quantity or quality of the results which it can and does accomplish. It is only when the actual effect of slight changes in design can be accurately deter- mined by careful experiment that a machine can be improved and practical or approximate perfection attained. The ease with which such determination can be made is usually a criterion of the rapidity with which the improvements in the de- sign and construction of a particular machine take place. Where such determinations are readily made, rapid advancement results, but where they are costly and require a considerable expenditure of time or money, the resulting delays and expenses usually so limit such determinations that good results are attained but slowly. The invention of the steam engine indicator and the Piony brake placed in the hands of the engineer instruments by means of which he could readily determine the action of steam within the engine cylinder and the actual power developed therefrom. The knowl- edge thus gained has been one of the most potent factors in the rapid advancement of steam engineering. 35^ Turbine Testing. The physical results of radical modifications or changes in de- sign are sometimes quite different from those anticipated by the designer. Improvement in any machine means a departure from the tried field of experience and the adoption of new and untried devices or arrangements. Frequently a line of reasoning, while apparently rational, is found to be in error on account of unfore- seen conditions or contingencies and the results anticipated are not borne out in the actual practical results. Unless, therefore, such results are carefully and accurately determined by exact methods the actual value of changes in design may never be known or appreciated and designs may be adopted which, while apparently giving a more desirable form of construction, actually accomplish less than the form from w r hich the design has departed. 167. The Testing of Water Wheels. The value of the testing of water wheels was recognized by Smeaton who- tested various models of water wheels about the middle of the Eighteenth Century. Methods of turbine testing were also devised with the first develop- ment of the turbine, which have been potent factors in the improve- ment of the turbine. While the methods of testing have been greatly improved since that time, they have not as yet reached a state that can be considered reasonably satisfactory, and turbine testing has not become so general as to assure the high grade of design and workmanship in their manufacture as in other machin- ery where testing is more easily and regularly practiced. The principal causes of the backward condition of turbine test- ing lie in the difficulties and expense of making an accurate test in place, and the expense and unsatisfactory results of testing tur- bines in a testing flume where the head and capacity are so limited as to confine satisfactory tests to heads of 17 feet or less and to wheels of a capacity of about 250 cubic feet per second, or less if the full head of 17 feet is to be maintained. There is an urgent demand for accurate and economical methods for the measurement of the water used and of the power developed by water wheels in place, that can be readily and quickly applied without the almost prohibitive expense of the construction of expensive weirs and other apparatus now used for such purposes. Apparently slight variations in turbine construction produce radical changes in prac- tical results. The high results achieved under test by a well- designed and well-constructed wheel is no assurance that wheels of the same make and of the same design, even though they be ~>f the same size and even from the same pattern, will give similar Smeaton's Experiments. 357 results. This is especially true when the contingencies of compe- tition and the knowledge that a test of the wheel is impossible, or at least highly improbable, offer a premium on careless construc- tion and cheap work. A brief examination of the work already done in this line, and of the methods now in vogue, may afford suggestions for future improvements and development in this important w r ork. 1 68. Smeaton's Experiments. John Smeaton, the most experi- enced and eminent engineer of his time, made a series of experi- ments on the power and effect of water used by means of various forms of water wheels for mill purposes. Accounts of these experi- ments were published in the Transactions of The Royal Society of England in 1759. Until that time the relative values of the different types of water wheels of that day were very poorly understood and ap- preciated. Smeaton's apparatus for measurement of the power of overshot and undershot wheels is shown by Figs. 223 and 224 taken from "The Encyclopedia of Civil En- gineering" by Edward Cressy. Water was pumped by means of the hand pumps from the tail basin, X, to the supply cistern, V, from which it was admitted to the wheel through an adjustable gate. The power developed was measured by the time re- Fig. 223. Smeaton's Apparatus for Testing Water Wheels. quired to raise a known weight through a known height by means of a cord passing through a system of pulleys and attached to a small wind- ing drum or collar upon the wheel shaft. This drum revolved only when, by slight longitudinal movement, it was made to engage a pin on the shaft. In these experiments Smeaton found a maximum efficiency of 358 Turbine Testing. 32 per cent., and a minimum efficiency of 28 per cent, for undershot wheels. He also observed that the most efficient relations between the peripheral velocity of the wheel and velocity of the water were attained when the former was from 50 per cent, to 60 per cent, of the latter, and that the force that could be exerted by a wheel to Fig 224. Section of Smeaton's Apparatus for Testing Water Wheels. advantage was from 50 per cent, to 70 per cent, of tne force re- quired to maintain it in stationary equilibrium. For overshot wheels Smeaton found that the efficiency varied between 52 and 76 per cent. From his experiments he concluded that the overshot wheel should be as large as possible, allowing, however, a sufficient fall to admit the water onto the wheel with a velocity slightly greater than that of the circumference of the wheel itself, and that the best velocity of the circumference of the wheel was about three and one-half feet per second. This speed he found applied both to the largest as well as to the smallest water wheel. From these experiments Smeaton concluded that the power of water applied directly through the exertion of its weight by grav- ity, as with the overshot wheel, was more effective than when its power was applied through its acquired momentum, as in the The Early Testing of Turbine Water Wheels. 359 undershot wheel, although his line of reasoning indicated other- wise. The later development of impulse wheels shows that his reasoning was correct, and that the low efficiency of the impulse wheel was due to the method of applying the momentum of the water rather than to any inherent defect in the impulse principle. The experiments or tests of Smeaton, while crude and imperfect and performed upon wheels which were merely models, afforded a comparative measurement of the efficiency of the undershot, over- shot and breast wheels then in use and had a marked effect on the further selection of such wheels. 169. The Early Testing of Turbine Water Wheels. The testing of turbine wheels began many years ago in France before the turb- ine became well known in the United States.* Fourneyron began the study of the early forms of turbines as early as 1823, and, in 1827, he introduced his well-known wheel and also brought into notice a method of systematic testing of the same by means of the Prony brake. "La Societe d' Encouragement pour T Industrie Nationale" is credited by Thurston with the introduction of a general system for the comparison of wheels and correct methods of determining the efficiency.** Other engineers immediately accepted this method of comparison of wheels. Morin, in 1838, reported the results of a trial of a Fourneyron wheel as giving an efficiency of 69 per cent, with only slight changes in values for a wide range of speed. With another wheel he obtained 75 per cent, efficiency.f Combes tested his reaction wheel and found that an efficiency of about 50 per cent, could be obtained.]! The first systematic test of turbines in the United States was made by Mr. Elwood Morris of Philadelphia in 1843 and reported in the Journal of The Franklin Institute for December of that year. The maximum efficiency reported was 75 per cent. This result was reached when the value of < for the interior circumference of the Fourneyron turbine was .45. In 1844 Mr. James B. Francis determined the power and efficiency of a high breast water wheel * See "The Systematic Testing of Water Wheels in the United States," by ft. H. Thurston, Trans. Am. Soc. Mech. Eng. vol. 8. * :: See "Memoire sur les Turbines Hydrauliques," by H. Fourneyron, Brus- sels, 1840. t See "Experiences sur les Power Hydrauliques," Paris, 1838. t See "Mechanics of Engineering," Weisbach. Translated by A. J. DuBois. Hydraulics and Hydraulic Motors, vol. II, part I, p. 470. 360 Turbine Testing. in the City of Lowell, using a Prony brake fitted with a dash-pot to prevent irregular operation. In 1845 M r - Uriah A. Boyden made a trial of a turbine designed by himself, using the Prony brake, and obtained an efficiency of 78 per cent, as the maximum. In 1846 a similar test of one of the Boyden turbines was made at the Appleton Mills in Lowell, and an efficiency of 88 per cent, was reported. He continued the work of the testing of water wheels for several years and tested many wheels of various types.* Mr. Francis introduced the system of testing wheels which were to be used by purchasers of water from the water power company which he represented. The chief pur- pose of the tests was that the wheels might be used as meters in determining the amount of water used by the various purchasers. In 1860 the City of Philadelphia undertook a comparative trial of various turbines in order to determine their relative merits for used in the Fairmount Pumping Plant. The results o'f these tests given in Table XXXIII are somewhat questionable but have a comparative value. TABLE XXXIII. Water Wheel Tests at Philadelphia in 1860. Name of Wheel. Kind of Wheel. Per cent of Effect 3 per cent added for frict'n Where built. Stevenson's second wheel Jonval . .8777 9077 Paterson N J Geyelin's second wheel Jonval . .8210 8510 Philadelphia P^ Andrews & Kalbach's third wheel Collin's second wheel Spiral . . Jonval .8197 7672 .8497 7972 Bernville, Pa. Trov N Y Andrews & Kalbach's second wheel Spiral . . .7591 .7891 Bernville Pa Smith's, Parker's fourth trial Smith's, Parker's third trial. .... Steven's first wheel Spiral . . Spiral . . Jonval . .7569 . 7467 7335 .7869 .7767 7635 Reading, Pa. Reading, Pa. Paterson N J Blake Scroll . . 7169 7469 East Pepperell Mass Tyler Scroll . . .7123 .7423 West Lebanon N. EL (jlevelin's first, wheel Jonval 6799 7099 Philadelphia Pa Smith's, Parker's second wheel. . Merchant's Goodwin Spiral. . Scroll . . .6726 .6412 .7026 6712 Reading, Pa. G nil ford, N Y Mason's Smith Scroll . . . 6324 .6624 Buffalo N Y Andrew's first whefl Spiral 6205 6505 Bernville PH Rich Scroll . 6132 .6432 Salmon River N Y Littlepa^e Spiial. . 5415 .5715 Austin Texas Monroe Scroll . . .5359 . 5659 Worcester Mass Collin's first wheel . . Jonval 4734 5034 Troy N Y * See "Lowell Hydraulic Experiments. The Testing of Turbines by James Emerson. 361 170. The Testing of Turbines by James Emerson. One of the men who did much valuable work of this character was Mr. James Emerson who designed a new form of .dynamometer of the trans- mitting kind. At the request of Mr. A. M. Swain, Mr. Emerson designed a Prony brake, embodying this dynamometer for the pur- pose of testing a Swain turbine in a flume built from designs by Francis. The results obtained by Mr. Emerson from this test were so satisfactory that The Swain Turbine Company decided to open the flume for the purpose of a competitive test of all turbines which might be offered for this purpose. Announcement of this test was dated June i6th, 1869. The pit was fourteen feet wide, thirty feet long, and three feet deep, measured from the crest of the weir. The best results of this competitive test, the accuracy of which has since been .questioned by Mr. Emerson, were attained with the Swain and Leffel wheels. The former ranged from 66.8 up to 78.9 per cent, efficiency, and the latter from 61.9 to 79.9 per cent, efficiency. This competitive test was the beginning of a series of such tests as well as of a general system of the public testing of turbines. The testing flume was opened to all builders and users of turbine wheels and such tests have been continued in the United States up to the present time. The report of the results of this test attracted the attention of Mr. Stewart Chase, then agent of The Holyoke Water Power Com- pany, who, recognizing its very great importance, secured the adoption of a systematic testing of water wheels at Holyoke for the benefit of the Company and wrote to Mr. Emerson as follows: 'The testing of turbines is the only way to perfection, and that is a matter of great importance. Move your work to Holyoke and use all the water that is necessary for the purpose, and welcome, free of charge." Mr. Emerson, who had been conducting the testing of water wheels as a matter of private business at Lowell, at which place he was obliged to pay for the water used, at once accepted the liberal offer thus tendered him and removed to Holyoke where he continued the testing of water wheels until it was taken in hand by The Holyoke Water Power Company. The reports of Mr. Emerson's work were published and undoubt- edly were the means of bringing a number of wheels up to a state of high efficiency. The reports were found to be full of valuable 362 Turbine Testing. data, and, although not systematically arranged, formed an exten- sive and valuable collection of figures.* In 1879, The Holyoke Water Power Company, for the purpose of determining the standing of wheels offered for use at that place, 80 70 60 so 40 30 GATE | GATE 5 GATE Fig. 225. GATE FULL GATl : arranged for a comparative or competitive turbine test at the flume constructed by Mr. Emerson at Holyoke. The wheels were set under the direction of Mr. Emerson and a part of the tests were * See James Emerson's "Hydro-Dynamics." The Testing of Turbines by James Emerson. made or witnessed by Mr. Samuel Weber and Mr. T. G. Ellis. Their report was accompanied by a graphical diagram (Fig. 225 and Table XXXIV) on which they commented as follows : "By examining the diagram and table, the peculiarities of the several wheels will be readily seen. It will be observed that the Houston turbine, which has the highest percentage of effect at full gate, is really the least efficient at from half to three-quarters, and from half to full gate, of all those shown on the diagram, and is only superior to the Nonesuch at from three-quarters to full gate, and that by a very trifling amount; so that the wheel which ap- parently has the highest percentage is really the least desirable for actual use. The Thompson turbine, which has the lowest percentage of those shown at full gate, rises to the sixth place at from one-half to full gate, and to the fourth place at from one-half to three-quart- ers gate. The Tyler turbine, which has the second highest per- centage at full gate, falls to the sixth place at from one-half to three-quarters gate. The Hercules turbine, which stands third only at full gate, takes the first rank at from half to full gate, or any of its subdivisions. The New American turbine, which stands only fifth in the percentage at full gate, is second only to the Her- cules at from one-half to full gate or either of its subdivisions, and, indeed, differs from the Hercules very slightly in its useful effect through the whole range shown. "Taking the average useful effect of the wheels shown from one- half to full gate as a measure of their efficiency, their relative value is in the order shown in the table." TABLE XXXIV. Showing Average Percentage at Part Gafe. Name. ^toM Per cent. % to Full Per cent. K to Full Per cent. .737 .805 .771 .732 .795 .763 .708 .786 .747 Tyler .665 .766 .715 Tait .680 .744 .712 .696 .721 .709 .619 .712 .666 .397 .717 .557 364 Turbine Testing. The report of Mr. Emerson covered a much larger number of wheels. The diagram accompanying Mr. Emerson's report* is re- produced in Fig. 226. | GATE FULL GATE Fig. 220. 171. The Holyoke Testing Flume. The later work of systematic testing of American turbines has been carried on principally at the Holyoke flume. t "The object aimed at by the. Water-power Companies of Lowell and Holyoke, in the establishment of testing flumes for turbines, * Emerson's "Hydro-Dynamics," page 300. f"The Systematic Testing of Water Wheels," by R. H. Thurston. The Holyoke Testing Flume. 365 is the determination of the power and efficiency, the best speed, and the quantity of water flowing at from whole, to, say, half gate, so exactly that the wheel may be used as a meter in the measure- ment of the water used by it. The quantity of water passing through the wheel, at any given gate-opening, will always be prac- tically the same at the same head, and the wheel having been tested in the pit of the testing flume, and its best speeds and highest efficiency determined, and a record having been made of the quan- tity of water discharged by it at these best speeds and at all gates, the turbine is set in its place at the mill, speeded correctly for the head there afforded, and a gauge affixed to its gate to indicate the extent of gate opening. The volume of water passing the wheel at various openings of gate having been determined at the testing flume, and tabulated, the engineer of the Water-power Co. has only to take a look at the gauge on the gate, at any time, or at regu- lar times, and to compare its reading with the table of discharges, to ascertain what amount of water the wheel is taking and to de- termine what is due the company for the operation of that wheel, at that time. The wheel is thus made the best possible meter for the purposes of the vender of water." The present Holyoke Testing Flume was completed in 1883. The plan of this flume is shown in Figs. 227 and 228. The testing flume consists of an iron penstock, A, about nine feet in diameter, through which the water flows from the head race into a chamber, B, from which it is admitted through two head gates, G,G, into the chamber, C, and from thence through trash racks into the wheel pit, D. Passing through the wheel to be tested, it flows into the tail-race, E, where it is measured as it flows over a weir, at O. The object of the chamber, B, is to afford opportunity for the use of the two head gates, G,G, to control the admission of water, and consequently the head acting on the wheel. There is also a head gate at the point where the penstock, A, takes in water from the first level canal. A small penstock, F, about 3 feet in diameter, takes water from the chamber, B, independently of the gates and leads to a turbine wheel, H, set in an iron casing, in the chamber, C, in order that this wheel can run when C and the wheel pit, D, are empty. The wheel, H, discharges through the floor at the bottom of C, and through the arch, I, and the supple- mentary tail-race, K, into the second level canal. This wheel is used to operate the repair shops ; also to operate the gates, G. The chamber, C, is bounded on one side by a tier of stop-planks, L, and, 3 66 Turbine Testing. The Holyoke Testing Flume. 367 on another side, by a tier of stop-planks, M. The object of the stop-planks, L, is to afford a waste-way out of the chamber, C. This is of especial use in regulating the height of the water when testing under low heads. The water thus passed over the planks, L, falls directly into the tail-race, K. and passes into the second level. The stop-planks, M, are used when scroll or cased wheels Fig. 228. -Testing Flume of Holyoke Water Power Co. Arranged for Testing Horizontal Turbines. are tested. In such cases D is empty of water and the wheefr case in question is attached by a short pipe or penstock from an open- ing cut in the planks, M. Flume wheels are set in the center of the floor of D, and D is filled with water. They discharge through the floor of D and out of the three culverts, N,N,N, into the tail-race, E. Horizontal wheels are set in the pit, D, with their shafting projecting through a stuffing-box in the side of the pit (See Fig. 228). At the down-stream end of the tail-race is the measuring weir, O (Fig. 227). The crest of the weir is formed of a strip of planed iron plate twenty feet in length. The depth of water on the weir is measured in a cylinder, P, set in a recess, Q, fashioned in the sides of the tail-race. These recesses are water-tight, and the observer is thus enabled to stand with the water-level at convenient 368 Turbine Testing. height for accurate observation. The cylinder, P, is connected with a pipe that crosses the tail-race or weir box about ten feet back of the weir crest. The pipe is placed about one foot above the floor and is perforated in the bottom with inch holes. A platform, R, surrounds the tail-race, and is suspended from the iron beams that carry the roof. Above the tail-race is the street, over which the wheels to be tested arrive on wagons from which they are lifted by a traveling crane that runs on a frame-work over the street, and by means of which the wheels are carried into the building and are lowered into the wheel pit, D. Spiral stairs lead into a passageway that leads in turn to the platform, R. In the well-hole of these stairs are set up the glass tubes which measure the head of water upon the wheel. These gauge tubes are connected with the pit, D, and the chamber, C, by means of pipes, one of which enters the wheel pit through a cast iron pipe, T, built into the masonry dam which forms the down stream end of the wheel pit, D. The other pipe passes back under the wheel pit, D. and crosses the tail-race at the extreme back line and close under the pit floor. This pipe is perforated throughout its length across the race in a manner similar to the pipe used for determining the head on the weir. To enable the observers at the brake wheel, head gauge and measuring weir to take simultaneous olbservations, an electric clock rings three bells, simultaneously, at intervals of one minute. The usual method of testing a wheel is as follows : After the wheel is set in place (See Figs. 227 and 228) a brake pulley and Prony brake are attached to the shaft, the gates are set at a fixed opening and water is admitted. The runaway speed of the wheel is first determined with the brake band loose, after which a weight is applied and the brake tightened until the friction load balances the weight. As soon as this balance is attained, which requires only a few seconds, the revolution counter is read and the heads in the head-race, tail-race and on the weir are observed. Observa- tions are repeated simultaneously each minute at the stroke of the bell and for a period of from three to five minutes. The weight is then changed and the observations repeated for a different load and speed. After observations are made over the range of speeds desired, the gate opening is changed, and a similar series of obser- vations are made for the new gate opening. This is repeated for each desired gate opening, usually from full gate to about one-half gate. The results are calculated and reported in the form shown in Table LX. It is usually stated in the report whether the test is The Value of Tests. 369 made with a plain or conical draft tube, whether plain or ball bear- ings are used, and also the pull necessary, at a given leverage, to start the turbines in the empty pit. No attempt is made in these reports to describe the bearings or finish of the wheels in detail. The maximum head available is about 17 feet under small dis- charges and this decreases to about 9 feet under a discharge of 300 cubic feet per second. The capacity of the tail-race and weir is hardly sufficient for the accurate measurement of the latter quan- tity. 172. The Value of Tests. There can be no question as to the very great value of carefully-made tests of any machine. It must be borne in mind, however, that any test so made represents results under the exact conditions of the test, and, in order to duplicate the results, the conditions under which the test 'was made must be duplicated. Any changes in the design or finish of the wheels, any alterations in the method of setting, or in the gates, draft tube or other appurtenances connected with the same are bound to affect the power and efficiency to a greater or less extent. It is unfortunate for the world's progress that the records and conditions of failures are seldom made known. The record of a failure, while of great value from an educational standpoint, may considerably injure the reputation of an engineer or manufacturer, and consequently results of tests and experiments, unless fully satisfactory, are seldom published or known except by those closely interested. For this reason, the published tests of water wheels usually represent the most successful work of the maker and the best practical results he has been able to secure. Tests, unless fairly representative, do not assure that similar turbines of the same make, or even similar turbines of the same make, size and pattern, will give the same efficient results unless all details of their design, construction, and installation are duplicated. There is no doubt that in many cases the published tests of water wheels are the final consummation of a long series of experiments, made in order to secure high results, and do not give assurance that such results can be easily duplicated. The manufacturers have acknow- ledged this by calculating their standard tables on a basis of power and efficiency below that of the best tests they are able to obtain, and it is only a matter of reasonable precaution for the engineer, who is utilizing the results of any such tests for the purposes of his design, to discount the test values to such an extent as will assure him that his estimates will be fulfilled. 370 Turbine Testing. In water wheels for high-grade work, it is important that the specifications for their, construction be carefully drawn and that, by inspection and tests, the results of the work be fully assured. It is unfortunate that no easily applied method is available for the testing of water wheels in place. Such tests as are now carried on involve the shipment of one or more of the wheels from the place of manufacture to Holyoke, their tests under the conditions there obtainable and their reshipment to the point where they are to be installed. Here they may be set to operate under conditions en- tirely different from those of the Holyoke test and the actual results obtained cannot usually be determined. The most satisfac- tory test of any machine is a test made under the conditions of actual service, and, when such tests can be made, the results are much more definite and of greater value than the tests of the wheel made under conditions entirely different from those under which it is to operate. The Holyoke Testing Flume is performing valuable service and the results of its work have been of material assistance in the de- velopment and improvement of a number of high grade wheels. Much remains to be done, however, in the development of turbine testing so as to make it possible to more readily determine results under working conditions. More uniform work will undoubtedly result as the mechanical methods of manufacture improve and man- ufacturers are able to more nearly duplicate the satisfactory con- ditions which they have found to obtain in special cases. 173. Purpose of Turbine Testing. Water turbines may be tested for various purposes among which may be named: 1. To establish the general principles of the operation of such wheels. 2. To ascertain the most favorable condition for the operation of a particular type of wheel. 3. To ascertain the results of operating a particular wheel, or size or type of wheel, under particular conditions. 4. To investigate the various losses in the turbine in order that such losses may be reduced as low as possible. The quantities to be measured in a water wheel test are revolu- tions per minute or speed, discharge, and power output. In the fourth case the determination of heads, velocities and friction losses at various points in the wheel case and wheel may be essential. The extent to which a test should be carried will depend on its Factors that Influence the Results of a Test. 371 purpose. For the first purpose above mentioned the range of ex- periments should be as complete as possible, the discharge, and power of the wheel being determined from numerous speeds from zero to the runaway value and at various heads within the limits of the physical conditions. For the second purpose mentioned, the test may be carried only through the range of commercial conditions under which the wheel would ordinarily operate, but should, however, be broad enough to include the range of conditions which will obtain in practice due to the variations in head which are anticipated at various seasons. For the third purpose mentioned, the wheel need be tested only under the particular condition for which information is desired. The test may be to determine whether or not certain guarantees of the manufacturer have been, or will be, fulfilled. For the fourth purpose a special line of investigation and tests are necessary, which, while of great importance, are of special in- terest to the manufacturer only or to those interested in the detail development of some wheel for 'special purposes. For the purpose of any test a clear conception of the nature of the information sought is essential and each determination must be made with proper precaution in order to secure accurate results, 174. Factors that Influence the Results of a Test. It is appar- ent from the principles discussed in Chapter II that the actual power developed by a turbine will be somewhat less than the theoretical power of the water passing into it, depending on the character of the wheel and the various energy losses involved in its operation. The efficiency of the wheel, representing the ratio of power developed to power applied, depends on the same factors. These losses, incidental to the operation of a turbine, include the friction of the shaft on its bearings, the hydraulic resistance from the friction and shock of the water in the guides and passages, the slip or leakage between the fixed and revolving parts of the wheel, and the unutilized energy due to the velocity remaining in the water when discharged from the wheel. These losses are estimated as follows :* Shaft friction from 2 to 3 per cent. Slip or leakage from 2 to 3 per cent. Hydraulic friction and f^hock from 10 to 15 per cent. Energy in water leaving wheel from 3 to 7 par cent. Total loss of energy from 17 to 28 per cent * See "Development of Transmission of Power," by Unwin, p. 104; also- 'Francis Turbinen," by Muller, p. 18. 37 2 Turbine Testing. The total lasses given above correspond well with current prac- tice. Under the best conditions efficiencies greater than 83 per cent, are often obtained, and, under unfavorable conditions with poor design and poor construction, efficiencies much less than the minimum of 72 per cent, are common. While these losses can never be entirely obviated they should be reduced to the practical mini- mum that good design and good workmanship will permit. 175. Measurement of Discharge. The discharge, q, of the wheel is commonly measured in cubic feet per second and should repre- sent only the actual discharge through the wheel itself. This dis- charge is usually measured, after it has passed the wheel, by the flow over a standard weir. Any leakage around the wheel into the weir box or from the weir box around the weir must be determined and deducted from or added to the amount passing the weir. The actual weir discharge must be known either by a direct calibration of the weir or by the construction of the weir on lines for which the discharge coefficients are well established. Errors in weir measurements often reach values of nearly 5 per cent, due to the erroneous use of coefficients obtained from other weirs not strictly comparative. The head on the weir must be accurately determined by means of a hook gauge which should usually read to .001 of a foot. An error of .01 foot in reading the head on the weir represents about i per cent., and an error of .001 about .1 per cent., in the computed discharge with a 1.5 foot head on the weir and a much greater error at a lower head. The construction of weirs in the tail-race of power plants, es- pecially where large quantities of water are used under low heads, involves an expense which is often prohibitive. In addition to this, the construction of such weirs in plants working under low heads wooild often seriously reduce the head and alter the working conditions. Other methods of accurately determining the flow should be developed. There are two methods which seem to give promise of good results: First: By the careful determination of the velocities of flow in the cross-section of the head or tail-race at points far enough from the wheel to guarantee steady flow. This may be done by means of a carefully calibrated current meter, a pitot tube, or by floats To secure good results these instruments must be in the hands of Measurement of Head. 373 one familiar with their use and with the sources of error to which each is liable if carelessly used. (See Chapter XL) This method in- volves no loss in head. Second : By the construction in the head or tail race of sub- merged orifices of known dimensions and of a character for which the coefficient of discharge has been determined. Some work in this line has been done at the University of Wisconsin (See pages 43 to 45) which will soon be made accessible in detail in a bulletin now in press. This method will involve only small losses of head and by a sufficient range of experiments can perhaps be made nearly as accurate as weir measurements. Fig. 229. Doble Tangential Wheel Arranged for Brake Test. 176. Measurement of Head. The power of water applied to the wheel depends on both quantity and head. The head is more easily measured than the quantity, but, nevertheless, requires consider- able care for its accurate determination. The head of the wheel must be measured immediately at the wheel both for the head-water and tail-water. If measured some distance away it is apt to include friction losses, which should not be charged against the wheel in raceways, penstocks and gates. The measurement of head should usually be to about .01 feet, al- though this depends on the magnitude of the heads involved. 177. Measurement of Speed of Rotation. The speed of the wheel is usually recorded in revolutions per minute and may be Turbine Testing. 230. Section and Plan of Apparatus for Testing Swain Turbine (by James B. Francis). Measurement of Power. 375 determined by a revolution-counter which records the number of revolutions made in a given interval of time ; or by a "tachometer" which, by means of certain mechanism, indicates at once on a dial the revolutions per minute. The latter method is more convenient if the instrument is correct, but frequent calibration and adjustment are necessary and a correction must usually be applied to values thus observed. The revolution-counter is more accurate, and, while not so con- venient, is to be preferred. 178. Measurement of Power. The power of the wheel may be determined by placing a special brake pulley on the turbine shaft and applying a resistance by means of a Prony brake or some other form of dynamometer. This resistance is then measured by some form of scales (See Figs. 229 and 230). The power thus consumed by the friction of the brake can be calculated by equation (i) 2/r 1 n w W Pl 33000 ^ which P = Horse power 1 = length of lever or brake arm from center of revolution, in ft. n = revolution per minute. it = ratio of the circumference to the diameter of a circle = 3.1416. w = weight on the scale in pounds. This is the method applied in all laboratory work (see Fig. 229) and is that used at the Holyoke Testing Flume. If properly applied, it is probably subject to minimum error. When wheels are tested in place, it is sometimes more convenient, and often essential, to determine the power output from the current generated by elec- trical units, which, when measured by aid of the known efficiency of the generator, will give the actual power of the wheel. If these units be direct-connected so that little or no transmission loss is involved, and if the generator is new and its efficiencies have been accurately determined, the errors involved by this method are comparatively small. The transmission of the power before mea- surement through gearing, through long shafts and bearings or by other means, involves losses, the uncertainties of which must be avoided if accuracy is essential. 179. Efficiency. The efficiency of a machine is the ratio of energy delivered by the machine to that which was supplied to it and it may have various significations. In an impulse wheel (See Section 152) the theoretical energy of the water in the forebay in foot pounds per second is : (2} E -- qwh 376 Turbine Testing. The energy just inside the outlet of the pipe is (3). E x =qw(h' + h") The energy of the jet is (4) E * = ^ir ' and the theoretical power delivered to the bucket is qw (1 Z 1800 4-S / i / . -r^. Z BO 2 7 /A UI u or / i * 2 / IDDD 25 \J 5Q f BO 55 BO 85 70 75 80 PER CENT GATE OPENING 85 80 95 Fig. 235. The water was measured by a standard contracted weir 16.23 feet long and discharge computed by Francis' formula: q = 3.33(L 0.2h) h The load was computed from the voltmeter and ammeter read- ings of two generators Nos. 5 and 12 which were both driven by this wheel and then corrected for the generator loss by a factor estimated from the shop tests of the generators. Tests of Wheels in Place. TABLE XXXVI. Test of a Double Horizontal Leffel Turbine installed in the plant of the Niagara Hydraulic Company, Niagara Falls, N. Y. GATE OPENING. .45 .7 1.0 Dec. 5th Dec. 6th Xiine 3:21 p. m. 1.365 84.76 213.0 2045 255 178 5065 .92 1314 Friction Load Only 17 1331 .651 5:01 p. m. 1.978 146.6 212.4 3528 259 178 5020 .92 1302 12200 57.7 .95 1720 3022 .856 4:59 p. m. 2.257 178.3 212.7 4320 250 184 5833 .92 1563 13000 60.5 .955 1912 3475 .805' Hook gaujje readin * (corrected) . Discharge of wheel by Francis' formula Head on turbine Hydraulic horse power R. P. M Generator No. 5* V ]ts Amperes Efficiency Horse power taken from wheel by generator .... Generator No. 12** Volts Efficiency Horse power taken from wheel by generator Total horse power output of wheel Efficiency of wheel 8000 4000 6000 8000 HORSE POWER Fig. 236. 10000 9GO 800 a 700 600 500 400 5 3002 200 100 a 12000 * Generator No. 5 is a G. E. 5000 A. 175 V., D. C. machine. ** Generator No. 12 is a Bullock 1000 W. W., 3 phase A. C. generator. 332 Turbine Testing. The 10,500 h.p. turbine manufactured by the. I. P. Morris Com- pany for the Shawinigan Power Company was also tested in a similar mariner. A brief outline of this test is given on page 416 The graphical result of the same is shown by Fig. 236. Fig. 237 illustrates the test of a 25" Victor High Pressure Turbine, manu- factured by the Platt Iron Works Co., at the Houck Falls Power Station at Ellensville, New York. The results of various tests at the Holyoke Testing Flume, col- lected from divers sources, are given in the appendix. Most of the later tests have been furnished by manufacturers and represent the best results of modern turbine manufacture. 70 8 tf> 609 SCO 300 "1.0 200 .8 .i <: a 200 400 600 800 1000 1200 1400 1600 4800 2000 2200 8400 DISCHARGE IN CUBIC FEET PER MINUTE/ .2 Fig. 237. Literature. 383 LITERATURE. TURBINE TESTING. 1. Smeaton, James. "An Experimental Inquiry, read in the Philosophical Society of London, May 3rd and 10th, 1759, concerning the Natural Powers of Water to Turn Mills and Other Machines, Depending on a Circular Motion." 2. Morin. "Experiences sur les Power Hydraulicques." Paris, 1838. 3. Fourneyron, H. "Memoire sur les Turbines Hydraulicques." Brussels, 1840. 4. Francis, J. B. Tests of Several Turbines Including the Tremont-Fourney- ron and the Boott Center Vent Wheels. Lowell Hydraulic Ex- periments, 1847-1851. 5. Francis, J. B. Test of Humphrey Turbine, 275 h. p. Trans. Am. Soc. C. E., vol. 13, pp. 295-303. 1884. 6. Webber, Samuel. Turbine Testing. Elec. Rev. Oct. 18, 1895, p. 477. 7. Webber, Samuel. Instructions for Testing Turbines. Eng. News, 1895. Vol. 2, p. 372. 8. Cazin, F. M. F. The Efficiency of Water Wheels. Elec. Wld. Jan. 9, 1897. 9. Report of Tests of a 28-inch and. 36-inch "Cascade" Water. Wheel. Jour. Fr. Inst. May, 1897. 10. Hitchcock, E. A. Impulse Water Wheel Experiments. Elec. Wld. June 5, 1897. 11. Hatt, W. Kendrick. An Efficiency Surface for Pelton Motor. Jour. Franklin Inst, June, 1897, vol. 143, p. 455. 12. Thurston, R. H. Systematic Testing of Turbine Watev Wheels in the United. States. Am. Soc. Mech. Eng. 1897, p. 359. 13. Results of Tests of Cascade Wheel. Eng. News, 1897, vol. 2, p. 27 14. Results of Tests of Hug Wheel. Eng. News, 1898, vol. 2, p. 327. 15. Efficiency Curves. Eng. News, 1903, vol. 2, p. 312. 16. Houston, W. C. Tests with a Pelton Wheel. Mech. Engr., May 30, 1903. 17. Henry, Geo. J., Jr. Tangential Water Wheel Efficiencies. Am. Inst. Elec. Eng., Sept. 25, 1903. 18. Crowell, H. C. and Lenth, G. C. D. An Investigation of the Doble Needle Regulating Nozzle. Thesis, Mass. Inst. of Tech. 1903. 19. LeConte, Joseph N. Efficiency Test of an Impulse Wheel. Cal. Jour, of Tech. May, 1904. 20. Groat, B. F. Experiments and Formula for the Efficiency of Tangential Water Wheels. Eng. News, 1904, vol. 2, p. 430. 21. Webber, Wm. 0. Efficiency Tests of Turbine Water Wheels. Am. Soc. of Mech. Engrs., May, 1906. 22. Horton, R. E. Turbine Water Wheel Tests. Water Supply and Irriga- tion Paper 180, 1906. 23. Westcott, A. L. Tests of a 12-inch Doble Water Wheel. Power, Dec. 1907. CHAPTER XVI. THE SELECTION OF THE TURBINE. 182. Effect of Conditions of Operation. For high and moder- ate falls the variations in head under different conditions of flow are of small importance and water wheels can commonly be placed high enough above tail-water to be practically free from its influences. In such cases variations in head are comparatively so slight as to have little effect on the operation of the wheels which can therefore be selected for a single head. Such condi- tions are the most favorable for all types of wheels. When low falls are developed the rise in the tail-water is often comparatively great, and, as the head water cannot commonly be permitted to rise to a similar extent on account of overflow and damage from back water, the heads at such time are consider- ably reduced. As is pointed out in Chapter V, under such con- ditions and for continuous power purposes wheels must be se- lected, if possible, that will operate satisfactorily under the entire range of head variations that the conditions may demand, or at least under as great a range of such variations as practicable. In some cases the change in head is so great that no wheel can be selected which will work satisfactorily under the entire range of conditions. In other cases, the head becomes so small that the power which can be developed is insufficient without a large and unwarranted first cost. In many such cases the use of the water power plant must be discontinued, and, if the delivery of power must be continuous, it must be temporarily supplemented or replaced by some form of auxiliary power. In Chapter XVII it is shown that, almost without exception, great variations take place in every power load and that a plant must therefore be designed to work satisfactorily under consider- able changes in load. Most plants are called upon to furnish power for a considerable portion of the time under much less than their maximum load, but must occasionally furnish a maxi- mum load for a short period. Basis tor the Selection of the Turbine. 385 If power is valuable, and the quantity of water is limited, it is desirable to select a wheel that will give the maximum efficiency for the condition of load under which it must operate for the .greater portion of the time and that will also give, if possible, high efficiency under the head available at the lowest stages of the water. High efficiency is not essential to economy during high water, for there is plenty of water to spare at such times; neither is high efficiency as important during unusual load con- ditions, which obtain for only brief intervals, as it is during the average conditions under which the plant operates. 183. Basis for the Selection of. the Turbine. In Chapter XV the testing of water wheels has been discussed and a number of tabulated results of such tests are given. (See appendix D). The standard water wheel tables are calculated from the results of these tests but the values of power and efficiency, as given therein, are usually reduced somewhat for safety from the results deter- mined experimentally. Such tests also give data for a much broader consideration of the question, and for the determination of the results that can be obtained under the actual conditions of installation and operation, even when such conditions are sub- ject to wide variations. In Chapter XIV the hydraulics of the turbine are discussed, various turbine constants are considered, and the constants are calculated for a number of standard American turbines in accord- ance with the conditions of operation as recommended in the -cata- logues of their makers. It will be seen from a study of the tables that the turbines designed and built by various manufacturers sometimes have widely different constants, indicating that each is best adapted to certain conditions of which the values of these constants are an index. It is also shown that the various constants for a homogeneous series of wheels may be calculated from experimental data for any desired condition of gate opening and fixed value of , and that from these constants the operating results, that is, the dis- charge, power, speed, and efficiency for any wheel of the series, with the given gate opening and value of (f> and for any desired head, can be calculated. For most purposes, where the head is constant or where the range in heads and other conditions to be considered are not extreme, the necessary calculations can be readily made from a satisfactory test, by applying some of the 38 The Selection of the Turbine. formulas developed and discussed in Chapter XIV. The formu- las of greatest value for this purpose are as follows: ^ ^ P n 1842 cp 2 Hi= jr , when h = 1 D n _ D, n t 3 A = / . / when cp is constant. v h V h , 4 / : = " /- when q> and D are constant. Vh 1/h, 5 n = n, Vh when (p and D are constant. 7 7= = -7= when cp and D are constant. Vh Vh, ^ > g q = q, Vh when (p and D are constant. P PI 9 K 2 = ~ = TTn 7" when (p is constant. D* h DI hjk P PI 10 - 3 = 3 when (p is constant. p _ p iva when <^ and D are constant and hi = 1. 12 In using these formulas it must be remembered that each is essentially correct only when the condition specified after each equation obtains ; also that as long as remains constant the efficiency obtained by the test will remain practically constant for the same wheel, under all conditions of head. It should also be noted that, with a fixed diameter of wheel and a fixed head, and n are in direct proportion, and most calculations can be made by a direct consideration of the values cf n without a determina- tion of the value of . When the operating results are calculated for a wheel of a given series but of a diameter differing from that on which the experi- ments were made, the results are liable to differ from the true results on account of variations in manufacture, and allowance must be made for such differences, at least until the art of manu- facturing turbines has further advanced. Selection of the Turbine for Uniform Head 387 184. Selection of the Turbine for Uniform Head and Power. The conditions of operation, as catalogued, are usually based upon tests of a few turbines of the series, and represent the best con- ditions of operation for that series of wheels as determined by such tests. Where the conditions of installation and operation are fixed, and are not subject to radical changes in head or to great variations in the demand for power, the selection of a wheel may be made by inspection directly from the catalogues. This method of selection is based on the assumption that the catalogue data is correct, which assumption should be verified by the records of an actual test of the series of wheels and, if possible, of the size and hand which are actually to be used. The examination of the many catalogues of turbine manufactur- ers, in order to determine the wheel best suited to the conditions, is a tedious method of procedure and can be greatly shortened by brief calculations which are described in the following sections : 185. The Selection of a Turbine for a Given Speed and Power to Work under a Given Fixed Head. It is frequently necessary to select a turbine which must have a given speed and power in order to successfully operate machinery for w 1 iich such require- ments obtain. It is desirable to select a wheel which will furnish essentially the amount of power required as all machinery will work more efficiently and more satisfactorily at or near full load conditions. It is also desirable to use a single turbine rather than two turbines, and if more than one turbine is required, the least number found practicable should usually be selected because the multiplication of units involves an increase in the number of bear- ings which must be maintained and kept in alignment. To determine the best installation of turbines necessary to ful- fill the given conditions, the value of K 5 as given by equation (12) should be determined. Having determined the value of K 5 , a turbine should be selected having a constant K 5 not less than the amount determined, and if it is desired to operate the turbine at its maximum efficiency, the value of K 5 for the turbine selected should not greatly exceed the value found by computation. If the value of K 5 as computed greatly exceeds the value of K 5 for the various makes of turbines, then the power must be divided between two or more units in order that the conditions may be satisfied. As K 5 is in direct proportion to P, one-half, one-third or any other fraction of K 3 will give the value of K 5 for a wheel having a similar fractional value of the power, P, and will there- 388 The Selection of the Turbine. fore show the type of wheel which' must be selected in order that two, three, or more will do the work in question. The great varia- tions in the value of K 5 for different types of wheels and the in- fluence of this variation on the relation of speed and power will be seen by reference to Fig. 222 which shows the curves of re- lation between revolution and power of various wheels for one foot head. This may be used for any other head by considering the revolutions in proportion to the square root of the head and the power in proportion to the three-halves power of the head. A brief study of this diagram will show its use more plainly. For example : under a one foot head, and for 30 revolutions per minute, turbines may be selected that will deliver from 1.3 to 6.6 horse power. Suppose we desire to determine the power that will be available under a 16' head at 100 revolutions per minute. 100 revolutions per minute at 16' head would correspond to 25 revolutions per minute at i' head. For since n = -7=5=1 Vh> vr therefore n 1 = -j= 100 = .25 X 100 = 25. V10 At 25 r. p. m. the diagram shows that turbines are obtainable that will give 1.8 to 10 horse power at one foot head. The power at 16 foot head will be to the power at one foot head as the three-halves power of the head. The three-halves power of 16 is 64; hence the power at 16 feet will be 64 times the power at ooie foot head, and, hence, wheels under a 16 foot head operated at 100 revolutions per minute, will furnish from 122 to 657 horse power and the most satisfactory wheel within these limits for the problem at hand can be selected. The diagram, however, is a convenience, not a necessity, and a problem can often be more readily solved by the direct applica- tion of equation 12. If, for example, it is desired to operate a turbine at 100 revolutions per minute under 16 foot head to de- velop 400 h. p., the corresponding value of K 5 will be nap 100 X 100 X 400 By examination of Table XXXII it will be found that the Victor Standard Cylinder Gate or the United States Turbine wheels have To Estimate Probable Results From a Test. 389 practically this value of K 5 and will therefore fulfill the conditions. Having determined from the calculated value of K 5 the makes and types of the several wheels which will satisfy the requirements, the size of the wheel may immdiately be determined by determining the value >of K 2 for the same series of wheels from Table XXX, Chap. XIV, and calculating the size of the wheel by the use of for- mula 9. Thus for the Victor Standard Cylinder Gate wheel the value of K 2 is 0.00205. Therefore from equation (9) D * *pLl * JZIJ?OII = 55,2' V K 2 h| ^.00205 X 64 which is the size of this series of wheels needed to fulfill the as- sumed conditions. Having thus selected several possible wheels, tenders for these wheels may be invited from their makers. These tenders should be accompanied by an official report of a Holyoke test for the wheel in question, or, if this is not available at the time, for the next larger and the next smaller wheels of the series which have been tested. From these tests the catalogue values of K 2 and K 5 which were used in their selection can be checked. In addition to this the several prospective wheels may be compared as to their operation at part gate, which comparison is equally important for the final choice to be made. As the wheels are seldom or never tested for the head under which they are to work, and as tests are not always available for the size of wheel to be used, it is necessary to predict from the test data furnished by the wheel makers the efficiency, power and water-consumption curves which can be anticipated under the given head. This can be done as illustrated in the next two articles. 1 86. To Estimate the Operating Results of a Turbine under one Head from Test Results secured at another Head. For the purpose of illustrating the methods of calculation, Table l-XX tit may be considered. This table gives the results of certain tests of a 33" special, left-hand turbine wheel, with conical draft tube and balance gate, manufactured by the S. Morgan Smith Com- pany. While the heads in the different experiments of this test vary slightly, they are so nearly uniform that the table may be considered as developed under a uniform head of 17.15 feet. If greater accuracy is desired, however, the square root of the actual head can be considered each time. 39 The Selection of the Turbine. Let it be assumed that the wheel is to be operated under a 20 foot head and with a speed* of 200 r. p. m. with the average load at about .75 gate. The maximum efficiency at .75 gate is repre- sented by experiment No. 43 of this table. In order that the wheel shall work under the new head with this efficiency, equation (4) must be satisfied. In all of these equations the primed char- acters are used to represent the experimental conditions. The most efficient revolutions under the new head will therefore be determined as follows : 172.75 X 4.46 n = 4 14 = 186 r. p. m. The wheel to be chosen must, however, in this case operate at 200 revolutions per minute. At 200 r. p. m. the wheel will not run at its maximum efficiency. The actual efficiency at this speed may be determined by finding what speed at the experimental head corresponds with the speed to be used, and noting the effi- ciency corresponding to the same. This is done on the assump- tion that the efficiency remains constant as long as remains constant which is shown to be essentially true by Fig. 214, Chap. XIV. The revolutions under 17.16 ft. head corresponding to 200 r. p. m. under 20 feet will be determined as before : 2GO x 4.14 n : 4.4(5 - - . The result, 187 r. p. m., lies between the conditions of experi- ments 41 and 40. By proportion, the efficiency corresponding to 187 r. p. m. will be found to be about 83.25 at .75 Jgate. If the efficiency corresponding to 187 r. p. m. in the table is now determined from each gate opening, it will be found that at full gate the efficiency will be slightly below that shown in experiment 16, and can be determined by interpolation, or graphically, to be about 81%. At gate .9448 the efficiency can be determined in the same way to be about 82.75%. At gate .883 the results will fall between experiments 69 and 70 and the efficiency will be found to be about 86%. At gate .851 the result falls below experiment 54,. and, by calculation from a graphical diagram or by interpolation, the results are found to be about .86. At gate .702 the revolutions correspond exactly with experiment 56, and the efficiency from the table is found to be 81.01%. At gate .636 the revolutions fall be- tween experiments 24 and 25 and, by proportion, the efficiency is Effects of Diameter on Results. 39 1 found to be 80.25%. At gate .556, the efficiency is found, by pro- portion, to be 77%. To determine the power of the wheel under the new conditions, and for each condition of gate, the power of the wheel as found by the test must be determined for the same value of $. The power of the new head can then be calculated by \ise of formula (n). In the same manner the discharge of the turbine can be deter- mined by finding the value of q corresponding to the value of for the experimental head, and from this value so determined the value of q under the 20 foot head can be calculated by formula (7). The results of these calculations, together with the efficiency as determined for 20 foot head and for 200 revolutions per minute, are given in Table XXXVII. Having computed a similar table for each of the several pros- pective wheels the one best suited to the given conditions can be chosen. TABLE XXXVII. Showing Horse Power, Discharge and Efficiency of 33-inch Special Left Hand S. Morgan Smith Turbine, with 20-foot head and 200 R. P. M. Calculated from test of 33-inch wheel under a head of 17.15 feet. Proportional Gate Opening. Horse Power Discharge, cubic feet per second. Efficiency. 1 COO . . 222.1 120.4 81.6 .948 >>$ . 1 117.0 83.2 .883 217.7 111.3 85.6 .851 212.7 100.2 86.3 76o 188 I 97 5 83.2 702 1(>5 1 87.8 81.3 .636 154.7 81.5 80.7 55 1> . . 136.7 75.0 79.0 187. To Estimate the Operating Results of a Turbine of one Diameter from Test Results of Another Diameter of the Same Series. It is always desirable for the purpose of calculations to use the results of a test made on a wheel of the same size and hand as that which is to be used in the installation for which the wheel is being considered. It is seldom, however, that all of the various sizes of wheels in a series of wheels have been tested, and the manufacturers therefore frequently base their estimates and guar- antees of wheels of an untested size on the test of some other wheel of the series which may be larger or smaller than the wheel 392 The Selection of the Turbine. offered. Sometimes tests of wheels both larger and smaller than the wheel to be used are available, in which case both sets of tests should be used as a basis of calculation. Let it be assumed that a 40" wheel is to be installed of the -same series as the 33" wheel just considered, and that no tests of such a wheel are obtainable. The tests of the 33" wheel may therefore be used as the best information available. Let it be assumed that the 40" wheel is to be operated under a 9 foot head-. For these- calculations formula (3) must be satisfied. Let it be assumed that the wheel is to operate at nearly full load* and the best efficiency is desired at about .85 gate. From the 1 tests it will be found that at .85 gate, and with a 17.15 foot head and 191 revolutions, the wheel gave 85.97% efficiency and 170.08 horse power. Substituting these values in equation (3) there results : 33 X 191 40 X n T~T7 o ) from which n = 114 r. p. m. One hundred and fourteen revolutions per minute is therefore the speed under which the wheel must operate in order to give this maximum efficiency at this gate. Let it be assumed, however, that the wheel must be run at 120 r. p. m., on account of the class of machinery to be operated By substituting the value n=J2O, in equation (3), it is found that n'=2O2. The experimental efficiency at 202 r. p. m. under the I7-J5 foot head and with the 33" wheel, will therefore, corres- pond to 120 revolutions under a 9 foot head with a 40" wheel, and will indicate the efficiency under which the wheel will operate under these conditions. This is found to be about 81.5 at .85 gate. In order to determine the horse power of the wheel under the new conditions, the horse power of the wheel under the test con- ditions must first be determined for that gate; the resulting horse power can then be determined by equation (9). For 202 r. p. m. at 17.15 foot head for this 33' wheel P=158- which, substituted in equation (9), gives 158 P 33 X 33 X 71 = 40 X 40 X 27 from which P = 88 Jn the same manner, the discharge of the larger wheel under the lower head can be determined by equation (6), and q is found ta equal 104 cu. ft. per second. To Estimate Results with Variable Heads. 393 In this way the discharge, efficiency and power of the larger wheel under the chosen r. p. m. can be determined for each condi- tion of gate, as shown in Table XXXVIII. TABLE XXXVIII. Showing Horse Power, Discharge and Efficiency of a 40-inch Special Left Hand S. Morgan Smith Turbine, with a 9-Joot hea i and 120 R. P. M. Calculated from test of 33-inch wheel under a head of 17.15 feet. Proportional Gate Opening. Horse Power Discharge cubic feet per second. Efficiency. 1 000 100 119 8'? 1 948 . 100 112 84 2 .883 92 108 82 5 .851 88 104 81 5 .765 76. 91. 78.1 70? 68 83 77 8 .36 64. 76. 78.8 .550 58 73 75 1 1 88. To Estimate the Operating Results of a Turbine under Variable Heads from a Test made under a Fixed Head. Where the variations in the head under which a wheel is to operate are considerable, the variation in <, and consequently in n, are some- times found to be beyond the limits of the test. Where the test conditions are not greatly exceeded, the experiments may be ex- tended graphically without any serious error. Let it be assumed that the 33" wheel above considered is to be operated under a maximum head of 25 feet, and that the head will decrease to 16 feet at times of high water; also, that the wheel is to be operated for the major portion of the time under about .75 gate. The best condition for operation is shown by test 43, which shows an efficiency of 86.3% at n' = 172.75 r. p. m. n may be calculated from equation (4) for the 25 foot head as follows : n = 172.75 X 5 4.14 = 208 r. p. m. That is : the best number of revolutions for a 25 ft. working head would be 207 r. p. m. The best number of revolutions for a six- teen foot head would be determined as follows : n = 172.75 X 4 4.14 = 166 r. p. m. 24 394 The Selection of the Turbine. The wheel, for the best efficiency, should be run at a different speed for each head, but under practical conditions of service must be run at a constant speed. Let it be assumed that, on account of the machinery operated, it is desirable to adopt for the plant a speed of 200 r. p. m. Let the 25 foot head be first considered. For considering the 25 foot head the equivalent value of n under the test conditions is found as follows: =167r.p.m. It will be noted from experiment 44 that at 169.25 r. p. m. the efficiency is 85.55. At 167 revolutions per minute the efficiency would therefore be about 85%. Under a sixteen foot head n must also equal 200 r. p. m., hence, for this case, the equivalent value of n' for the test conditions is n'= 200X4.14 = 20S revoh . tions . Test 39 shows that, with 206.25 revolutions, the efficiency is 76.66. At 208 revolutions the efficiency is therefore less than this amount and the probable efficiency under these conditions can be estimated by platting the relation between revolutions and ef- ficiency as shown in Fig. 238. By prolonging the line from the actual experiments, the efficiency indicated for 208 revolutions, under the experimental conditions, is found to be about 76%. As far as efficiency is concerned, therefore, the arrangement is very satisfactory, for a sufficiently high efficiency will be obtained un- der conditions of high water, and when the quantity of water used is immaterial. The relations of efficiency to speed, under the experimental con- ditions and at various gate openings, are shown by the points platted on Fig. 238. Through these points mean curves are drawn, which are extended where necessary to intersect the ab- scissa of 167 revolutions, which corresponds to the condition of efficiency for 25 foot head, and to the abscissa of 208 revolutions, which corresponds to the condition of efficiency for a 16 foot head. From these results the relations of efficiency at various gates and at the two heads named are platted in Fig. 239. The relations of power to speed are shown by Fig. 240, which has been platted in the same manner as Fig. 238. From Fig. 240; Estimate of Efficiency with Variable Head. 395 ..-_ ISO BOO _., RC VOLUTIONS PER Ml MUTE. Fig. 238. Curves Showing the Efficiency Obtained at Various Speeds un- der a Test Head of about 17.15 Feet from a 33-Inch Special Left- Hand Wheel with Balance Gate, Manufactured by the S. Morgan Smith Co. 70 50 60 70 80 PER CENT GATE OPENING. 90 Fig. 239. Curves Showing Estimated Efficiency at Various Gate Openings and at Two Heads for 33-Inch S. Morgan Smith Wheel. (Taken from Fig. 238.) 39 6 The Selection of the Turbine. the power of the wheel at 25 and 16 feet can be determined by equation (10). The power at 25 feet will be 125 j = =g-g = l . 77 times the power determined by the exper- h'* iment at 17.15 feet and 167 r. p. m. The power at 16 feet will be 64 = ;=7r~7: = .91 times the power, as determined by the ex- periment at 17.15 feet, and at 216 r. p. m. 180 I DO 180 REVOLUTIONS PER MINUTE HDD 220 Fig. 240. Curves Showing the Power Obtained at Different Speeds under a Test Head of about 17.15 Feet from the S. Morgan Smith 33-Inch Wheel. .91 times the power, as determined by the experiment at 17.15 feet, and at 216 r. p. m. Curves of the pow r er of this wheel under 25 and 1 6 foot heads, and at various gates, as determined in this manner, are shown by Fig. 241. The experimental relations of speed and discharge for the wheel are shown in Fig. 242 which was platted in the same manner as the diagrams for efficiency and power. A graphical representa- tion of the discharge under 25 and 16 foot head and at various gates is shown in Fig. 243. 189. A More Exact Graphical Method for Calculation. The method outlined in section 188 is subject to some error as the re- sults are platted regardless of head. The graphical method is therefore applicable without correction only when the experimen- A Graphical Method of Calculation. 397 tal head remains nearly constant. For a more complete, accurate and satisfactory analysis the discharge, power and revolutions should be reduced to their equivalents i. e. at one foot head JL P . _L. h * 41 Vh, hi Vh 300 260 J220 80 140 100 GO 70 CENT OPENING. 90 1QD PER CENT GATE Tig. 241. Curves Showing Estimated Power Obtained at Various Gate Openings and at Two Heads for 33-Inch S. Morgan Smith Wheel. (Taken from Fig. 240'.) and platted as shown in Fig. 244 where the r. p. m. under one foot head is used as abscissas, and the power, discharge and efficiencies are used as ordinates. The* condition at any given number of revolutions under a given head can be calculated by dividing the given number of revolutions by ttte square root of the head. The 398 The Selection of the Turbine. 115 160 180 EDO REVOLUTIONS PER MINUTE 220 Fig. 242. Curves Showing the Discharge at Various Speeds under the Test Head of about 17.15 Feet of ths 33-Inch S. Morgan Smith Wheel. 140 120 u 100 5 BO u en 60 50 60 70 80 PER CENT GATE OPENING 30 100 Fig. 243. Curves Showing the Estimated Discharge at Various Gate Open- ings and at Two Heads for the 33-Inch S. Morgan Smith Wheel. Taken from Fig. 242.) A Graphical Method of Calculation. 399 88! 52 54 36 38 40 Fig. 244. Curves of the 33-Inch S. Morgan Smith Wheel for One Foot Head. 42 44 46 48 50 R.P.M. UNDER ONE FOOT HEAD. 400 The Selection of the Turbine. result is the comparative revolutions under one foot head, and a line drawn vertically at the point so located on the diagram will .give the basis of calculations for power and discharge by multi- plying by hi and ha, respectively, for each gate opening and by reading the efficiency direct. For the wheel under 200 revolutions at 25 and 16 foot heads the equivalent speeds on the diagram are 40 and 50, respectively, Lines drawn vertically at these points will intersect the curves of efficiency, power and discharge and if reduced by a similar method will give curves essentially the same as those shown in Figs. 239, 241 and 243. This is probably the best method for common use in studying, from test data, the operation of a wheel under a va- riable head. 190. The Construction of the Characteristic Curves of a Tur- bine. It is frequently desirable to make a more thorough analy- sis, based on the available test, of the conditions under which a wheel can operate. For this purpose, the writer finds the use of what he has termed "the characteristic curve" of a turbine to be the most comprehensive method for such an analysis. For this purpose, prepare a diagram on which the ordinates rep- resent the values of and the r. p. in. under one foot head, and the abscissas the discharge of the wheels in cubic feet per second under one foot head. It is also found desirable to show on the upper margin of the diagram the horse power under one font head with 100% efficiency, corresponding to the discharge shown below. For each experimental result the values of and of the discharge under one foot head are determined by formulas (i) and (3). The point representing these values is then platted on the dia- gram, and the efficiency, as determined by the test for that experi- ment, is written closely adjoining the platted point. This is done for each experiment at each condition of gate. After all the ex- perimental points are platted, and the resulting efficiency at each given point is expressed, lines of equal efficiency are interpolated on the drawing, and will indicate the general law of the variation of efficiency as represented by the test. It is, of course, possible to reduce the horse power determined for each experiment to the theoretical horse power under one foot head, and record it at the corresponding point, and then interpolate horse power curves, as in the case of the efficiency curves. It has been found by the writer, however, to be more satisfactory to use The Characteristic Curve. 401 the horse power scale at the top of the diagram, together with the efficiency lines already drawn, for the calculation and platting of the horse power curves. The horse power at any point will, of course, equal the theoretical horse power expressed at the upper margin, multiplied by the efficiency at the given points. In determining the horse power curve, it is best to assume the horse power of the desired curve, and then determine its location in regard to the theoretical horse power from the equation. A. H. P = T. H. P. X Efficiency. For example, on Fig. 245, if it is desired to plat the curve rep- resenting 2 A. H. P. it may be done as follows : The line repre- senting two actual horse power will intersect the 70% efficiency line at two points whose abscissae are determined from the T. H. P. scale by the equation T . n . p. = If, therefore, the two points of intersection of the abscissa 2.86, as indicated on the upper T. H. P. scale, with the 70% efficiency line, are marked, two points will be established on the 2 A. H. P. line. As many of the lines of equal efficiency and equal horse power can be drawn on the diagram as may be desired, but if the lines of the drawing or diagram are too numerous, confusion will result rather than clearness. One of the most complete sets of experiments with, or tests of, a turbine water wheel which the writer has been able to obtain is the set of experiments made for the Tremont and Suffolk Mills at the Holyoke Testing Flume, December 3-5,1890, on a 48 inch Victor turbine, with cylinder gate (See ''Notes on Water Power Equipment," by A. H. Hunking), which is given in full in Table LX.* From this table, and in the manner above described, a char- acteristic curve of this wheel has been prepared, and is shown by Fig. 245. In this Figure the efficiency curves are shown in black, the horse power curves are shown in red, and the lines showing the relations of discharge and at various gate openings are shown by the dotted lines connecting the experimental points. 191. The Consideration of the Turbine from its Characteristic Curve: From this characteristic curve the action of the wheel under all conditions of operation within the experimental limits of can be readily determined. The use of the characteristic * See Appendix D. HORSE POWER UNDER ONE FOO .7 i.s I.Q e.a s..\ s.z 2.3 a.** e. so 6 17 IB |g 20 21 2 DISCHARGE IN CUBIC FEET F Fig. 245. "Characteristic Curve" of ME1AD WITH I DO PERCENT EFFICIENCY 23 S4 25 25 27 28 29 3D SECOND UNDER ONE ROOT MEAD 18-Tnch Victor Turbine, with Cylinder Gate. 35 36 404 The Selection of the Turbine. curve is based upon the assumption that the efficiency will remain constant for a variable head as long as 4> remains constant. The efficiency and horse power lines as interpolated, are sub- ject to errors of interpolation, the extent of which can be readily judged from the diagram made. The conditions of the test are approximately checked by this diagram, for any marked irregulari- ties in these curves must be due to errors in testing, or to poor workmanship. By inspection it is possible to decide immediately the value of that must be maintained in order to maintain the maximum efficiency at any particular condition of gate. For example: if the maximum efficiency at full load is desired, < with this wheel should equal about .69. If the maximum efficiency at .75 gate is desired, the value of should be about .65, and for maximum ef- ficiency at .50 gate, < should be reduced to about .64. Knowing the head under which the wheel is to operate, the nec- essary number of revolutions at any head can be calculated by formula (i) or by multiplying the r. p. m. at one foot head by the i/h and the conditions of operation, in regard to both power and efficiency at all gates, will be determined by the intersection of a horizontal line through the chosen value of < with the efficiency and horse power lines. If, for example, it is decided that $ shall be .66, a horizontal line running directly through the diagram at < = .66 will, by means of the various points of intersection with the gate opening, efficiency and horse power lines, give all infor- mation desired and from it can be calculated the efficiency, speed, discharge and horse power of the wheel for the head under which it is to operate. The intersection of this .66 line with the va- rious efficiency curves will give the relation of efficiency to dis- charge with one foot head. The discharge under the required head can be calculated by equation (9), i. e. by multiplying the dis- charge shown at the bottom of the diagram (cine foot head) by yh. The efficiencies at each gate position will remain unchanged by this change in head since < is fixed at .66. If a 16 foot head be considered, the discharge at any point will be four times the dis- charge read from the diagram. The relation of horse power to discharge is aiso shown by the intersection of the line with the horse power curves. The ac- tual horse power under any head can be determined by equation (u) i. e. by multiplying the horse power, as read from the dia- The Characteristic Curve. .-gram (one foot head) by h~. The horse power at 16 foot head will therefore be 64 times that given by the diagram. If it is desired to utilize the characteristic curve for the consid- eration of a wheel of another size but of the same series, the power D 2 .and discharge must be multiplied by the ratio -jj All of the various types of curves showing the results of opera- 80 40 GO 80 100 DISCHARGE IN CUBIC FEET PER SECOND . 120 Fig. 246. 406 The Selection of the Turbine. tion of the wheel as hitherto described are shown by, or can be calculated from, the characteristic curve. Fig. 246, showing the relation of the number of revolutions to the efficiency and discharge of the wheel, is one example of such use. 192. Other Characteristic Curves. Fig. 247 is the characteristic curve of a 44 inch "Improved New American" turbine showing the HORSE POWER UNDER ONE FOOT HEAD WITH 100 PERCENT EFFICIENCY 2.0 2.5 3.0 3.5 4.0 4.5 5.0 18 I* 20 22 24 26 28 30 32 34 36 38 40 42 44 46 4f~ DISCHARGE IN CUBIC FEET PER SECOND UNDER ONE FOOT HEAD Fig. 247. Characteristic Curve of a 44-Inch ""-Improved New American' Turbine. The Characteristic Curve. 407 operation of the wheel through a considerable range of heads. The outer line entitled "Head at 120 r. p. m., shows the values of and n- L at which the wheel would have to operate to 1 maintain 120 r. p. m. at the indicated heads. The location of these points may be determined in two ways : First. By calculating the values of Fig. 248. Curves Constructed from Fig. 247 Showing the Power at Two Speeds of Six "Improved New American" Wheels. for a given head and number of revolutions, and locating the corresponding point from the scale on the left of the diagram; Second. By dividing the number of revolutions by the square root of the head and fixing the point by the corresponding revolu- tions under one foot head, as shown on the scale of r. p. m. at the right of the diagram. 408 The Selection of the Turbine. At 14 foot head the wheel will operate at about the maximum ef- ficiency. If the head be decreased to 12', the relative efficiencies will still remain fairly satisfactory, but will decrease rapidly at 10' as shown by a horizontal line drawn through the corresponding point. It is also evident that at 8' the efficiency becomes very low. and below this head the wheel would probably be unable to main- tain 1 20 r. p. m. HORSE POWER UNDER ONE FOOT HEAD WITH 100 PERCENT EFFICIENCY 3.4 3.6 3.8 4.0 4. 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 DISCHARGE IN CUBIC FEET PER SECOND UNDER ONE FOOT HEAD Fig. 249. Characteristic Curves of a Wellman-Seaver-Morgan 51-Inch Mc- Cormick Wheel. The second line at the right shows the value of $ and n, at va- rious heads when operating at 100 revolutions per minute. At this speed the wheel will operate satisfactorily under heads from 14' to as low as 7', or even less. The efficiency at 14 foot head in this c'ase will be less than at 120 r. p. m., and the efficiency of oper- ation will increase as the head diminishes to the 9 and 10 foot' point, where the best efficiencies are obtained at 100 r. p. m. Be- low this point the efficiency of operation will gradually decrease. Provided the revolutions per minute are satisfactorily selected, it will be seen that the wheel will meet successfully a wide variation in the operating conditions. The Characteristic Curve. 409 Fig. 248 is a diagram constructed from this characteristic curve and shows the power of six turbines of this series but of 49" diam- eter connected tandem to a horizontal shaft and operated at the various heads and revolutions above discussed. The curves show the condition both at full and at part gates. The gradual change 145 140 HORSE POWER UNDER ONE FOOT HEAD WFTH 100 PERCENT EFFICIENCY 1.5 2.0. . .2.5. . . ..-0 3.5. 4.0 4.5 5.0 25 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 4244 DISCHARGE IN CUBIC FEET PER SECOND UNDER ONE FOOT HEAD Fig. 250. Characteristic Curves of the 99i/,-Inch Tremont Fourneyron Wheel. 410 The Selection of the Turbine. in the relative position of the 100 and the 120 r. p. m. curves, as the head changes, should be noted. Fig, 249 shows the characteristic curve of a 51" McCormick tur- bine, as manufactured by Jolly Brothers for the Wellman-Seaver- Morgan Company. At the right of the diagram are shown the relative values of and at the left the values of n for heads from HORSE POWER UNDER ONE FOOT HEAD WITH 100 PERCENT EFFICIENCY 83 26 27 38 29 30 31 32 33 34 35 36 37 38 39 40 4.1 43 43 44 45 4.6 4.7 48 49 , 24 25 26 27 28 23 3D .31 32 33 34 33 36 37 38 39 40 4 4Z 43 44 43 DISCHARGE IN CUBIC FEET PER SECOND UNDER ONE FOOT HEAD Fig. 251. Characteristic Curves of a 45-Inch "Samson" Wheel. (James Leftel & Co.) 16 to 8 feet, at 90 and 100 r. p. m. This curve shows that this wheel will work satisfactorily under a wide range of conditions, if a suitable speed is chosen. Fig. 250 is the characteristic curve of the Tremont turbine tested by James B. Francis, and described in the "Lowell Hydraulic Ex- periments." This wheel was a Fourneyron turbine of about 700 horse power at 13' head. Fig. 251 is the characteristic curve of a 45" Leffel turbine, which has been selected for the Morris Plant of the Economy Light and Power Company, now under construction on the Des Plainas River, about twelve miles south of Joliet, Illinois. It is to be op- erated at 120 revolutions per minute and under variations in head The Characteristic Curve. 411 from 16 to 8 feet. Eight units, each consisting of .eight of these wheels, connected tandem, are to be installed to operate eight 1,000 K. W. alternating generators. This diagram was prepared from the test sheet accompanying the bid of the James LefTel & Com- pany. In the construction of the wheels for the plant, an attempt was made to so alter them as to maintain a high efficiency for a HORSE POWER UNDER ONE FOOT HEAD WITH 100 PER CENT EFFICIENCY 2B 23 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.8 4.8 5.0 5.2 26 28 30 32 34 36 38 40 42 DISCHARGE IN CUBIC FEET PER SECOND UNDER ONE FOOT HEAD 46 Fig. 252. Characteristic Curves of a 45-Inch "Samson" Wheel. (James Leffel & Co.) greater range of gate conditions than ordinarily obtained. Fig. 252 shows a characteristic curve of one of the new wheels as con- structed for this plant. The analysis was made for the purpose of estimating the results which would probably be secured under service. In Fig. 253 are shown the discharges, powers, and efficiencies of one unit of eight wheels under all heads from 8 to 16 feet at full and seven-eighths gate. Allowances would have to be made in order to take into account the difference between the operation of the eight wheels in the horizontal position connected in tandem, and in the position in which they were tested ; but the diagram 4 I2 The Selection of the Turbine. shown gives an analysis from which fairly satisfactory conclu- sions can be drawn. 193. Graphical Analysis as Proposed by Mr. W. A. Waters. A valuable method of graphical analysis is shown in Bulletin No. 88 23C3 2IC3 ^ 1900 1700 1500 1300 700 500 Fig. 253. Curves Showing the Efficiency and the Maximum and Ordinary Power and Discharge of One Unit of 8 45-Inch Samson Wheels. 2 of the I. P. Morris Company, in which is discussed the variations, in power and efficiency of a turbine wheel capable of giving 13,500 horse power under a head of 65 feet, and at a speed of 107 revolu- tions per minute. This wheel was designed by this Company for the McCall-Ferry Power Company, and was to work under heads varying from 50 to 70 feet. Graphical Analysis of W. A. Waters. 414 The Selection of the Turbine. Figs. 254, 255 and 256 and the following description are taken, with slight alterations, from the above named Bulletin. Curve No. I. Fig. 254, shows the power which the wheel will give for heads varying from 70 feet to zero, provided that the revo- lutions are allowed to vary as the square root of the head, and is based on equation (15). From Curve No. i, Fig. 254, it will be noted that at 70 foot head the wheel will develop 15,000 horse power, and from Curve No. 6, of the. same Figure, it will be noted that the best speed of the wheel under the conditions of 70 foot head will be in revolutions per minute. It will also be noted from Curve No. I that, under 50 foot head, the wheel will develop 9.150 horse power, if it be run at 94 revolutions per minute. That is to say, by keeping a constant ratio between the peripheral speed of the runner and the square root of the head the efficiency of the wheel at varying heads is not changed for any given setting of the gate. In order to properly utilize the output of the wheel, it is neces- sary that the speed be kept constant. In order to determine the amount of power that will be lost by keeping the speed constant while the head varies, the curves of Fig. 255 were platted from actual observations. Curve No. I, Fig. 254, is the full gate readings of the 10,500 horse power turbine, which was installed for the Shawinigan Wa- ter and Power Company. This wheel was designed for 10,500 horse power when working under a head of 135 feet, and when running at 180 revolutions per minute. The observations which are platted on this curve were obtained by using the generator as a brake for the wheel, and a water rheostat was used as a means of loading the generator. The speed was then adjusted to 180 revolu- tions per minute at the wide open gate and an observation made. By varying the field of the generator, the speed of the unit was varied without materially affecting the power and without moving the gate of the wheel. Observations were made above and below the normal speed through as wide limits as the rheostat in the field circuit of the .generator would permit. The power output was determined by means of accurately calibrated electrical in- struments. The speed was determined by an accurately calibrat- ed tachometer. The curves on this sheet give the relation between and horse power. Referring back to Fig. 254, and taking the 50 foot head condi- tions, it should be noted that for a constant speed of 107 revolu- Graphical Analysis of W. A. Waters. 4*5 and Power of Several I. P. Morris Wheels. (Repro- duced from Bull. No. 2 of I. P. Morris. Co.) "^ -. -V J i - - 416 The Selection of the Turbine. tions per minute would have to increase from the normal value of about .68 to .08. By referring again to Fig. 255, it will be noted that when was 0.8, with full gate opening, the power .dropped from 10,650 horse power to 10,250 horse power, or about 3.3 per cent. From this fact the normal power as shown by Fig. i may be corrected for the new speed of rotation and a point on Curve No. 2, Fig. 254 obtained, giving the actual power which would be developed by the wheel under the 50 foot head, and running at the constant speed of 107 revolutions per minute. Curve No. 2 is platted in this jnanner from Curve No. i. As a check to Curve No. 1, Fig. 255, Curves Nos. 5, 6, 7, and 8 have been platted, all of which were made from actual observa- tions, in the same manner as Curve No. i. All of these wheels are of the Francis inflow type, and were designed for $-.7, except Curve No. 6, which is an outward flow Fourneyron wheel, and was designed for ^=.5. Curve No. 5 is for a 6,000 horse power wheel with gates in the draft tubes. The shape of the curve shows that the gate was probably not entirely open when the ob- servations were made. In Fig. 256 has been platted efficiency curves, which the de- signed wheel would give under varying heads, and running at a constant number of revolutions. Curve No. I is an exact dupli- cate of the efficiency curve which was obtained on a 3,500 horse power wheel working under 210 foot head, and making 250 revolu- tions per minute. The wheel is of the Francis inflow type, with double runners, fitted with movable guide vanes, similar to those which are proposed to be used in the wheels for the McCall-Ferry Power Company. It will be noted that the efficiency of the wheel reaches 82.3 per cent, at about seven-eighths power, the efficiency dropping to Si 1 /^ per cent, at full gate. It will be noted that the efficiency is very high at part load. This was accomplished in the design of the wheel by sacrificing a higher efficiency at full load. This curve has. been taken as typical of the efficiency which would be obtained by the wheel proposed for the McCall-Ferry Power Company, when work- ing under a 65 foot head. The efficiency curve of the 10,500 horse power wheel which was supplied by the I. P. Morris Company to the Shawinigan Water and Power Company (See Fig. 236), gives higher results than the curve selected, but it was thought that Curve No. i is the best for a typical curve. Graphical Analysis of W. A. Waters. 417 Curve No. i, Fig. 256 was platted by assuming that, at full gate, 3,500 horse power corresponded to 13,500 horse power in the wheel to be designed. The part gate points of the curve were ob- tained by proportion. Curve No. 3 represents the efficiency and power of the wheel when working under 50 foot head, and at 94 r. p. m. Point X on this curve was obtained in the following manner: First, read on Curve No. 1, Fig. 254 the power which the wheel would give under the 50 foot head, and revolutions best suited. This is found to be 9.150 horse power. On Scale B, Fig. 256 a line is drawn from 9,150 horse power to zero, forming Curve No. 10. To find what the efficiency would be at 8,000 horse power un- der the 50 foot head, take the point at 8,000 horse power on Scale B, projected horizontally until it intersects Curve No. 10, and 11,800 horse power will be read from Scale A. From the effici- ency curve directly over 8,000 horse power on Scale A, the point, X, will be found on Curve No. 3,. which gives the efficiency of the wheel when developing 8,000 horse power under the 50 foot head, and running at the revolutions best suited, namely 94. This wheel is to run, however, at 107 revolutions per mirtute, under all conditions of head, and it is necessary to correct Curve No. 3 for the drop in power and efficiency due to the increase in speed. Referring to Curve No. I, Fig. 255, it will be noted that the pow- er varies when the speed varies, and in the calculations of effi- ciency in Fig. 256, it has been assumed that the efficiency varies directly as the power. In other words, it has been assumed that the quantity of water does not vary when the revolutions are changed with the constant setting of the gate. This is not strict- ly true but for the observations as platted on Curve No. I, Fig. 255 the quantity of water would probably vary only one-half of one per cent., increasing as the revolutions increase from 158 to 201. Referring to Fig. 254, and the 50 foot head, it will be noted that when the speed is increased from the best speed of 94 revolutions to the desired speed of 107 revolutions, the power falls 3.3 per cent, and the power and efficiency of the full gate point on Curve No. 3, Fig. 256 can be decreased 3.3 peir cent, resulting in the full gate point on Curve No. 2. Referring to Fig. 255, Curves Nos. I, 2, 3, and 4, it will be noted that the slope of these curves between < = 0.7 and --=0.8 is about the same, and, therefore, the power and efficiency of all the points The Selection of the Turbine. Fig. 256. Estimated Efficiency Power Curves of the Proposed McCall-Ferry Wheel. (Reproduced from Bull. No. 2 of 1. P. Morris Co.) Graphical Analysis of W. A. Waters. 419 on Curve No. 3, Fig. 256, can be reduced by the same percentage, namely, 3.3 per cent. In this manner Curve No. 2, Fig. 256. is ob- tained, which gives the power and efficiency of the wheel when working under the 50 foot head, and running at the speed of 107 revolutions per minute. In the same manner Curves Nos. 5 and 7 are platted, Curves Nos. 4 and 6 being deduced therefrom, respec- tively. In the same manner Curve No. 9 is platted, and Curve No. 8 deduced therefrom. It will be noted that Curve No. 8 lies on the opposite side of the parent curve to that of the other curves. Curve No. 8 crosses Curve No. 9 at 13,500 horse power on Scale A, and beyond this point would drop below Curve No. 9. The reason Curve No. 8 falls to the left of Curve No. 9, and shows greater efficiency at part gate for the 70 foot head, is because when changes from 0.7 to 0.65, Fig. 255, the partial gate Curves Nos. 2, 3, and 4, Fig. 255, show the increase in power and efficiency. These points, however, cannot be very definitely determined, but it does show that the assumption is correct that the designed wheel, working under the head of 70 feet, and running at 107 rev- olutions, will show higher percentage of efficiency at part gate than when running at the 65 foot head and the same powers. The curves on Fig. 256 show that the efficiency is not serious- ly affected by keeping the speed of the wheel constant under the varying conditions of head. They do show, however, that the power is seriously affected by keeping the speed of the wheel con- stant under the varying conditions of head. The endings of the various curves show the maximum power, as read on Scale A, which the wheels will give under that head. These curves, therefore, give the performance of the wheel when running at a constant number of revolutions, and working under varying heads from 50 to 70 feet. The curves, of course, are not absolutely correct. They show, however, fairly accurately, the amount of variation in efficiency and power which may be ex- pected from the actual conditions obtained with the proposed wheel under the head for which it was designed. CHAPTER XVII THE LOAD CURVE AND LOAD FACTOR, AND THEIR INFLUENCE ON THE DESIGN OF THE POWER PLANT. 194. Variation in Load. All power plants are subjected to more or less change in load, and this continually changing load has an important bearing on the economy of the plant, and should be care- fully considered in its design and construction. If the power output of any plant be ascertained, minute by min- ute or hour by hour, either by means of recording devices or by reading the various forms of power indicators usually provided for such purposes, and a graphical record of such readings be made, a curve varying in height, in proportion as the power varies from time to time, will result. This curve is termed the daily load curve. The load curve itself will vary from day to day as the various demands for power vary, but it usually poss.esses cer- tain characteristic features which depend on the load tributary to each plant and which vary somewhat as the seasons or other con- ditions cause the load to vary. The characteristics of the load curve, due to certain demands, can be quite safely predicted. A power plant in a large city, for example, will carry a comparatively small continuous night load. This, in dark weather and in winter, will be increased by the early risers who are obliged to go early to shop and factory. These demands usually begin to affect the load curve about 5 A. M. and may cease wholly, or in part, by 7 A. M., depending on the season and latitude. From 7 to 8 A. M. the motor load begins to be felt. This may reach a maximum from 10 to 12, and usually decreases from 12 to 2 during the lunch hours. The maximum load usually comes in the afternoon when business reaches a maximum, and when the largest amount of power and also light (in the late aftej;- noon) are used. The< load begins to decrease after the evening meal, as the demand for light lessens, and may again increase some- what as the theatres and halls open for evenings' amusements. The character of the load curves, due to various loads, is best under- stood by a study of the actual curves themselves. Load Curves of Light and Power Plants. 421 195. Load Curves of Light and Power Plants. The curves shown in Fig. 257 are from the plants of the Hartford Electric Light Co., of Hartford, Conn., and will illustrate variation of the load curve at different seasons of the year. These curves were taken from an article in "The Electrical World and Engineer" of March 8th, 1902. This plant is a combined water and steam pow- er plant, and is provided with a storage battery to assist in equal- izing the load. These curves are described as follows : "On a week day in March, 1901, the maximum load was 1720 k. w. and the total energy output was 30249 k. w. hours. The aver- age hourly load was then 1260 k. w. or 46 per cent, of the maximum load. On- this same day the battery discharged at the rate of 260 k. w. at the peak of the load. In the early morning hours of this day the load on the system, apart from battery charging, reached its minimum at 612 k. w., or only 22.5 per cent, of the maximum load. In June, 1901, the maximum load on a certain week day was 1390 k. w., and the minimum 250 k. w., or 18 per cent, of the former. The total output on this day 'was 2505 k. w. hours, so that the average load during the 24 hours was 1046 k. w. or 75 per cent, af the maximum. In January, the maximum load came on between 4 and 5 P. M., when lighting was the predominant factor, but in July the greatest demand came on the system in the latter part of the forenoon, and must have been made up in large part by re- quirements for electric power. By December 1901, the maximum load reached 2838 k. w. and the minimum 612 k. w. The approxi- mate capacity of all connected lamps and motors in that month was 8530 k. w. The maximum load for the December day of 2838 k.w. is only 33 per cent, of the connected capacity. On this day the total output was 3219 k. w. hours, so that the average load during the 24 hours was 1342 k. w. This average is 15 per cent, of the total capacity." Fig. 258 is a combined annual load curve for several years, and not only shows the increase in the electrical output of this system for the years from 1898 to 1905, but also the annual monthly change in load from a maximum in December or January to a minimum in June or July. This variation fortunately accompanied similar variation in the flow of the Farmington River on which most of .the power was developed. Up to the middle of 1898. the entire load of this Company was carried by a single water power plant. The natural increase in demand for power necessitated the construction of a second plant 4 22 The Load Curve. Kilowatts. Load Curves of Light and Power Plants. 4*3 on the same river, and up to January 1905, the two water power plants were able to carry most of the load, steam auxiliaries, how- ever, being occasionally used, as indicated by the dotted line. Fig. 259 shows daily load curves from the Christiania Power Stations, of Christiania, Norway. In this figure are shown the max- imum, the minimum, and a mean curve for the entire year. > The 1000000 750000 500000 250000 *H Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. Jan. JuL Jan. Jul. 1898 1899 1900 1901 1902 1908 1904 1905 Steam Water Total Fig. 258. Energy Output of Hartford Electric Light Co. (From Electrical World and Engineer. ) difference between the maximum and minimum curves is here very marked. This is readily ascribed to the high latitude of Christiania as the long twilights of summer render lighting at that season almost unnecessary, while the very short and dark days of winter create not only a high maximum but a high continual demand dur- ing the entire day. No data as to kind of load is available. Fig. 260 is a power curve from the New York Edison Company. On August ist, 1905, there were connected up to the system of the New York Edison Company an equivalent of 1,651,917 incan- descent lamps, 22,093 arc lamps, 2,539 k. w. in storage batteries The Load Curve. and 99,258 H. P. in motors. The lighting load forms 52.2 per cent, of the connected load. The effect of extraordinary conditions on the load curve and the necessity of some kind of storage to provide for the same, is well illustrated by Fig. 261 which shows the effect on the load curve 1000 A.M. 4 6 P. M. Fig. 259. Typical Electric Lighting Load Curves. Christiana, Norway, Power Stations. of a lighting plant of a sudden thunderstorm. When such a storm occurs in the late afternoon the light load from schools, offices, stores, etc., may be suddenly thrown on, and the result may be an extraordinary load which the plant must meet. 196. Factory Load Curves. Shop and factory loads are sup- posed to be the most uniform in character, yet they are subject to great variation, due to the sudden turning on or off of the ma- chines. Fig. 261 shows the load curve of the Pennsylvania Rail- road Shops at Altoona, Pennsylvania. The shops of the Pennsylvania Railroad are located in and around Altoona, Pennsylvania, in groups, each group being supplied by its own power station. No data as to the number and power of motors connected up is available, but the following shows to some extent how the load is divided. The Machine Shop power plant embraces Factory Load Curves. 425 2 300 k. w. generators, I Brush arc generator (power unknown), and a 40 H. P. Thompson-Houston arc generator for lighting shop and grounds. At the Car Shops 4-250 k. w. and 1-625 k. w. gen- erators are used. Current is supplied to 75 arc lights in shops and yards. At the Junita shops 3-300 k. w. generators are used for power purposes only. At South Altoona the generating station 60000 10 12 A. M. M. P. M. New York Edison Co., Load Curve, day of Max. load, Dec. 22, 1904. * Including 3100 K. W. delivered directly at 6600 Volts A. C. Fig. 260. Typical Electric Lighting Load Curve. embraces 1-50 k. w., and 2-500 k. w., and 2-300 k. w. generators. The loads are quite variable, as would be expected in a railroad shop, there being some very heavy machines in intermittent opera- tion, one planer running as high as 80 H. P., while 20 H. P. motors are numerous. The normal load is less than the maximum, but the latter is frequently reached. A, B and C, Fig. 263, are three typical factory lo&d curves which represent types of load curves from three different electric power stations, A in an Eastern, B in a Central, and C in a far Western state. These curves are taken from an article on "The Economics of Electric Power" in Cassier's Magazine for March, 1894. The circuits from these stations are exclusively motor circuits, the num- ber of motors connected being given in the following tables ; 426 The Load Curve, 5000 4000 3000 2000 1000 A. M. 10 Fig. 261. Sharp Thunder Storm Peak, Dickenson St. Station, Manchester, Eng. A B C Size of Motor i BU 'FA LO BA TT ERI ES^ y i I ^ N 4 / / - / t Vl I i N 4 ^-A.C. STEAM yo^^. ; 1 ^7 J /\ S / I ^ s (J -D.C 8TEAW POWER. s \k \ \ > v^ -/\ $ ^ ^"^ ^: ^v< V R5 \ x^- ^ FA A^ LLS d I ^ ov\ ^^ ER -B /V IFF /V ^ \ t ^ a ^ ?v /^/ \ m - T^ i*"^. K5= C^X \y i \ i V Vv ^ j v \ --'> -\ X i AL LS PO AA WE > r R- 6 T0> A* r> 'AN ^\ 3A^ A LC CK /V. POR A T A AN 1 1 LC DTT I v\ i. \y v^- ^x^ 1 ^/ j 7"\/ V Lr^ s^A 7T 12 2 4 6 8 10 12 2 4 A.M. M. 6 8 P.M. 10 12 Fig. 2C6. Typical Railway Load Curves, International Ry. Co. (From Elec- trical World and Engineer.) Railway Load Curve. 431 day load. The London Hydraulic Supply Company furnishes water under a pressure of 750 pounds per square inch through a sys- tem of mains 86 miles long. In 1894, 2915 machines were connected to this system, of which 650 were passenger elevators, 2000 freight elevators and cranes, 90 presses of various kinds, 95 motors, and 80 fire hydrants. Each 1000 gallons of water pumped represents 8.738 H. P. hours, therefore, the maximum on the diagram repre- sents about 1200 H. P. The preponderant influence of the elevator load is shown in the rapid rise from 6 to 10 A. M. and the some- what slower decline from 4 to 12 P. M. 198. Railway Load Curves. The power load most subject to violent fluctations is that utilized for railway purposes. The sud- den changes in the demand for power occasioned by stopping and starting of cars, which may, under some conditions, occur simul- taneously are often very rapid and the resulting load fluctuations very great. Figs. 265 and 266 show two sets of curves taken from the power charts of the International Railway Company of Buffalo, which may be considered typical for electric railways. Each chart has two sets of curves, one for the city lines, on which the traffic is purely urban in character, and the other for the Tonawanda, Lock- port and Olcott Line, which is an interurban line. In either set the total load at any time is represented by the ordinate to the highest curve in that set. The amount of load carried by any portion of the system is represented by the difference between the ordinates to the curve of that portion and to the curve next below. On the urban lines two peaks will be observed, one at 8 A. M. and one at 6 P. M., for both winter and summer, the afternoon peak of the former being nearly 75 per cent greater than the latter, however. The load curve of the interurban line appears to be nearly uniform throughout the year. The data, on page 432, concerning these curves are taken from "The Electrical World and Engineer" of December 10, 1904. 199. Load Conditions for Maximum Returns. It is manifest that no plant will receive its maximum returns without operating at full load all of the time ; that if it operates at less than full load its income will be reduced unless more is charged for power so delivered ; and that if the load carried for a large portion of the time is comparatively small and the returns for such power are not proportionately large the plant may be found to be an unprofitable 432 The Load Curve. investment. On every plant the fixed charges, which include in terest on first cost, depreciation charges and taxes, continue at a uniform rate every hour of the day and every day of the year. The operating expenses increase somewhat with the total amount of power furnished but not in proportion. An increase in the total Data from Curves of Figure 265. PURCHASED POWER. STORAGE BATTERIES. Grand Total. Tonawanda. Tonawanda. Buffalo. Lock- port. Olcott Total. Buf- falo. Lock- port. Total. Maximum H P 6,114 1,667 4, 636 111,272 83,009 1,985 319 1,221 29,302 21,859 8,099 1,985 5,857 140,574 104,868 3,752 79 1,262 8,406 6,271 635 40 274 3,480 2,596 4,387 119 1,536 11,886 8,867 12,486 2,104 7,393 152, 460 113,735 Minimum H. P Average H. P H P hours K W hours Maximum number of cars in service in Buffalo, 408. Average volts at D. C. busbars, 592. State of weather: 8 a. m., cloudy; 6 p. m., fair. Temperature: 8 a. m., 66 degrees F.; 6 p. m., 74 degrees F. Data from Curves of Figure 26S. PURCHASED POWER. STEAM POWER. Grand Total. Tonawanda. Buffalo. Lock- port. Olcott Total. Niag- ara St Vir- ginia St. Total. Buf- falo. Maximum H. P. ... Minimum H. P Average H. P 7,622 2, 303 6,002 144,046 107,458 2,025 199 1,149 27,584 20,578 9,647 2,502 7,151 171,630 128,036 3,414 953 2,115 38,442 28,678 2,064 715 1,641 4,367 3,238 5,478 1,668 3,756 42,809 31,936 3,970 79 1,224 7,344 5,479 19, 095 4,249 12, 131 221,783 165,451 H. P., hours K. W., hours. . Average volts at D. C. busbars, 592. State of weather: 8 a. m., cloudy; 6 p. m., cloudy. Temperature: 8 a. m., 20 degrees F.; 6 p. m. 26 degrees F. output of a given plant, therefore, means a direct increase in the net earnings of the plant and unless the power plant is constantly operating at its maximum capacity, its earning efficiency is not at the highest point. The Load Curve in Relation to Machine Selection. 433 It will be noted at once that if a machine can be operated at its full capacity for the entire time, that the work done will be done under the most economical conditions as far as each unit of output (Horse Power Hour or Kilo-Watt Hour) is concerned. The in- terest on the first cost and other fixed charges will be distributed among the maximum number of power units. The cost of wear, and the repairs, while they increase with the amount of power fur- nished, are not in direct proportion thereto, and decrease per unit as the average load carried reaches nearer the maximum of the machinery used. The same is true of the cost of attendance and most other operating expenses. 200. The Load Curve in Relation to Machine Selection. A com- parison between the average load carried and the maximum load will show the relation between the machinery which it is necessary to install and the active, work which it has to do, and furnishes a basis for the study of the possible earnings of the plant. The ratio between the maximum load and the average load is \ called the "load factor." Some engineers use the term "load factor" as representing the ratio between the average load actually carried and the maximum capacity of the machinery operated. The writer, however, prefers the term "machine factor" to represent this ratio. The same term is also sometimes applied to the ratio of the aver- age load to the machinery in hourly operation, but to this the term "hourly machine factor" seems more applicable. The ratio of the average load to the total capacity of the station would seem best represented by the expression "capacity factor." In order to have a plant work at the maximum advantage, it must be designed to fit the contingencies of the load. The opera- tion of a machine at partial load is not only expensive on the basis of fixed charges, but is still more so on account of the decreased efficiency under such conditions. With a varying load, efficient operation usually involves the in- stallation of two or more generators of such capacity that a single unit will furnish the power required during the hours of minimum demand and at the same time operate at a fairly efficient rate. As the daily demand for power increases, additional units are started and operated, still under economical conditions, and at the peak of the load one or more additional units may be cut in and operated for the limited time during which the maximum demands prevail. Such an arrangement assures reasonable economy of operation at all times, even when great changes of load are of daily occurrence. 434 The Load Curve. 201. Influence of Management on Load Curve. The relations of the "load curve," the "load factor," the "machine factor" and the "capacity factor" are, or may be, to an extent controlled by the business management of any plant, and by the selection and the character of the load to be carried, where such selection is possible. Each consumer of power will develop a particular curve due to the character of the work done, and it is frequently possible, by a ju- dicious selection of customers, and especially by a proper grading of rates, to raise the load factor and thereby decrease the cost of operation and increase the net profits from the plant. A study of the probable plant factors is necessary for the judicious selection of machinery in order to attain the most efficient operation and, in a hydraulic plant, in order to properly design it and conserve the maximum energy of the stream that is being developed. 202. Relation of Load Curve to Stream Flow and Auxiliary Power. Some of the relations between the load factor and the conditions under which a hydraulic plant may have to be operated are shown by Figs. 267, 268 and 269. In Fig. 267, diagram A shows a typical daily load curve from the terminal station at St. Louis, a curve quite similar in general char- acter to those previously shown. Diagram B shows the power that must be developed by a stream in order to take care of the load represented by this load curve, under conditions where no auxiliary power or storage are available. In this case, it will be noted that the available water power must be equivalent to or greater than the maximum peak load, and that all power represented by the area above the load line, amounting in the case illustrated to about 40 per cent, of the total available power, will be wasted. Diagram C illustrates a condition where the average load and water power are equal. In this case, pondage or storage, repre- sented by the cross-hatched area below the average line, may be utilized to furnish the peak power represented by the cross-hatched area above the average line. Without pondage, the cross-hatched area below the average load line will represent the energy wasted, and the cro,ss-hatched area above the average load line will repre- sent the energy which must be supplied by auxiliary power. With- out pondage the power of the stream must be utilized as it passes, and in the diagram B, of Fig. 267, the power represented above the load line under such conditions must be wasted. Relation of Load Curve to Water Power. 435 sue 400 300 ; 800 100 500 f \ -(/ >i / \ N V / \ / \ f s A VER HGE 2.6 > -X / N N A VER GE 2.9! A s r r- '~ J N B / \ X* X| A VER *GE 2. IB ->. 2 \ -^ ^-~ ""7^ ^ s- ^ ^ A C RATIOS. MINIMUM TO AVEBAtC 1 TO 1.7 MINIMUM TO MAXIMUM 1 TO .8 AVERAGE TO MAXIMUM 1 TO 1.87 A.M. f It AM. 8 10 12 e 4 6 8 10 IE E 4 TYPICAL DAILY LOAD 'CURVE UNION TERMINAL STATION ST. LOUIS. WATER POWER REQUIRED WITH 10 AUXILIARY POWER STORAGE 500 AVERAGE LOAD AND WATER POWER EQUAL. STORAGE OR AUXILIARY POWER REQUIRED, WATER POWER UTILIZED. POWER WASTED. FIOM STORA8E . AUXILIARY POWER. RELATION OF POWER SUPPLY AND DEMAND Fig. 267. 43$ The Load Curve. These same conditions are shown both by diagram C, Fig. 268, and diagram A, Fig. 269. In the latter, with water power above the average load of the plant, the peak load must be supplied by auxiliary power, although more water power than would be suffi- cient to handle it is daily wasted. Diagram B, Fig. 268, shows a condition with low water power no storage available, and the power less than the average load. In this case the water power wasted is comparatively small, and the amount, and especially the capacity, of the auxiliary power be- comes large. Diagram C, Fig. 268, represents a water power condition, where the power available is less than the average load, where storage is practically unlimited, and some auxiliary power is necessary in order to carry the peak of the load. Under these conditions, the water power, which would otherwise be wasted during the time of minimum load, is impounded, and can be utilized together with the auxiliary power at times of maximum load. The diagram shows a method of utilizing the minimum capacity of auxiliary power by utilizing the stored water power to its greatest advan- tage, and utilizing auxiliary power uniformly throughout the period where auxiliary power is demanded. Diagram A, Fig. 269, represents the same conditions where stor- age is limited, and auxiliary power is necessarily required to help out the peak load conditions. In this case only a certain amount of the spare water can be stored, the balance being wasted at times where it cannot be continuously utilized. The conditions for reducing the total amount of auxiliary power by utilizing the storage to advantage is shown in the same manner as in diagram C, Fig. 268. Diagram B, Fig. 269, shows a method of utilizing the minimum capacity of auxiliary power in a plant where the water power is below the average load and the pondage is practically unlimited. This is accomplished by the continuous operation of the auxiliary plant and the storage of water power during the hours of low con- sumption, for utilization during the hours of peak load. A careful and detailed study of the load curve and load factor; the method of increasing the latter and of designing the most economical plant to take care of the condition to be met; and the adjustment of rates to attain equitable returns to the investor at reasonable price to the consumer, are matters of plant design worthy of the best efforts of the engineer. Relation of Load Curve to Water Power. 437 5CU 400 300 -i ~ aoo 100 SOD AUXILIARY POWER REQUIRED . NO STORAGE AVAILABLE WATER POWER GREATER THAN AVERAGE LOAD . AUXILIARY POWER REQUIRED. NO STORAGE AVAILABLE WATER POWER LE88 THAN AVERAGE LOAD . 500 AUXILIARY POWER REQUIRED . STORAGE UNLIMITED WATER POWER LESS THAN AVERAGE LOAD WATER PfiWER UTILIZER. POWER WASTED FROM ITOA(E AUXILIARY POWER RELATION OF POWER SUPPLY AND DEMAND . Fig. 268. 433 The Load Curve. AUXILIARY POWER REQUIRED STORAGE LIMITED WATER POWER GREATER THAN AVERAGE LOAD 500 400 I ""===:? r: Z-00 100 - AUXILIARY POWER [MINIMUM REQUIRED] IN CONTINUOUS SERVICE STORAGE UNLIMITED WATER r\KKXiPowru .*, x STORAGE POWtB UTILIZED < POWER WASTED POWER FROM STORAGE AUXILIARY POWER RELATION OF POWER SUPPLY AND DEMAND Fig. 269. Literature on Load Curve. 439 LITERATURE. REFERENCES OF LOAD CURVES AND LOAD FACTORS. 1. Load Curves of Electric Central Station. Elektrotechnische Zeitschrift Vol. 25, page G8. Jan. 28, 1904. 2. Influence of Load Factor on the Cost of Electrical Energy. Edmund I*, Hill. Electrician (Lon.). Feb. 10, 1905. 3. Load Factor Its Effect upon an Electricity Station. Alex Sinclair. Elec trician, London, June 30, 1905. 4. Distribution of Power Load of Electricity Works. Electrician (Lon.), July 28, 1905. 5. The Load Factor of Electric Generating Stations. Norberg^Schultz, Coustiania. Elektrotechnische Zeitschrift. Vol. 26, p. 919, Oct. 5, 1905. 6. The Effect of Load Factor on Cost of Power. E. M. Archibald. Eng. News, Vol. 53, p. 169. Feb. 16, 1905. Elec. Age, Nov. 1906. 7. Electrical Transmission of Water Power. Alton D. Adams. Chap. I and II. New York. McGraw Pub. Co. 1906. 8. Economy of Continued Railway -and Lighting Plants. Ernest Ganzen- bach. St. Ry. Review, Feb. 15, 1906. Elec. World and Engr. Jan. 27, 1906. 9. Central Station Power. E. P. Espenschied, Jr. Proc. Engrs. Soc. Wes. Penn. Mar. 1906. 10. Relation of Load, Factor to the Evolution of Hydro-Electric Plants. S. B. Storer. Am. Inst. Elec. Engrs. Mar. -23, 1906. 11. Notes on Design of Hydro-Electric Stations (With Reference to the In- fluence of Load Factor). David D. Rushmore. Proc. Am. Inst. Elec. Engrs. April, 1906. 12. Effect of Day Load on Central Station Economy. J. P. Janes. Elec. Re- view, N. Y. May 12, 1906.. 13. Sale and Measurement of Electric Power. S. B. Storer. Electrical Age, Aug. 1906. 14. Sale of Water Power from the Power Company's Point of View. C. E. Parsons. Eng. Record, Aug. 11, 1906. 15. Contracting for Use of Hydro-Electric Power on Railway Systems. G. A. Harvey. Elec. Age, Sept. 1906. 1C. The Sale of Electric Power. Eng. Record, Nov. 3, 1906. 17. Flat Rates for Small Water Power Plants. J. S. Codman. Elec. Wld, and Engr., Nov. 3, 1906. CHAPTER XVIII. THE SPEED REGULATION OF TURBINE WATER WHEELS. 203. The Relation of Resistance and Speed. The power delivered by any water wheel may be expressed, in terms of resistance over- come by the wheel through a known distance and in a known time by the formula (See equation i, Section 177, Chap. XVI). 2x1 w n (1) P = 33000 The second term of this equation may be divided into two fac- tors : first, 2x1 w 33000 which may be called the resistance factor and which is the resist- ance overcome or power produced by the wheel per revolution per .UTlONS PCP HINUTC Fig. 270. minute ; and n, the number of revolutions per minute. The product is the horse power of the wheel. ^ In any wheel operating with a fixed gate opening and under a fixed head the speed, n, will always increase as the resistance, w, decreases, and will decrease as the resistance increases. Self Regulation with Variable Speed and Resistance. 441 In Fig. 270 the line AB shows the relation of speed to resist- ance in a turbine operated with a single fixed gate opening and for the full range of load conditions (as determined by experiment) from A, at which the resistance, w, was so* great as to hold the motor stationary, to B where the resistance was completely re- moved and the entire energy of the applied water was expended in overcoming the friction of the wheel, or rejected as velocity en- HEAD WATER Fig. 271. ergy in the water discharged therefrom. From this figure it is evident that if, at any fixed gate opening, a wheel 'is revolving at a given speed, n, and the resistance, w, is decreased to w" the speed will increase to n", while if the resistance increases to w' the speed will decrease to n'. 204. Self-Regulation in a Plant with Variable Speed and Resist- ance. At Connorsville, Indiana, is a pumping plant (Fig. 271) in which a horizontal shaft turbine is directly connected through friction clutches to two rotary pumps. For operation the turbine gates are opened until the pump, or pumps, speeding up to a suit- able r. p. m., produces the desired pressure in the distributing sys- 442 The Speed Regulation of Turbine Water Wheels. tem. The work of the pump under these conditions in pumping water at the speed of operation against the desired pressure equals the work done by the quantity of water q passing through the tur- bine, less friction and other losses. If the pressure falls, the loads become unbalanced: i. e., the resistance is reduced and the tur- bine and pump increase in speed until the balance is restored. If the pressure rises the machine slows down until there is again a restoration of balance between the power of the turbine, the purnp load and friction losses. IONS pen MINUTE Fig. 272. To pump water against an increased pressure, it is necessary to increase the gate opening of the turbine. In its regular daily work the varying demand for water is thus supplied by the self-regula- tion of the two machines used and no governor is needed. The conditions of operation are similar to those illustrated in Fig. 270. 205. The Relations Necessary for Constant Speed. Fig. 272 is a diagram drawn from experimental or test observations and similar to Fig. 270 except that the relations between speed and de- sistance are shown for various gate openings. It is evident that if the wheel must operate at a fixed speed, n, and the resistance, w, increases to w' or decreases to w", it will be neces- sary to increase the gate opening from % gate to full gate in the first case and to decrease it to % gate in the second case in order to' maintain the speed uniform. The Ideal Governor. 443 An examination of the load curves described in Chapter XVII shows that changes in load are constantly in progress. For the satisfactory operation of water wheels, under these constant and irregular changes in load, automatic regulation of the turbine gates becomes necessary- This is accomplished through the water wheel governor which regulates the gates through the various classes of ' gate mechanisms described in Chap. XIII. 206. The Ideal Governor. The power output of a water tur- bine in terms of energy applied to the wheel is expressed by the formula. (2) q = cu. ft. per second of water used by the wheel. H' = net available head. E = efficiency of the wheel. P = horse power developed. Any sudden increase or decrease of load, w, will produce a cor- responding decrease or increa'se, respectively, in the speed, n, of the machine as shown by Fig. 270 unless the energy applied to the turbine is immediately changed to correspond. The ideal turbine governor would effect a change in output by varying only q, thus obtaining perfect water economy by conservmg^ttnneeded water for future use. This is not possible in practice as head, water, and therefore efficiency are usually wasted when operating a wheel un- der other than its normal load and during the change in load. 207. Present Status, The success of the comparatively recent application of hydraulic power to the operation of alternators in parallel and to the generation of current for electric lighting street railway and synchronous motor loads has been largely dependent upon the possibility of obtaining close speed regulation of the gen- erating units accompanied with good water economy and without undue shock upon machinery and penstocks while working under extremely variable loads. The degree of success thus far obtained in the development (necessitated by the above conditions) of automatic turbine gov- ernors, although achieved from the experimental standpoint almost exclusively, has been remarkable. Instances are now by no means uncommon where hydro-electric units working upon variable loads are controlled as , satisfactorily as modern steam driven units. To accomplish this result the conditions must be especially favorable. 444 The Speed Regulation of Turbine Water Wheels. Success in this feature of hydro-electric design is by no means uniform, however, and the fre.quent failure to realize satisfactory results can often be ascribed to the lack of proper consideration of the arrangement of the mechanical, hydraulic, and electrical ele- ments of the plant, wheels, and generators, rather than to any in- herent defects in the governor itself. The power plant, the tur- bines, the generators, and the governors are commonly designed by four different parties without proper correlation of study and de- sign. At present neither experimental data nor theoretical formula are available by which the hydro-electric engineer can design hi? plant for an assumed speed regulation, or can predetermine the speed regulation which is possible with a given installation or the 120 140 PERCENT OF NC3MAL CANDLE PCWER i60 130 Fig. 273. time required for the return to normal speed, and yet the gov- ernor builder is. commonly required by the engineer to guarantee these operating results. The predetermination oif speed variations 'during portions of the steam cycle and at load changes has received careful study in the design of reciprocating steam engines and the desirable per cent of speed regulation is freely guaranteed and readily obtained through careful study and analysis by the designer. The same amount of study is warranted but seldom or never given to the problem of speed regulation in water power work. 208. Value of Uniform Speed. Uniform, or nearly uniform, speed is of great economic value in the operation of a plant but adds to the first cost and may also result in a waste of water. The cor- rect solution of any given problem of speed regulation involves a compromise between first cost, water economy and speed regula- tion. A pecuniary value cannot well be placed upon good speed regu- lation. It differs from poor speed regulation chiefly in procuring a more satisfactory operation of motor driven machinery and in pro- ducing a more constant incandescent light. Fluctuations in the brightness of a light are annoying, and tend to create dissatisfac- tion among consumers. Fig. 273 shows the general way in which The Problem. 445 the candle power of an incandescent light varies with the impressed voltage.* A pressure variation of 5 per cent., and hence also a speed variation of a similar amount, is shown to produce a much larger variation in candle power of the light, in this case about 25 to 30 per cent. 209. The Problem. Where (as in Fig. 271) a turbine is operating under balanced conditions and the resistance changes in magni- tude, the turbine does not at once assume the new speed relations corresponding to the change in resistance. The inertia of the mov- ing parts of the wheel and of the column of water in the penstock, Fig. 274. Fig. 275. turbine and draft tube, tends to maintain uniformity of speed, and the wheel gradually changes in speed to that corresponding to the new conditions. In such cases the speed of operation is not essen- tial and the delay in reaching the speed corresponding to the re- sistance or work the turbine must perform is usually unimportant. When, as in Fig. 272, the wheel is designated to operate at a fixed speed, the uniformity of speed becomes a matter of greater or less importance depending on the character of the work the wheel is to perform. In this case the inertia of the wheel and of all rotat- ing parts of other machinery connected thereto tends to maintain a constant speed. On the other hand, the flow of water in penstock, turbine, and draft tube must ,be changed in quantity, (Eq. 2), hence in velocity, and its inertia therefore tends to produce a change in head and to produce effects opposite to those desired for efficient regulation. The conditions of installation have a marked effect on the diffi- culties of turbine governing. If (as in Fig. 274) the turbine is in- stalled in an open pit and has only a short draft tube, and the water * See American Electrician, Vol. XIII, No. 7. July, 1901, by F. W. Wilcox. 27 446 The Speed Regulation of Turbine Water Wheels. flows to the gates from every direction, the velocity of flow from all directions is very low. The quantity of water which moves at a high velocity in confined to that in the wheel and draft tube and the change in the velocity and momentum, due to a change in the gates, produces no serious effects. If, however, water be con- ducted to and^from the wheel through a long penstock and draft tube (as illustrated by Fig. 275) the conditions become quite differ- ent. In this case a large amount of. energy is stored in the moving column of water and a change in its velocity involves a change in its kinetic energy which may, if an attempt is made at too rapid reg- ulation, leave the wheel deficient in energy when increased power is desired, or, when the power is decreased, may produce such shocks as will seriously affect regulation or perhaps result in .serious in jun- to the penstock and wheel. 210. Energy Required to Change the Penstock Velocity. An increase or decrease of load requires an ultimate increase or de- crease in velocity of the water in the penstock. Work has to be done upon the water to accelerate it and must be absorbed in order to retard it. The total available power which can be expended for all purposes at any instant during the acceleration is (since vH is proportional to qH)' proportional to the product of the instantane- ous velocity and the supply head. This total power is thus defi- nitely limited and, hence, the work required to accelerate the water must be obtained at the expense of the work done upon the wheel. Thus, when an increase of load occurs the gate is opened by the governor, and the immediate result is a decrease in the power out- put of the wheel, even below its original value, and is diametrically opposed to the result desired. This counter effect may last for sev- eral seconds, and, unless sufficient reserve energy in some form is available to partially supply this deficiency, the speed of the wheel may fall considerably before readjustment to normal power can take place. In the same way an excess of energy must be absorbed to de- crease the velocity at time of decreasing load. This may be ex- pended upon the wheel thus increasing the speed above normal, or it may be dissipated in one of several ways to be discussed later. The water in the draft tube must be accelerated and retarded at each change of gate opening and its kinetic energy changed at the expense of the power output in exactly the same manner as that in the penstock. For this reason it should be included in all calcula- tions as a part of the penstock. One additional precaution must be Hunting or Racing. 447 taken : if the draft head is large a quick closure of the turbine gate may cause the water in the draft tube to run away from the wheel (actually creating a vacuum in the draft tube) and then return again causing a destructive blow against the wheel. 211. Hunting or Racing. The regulation of both steam engines and hydraulic turbines as now accomplished is one of degree only since a departure froim normal speed is necessary before the gov- ernor can act. Since the immediate effect of the gate motion is op- posite to that intended, the speed will depart still further from the normal. This tends to cause the .governor to move the gate too far with the result that the speed will not only return to normal as soon as the inertia of the water and of the rotating parts is over- come, but may rush far beyond normal in the opposite direction. The obvious tendency is thus to cause the speed to oscillate above and below normal to the almost complete destruction of speed reg- ulation. A successful governor must therefore "anticipate" the effect of any gate movement. It must move the gate to, or only slightly be- yond, the position which will give normal speed when readjust- ment to uniform flow in the penstock has taken place. A governor with this property or quality is commonly said to be "dead-beat." In Chap. XX several expedients are shown for the automatic elim- ination of excessive racing. 212. Nomenclature. The following symbols will be used in the mathematical discussions which follow : A = cross-sectional area of penstock in sq. ft. R V + V ~-^=^ c = friction coefficient for flow in pipe lines = (1 -f- f -^ 4- etc.) D a = maximum rise of water in standpipe above the forebay when full load (v = Vf) is rejected by the wheels. D' = drop of water in standpipe below original friction gradient all in- fluences considered. D =' ditto, friction in penstock neglected. Db = drop of level in standpipe below forebay. d = diameter of penstock (closed circular) in feet, e 2.71828 = base of natural system of logarithms. F = cross-sectional area of the standpipe in square feet, f "friction factor" in penstock, g = acceleration due to gravity in feet per second. H total available power head in feet. H' = effective head at the wheel = H h for any given uniform velocity, V, in the penstock. 448 The Speed Regulation of Turbine Water Wheels. h = instantaneous effective head at the wheel during changes of velocity in the penstock, hg = head which is effective at any instant in accelerating the water in the penstock and draft tube. h F = friction loss in penstock for normal flow with a given head and gate opening, hf = variable head lost by friction entrance, etc., in penstock when the velocity is v. I = moment of inertia or fly wheel effect of revolving parts in pounds at one ft. radius = ft. 8 Ibs. K = energy delivered to the wheel. A K = excess or deficient energy delivered to wheel during change of load. A, Ki = excess of deficient energy delivered to wheel due to excess or defic- iency in quantity of water during load change. A 2= ditto, due to energy required to accelerate or retard the water in the penstock . A Ka ditto, due to sluggishness of gate movement. K' = kinetic energy in foot pounds of revolving parts at speed S. A K' increment (+ or ) in K' due to load change. 2.31V 1 1= length of penstock in feet. M = slope of the v-t curve when v = ^-~ (equation 19). Po = initial horse power output from the water wheel. pi = the horse power output from the water wheel corresponding to the new load. Q = discharge of the wheel under normal effective head H' for any given load, q = instantaneous discharge of wheel in cubic feet per second during load change. R = ratio of actual deficient or excess work done on wheel to that com- puted. S = normal r. p. m. of the wheel and other rotating parts. A S S Si = temporary change in speed. Si = speed in revolutions per minute after load change. T' = approximate time required lor acceleration or retarding of water from velocity v to vi. T" = the time required for the governor to adjust the gate after a change of load. t = variable time after gate movement. V - normal (and hence maximum possible) velocity in the penstock with given head and gate opening, v = instantaneous variable velocity in the penstock while adjusting to a new value. v = velocity in penstock at the instant of gate change. Vj = velocity in the penstock required for new load. Water Hammer. 449 w = weight of a cubic unit of water in Ibs. Y = maximum departure of head, h, from normal with use of stand- pipe, discharge of wheel assumed constant at the abnormal head (see D a and D b ). y = variation of water level in the standpipe from forebay level = H h. d = speed regulation or per cent variation of speed from normal. 213. Shock or Water Hammer Due to Sudden Changes in Ve- locity. The acceleration or retardation of a moving body requires an unbalanced force. Since acceleration and retardation are iden- Fig. 276. tical, except as to sign, the required accelerating force may in all cases be expressed as follows : Force = mass X acceleration. Acceleration, or the rate at which the velocity increment in- creases per increment of time, is expressed by the formula : dv (3) Acceleration r The mass of water to be accelerated is (4) Mass Alw Figs. 276 and 277 show the conditions existing during an in- crease and decrease of velocity respectively. If the draft tube were closed at the lower end and no water leaving, there would be a total force, equal to the hydraulic pressure over the area of the penstock, or wAH, tending to move the water. 450 The Speed Regulation of Turbine Water Wheels. If the water is flowing with a velocity v the turbine offers a re- sistance to flow represented by the effective head, h, at the wheel, and the penstock offers a resisting head h F composed of friction, en- trance, and other losses. If the velocity remains uniform, h=H', and the forces are balanced thus: (5) H = H' + h P If the opening of the turbine gate is now suddenly increased, the head H' at the wheel, will fall to the value, h, (shown in Fig. 276) which is required to force the given amount of water, Av, through Fig. 277. the wheel. On the other hand, if the gate opening is decreased the pressure head must rise above H' (as shown in Fig. 277) in order to discharge the water through the wheel. This change h a in the head H' disturbs the equilibrium of forces shown by equation (5) making (6) h a = H h h f Only the head h a is effective in accelerating or retarding the water and the force resulting from this head is wAh a . Substitut- ing this value and those of equations (3) and (4) in equation (2) we obtain: Alw dv dt or (7) dv of velocity change) Permissible Rate of Gate Movement. 451 The value of h a given by formula (7) is a general expression for the change in pressure-head due to a change of velocity or for the head which must be impressed to produce a desired change in velocity. When in excess of the static pressure as shown in Fig. 277, it is commonly called "water hammer." (See Appendix A.) If the closure of the gates is rapid the value of h a is large and the column of water is set into vibration or oscillation. If the partial closure of gate is sufficiently slow to allow a distribution of each increment of pressure along the pipe, this oscillatory wave is avoided and the pressure produced at, any instant during closure (given by equation (7) is that which is necessary to retard the moving column of water at the rate at which its velocity actually decreases at that instant and can be reduced below any assumed maximum allowable value by a sufficiently slow, gate movement. When a penstock is long, these oscillatory waves become a source of great danger to ,the turbines and also to the penstock, especially at bends. The extinction of a velocity of 4 feet per second at a uniform rate in one second in a pipe 1,600 feet in length would create a pressure-head of about 200 feet, or a total longitud- inal thrust on the pipe line at each bend, and upon the wheel gate, if 24" in diameter, of abo ( ut 20 tons. These dangers are further augmented by the fact that several waves, if succeeding each other by an interval which is approxi- mately a multiple of the vibration period of the pipe, may pile up, so to speak, crest upon crest and cause a pressure which no possi- ble strength of parts could withstand. Fig. 278. 214. Permissible Rate of Gate Movement. Gate movements must be sufficiently slow to avoid oscillatory waves of dangerous amplitude. No general quantitative rule can be given for the re- quired rate o;f movement. It can be more rapid the shorter the penstock and the smaller the velocity in the same. The danger is much smaller during opening than during closure of a gate and 452 The Speed Regulation of Turbine Water Wheels. the rate of gate .movement could well be made much more rapid in the former than in the latter case. The rapidity with which a gate should be opened is limited for feeder pipes with an initial flat slope as shown in Fig. 278. Let h' be the lowest head obtained in opening the gate at an as- sumed rate and AB, the resulting hydraulic gradient. In case the gate opens so v rapidly as to cause the distance, a, at any point along the pipe to exceed suction limit, the water column m the penstock will separate (the portio,n of the column above A not being able to accelerate as rapidly as that below) and will again reunite with a severe hammer blow. Failure to- observe this precaution probably caused the destruction of the feeder pipe of the Fresno, California, power plant. The rate to be used can be chosen after a determina- tion, by the method discussed in Appendix A, of the pressures re- sulting from several assumed rates of movement. The method is te- dious but justifiable in many cases. 215. Regulation of Impulse Wheels. It is impracticable, if not impossible, to build a pipe line strong enough and well enough anchored at all points to withstand the enormous pressures and longitudinal thrusts which would result from rapid gate closures in a long closed penstock such as commonly used for impulse wheels. The adjustment of quantity, q, for changes in load % of short duration is hence impossible in such closed penstocks and the expedient usually adopted is to "deflect" the jet from the wheel by changing the direction of discharge of a pivoted nozzle. This re- quires that the "needle valve" (See Fig. 195) or gate maintain a jet sufficient to carry peak loads ; hence causing a waste of water at all other times. This condition is commonly improved somewhat by adjusting the valve about once each hour by means of a slow motion hand wheel for the maximum peak load liable to occur during that hour. An automatic governor has recently been invented which moves the needle valve or gate slowly, thus adjusting for changes of load of long duration while it still retains the deflector to provide for abrupt changes in the load curve. (See Fig. 282.) Another device proposed fo>r use in this connection is a by-pass nozzle arranged to open as the needle valve rapidly closes, and then automatically close again at a rate sufficiently slow to reduce the ex- cess pressure to safe limits. One advantage in favor of this ar- rangement is that the jet would then always strike the center of the buckets which is found to considerably reduce their wear. Influence Opposing Speed Regulation. 453 An automatic relief valve of hydraulic or spring type is nearly always used but serves more as an emergency valve to reduce water hammer pressures than as a by-pass to divert water from the wheel for the purpose of governing? For this latter use the spring type of valve has proven unsatisfactory. In some cases the water discharged from high head plants is used below for irrigation and must be kept constant, thus doing away with the necessity of varying the velocity in the feeder pipe for a varying load. Mr. Raymond D. Johnson proposes for these high head plants, the use of large air chambers or "Surge Tanks," placed near the wheels, of a sufficient size so that the governor can control the needle valve directly, thus dispensing with the deflector and by- pass and doing away completely with the waste of water occa- sioned by their use. He has derived formulas by which he claims to accurately proportion these tanks for an assumed maximum allow- able range of head fluctuation or surge.* 216. Influences Opposing Speed Regulation. Abrupt changes in the demand for power of a considerable proportion of the total capacity of a plant, take place at times in modern power plants. Three causes tend to make the change in output of a wheel lag be- hind the change in demand placed upon it; viz.: (i) the fact that the governor, however sensitive, does not act until an appreciable change of speed occurs, and then not instantly; (2) the fact that some time is required for the readjustment of penstock velocity, even after the gate movement is complete ; (3) the necessity of changing the velocity, and hence of overcoming the inertia of the water in the penstock and draft tube at each change of load. Each of these influences is directly opposed to speed regulation, as will appear in the succeeding articles, since each causes the power supplied to a wheel, at time of increasing load, .to fall short of the demand, the deficiency being supplied at the expense of the speed from the kinetic energy stored in the rotating parts. The ex- pression for the total deficient work, i. e. footpounds, is: (8) A K = A Ki + A K 2 + A K 8 for which see equations 22 and 23 and Section 221. 217. Change of Penstock Velocity. Assuming the gate move- ment to take place instantly, we will have the condition illustrated * See "The Surge Tank in Water Power Plants," by R. D. Johnson. Trans. Am. Soc. M. E., 1908. 454 The Speed Regulation of Turbine Water Wheels. in Figs. 276 or 277, for which equation 7 was derived (See Section 213). Solving equation (7) for -^- we have: dv 2* sr (9) Acceleration r = -f- X (accelerating head) = -f- h a Qt 1 1 The accelerating head as shown in equation 6 is H h h f . It is the general principles of hydraulics that the head lost in flow through any opening, pipe, orifice, etc., varies as the square of velocity. It was shown in Section 160, Chapter XIV, that the quantity flowing through a turbine varies as the square root of the head. Remembering that the quantity is proportional to the penstock velocity, we have : q v Vh (10) -Q = y- = /TJ > from which XT 2 h = V 2 12) h f = (l+f. 2g (is) --:---w Or (14) h f =4^h F From equation (6) h. = H-h-h f = H-H'^---h F -IL or (15) h a = H (H' + h F )^- And from equation (5) Hence from equation (9) dt 1 V 2 The integration of this equation as given in Appendix B gives the follpwing equation for the curve of velocity change in the pen- stock a sudden change of gate opening: (18) Bantilogk't-1 Bantilogk't + 1 As shown in Appendix this value of v approaches but never equals the value of V. The form of the curve for an increasing velocity is shown in Fig. 279. * See Merriman's Treatise on Hydraulics, Effect of Acceleration on Water Supplied to Wheel. 455 218. Effect of Slow Acceleration on Water Supplied to Wheel. Since velocity in the penstock, discharge of wheel, and loacl are approximately proportional to each other, the ordinates of Fig. 279 may be taken to represent loads. The load demand remains at a constant value v from A to B, where it suddenly increases to YJ, following the line A B C D T. The supply, however, assuming an instantaneous gate movement, follows the line A B D F. Now, the total quantity of water supplied to, and hence Fig. 279. the work (not power) done by the water upon the wheel, is propor- tional to the area generated by an ordinate to the latter, and the demand upon the wheel to the area generatd by the power curve. The area B C D B therefore represents a deficiency of developed w r ork which must be supplied by the energy stored in the rotating parts. For practical purposes this area may be assumed equal to the area L of the triangle B' C' D', where the line B' D' is tangent to the curve B M D at the point of mean velocity -o-^ The slope of the line B' D' for this mean velocity is readily ob- tained from equation 17. Call it M, then pr _ B' C' _ vi v o _ gH |~ (v + vi C' D' ~ T' "Tl 4V 2 (19) and 4 56 The Speed Regulation of Turbine Water Wheels. (21) Area B'C'D' = L This value of L is expressed in feet and represents the deficiency of lineal distance moved by the water column in the penstock. The deficiency of supplied water in cu. feet is, hence, A L and the de- ficiency of undeveloped work is (22) A K, - ALwH = -. ( vi - v ) 2 219. Value of Racing or Gate Over-Run. At D, Fig. 279, the supply line B D F crosses the load line C D E, and the speed which was lost from B to D begins to pick up again. The necessity also for an overrun of the governor is shown by Fig. 279. If the demand line were A B N F and the gate opened to the same place as before, giving the supply line B D F, the sup- ply of power would approach, but theoretically never equal, the demand and the speed would hence never pick up to normal. The NORMAL GATE - f> EW LOAD _______ NORMAL GATE - OLD LOAD __ Fig. 280. gate movement should therefore be similar to that shown in Fig. 280 in order to give the gate the small overrun which is necessary to bring the speed back to normal. 220. Energy Required to Change the ,Penstock Velocity. The energy involved in the change of velocity above described results in an excess or deficiency of energy delivered to the wheel (See Sec- tion 210). The amount of this excess or deficient energy is readily determinable. The kinetic energy in foot pounds stored in the moving column of water is K 2 = - O r , The amount which must be diverted from the wheel or dissipated when the velocity changes is therefore (23) A K 2 = 0.972 Al (vi 2 v 2 ) In this case it should be taken as the combined length of penstock and draft tube. The Fly- Wheel. 457 This deficient energy must be supplied, or the excess absorbed, by means of a flywheel or 'the installation of a stand-pipe connected with the penstock closely adjoining the wheel. 221. Effect of Sensitiveness and Rapidity of Governor. Referring again to Fig. 279, suppose the increase of load to take place at B'" giving the load line AB"' C" E. After -an interval from B'" to B", the speed has dropped an amount depending upon the sensitiveness of the governor. The gate will then begin to open ; the velocity in the penstock accelerating meanwhile along the dotted line B'"Y. The lack of sensitiveness of the governor has therefore added a de- ficient work area of B'" B" C" C'", and the sluggishness of its mo- tion an additional area C"B" B C, approximately. This deficiency A K 3 can be only roughly approximated without the detailed analy- sis given in Appendix B. 222. The Fly-Wheel. A fly-wheel is valuable for the storage of energy. Work must be done upon it to increase its speed of rota- tion, and it will again give out this energy in being retarded. From the laws of mechanics the number of foot pounds of kinetic energy stored in a body by virtue of its rotation is given by the formula : _2X 3.1416' ' ~iW ~ 32~15 X 60* (24) K' = .00017 IS 2 The amount of energy which must be given to or absorbed from the fly-wheel in order to change the speed is : (25) AK' = 000171 (? 2 Si 2 ) Thus a fly-wheel can store, energy only by means of a change in speed. By means of a sufficiently large moment of inertia the speed change of a fly-wheel, for any given energy storage, A 1C, can be re- duced to any desirable limit. The need of a fly-wheel effect to carry the load of a hydro-electric unit during changes of gate, and while the water is accelerating in the penstock at an increase of load has led to, the development of a type of revolving field generator, whose rotor has a high moment of inertia and is therefore especially adapted for speed regulation usu- ally making the use of a fly-wheel unnecessary. Warren* has simplified the expression for AK' (See equation 25), substantially as follows: * See "Speed Regulation of High Head Water Wheels," by H. E. Warren, in Technology Quarterly, Vol. XX. No. 2. 458 The Speed Regulation of Turbine Water Wheels. From equation (24) : (ae) |V = ^ = *; Hence, K 2 .0001/ I 02 82 (9-?\ Ki'-K,' _ S^-S 2 2 (Si + SQ (Si -SQ K/ ~~S?~ tf*' Put Si S 2 = A S and Ki x K 2 X = A K r For small differences between S, and S 2 equation (27) becomes approximately : A ~LT/ OQ \y AG O \/ A C (28) AK 2SXAS = 2XAS Qr JV (32 *5 (29) A K' = ^ Or the percentage change in speed is (SO) d = 100X 223. The Stand-Pipe. The function of the stand-pipe is two- fold: (i) to act as a relief valve in case of excess pressures in the penstock ; (2) to furnish a supply of energy to take care of sudden increases of load while the water is accelerating, and to dissipate the excess kinetic energy in the moving water column at time of sudden drop in load. For these purposes it should be of ample diameter and placed as close,to the wheel as possible. The analytical determination of the effect of a given stand-pipe upon speed regulation is very difficult if not quite impossible. Fur- thermore, it is not necessary, since the drop in effective head at an increase of load may (except in the case of maximum possible load) be compensated for by an increase of gate opening, hence main- taining a constant power and speed or at least a satisfactory degree of speed regulation. Thus the action of a stand-pipe in storing energy differs radically from that of the fly-wheel as the latter can store or give out energy only by means of a change of speed in the generating unit. The determination of the range of fluctuation of water level in an assumed stand-pipe, and the time required for return to normal level for various changes of load on the, wheel, will assist greatly in the design of the stand-pipe. Fig. 281 shows the condition when a stand-pipe is used. Assume that the wheel is operating under part load. The water normally stands a height h F below the supply level. If the load suddenly in- creases, the gates open, and the water level begins to fall, thus caus- ing an accelerating head h a = H h -- h f . Equation 9 then applies as before, where h a becomes (h cv 2 ). The Stand-Pipe. 459 If the governor keeps step with the change in head by increasing the gate opening to maintain a constant power then (31) q h = qi hi q (H y) = Avi (H h F ) = Avi (H cvr ) _ Avi (H cvi 8 ) or H y The rate of water consumption by the wheel at any instant is q ; the rate at which the water is supplied by the penstock is Av; and the rate of rise or fall of the water surface in stand-pipe is there- fore : ,o 2] dy __ dh _ Av - q _ A T vi (H-cvi 2 ) 1 dF".~dT- ~F~ "FT H-y The solutions of equations 9 and 32, which are necessary for determining the curves of variation of head and velocity, is imprac- Fig. 281. ticable, if not impossible, hence a different treatment is proposed and considered in Appendix C. If q be assumed constant (=Av 1 ) during the adustment of pen- stock velocity and the friction loss, cv 2 , in the penstock be neglected, then equations 9 and 32 simplify and become integrable. The re- sulting equations, showing the variations of v and y, are true har- monics or sine curves. The effect of friction and governor action is to produce a damped or somewhat distorted harmonic as discussed in Appendix C. Any change of load thus starts a series of wave like fluctuations of penstock velocity and stand-pipe level which con- tinue until this wave energy has been entirely expended in friction. 460 The Speed Regulation of Turbine Water Wheels. Analogous to all other wave motions these waves may pile up, (if two or more gate movements succeed each other by short intervals which are approximately multiples of the cycle, 2T) causing a very great flucuation in head and velocity. In fact by assuming a proper combination and succession of circumstances no limit can be as- signed to the range of fluctuation or "surge" which may occur. The probable combination of circumstances which will occur in any plant depends largely .upon the character of the load. Overflows from stand-pipes due to these surges have been known to do con- siderable damage and it is desirable to either provide for this over- flow either at the top or by relief valves at the bottom, or build the stand-pipe high enough to prevent it and thus gain the addi- tional advantage of conserving the water which would otherwise waste. If the change of load is assumed to occur when the water is at its normal level then the analysis given in Appendix C furnishes the following formulas : "A* (34) (35) D*-2HD= -(vi 8 - (36) (37) The value of T from equation (33) is one-half a wave cycle or the time required for return to normal head after a change of load. It is obtained by neglecting both friction and the compensating effect of the governor. These influences increase T in very nearly the ratio that D exceeds Y. Y from equation (34) is the maximum head fluctuation, or maxi- mum value of y, also obtained by neglecting friction and governor action. D from equation (35) is the maximum drop in standpipe level corresponding to Y except that governor action is included. If this value of D is added as shown in equation (36) to the initial friction loss, cv 2 , the result agrees very closely with the value of the maximum drop D where friction is included and is much more simple than the more exact equation given in Appendix C. A reasonable assumption for determining the probable maximum height to which the water will rise in the stand-pipe is that full Predetermination of Speed Regulation. 461 load is instantly thrown off the unit when the normal full load ve- locity v f exists in the penstock. This assumption leads to equa- tion (37). The verification of these formulas and some additional ones is given in Appendix C, and an example of their application in sec- tion 230. 224. The Air Chamber. There is a practical limit to the height to which a stand-pipe can be built. A high stand-pipe is also less effective due to the inertia of the water in the stand-pipe itself which must be overcome at each change of load, thus introducing to a lesser degree the same problem as in a penstock without stand-pipe. For some such cases the top of the tank can be closed and furnished with air by a compressor. The design of air chambers has been in- vestigated by Raymond D. Johnson.* An air chamber is less effec- tive in equalizing the pressure than a standpipe of the same diam- eter. 225. Predetermination of Speed Regulation for Wheels Set in Open Penstocks. The influences which oppose speed regulation have been partly discussed. At an increase or decrease of load there is a deficiency or excess of developed power due to (i) the inability of the governor to move the gate upon the instant that the load changes; (2) the necessity of accelerating or retarding the water in the penstock and draft tube as previously discussed. If no stand- pipe is used, reliance must be placed upon the fly-wheel effect of turbine, generator and additional fly wheel, if necessary, to absorb or give out the excess or deficiency of input over output of the plant at this time. The first influence opposed to speed regulation, that of slow gate movement, is of chief importance (a) where the plant is provided with large open penstocks and short draft tubes ; (b) where an am- ple stand-pipe, placed close to the wheel, and a short draft tube are used; (c) in the regulation of an impulse wheel where no at- tempt is made to change the velocity of water in the feeder pipe. Mr. H. E. Warrenf has analyzed this case essentially as follows: "As long as the output from the wheel is equal to the load, the speed S and kinetic energy K' of the revolving parts will remain constant. The governor is designed to adjust the output of the wheel to correspond with the load, but it cannot do this instanta- * See Trans, of Am. Soc. M. E., 1908. t See article by H. E. Warren on "Speed Regulation of High Head Water Wheels," previously referred to in Section 222. 28 462 The Speed Regnlation of Turbine Water Wheels. neously. Consequently, during the time T required to make the adjustment of the control mechanism after a load change there will be a production of energy by the water wheel greater or less than the load. The entire excess or deficiency will be added to or sub- tracted from the kinetic energy of the revolving parts, and will be- come manifest by a corresponding change in speed. Neglecting friction losses, and assuming that the power of the water wheel is proportional to the percentage of the governor stroke and that the movement of the governor after a load change is at a uniform rate, the excess or deficient energy which goes to or comes from the revolving parts after an instantaneous change of load from L to Lj is measured by the average difference between >the power of the wheel and the new load during the time T", while the gover- nor is moving, multiplied by T" or expressed in foot pounds : (38) A K' = P ~ Pl X T" X 550 From equation 24 the kinetic energy of the rotating parts is : K' = .00017 IS 8 From equations 24, 30 and 38 50X(p pi)T*X560 2X -00017 IS 2 (39) * = 81, 000, 000 ^5- ( Po - pi) 226. Predetermination of Speed Regulation, Plant with Closed Penstock. In this case the rotating parts must absorb or deliver up an amount of energy AK' (equation 29), equivalent to that given for AK in formula (8) AK = AKi+ AK 2 + AK 3 where, from equation 22, (22) AKl M being obtained from equation The value of A K 2 is obtained by equation (23) AK 8 = 0.972 Al (Vi 3 v 2 ) There is no simple way, as discussed in section 221, of determin- ing K 3 . It must be estimated or analyzed graphically as in Appen- dix C. From equation (24) K' = .00017 IS 2 Predetermination of Speed Regulation. 463 If R is the proportion of this theoretical energy which is given to the rotating parts at a decrease in load, or which the rotating parts must give out during an increase of velocity and load then (40) AK' =RX AK and we have from equation 50 X R X A K (30)- AK' = K' 50 x R X A K .00017 I (41) 5 = 294,000 RX AK !S S Solving for I we find the moment of inertia of the rotating parts, which is necessary to obtain any desired percentage of regulation to be (42) Although there can be no doubt as to the accuracy of the form of equations 41 and 42 yet their value for other than comparative pur- poses depends upon the accuracy with which we can estimate R. With perfect efficiency of the wheel under all conditions, R would be unity, but in actual cases R must be determined by experiment or by the graphical method given in Appendix B. It will be less for decreasing than for increasing loads since the inefficient operation of the wheel assists speed regulation in the former case, and hinders it in the latter. In addition to this fact, the excess energy at a de- crease of load can be partially dissipated through a relief valve, or a by-pass, etc. For practical cases it is therefore necessary to in- vestigate only the case of increasing load. A detailed analysis of a particular problem can be made, as in Appendix B, by which the velocity in the penstock, effective head, power of wheel, speed, etc., can be determined for each instant dur- ing the period of adjustment. From this also the time of return to normal speed can be determined. The method is somewhat tedious, but justifiable nevertheless. 227. Predetermination ' of Speed, Regulation, Plant with Stand- pipe. If the stand-pipe is of suitable diameter and close to the wheel the speed regulation will approach that obtainable in open penstock and as investigated by Warren in Section 225. Otherwise the prob- lem becomes that of a plant with a closed penstock, of a length equal to that of the draft tube, plus the penstock from stand-pipe to wheel. 464 The Speed Regulation of Turbine Water Wheels. 228. Application of Method, Closed Penstock. An example of the analysis of a problem in speed regulation is as follows : Assume the 48" Victor cylinder gate turbine, whose characteristic curve is shown in Fig. 245, page 402. Suppose it is supplied with water through a penstock whose diameter is 8 feet, jand whose length combined with that of the draft tube is 500 feet. The head is 50 feet which for ^=.664 gives 180 R. P. M. = S. Neglecting all losses of head except that in the turbine, we find from the characteristic curve for various loads as follows : Full load. .8 Load K Load. M Load. Brake Hors6 Power ll'^O 00 900 560 00 280 00 Qu&ntity of water p6r S6C ( cu ft 240 00 210 145 00 97 80 Velocity in Penstock V. 4 77 4 18 2 88 1 94 Efficiency of wheel 82 754 68 505 The above values will be considered as applying to the entire plant since the loss in the penstock is small in this case. Assume the load to increase suddenly from one quarter load to 0.8 load, while the gate at the same time opens to full load posi- tion. The nujmber of foot pounds of work which must be done to accelerate the water from a velocity of 1.94 feet per second to 4.18 feet per second is found from equation 23 to be AK 2 =0.972 Al K 3 v 2 ) = 0.972 X 50.3 X 500 (4.18 2 1.94 2 ) = 0.972 X 50.3 X 500 X 13.73 = 335,000 foot pounds. Referring to section 226, p. 462, to find the amount of deficient work due to insufficient supply of water we have From equation 19, section 226 32.15X50 500 V 4 X 4. - 32.15X50 500 = 2.88 From equation 22, -MXJ^^.^. = 187, 000 foot pounds. Predetermination of Speed Regulation. 465 The total deficiency for which formulas have been derived is hence, AK AKj + K 2 + (AK 3 undeterminable) = 335,000 + 137,000 = 472, 000 + ft Ibs. By means of the detailed graphical analysis given ,in Appendix B this deficiency is found to be 600,000 foot pounds for gate move- ment in one-half second showing that the estimated value should have been increased in this case by 12.7 per cent. (R = 1.127) to compensate for neglecting the effect of slow (% second) gate move- ment, or K 3 . It must be remembered that this quantity, AK, is the deficiency of ^theoretical hydraulic work done upon the wheel. For reasons discussed in Appendix B, it will, however, be found to differ but slightly from the deficiency of wheel output, in this case 586,000 ft. pounds. To determine the speed regulation which can be obtained, as- sume a generating unit whose rotor has a fly-wheel effect, or mo- ment of inertia, I, of 1,000,000 ,lbs. at one ft. radius. The normal speed S = 180, AK = 472,000 ft. Ibs., and R (in general to be esti- mated, but in this case obtained by the graphical method given in Appendix B, is 1,127. Therefore from equation (43) d - 994 000 1 ' 127 X 472 - 000 - 5 42* y4 ' UU 1,000, 000X180*- If a fly-wheel is to be designed for a given regulation say 4 per cent., then the required moment of inertia of same is, from equa- tion (42). I = 294, 000 ^- I ='1,355, 000 ft. 2 Ibs. 229. Application of Method, Open Penstock. As the penstock and draft tube are shortened, the excess or deficient energy area, A K 3 , .obtained during the gate movement becomes an increasing proportion of the whole until for a large open penstock and short draft tube the developed power ceases to lag and follows practically the same law of change as the gate opening. The estimation of excess i'or deficient energy, and consequently of speed, is then very simple by means of Mr. Warrens equation (39). For illustration: assume the same wheel as in the preceeding section, obtaining the outputs of 280 H. P.=P at one-fourth load and 1120 H. P.= P l at 466 The Speed Regulation of Turbine Water Wheels. full load, as in the other installation. Assume the same moment of inertia 1,000,000 and that the gate movement takes place in % second as before. Then T"= % ; S = 180. This gives t = 81.000.000 1>000| x 18Q2 (1120 - 280) = 1.05* This is a much closer regulation than obtained with the long pen- stock. 230. Application of Method, Plant with Stand-pipe. Assume a plant where the wheels develop 39,000 H. P. under 375 head, thereby requiring about noo cu. ft. of water per second (assuming 83 per cent, efficiency of the wheels). Assume this water is supplied through four 7' pipes about 4800 feet long, requiring a velocity in the feeder pipes at full load of about 7.15 feet. Suppose four pipes all connected at the lower end to a stand-pipe 30 feet in diameter. If a sudden load change, of about one third of the total is to be provided for this would require an ultimate change of velocity in the penstock from about 4.76 feet per sec. at two^thirds load to 7.15 feet at full load, or v = 4.76, and v = 7.15. Now, A = 4 X *-= 154 sq. ft, From equation 33 the time required for return to normal head, or the half period of oscillation, is T = This would perhaps be increased to nearly 100 seconds, due to the use of additional water during this period of low head, as discussed in Appendix C, but the value 82 should be used in equation 35. Equation 34 gives for the drop in water level in the stand-pipe, Y = J 154 X 480Q (7.15-4.76) ^707 X 32.15 =1/3275 X 2.39 = 13.6 feet. The more exact equations, 35 and 36, give for D and D, igg( 7 .l5^-4.76 2 )+ 37 f * 82 (7- D 2 750 D + 11,120 = Governor Specifications. 467 Solving this quadratic equation gives D - 750 T/750 2 4 X 11,120 75Q - 719 Qr = 15.5 feet D b = 15.5 + c X 4.76 2 = 15.5 + .176 X 4.76 s = 19.5 feet No attempt will be made 'to estimate the greatest drop in level which might occur, due to an addition of waves. 231. Governor Specifications. The present practice of requiring the governor builder to guarantee the speed regulation of a plant, in the design of which he has had no> voice, without even giving him the necessary information regarding the hydraulic elements which are considered in this chapter is wrong. It is partly the out- growth of the modern tendency to specialize, but perhaps more largely due to a lack of understanding on the part of the engineer of the nature of the problem, and a resulting desire to shift the respon- sibility for results upon some one else who is better informed upon the subject and thus protect results financially as well as save his own reputation in case of failure. Governor specifications should call for a guarantee of the (a) Sensitiveness or per cent load change which will actuate the governor ; (b) Power which the governor can develop, and force which it can exert to move the gates ; (c) Rapidity with which it will move the gates ; (d) Anti-racing qualities, such as number of gate movements re- quired to adjust for a given load change (See figure 280), or per- cent. over-run of the gate, etc. (e) General requirements of material, strength, durability, etc. Beyond this point the governor designor has no control. The engineer can, however, by choosing a generator whose rotor has a high moment of inertia (which quantity should be stated in tenders for supplying the generators), by the addition of a fly-wheel, if necessary ; by the construction of a stand-pipe ; by means of a re- lief valve, and very largely, also, by the general design of the pen- stocks, draft tubes, etc., greatly improve the governing qualities, and, in fact, reduce the speed variation to any desirable limit which the nature of load to be carried, magnitude of load changes antici- pated, and economy of first cost will warrant. 468 The Speed Regulation of Turbine Water Wheels. LITERATURE. TURBINE REGULATION. 1. Williams, Harvey D. A New Method of Governing Water Wheels. Sib. Jour, of Engng. March, 1896. 2. Electric Governors. Eng. News, 1896, vol. 1, p. 276. 3. Parker, M. S. Governing of Water Power Under Variable Loads. Trans. Am. Soc. C. E. June, 1897. 4. Regulation of Wheels. The Chavanne Nozzle Regulator. Mining & Sci- entific Press, Oct. 30, 1897. 5. Knight, Samuel N. Water Wheel Regulation. Jour, of Elec. Nov., 1S97. 6. Replogle, Mark A. Speed Government in Water-Power Plants. Jour. Fr. Inst., vol. 145, p. 81, Feb., 1898. 7. Regulation of Water Wheels under High Pressure. Pioneer Electric Power Co.'s Wheels. Eng. Rec., Feb. 5, 1898. 8. Garratt, Allan V. Elements of Design Favorable to Speed Regulation. Eng. News, 1898, vol. 2, pp. 51-159. 9. Modern Practice in Water Wheel Operation. Elec. World, May 5, 1900. 10. Cassel, Elmer F. Commercial Requirements of Water-Power Governing. Eng. Mag., Sept., 1900. 11. Garratt, Allan V. Speed Regulation of Water Power Plants. Cassier's Magazine, May, 1901. 12. A Water-Wheel Governor of Novel Construction. Eng. News, Nov. 13, 1902. 13. Thurso, J. W. Speed Regulation in Water Power Plants. Eng. News, 1903, vol. 1, p. 27. 14. Governing Impulse Wheel by an Induction Motor. Eng. News, 1903, vol. 1, p. 246. 15. Garratt, Allan V. Speed Regulation of Water Power Plants. Elec. Age, May, 1904. 16. Goodman, John. The Governing of Impulse Water Wheels. Engng., Nov. 4, 1904. 17. Church, Irving P. The Governing of Impulse Wheels. Eng. Record, Feb. 25, 1905. 18. Gradenwitz, Alfred. The Bouvier Governor for Water Turbines. Mach. N. Y. June, 1905. 19. Henry, Geo. J., Jr. The Regulation of High-Pressure Water-wheels for Power Transmission Plants. Am. Soc. of Mech. Engrs. May 1, 1906. 20. Replogle, Mark A. Some Stepping Stones in the Development of a Mod- ern Water-Wheel Governor. Am. Soc. Mech. Engrs. May, 1906. 21. Buvinger, Geo. A. Turbine Design as Modified for Close Regulation. Am. Soc. of Mech. Engrs. May, 1906. 22. Lyndon, Lamar. A New Method of Turbine Control. Proc. Am. Inst. of Elec. Engrs. May, 1906. Literature. 469 23. Water Wheel Governors. Elec. World. June 30, 1906. 24. A New Water Wheel Governor. Eng. Rec. Current News Sup. July 14, 1906. 25. Warren, H. E. Speed Regulation of High Head Water Wheels. Tech. Quar. Vol. 20, No. 2. 26. Johnson, R. D. Surge Tanks for Water Power Plants, Trans. Am. Soc. M. E. 1908. CHAPTER XIX. THE WATER WHEEL GOVERNOR. 232. Types of Water Wheel Governors. In all reaction turbines and in all impulse turbines, with the exception of tangential wheels, the governor affects regulation, i. e. controls the output, and hence the speed of the wheel, by opening or closing the regulating gates, thus varying the amount of water supplied to the wheel. In tan- gential wheels, under high head, this method of control, for obvious reasons (See section 215), becomes difficult and in extreme cases impossible and in such cases the governor must be arranged to af- fect regulation by the 'deflection of the jet from the bucket. (See Fig. 282). Fig. 282. Governing Impulse wheel with Automatic Needle and Deflecting Nozzle (after Warren). The force required to move the turbine gates is large (sometimes 50,000 Ibs. or more) and it is therefore evident that they cannot be moved by the direct action of the centrifugal ball governors, as with steam engines, but must be moved by a "relay." The relay, as its name implies, is a device for transmitting energy from a source of energy independent, as to quantity of the cen- trifugal governor balls but controlled by them in its application. Types of Water Wheel Governors. 471 If the relay is of "mechanical type" the power required to operate it and the gates is transmitted, when needed, from the wheel by means of shafts, gears, friction-clutches, belts and pulleys or other mechanical devices. In mechanical governors the flyballs may actuate pawls, friction gears or other mechanical devices which will bring the relay into action. Pig. 283. Woodward Standard Governor. If the relay is of the hydraulic type, it usually consists of a piston connected by some mechanical device to the gate rigging and moved by means of the hydraulic 'pressure of water taken from the pen- stock, or other source, or by oil supplied under high pressure from a reservoir. The pressure of the oil in the reservoir is maintained by compressed air supplied by power taken from the wheel itself. The oil thus used in moving the piston is exhausted into a receiver from which it is pumped back into the supply reservoir. The hy- draulic relay is commonly controlled by the ball governor through 472 The Water Wheel Governor. the medium of a small valve which by its motion either admits the actuating water (or oil) directly to the cylinder or to a secondary piston controlling a larger admission valve. Electrical methods of actuating the relays controlled by means of governor balls have been used to some extent but are not nearly so common as mechanical or hydraulic devices. Pig. 284. Diagramatic Section of Woodward Simple Mechanical Governor. 233. Simple Mechanical Governors. Fig. 283 is a view and Fig. ,284 a diagramatic section of a simple mechanical governor of the Woodward* Standard type. On the upright shaft are two frictioin pans (a and b). (See also Fig. 287). These pans are loose on the shaft, the upper one being supported in position by a groove in the "hub and the lower one by an adjustable step-bearing. Between these pans, and beveled to fit them, is a double-faced, friction wheel (c) which is keyed to the shaft. This shaft and friction wheel run *Woodward Governor Co., Rockford, 111. Anti-Racing Mechanical Governors. 473, continuously and have a slight endwise movement. They are supported by lugs on the ball arm and therefore rise and fall as the position of the balls varies with the speed. When the speed is normal, the inner or friction wheel revolves freely between the two outer wheels or pans which remain station- ary. When a change of speed occurs, the friction wheel is brought against the upper or lower pan as the speed is either slow or fast. This causes the latter to revolve and, by means of the bevel gearings, turn the gates in the proper direction until the speed is again normal. As the gate opens, the nut (d) travels along the screw (e) which is driven through gearing by the main governor shaft and as the gate reacts, the nut (d) coming in contact with the lever (f) throws the vertical shaft upward and the governor out of commission. This type of governor may be used to advantage where the water wheels operate a number of machines, connected to a main shaft and where, in consequence, the friction or constant load is a considerable percentage of the total load. In such cases the changes in load may not ibe a large percentage of the total load and the temporary variations in speed, which occur at times of changes of load, may not be of sufficient importance to necessitate the installation of a quick acting governor. When the water wheel is direct connected tora single machine, and the friction load is comparatively small, the relative change in load, and the consequent possible changes in speed, is much larger. In such cases the type of governor above shown will result in a serious hunting or racing (See Section 211) of the wheel during considerable changes of load, and in unsatisfactory regulation. In such cases governors with compensating or anti-racing devices must be used for satisfactory regulation. 234. Anti-Racing Mechanical Governors. The Woodward Com- pensating Governor. Fig. 285 is a view and Fig. 286 is a dia- gramatic section of a Woodward vertical mechanical governor of the compensating type. In the simple Woodward governor (See Figs. 283 and 284) the power necessary to actuate both the centrifugal governor balls and the relay is transmitted through a belt to a single pulley, P. In the Woodward compensating type of governor the relay is operated in a similar manner by ;a single pulley, P, while the centrifugal governor balls are actuated by an independent pulley, q, having an independent belt connected to the wheel shaft or to some other re- 474 The Water Wheel Governors. volving part connected therewith. From the driving pulley, q, power is transmitted to the governor balls through a shaft and gearing. The shaft supporting the centrifugal governor balls is hollow, and on the ball-arms are two lugs which connect with a Fig. 285. Woodward Compensating Governor. spindle (f), which therefore rises and falls as the positions of the governor balls vary with the speed. The movement of the centrifugal governor balls causing the spindle, f, to rise and fall changes the position of the tappet arm, g, to which it is connected, and causes one or the other of the two tappets, tt', to engage a double-faced cam, h. This cam is contin- uously rotated by means of the pulley above it, driven by a belt con- nected with the main vertical shaft of the relay. The tappets are Anti-Racing Mechanical Governors. 475 connected to a common suspension arm to which the vertical spin- dle, f, is attached. The suspension arm is hinged to the lever arm, j. The lever arm is connected to the shaft, K, which can be rotated on its bearings and which is connected with a tension rod, 1, by an eccentric at the bottom. The tension rod, 1, is in turn connected by Fig. 286. Diagramatic Section of Woodward Vertical Compensating Mechan- ical Governor, a lever, m, with the vertical bearing, e, on which the main shaft of the friction cone rests. This bearing is movable around the ful- crum, n, and is counterbalanced by an arm and weight, u. When either of the tappets engages the rotating cam, the resulting movement turns the rocker shaft, K, and, through its connection, raises or lowers the vertical bearing, e, which causes the friction wheel, c, to engage either the upper or the lower of the friction pans, a and b, as in the case of the simple governor. The compensating or anti-racing mechanism is just below the rotating cam. It is essentially alike in all of the Woodward com- pensating types of governors and is described in the governor cata- logue as follows : 476 The Water Wheel Governor. "On the lower end of the cam shaft is a friction disc, r, (Fig. 286) which rests on a rawhide friction wheel on a diagonal shaft. The hub of the friction wheel is threaded and fits loosely on the diagonal shaft which is normally at rest. The effect of the continually rotating friction disc upon the rawhide wheel is evidently to cause it to travel along the threaded diagonal shaft to the center of the disc. When the governor moves to open or close the gate, the diagonal shaft, which is geared to it, is turned and the friction wheel is caused to travel along the shaft away from the center of the disc Fig. 287. Friction Cone and Pans of Woodward Governor. and thus raise or lower the cam shaft so as to separate the cam from the tappet which is in action, before the gate has moved too far, thus preventing racing. As soon as the gate movement ceases the disc causes the friction wheel to return to the center of the disc along the threaded shaft." To prevent the governor from straining when the gate is fully open or closed, suitable cams are mounted on the stop shaft. "When the gates are completely opened, the cam engages the speed lever and holds it down so that it cannot raise the lower tappet sufficiently to engage the revolving cam ; this does not, however, interfere with the upper tappet, to prevent the closing of the gates, should the conditions demand. The closed gate stop acts in a sim- ilar manner on the upper tappet but does .not interfere with the lower tappet being engaged, should the conditions demand that the gate be opened. In addition to these stops, the governor is pro- vided with a safety stop whose function is to immediately close the gates should the speed governor stop through breakage of the belt or any other cause." The Woodward Governor. 477 235. Details and Applications of Woodward Governors. Fig. 287 shows the construction of the friction gearing of the Woodward Mechanical Governor. In the inner friction driving cone, corks are inserted in holes drilled in the rim and these are ground off true so that they project about one-sixteenth inch. This seems to give a very reliable friction surface not readily affected by either water or Fig. 288. Woodward Horizontal Compensating Mechanical Governor at Hy- dro-Electric Plant of U. S. Arsenal, Rock Island, 111. oil, and it is claimed to be superior to either leather or paper for this purpose. In order to cause the friction wheel to engage smoothly and noiselessly, a plunger attached to the shaft, just below the inner friction wheel, fits rather closely into a dash-pot formed in the lower pan. Fig. 288 shows a horizontal compensating type of Woodward governor as installed to control the gates of the turbines in the Hy- draulic Power Plant of the U. S. Arsenal at Rock Island, Illinois. The cables shown at the back of the cut operate the gates of the turbine. On the gate shafts of the latter are sheave wheels to which the cables are attached. These sheave wheels are fitted with 29 478 The Water Wheel Governor. clutches so that any gate may be disconnected from the governor. Each gate is provided with an indicator showing its position This provides means of coupling properly, after being disconnected, without closing the gates of the other wheels. Each governor is arranged to control six turbines, belonging to two different units. Two belts are provided so as to drive from either unit. The gover- Fig. 289. Lombard-Replogle Mechanical Governor. nor can thus be used to control three wheels on either side or all six when the two units are running in multiple. 236. The Lombard-Replogle Mechanical Governor.* Fig. 289 shows a Lombard-Replogle mechanical governor. The principles of operation of this governor are better illustrated in the diagram, Fig. 290. In the diagram A is a spherical pulley with its shaft turned down and threaded as at X. B and B are revolving concave discs lined with leather which are continuously revolving in opposite direc- tions. C and C are lignum vitae pins flush with the leather. D and D are compression springs for controlling the pressure between the disks and the sphere. When the spherical pulley A is shifted from its central position in the line of its axis, the springs are *The Lombard-Replogle Governor Co., Akron, Ohio. The Lombard-Replogle Mechanical Governor. 479 tightened automatically, causing increased traction as the smaller diameters of the sphere engage the larger diameters of the disc. E and E are the centrifugal governor balls so poised as to require the weight of the pulley A to balance them at normal speed. F is a loose collar to allow independent revolution of the balls EE. G is the point of connection between A and the gates or valve rigging of the wheel to be governed. X is the compensating device, and is orernor Ball Fig. 290. Diagram of Lombard-Replogle Mechanical Governor. for the purpose of reducing and controlling racing. Z is a sta- tionary spindle or connecting link between the collar F and the threaded shaft or pulley A. Z is only stationary in reference to revolution, as it rises or falls with the variations of the governor balls. The spherical pulley A is normally at test while the discs BB are continually revolving. A movement of the governor balls raises or lowers the shaft so that the spherical discs rotate the pulley. The greater the displacement of the shaft the more rapid the revolution since the circle of contact on the disc is increased. The rotation of the spherical pulley A either shortens or lengthens the distance to collar F by means of thread X. "This shortening causes A to be pulled back to the disc centers, thereby cutting the governor out of action" and preventing the gates from moving too far or racing. 480 The Water Wheel Governor. Essential Features of an Hydraulic Governor. 481 237. Essential Features of an Hydraulic Governor. The essen- tial features of an hydraulic water wheel governor are : 1. A tank for storing oil under air pressure. 2. A receiver tank for the collection of oil used by the governor. 3. A power pump driven from the water wheel shaft. 4. A hydraulic power cylinder for operating the gates. 5. A sensitive centrifugal ball system for controlling a valve which either admits oil directly to the power cylinder or to an inter- mediate relay cylinder the piston of which operates the admission valve to the power cylinder. 6. An anti-racing or compensating mechanism. The power pump is continually using power from the wheel to pump the oil from the receiver back to the pressure tank thus gradually storing the energy which is used intermittently to oper- ate the gates. Fig. 291 illustrates the Lombard Type "N" Governor and shows -clearly the relations of the various parts of an hydraulic governor. The centrifugal governor balls are connected by belt to the wheel shaft. These balls control a small primary or pilot valve of the cylinder type which admits oil from the large pressure tank under about 200 pounds pressure into one side of a cylinder where its pres- sure is exerted against one of two plungers. These plungers control a large valve, also of the cylinder type, which admits oil from the pressure tank to one or the other side of the power piston. The rectilinear motion of the piston is converted, by rack and pinion, into rotary motion for transmission to the wheel gates. The oil used for operating the power pistons and the plungers of the relay is exhausted into the vacuum tank from which it is pumped back into the pressure tank by means of the power pump shown at the left which is driven by belt from the wheel shaft. The speed variation necessary to actuate the governor depends upon the lap of the pilot valve and is adjustable. 238. Details of Lombard Hydraulic Governor. The details of the Lombard Type N Governor are best shown by the enlarged view of the upper portion of the governor (Fig, 292) and by the sec- tion of the relay valve (Fig. 293). The following description of the operation of this governor is taken from the Directions for Erecting and Adjusting Governors.* "The oil from the pressure-tank is supplied to the working cyl- inder 62 through the large relay-valve 106, arranged to discharge *PubHshel by The Lombard Governor Co., Ashland, Mass. 482 The Water Wheel Governor. or exhaust oil directly and rapidly into or from either end of the cylinder. The relay-valve 106, through the hydraulic system con- nected therewith, is under the simultaneous control of the reg- ulating-valve 14 and the displacement-cylinder 107- This is 10 Fig. 292. Upper Portion of Lombard Type N Governor. brought about in the following manner. The relay- valve A (See Fig. 293) is moved hydraulically by plungers B and C contained within cylinders D and E forming parts of the relay-valve heads F and G. Plunger B has about one-half the area of plunger C, consequently plunger C can over- power plunger B. if the pressure in cylinders E and D is nearly The Lombard Governor. 483 equal. The cylinder D is permanently in communication with the main pressure supply through the pipe H which also furnishes liq- uid to the regulating-valve 14. Therefore the tendency of plunger B is always to move valve A towards the relay-valve head G. Cylin- Fig. 293. Section Lombard Eelay Valve. der E is in communication through pipes I and J with the adjusting- valve 14, and also through the pipes J and K with the displacement- cylinder 107. The regulating valve 14 is capable, when moved in one direction, of admitting liquid under full pressure into the pipe, I, and, when moved in the other direction, of exhausting liquid through the pipe I. In the former case the action is to increase the pressure back of the piston C until it overpowers the piston B, thereby moving valve A towards the relay-valve head F, simulta- neously opening the upper cylinder-port to the main exhaust, and 484 The Water Wheel Governor. the lower cylinder-port to the main pressure supply. Instantly the main piston of the governor and with it the displacement-plunger 109 are set in motion. "As the displacement-plunger begins to move, a space is created back of it, into which a portion of the liquid flowing through the pipe I is diverted. As the motion of the displacement-plunger be- comes more rapid, a condition is reached when all the liquid flowing through I continues on through K into the displacement-chamber. The relay-valve A then ceases to move any further. The motion of the main governor-piston, however, continues as long as the regulating-valve 14 is open. When this valve 14 closes, the relay- valve A is immediately thereafter closed, because the liquid in the cylinder E instantly escapes through the pipes J and K into the space beneath the moving displacement-plunger; thus the whole governor is brought to rest. . "When the regulating-valve 14 is moved in the opposite direction by the centrifugal balls so as to allow liquid to escape through the pipe I, there results an immediate loss of liquid in the cylinder E, back of the plunger C ; this allows the plunger B to force the relay- valve A towards the rday-valve head G, thus opening the lower cylinder port to the exhaust, and the upper cylinder-port to the pressure supply. The main governor-piston instantly begins to move down, carrying with it the displacement-plunger, thus forcing liquid through the pipes K and I, reducing the flow outward through J, until finally the downward velocity of the displacement-plunger becomes rapid enough to entirely check the outward flow through J. Relay-valve A then remains stationary until the valve 14 has moved to a new position. As soon as regulating-valve 14 is closed, the liq- uid which has been flowing out through I immediately flows into J and, acting upon the plunger C, restores valve A to its closed posi- tion, stopping further movement of the governor. It will be seen that the governor when moving has a constant tendency to close the relay-valve which keeps it in motion, and this relay-valve can be maintained open only so long as the regulating-valve 14 is add- ing or subtracting oil to or from the system consisting of the pipes I, J, K, and parts connected therewith." Fig. 294 shows the Lomard Governor, Type R, the smallest of the various governors made by that company. This is a vertical, self- contained oil pressure machine. The oil is stored in a tank formed by the main frame. The governor is designed to exert 2500 pounds The Lombard Governor. 485 pressure and will make an extreme stroke of eight inches in one second. 239. Operating Results with Lombard Governor. Fig. 295 is a cut from a speed recorder strip taken from the Hudson River Fig. 294. The Lombard Type R Governor. Power Transmission Companies plant and shows the regulation of the Lombard Type B Governor regulating S. Morgan Smith tur- bines on an electric railroad load. The cars are large and the change in load rapid and large. 4 86 The Water Wheel Governor. 1 ! Fig. 296 shows the comparative regula- tion of two generators in the same plant. (See Bulletin No. 107 Lombard Gov- ernor Company.) The load was quite variable on account of beaters which had to be driven from the same shaft as the paper making machinery. The original governor used, the work of which is shown in the upper cut, was replaced by a Lom- bard Type D Governor. The work of the latter is shown in the lower tacho- meter chart, and the improvement in the uniformity of operation is readily seen by a comparison of the tw r o charts. 240. The Sturgess Hydraulic Gover- nor.* The Sturgess Type "M" Hydrau- lic Governor, with the omission of the pump and storage tank, is shown in Fig. 297 and in section in Fig. 298. This gov- ernor consists of a shaft-type centrifugal governor G attached to the top of the ma- chine and operated by a belt and pulley P from the turbine shaft. The governor balls BB in this machine control directly by means of a long vertical lever D a small primary or pilot valve S of cylinder type which admits oil to a cylinder controlling the main admission valve S. The main valves, attached to the side of the cylin- der, admit pressure directly into the cyl- inder S and on either side of the piston* S which, by its motion, rotates the gate shaft by means of the concealed steel rack R and pinion N, shown in the sectional view, Fig. 298. The valves for the admission of oil or water, as the case may be, in the cylinder are of the poppet type which avoid lap" and therefore increase the sensitiveness of the governor. The anti-racing mechanism *: Sturgess Engineering Dept. of The Ludlow Valve Mfg. Co., Troy,"N. Y. Operating Results with Lombard Governor. 487 4 88 The Water Wheel Governor. G P B Fig. 297. Sturgess Type M Hydraulic Governor. The Sturgess Hydraulic Governor. G 489 Fig. 298. Section Sturgess Type M Governor. consists of a rod A which is attached to the cross head of the governor. At the top of this rod is a projection to which is attached an adjustable piston rod reaching down into the open top dash pot F. The piston rod has a piston attached at its lower end fitting freely into the bore of the dash pot the top of which is 49 The Water Wheel Governor. formed into a cup which receives the excess oil. The bottom of the dash pot is closed and is attached to a tail, piece connected to the counter weighted locker lever, C. The piston rod and piston are hollow and near the bottom of the piston is a small by-pass which can be regulated by an adjusting screw which controls the rate of flow of the oil in the dash pot. The lever, C, is fixed on the rocker shaft the opposite end of which car- ries the short arm from which a link is carried to the bottom of the valve lever D which is free to move. Two weights, EE, are Speed 8. A B. TACHOMETER No. 10,205 ^Revolution* pc-r Miu. , Revolution* pi-r Mln. L\\\\\\ ffffff , \ \T\T\ \\\\\\\ U \\ \\.\\\\ '. 3 1 11 ''i L "- 1 1 Movements of , ^ A ll ! J In f tr j ; ui jvcraor and Gate' 5 ut U ,i j.,, n| i.'i-t .2 + Closed (/ I V, rr Fig. 299. Test Kesults with Sturgess Governor. hung loosely on the rocker shaft but a pin on the shaft engages with either one or the other of the weights and raises them whenever the rocker shaft moves. The function of the weights therefore is to keep the rocker shaft, and consequently the bottom of the valve lever, in normal position. When the main piston moves, it is ob- vious that it will tend to raise or lower the dash pot, F, through its connection to the ro^d I and this movement will swing the lever C and rocker shaft H thus deflecting the bottom of the valve lever D so as to compensate in the correct manner. The same movement raises one of the weights E, but as the dash pot permits a slow movement the weights will finally restore all parts to the middle or Test Results with Sturgess Governor. 491 normal position. In the smaller sizes the pilot valve is omitted and the centrifugal governor balls actuate directly through the lever the main valves of the system. 241. Test Results with Sturgess Governor. The action of any governor in maintaining a uniform speed may be shown graphi- cally by attaching a recording tachometer to the turbine shaft. In order to fully understand and appreciate the action of the governor, the tachometer chart should be considered together with the load curve and a diagram showing the movement of the governor dur- ing the same period. Fig. 299 shows a governor test made by Mr. John Sturgess on an 1 100 K. W. unit. "The curves were traced by a sp.ecial Schafer & Budenberg tachometer, the readings being sufficiently magnified to bring out the characteristics of the governor. * * * The load changes and governor movements are platted below. Note that when the whole load was thrown off (at 1 :55), the speed accelerated about 8 per cent, in an incredibly short time (under i sec.), and the gov- ernor had the gate shut in 14 sees, after the load went off. * * * It is to be noted that after the first quick result at 2 :oo mins. the governor slowly oscillated for about another minute, but with gradually increasing gate opening, the speed and load being prac- tically constant. This was due to the water rising in the forebay, and gradually subsiding in a succession of waves, the governor tak- ing care of these fluctuations, in effective head, in a very intelligent manner."* "The plant in which these tests were made was by no means a good one from the regulation standpoint, for it will be noticed that when the whole load was instantly thrown off the momentary rise of speed was about 8 per cent, although the governor shut the gate from full open position in the extremely quick time of 1.4 sees. There were five wicket gates, having a total of 96 leaves, and a heavy counter-weight to be moved a considerable distance in this interval. ** 242. General Consideration. Mechanical governors are cheaper than hydraulic, but, assuming the same gate movement, they are less effective at increasing loads since the power to move the gates must be taken as needed from the wheel itself instead of being taken * See American Society M. E., Vol. 27, No. 4, p. 8. ** Catalogue of Water Wheel Governors, Sturgess Engineering Department of the Ludlow Valve Co., p. 23. 492 The Water Wheel Governor. from a storage tank as with hydaulic governors. This is a factor of more or less importance in accordance with the degree of regu- lation required. The difference is manifest principally at low loads when the energy taken by the governor relay from the water wheel is a considerable percentage of the total energy being generated. As the power exerted by the relay is usually comparatively small, the difference in action from this cause between the two types of gov- ernors is often unimportant- ^4 i Fig. 300. Governor Connection by Diaw Rods. The hydraulic governor possesses an additional advantage in its ability to start a stationary wheel into action by means of its stored energy. The mechanical governor depending as it does on the power of the wheel itself is only effective after the wheel has been started by other means. 243. Control From the Switchboard. Electrical devices can now be purchased by which the normal speed of the wheels can be con- trolled from the switchboard in case the governor is so designed that it can be adjusted while in motion, which is true of most high class machines. It is also possible to start and stop the wheels electrically from the switchboard or from a distant station. Connection of Governors to Gates. 493 244. Connecton of Governors to Gates. The following discussion of this subject and the accompanying figures are taken with slight changes, from a paper by Mr. A. V. Garratt.* * * * rpke most successful method of connecting the cylinder gates of several turbines to the same governor is shown in Fig. 300. In this case each pair of drawrods is connected to a pair of walking beams which carry counterweights on their opposite ends. Each walking beam carries a gear sector which engages a rack on a long, horizontal reciprocating member terminating at the governor. The racks on the reciprocating member are "sleeved" on it, and held in place by pins, which may be removed if it is desired to discon- nect any turbine from the governor. "By this method any one, or any combination of turbines, may be handled by the governor or any turbines by hand, at will, by means of a lever shown in the end projection. "Fig. 301 shows a good method of connecting a governor to a pair of horizontal wicket-gate turbines. It will be noted that the shaft connecting the two gear sectors on the gate stems goes di- rectly to the governor, and is connected to it through a pin clutch which may be opened, and a hand-wheel on the governor may then be used to move the gates by hand. The only improvement on this design which can be suggested would be to eliminate the coun- ter-shaft between the governor pulleys and the turbine shaft by plac- ing the governor beyond the draught-tube quarter-turn, so that the governor pulleys might belt directly to the turbine shaft. The limitations of available space prevented the location of the governor in this manner on the drawing which shows the design used for three units in a modern power plant. "Frequently the only possible location of the governor prevents anything like direct connection between it and the turbines. In such cases experience has shown that it is wisest to avoid the use of several pairs of bevel gears and long shafts, and in their place nse a steel rope drive. This method has great flexibility, and per- mits of governor locations which would otherwise be impossible. Fig. 302 shows a design of this kind. The governor is located in the only available space, and yet its connection to the turbines is perfectly adequate. The steel rope used is small in size, made of very small wire, especially laid up, and its ends are fixed to the grooved sheaves, which are provided with internal take-ups, so * See "Speed Regulation of Water Power Plants," by Allan V. Garratt. Cas- sier's Magazine, May, 19'01. 30 494 The Water Wheel Governor. nnn Fig. 301. Governor Connection by Shaft and Sectors. Relief Valves. 495 that the rope may be kept tight as a fiddle string. This general method of connection is in successful use in many plants where the requirements for speed regulation are most exacting. "In the above examples the two ends which have governed the design are simplicity and directness. These two factors should never be lost sight of, and the more completely they are embodied in the design, the better will be the speed regulation. To these two may be added another, and that is freedom from lost motion. These Fig. 302. Governor Connection by Cable. three factors are absolutely necessary if successful results are to be expected. The slightest motion of the governor must be trans- mitted in the simplest and most direct manner, and in the shortest possible interval of time, to the turbine gates/' 245. Relief Valves. Relief valves are very necessary on long feeder pipes and penstocks to avoid excess pressures of an acci- dental nature as well as those produced by closing of the turbine gates. A group of such valves installed on the end of one of the penstocks of the Niagara Falls Hydraulic Power and Manufactur- ing Co. is shown in 'Fig. 303. Relief valves should be arranged to open with a slight excess of the penstock pressure but should close very slowly in order to avoid oscillatory waves. Spring balanced 49 6 The Water Wheel Governor. relief valves have proven objectionable for this purpose. If set to open at a small excess pressure they are apt not to close on ac- count of the impact of the discharging water against the valve, In order that they may close, the balancing spring must be so strong that a considerable excess is required to open the valve which does not therefore serve the desired purpose. All types of -valves are also hindered by the fact that corrosion is apt to seal the valve so that a considerable excess is required to open it. 246. Lombard Hydraulic Relief Valve. The Lombard Gov- Fig. 303. Relief Valve on end of Penstock. Niagara Falls Hydraulic Power Manufacturing Co. (Electrical World, Jan. 14, 1899.) ernor Company have designed a valve in which they claim to have eliminated the difficulties of the spring valve. This valve is shown in Fig. 304* and is described as follows : "The valve consists of the following parts, viz : A valve disc, c, capable of motion to or from its seat, b, rigidly connected by means of a rod, i, with the piston, f, in the cylinder, e. The whole valve is bolted to a flange upon the supply pipe, d, wherein the pressure is to be controlled. The area oi piston, f, is somewhat greater than that of the valve disc, c, so that when water at the same pressure is behind the piston and in front of the valve there is a positive and strong tendency to hold the valve closed. For the purpose of al- * Lombard Bulletin No. 101. Lombard Hydraulic Relief Valve. 497 lowing the valve disc, c, to open at proper times to relieve excess pressure in the supply pipe, d, there is provided a regulating waste valve, C. This valve is opened or closed by a piston, n, opposed by a very oblong and strong spiral spring, p. Piston, n, is a loose fit in its cylinder, o, so that it moves upward freely in response Fig. 304. Lombard Hydraulic Relief Valve. to the least excess in pressure upward due to the water in the cylin- der, o, opposed to the downward pressure of the spring, p. * * * The piston, n, is connected by means of the stem, m, with a double- seated balanced valve, d, which of course, opens simultaneously with any upward movement of the piston. Water under existing pressure is admitted into the cylinder, e, through the pipe, k, and throttle valve, i. 498 The Water Wheel Governor. "The spring, p, is adjusted by means of the screw, s, and lock-nut, y, so that the effective normal pressure of the water in the chamber is just insufficient to overcome the downward pressure of the spring. The valve, D, will therefore remain closed normally ; con- sequently the main valve disc, c, will also remain closed normally, because water flowing in through the pipe, k, and throttle valve, I, will produce an excess closing pressure upon the piston, f. When thus adjusted any increase in pressure above the normal will immediately force the piston, n, upward, and will thereby open the balanced valve, D. This instantly relieves the pressure back of the piston, f, which of course then gives way to the superior pres- sure back of the piston, f, which of course then gives way to the superior pressure in front of valve, c. In this manner practically the whole pressure in front of the valve disc, c, is available for opening it. * * * Valve disc, c, will continue to open until the limit of its travel has been reached, or the pressure in the supply pipe, d, has been reduced to a point where the piston, n, will close the balanced valve, D. Immediately on the closing of balanced valve, D, water begins to accumulate behind the piston, f, flowing in through the throttle valve, I. This water gradually and surely forces the valve disc, c, to close. The speed of closing is adjustable by the opening through the throttle valve, i, and may be made as slow as several seconds or even minutes. The closing motion is * * uniform and there is not the slightest ten- dency to set up vibrations in the water column, a very serious ob- jection to the ordinary types of spring balanced valves which open and close suddenly and are liable in the latter operation to set up water hammer effects even more dangerous than those which they are designed to relieve." 247. Sturgess Relief Valves. The Sturgess Engineering De- partment of the Ludlow Valve Manufacturing Company makes two forms or relief valves, the "Automatic" and the "Mechanical." The Automatic Relief Valve is shown in Fig. 305 and is described as follows: "The essential element in the Automatic Relief Valves is a large, very sensitive diaphragm o.f special construction. This is under the influence of the water pressure in the pipe-line and its move- ments are communicated to a small pilot valve controlling a hy- draulic cylinder, which in turn operates the relieving valve on the relief valve proper. After the pressure in the pipe-line is restored to normal, the relief valve gradually closes automatically. Sturgess Relief Valve. 499 "The action of this valve is almost instantaneous, and it will iully open on a very small rise of pressure. "These valves can either be made in self-contained form, or the sensitive parts (diaphragm, pilot valve, and hydraulic cylin- Fig. 305. Sturgess Belief Valve. der) may be mounted on a pedestal placed in the power house, and the relief valve proper attached to the penstock or wheel cas- ing, a rod or link being provided to connect the two (as in Fig. 305). NOTE. See Appendix for descriptions of two new governors. CHAPTER XX. ARRANGEMENT OF THE REACTION WHEEL. 248. General Conditions. The reaction turbine may be set or ar- ranged for service in a water power plant in a variety of ways, and the best way may differ more or less with each installation. The arrangement of wheels should always be made with due regard to machinery to be operated, the local conditions that prevail, and es- pecial consideration should be given to securing the greatest economy in the first cost of installation, maximum efficiency and facility in operation, and minimum cost of operation and mainte- nance. Impulse water wheels of the tangential type have always been set with their shafts horizontal. An installation with vertical shaft was proposed for one of the first Niagara plants but was not con- sidered on account of the lack of actual experience with such a form of installation. Impulse wheels of the Girard type have been used with both vertical and horizontal shafts. In general, how- ever, because of the high heads under which impulse wheels usually operate, the horizontal shaft arrangement is readily adapted. When an impulse wheel is installed it must be set above the level of maximum tail water, if it is to be operated at all stages of water. The wheel arrangement is therefore dependent principally on the arrangement of the machinery to be operated. By far the greater proportion of such machinery is built with horizontal shafts and hence in most cases where machinery is not special, horizontal shaft arrangements are desirable. Reaction wheels are often used on streams where the relative variation in position of the tail-water is considerable, and it is both desirable to utilize the full head and to have the wheel set at an ele- vation at least above the lowest elevation of the tail-water in order that they may be accessible for examination and repairs. By the use of the draft tube this can often be done without the sacrifice of head. If the wheel must be set below tail-water, gates must be provided for the tail-race with pumps for the removal of the water when access to the wheels is necessarv. Necessary Submergence of Reaction Wheels. 501 The arrangement of reaction water wheels is susceptible only of general classification, which, however, may assist in the under- standing of the subject and the selection of the best methods to be adopted under any set of local conditions. Wheels may be set vertically or horizontally, as the conditions of operation demand, without materially affecting their efficiency, provided that in each instance the turbine case, draft tubes, etc., are suitably arranged. The improper design of the setting may materially affect the effi- ciency of operation in either case. 249. Necessary Submergence of Reaction Wheels. In order to prevent the formation of a vortex or whirlpool, which will draw air into the wheel and often seriously affect its power and efficiency, it is necessary that the gate openings of the wheel be placed from one to one and one-quarter wheel diameters below the water surface. The head under which the wheel is to operate, however, greatly affects the formation of the vortex. High velocities of flow will facilitate their formation,; therefore greater heads will require a greater water covering or other means for the prevention of vortex formation. As the wheel usually has a greater diameter than the height of the gate it can be set vertically with less danger of air inter- ference than when set horizontally. For this reason the vertical wheels are more readily adapted to low heads and have in the past been more widely used for developments under low and moderate heads. With both horizontal and vertical wheels the wheel may be pro- tected from the formation of the vortex by a solid wooden float, or may be partially encased or covered with an umbrella-shaped cover the edges of which can be brought below the level of the upper gates of the turbine thus allowing the wheel to be set near the head water surface without the serious interference above men- tioned. In all such cases the float or cover must be so arranged as to admit the water to the wheel gates without undue velocity in order to prevent the loss of head. If this is done the efficiency and power of the wheel will not be affected (see Appendix E). Arrange- ments of this sort were designed by the writer, in the fall of 1906, for the water power plants at Kilbourn and at Dresden Heights. 250. Arrangements of Vertical Shaft Turbines. Figs. 306 and 307 show twelve typical arrangements of reaction turbines. Figs. A, B, C and D of Fig. 306 show typical arrangements of vertical 502 Arrangement of the Reaction Wheel. A Fig. 306. Arrangement of Vertical Shaft Turbine. 503 wheels. Diagram A is the most common arrangement of the re- action turbine in an open penstock for low head. In this case the wheel is set in a chamber called the wheel pit, the flume, or some- times the penstock, and is connected with the head race from which it should be separated by gates. The wheel pits in the smaller plants have commonly been constructed of timber; but in the larger plant, they are usually built of a more substantial character, often of iron or concrete, usually reinforced. Sometimes two or more wheels are set in a single pit ; but in the better class of con- struction, a pit is supplied for each individual wheel or each unit combination of wheels so that each unit can be cut off from its fellows, disconnected from the transmission mechanism to which it is attached, and examined or repaired without interference with the remainder of the plant. Open pits are commonly used for heads up to 18 or 20 feet and may be used for considerably higher heads under favorable conditions. For higher heads, the arrangement shown in diagram B, or some other form similar thereto, is often found more desirable. In this case closed flumes of steel or reinforced concrete are used, and are connected with the head race by metal, wood, or reinforced con- crete pipes to which the term "penstock" is commonly applied. This form of construction permits of the use of vertical wheels with almost any head. In Diagram B the turbine is shown as di- rect connected to an electrical generator of special design with ver- tical shaft. In Diagram A the shaft of the turbine is shown as directly at- tached to a crown gear which in turn is connected by a spur gear with a horizontal shaft. This horizontal shaft may be direct-con- nected to a generator as shown in Fig. 325, or may be attached by belting, ropes, cable or other mechanical means with one or more machines which it is designed to operate. Diagrams C and D show two vertical types of settings of tan- dem or multiple wheels. Such arrangements are introduced when it is necessary to reduce the diameter of the wheels on account of in- creased speed, and at the same time maintain the power of in- stallation by increasing the number of wheels for the purpose of direct connection to some machine to be operated . In all cases where two wheels discharge into a common draft tube sufficient space is necessary between the wheels to prevent interference and consequent loss in efficiency. The arrangement 504 Arrangement of the Reaction Wheel. of wheels in this manner therefore requires a considerable amount of vertical space and, under low or moderate head, involves the construction of a wheel pit of considerable depth in order to se- cure proper submergence of the upper wheel. This arrangement results in the lower wheel being often considerably below the tail- water and necessitates the use of tail gates and a pumping plant to remove the water in order to make the lower wheels accessible. With this design the plant is made comparatively narrow but the greater depth of construction means an additional expense in the foundation work. Vertical wheels of all types involve a design of satisfactory vertical bearings which are usually less accessible than in the case of horizontal bearings which can be placed at an elevation above the power house floor, and are consequently more readily accessible. The st$p bearings for single vertical wheels have been long in use and are reasonably satisfactory. The sus- pension bearing, which is involved in the use of large vertical in- stallations, is not universally satisfactory and, in fact, considerable difficulties have been encountered in so designing a bearing that it will operate without undue expense for maintenance. 251. Arrangement of Horizontal Turbines. Single horizontal wheels of the common type are shown in Diagrams E and F of Fig. 306 and in Diagrams A, B, C, and D of Fig. 307. In each case the gates of the turbine must be readily accessible to the entering water without undue velocity, and the wheel pit, or penstock, must be designed with this requirement in view. Diagrams E and F, Fig. 306, and A, Fig. 307, show horizontal types of wheels set in an open wheel pit or penstock. In Diagram E the wheel has the quarter turn set entirely in the pit, and the main shaft passes through a bulkhead in the wall of the station with a packing gland to prevent the passage of water. In this case the water must flow by the quarter-bend and hence, in order to secure sufficiently slow velocity, the wheel pit must be wider or deeper than in the case shown in Diagram F of Fig. i. Here the gates of the turbine are placed toward the entering water and the flow is interfered with only by the pedestal bearings which, being placed in the center of the crown or cover plate of the wheel, occupy but little space and offer practically no obstruction to flow. Diagram A of Fig. 307 is essentially the same in arrangement as Diagram F in Fig. 306, except that in this case instead of a me- tallic quarter-turn and draft-tube, the quarter-turn and draft-tube are constructed in the masonry of the power station and the bulk- Arrangement of Horizontal Shaft Turbine. 505 Fig. 307. 506 Arrangement of the Reaction Wheel. head is reduced to simply a packing gland through which the shaft enters the power station. Diagrams B, C, and D, Fig. 307, illustrate three methods of en- closing a turbine in a closed flume which is connected with the head water by a closed penstock. In Diagram B the turbine case is spiral, the water enters tangent to the wheel and at right angles to the shaft and is discharged through a metal quarter-bend into a concrete draft-tube. In Diagram C the water enters the metallic flume in which the wheel is placed at right angles to the shaft, and is discharged through a metal quarterrbend and draft-tube. In Diagram D the water enters the wheel case parallel to the shaft of the wheel and is discharged through a metal quarter-bend into a concrete draft-tube. Figs. E and F of Fig. 307 show methods of setting horizontal shaft wheels in tandem. Diagram F is for setting in an open flume or penstock. The two wheels discharge into a common shaft chest and use a common draft-tube. In Diagram E the wheels have a common closed case or flume connected by a penstock with the head waters and each discharges through an independent quar- ter-turn and an independent draft-tube into the tail-waters beneath. With the closed flume removed, this arrangement can also be used in an open penstock. These diagrams are simply typical of various possible arrangements of wheels that can be adapted with various modifications of detail to meet the local requirements of the en- gineer for any hydraulic plant which he may be called upon to de- sign. 252. Classification of Wheels. The classification of the arrange- ment of wheels as shown in Figs. 306 and 307 may be reviewed briefly as follows : In this review reference is given to various figures in the pre- ceding and following text in which the type of wheel described is illustrated with more or less modifications. ist. Vertical single wheel, open wheel pit. (See Diagram A, Fig. 306, also Figs. 329, 331, 333 and 334.) 2nd. Vertical single or tandem wheels in metal casing con- nected by cylindrical penstock with supply. (See Diagram B, Fig. 306, also Figs. 132, 181, 310, 311.) 3rd. Vertical tandem wheels, two or more wheels in open pit. (See Diagrams C and D, Fig. 306, also Figs. 134, 138, 173, 339.) Classification of Wheels. 507 4th. Horizontal turbine, open wheel pit, quarter-bend and draft- tube within wheel pit, quarter bend of metal. (See Diagram E, Fig. 306.) 5th. Horizontal turbine, open wheel pit, quarter-bend, and draft- tube exterior to pit, quarter-bend may be of metal or concrete construction. (See Diagram F, Fig. 306, also Diagram A, Fig. 307 and Figs. 314, 322.) 6th. Horizontal turbine in spiral case at end of penstock, single or double draft-tube. (See Diagram B, Fig. 307, also Figs. 159, 162, 338.) 7th. Horizontal turbine in cylindrical or conical case at end of penstock. (See Diagrams C and D, Fig. 307, also Fig. 335.) 8th. Tandem horizontal turbines in open wheel pit, single dis- charge through common or independent draft tubes. (See Diagram F. Fig. 307, also Figs. 315, 319 to 324 inclusive.) 9th. Tandem horizontal turbine in enclosed cylindrical case with common penstock and common or independent draft-tubes. (See Diagram E, Fig. 307, also Figs. 13, 140, 152, 317.) 253. Vertical Wheels and Their Connection. The vertical set- ting of single wheels is usually the cheapest in first cost, which fact is an important factor that has been largely instrumental in the adoption of this arrangement in most of the older plants. Ver- tical wheels are most commonly set in open wheel pits. They may, however, be set in a cast iron or steel casing which is then con- nected to the headrace or dam by a proper penstock. Single ver- tical wheels can be connected to the machine they are to drive by various means. Belting, transmission ropes, cables, and shaftings, are in common use for such connections. The shaft is usually placed horizontally and is connected by a crown beveled gear and pinion to the wheel. Frequently belts, ropes, and cables are connected by pulleys or sheaves to a short horizontal shaft driven in the same manner. When the power of a single vertical wheel is insufficient, two or more may be harnessed by gearing to a line shaft which may be directly connected to the machine or machines to be operated, or otherwise connected as convenience and conditions may require. 254. Some Installations of Vertical Water Wheels. Figs. 329 to 332 inclusive, show the plans, elevations, sections, and details of a small plant of vertical water wheels designed by the writer for the Sterling Gas, Light and Power Company of Sterling, Illinois. The details of this plant are clearly shown by the illustrations and will be discussed at some length later. This plant is located on the 5 o8 Arrangement of the Reaction Wheel. oo o CO to Some Installations of Vertical Water Wheels. 5o9 Sterling side of the Rock River (See Fig. 345) and is next to the last plant on the Sterling Race. The head developed is about eight feet and the power of each wheel is about 115 h. p. under this head. Each wheel of the installation is set in an independent pit -or pen- stock which can be closed by means of a flume gate. The wheels are connected to a common shaft extending into the power house and connected with pulleys and belts to the generator. The plan of the South Bend Electric Company at Buchanan, Michigan, is of similar type and is shown on page 544, Fig. 334. The main shaft is here connected with ten turbines and is in turn directlv connected to an electric alternator. Fig. 309. Low Head French Water Power Plant. The adaptability of the vertical shaft turbine to low head is well shown in Figs. 308 and 309. Fig. 308 shows three turbines manufac- tured by The Trump Manufactnring Company of Springfield, Ohio. These turbines are 61, 56 and 44" respectively, and by suitable gear- ings are connected with a common shaft. These wheels were in- stalled at Bologna, Italy, and operate under a low water head of 42" and under a high water head of 28". It was necessary to set the wheels considerably below the level of the tail water in order that 31 Arrangement of the Reaction Wheel. the turbines should have a sufficient submergence for operation. Fig. 309 is a similar plant installed at Loches, France. In this case the water is conducted to the turbines by means of a syphon supply pipe in order that the turbine might be placed high enough above tail-water that it be accessible at all times without the __ use of a tail-gate. Air is exhausted from the crown of the syphon by use of a steam ejector whenever the plant is to be started up. This plant operates under the low r head of thirty-one inches and is said to work very satisfactorily. Fig. 310 shows a vertical shaft turbine of the Victor cylindrical gate type man- ufactured by The Platt Iron Works. This wheel is set in an independent case with provision made for the attachment of a cylindrical penstock con- ducting the w r ater from the head work to the wheel. This figure shows a special design by which the spec- ial generator is set on col- umns resting directly on the wheel case. Fig. 311 shows the plant of Trenton Falls, New York, of the Utica Gas and Electric Company. The wheel is a Fourneyron turbine, manufactured by The I. P. Morris Company, operating under a 266 foot head, the water being conducted to the wheel through a penstock the length and arrangement of which are shown in Fig. 353. The wheel is provided with a draft-tube and is regularly connected with the generator above. The moving parts of both machines are carried by a vertical shaft bearing, shown in cut. 255. Some Installations of Vertical Wheels in Series. In the last three illustrations wheels are shown of sufficient size and operat- Fig. 310. Some Installations of Vertical Water Wheels. 511 Fig. 311. The Trenton Falls Plant of the Utica Gas and Electric Co. (I. P. Morris Co.) 512 Arrangement of the Reaction Wheel. ing under sufficient head to be suitable for the independent operation of the machine attached to them. In many cases, however, espe- cially with low head, the arrangement shown in Fig. 308 and in Figs. 325 to 329 inclusive, becomes necessary. In such cases considerable loss is entailed by the use of shafts, gearings, and belts. Fig. 312. Vertical Turbine for Sewall's Falls Plant of the Concord Electric Co. These losses are so large that it is desirable to avoid or reduce them if possible. For this purpose vertical wheels are sometimes placed tandem as shown in Diagrams C and D, Fig. 306. This type of plant is also illustrated by Figs. 312 and 313 which are illustrative of wheels installed in the plant of the Concord Electric Company, at Concord, N. H. Some Installations of Vertical Wheels in Series. 513 Fig. 312 shows tandem wheels for this plant as designed and manufactured by The Allis-Chalmers Company of Milwaukee, .. and are described in further detail on page Fig. 313 is a view of a double vertical unit, designed and built for the Concord Electric Company by The S. Morgan Smith Company of York, Pa. This form of in- stallation has the advantage of a greater concentration of the machinery. This type of installation, while quite com- mon in Europe, is somewhat new in this country and pre- sents several novel and desir- able features. 256. Some Installations of Horizontal Water Wheels. Most machines to be operated by water wheels are built with horizontal shaft, and, as a direct connection of wheels to the machinery to be operated involves a min- imum loss in power and con- sequent greater efficiency than with the various com- plicated arrangements often necessary with vertical wheels, the horizontal wheel becomes desirable and is adopted whenever practicable in a modern water power plant. The type of such a plant is well illustrated by the power-plant at Turner's Falls, Massachusetts, shown by Fig. 314. The single horizontal wheel, direct-connected to th*e machinery to be operated, is perhaps already sufficiently described in the preceding pages. The arrangement of two or more wheels for such purposes deserves careful consideration. Figs. 315 and 316 show a plan and section of a double unit, for use in an open penstock, as manufactured by The Dayton Globe Iron Works Company of Dayton, Ohio. These figures show a plain, Fig. 313. 5i4 Arrangement of the Reaction Wheel. Some Installations of Horizontal Water Wheels. cylindrical, draft-chest connected with a common draft-tube. The details of the arrangement can perhaps be better seen from the half- tone, Fig. 320, which illustrates two of these units conneted together tandem. Fig. 315. Section Double Wheel with Common Draft Tube. (Dayton, Globe Iron Works Co.) Fig. 316. Plan. Figs. 317 and 318 show a similar double unit manufactured by the same company. This unit is shown set in a closed flume for connection by a penstock of suitable size with the head works. In Fig. 318 the chest, into which the turbines discharge, is designed so as to give a certain independence to- the discharge of the two turbines until they come to the draft-chest below the wheel. The turbine case, shown in Fig, 316, seems to have more room than 516 Arrangement of the Reaction Wheel. necessary in the upper portion of the case in which interference of the two streams and much eddying are possible, all of which is ob- viated in the the design .shown in Fig. 317. The writer knows of no experiments which show conclusively that such loss actually occurred. More information is needed along this line than is now accessible to the engineer. Fig. 317. Double Horizontal Turbine in Closed Penstock (Dayton Globe Iron Works Co.) Fig. 318. Plan. Fig. 319 is a cross-section of a double unit of the Samson tur- bine, manufactured by The James Leffel and Company of Spring- field, Ohio. This shows a design in which careful attention is given to the maintenance of a uniform and slowly decreasing ve- locity from the time the water reaches the wheel until it passes from the common draft-chest into the draft-tube below. Some Installations of Horizontal Water Wheels. 257. Some Installations of Multiple Tandem Horizontal Wheels. Two double units of the wicket gate type, similar to the double units shown in Fig. 315, are illustrated by Fig. 320. These turbines were manufactured by The Dayton Globe Iron Company of Day- ton, Ohio, and are shown with the upper portion of the case removed so that the arrangement of the wheels and the gate mechanism are clearly visible. The gates are moved by a cylindrical ring to which Fig. 319. Double Horizontal Turbine for Open Penstock. (James Leffel & Co.) each gate is attached independently. The ring is moved by the link connecting the gate ring to the governor rod which, by its ro- tating, opens or closes the gate as the power needed requires. Two double units with cylindrical gate, as manufactured by The S. Morgan Smith Company of York, Pennsylvania, are shown in Fig. 321. The bulkhead casing and the coupling to which the machinery to be operated must be attached, are shown at the left. In this case the governor rods have a horizontal movement, the upper rod moving backward and the lower forward in order to open the cylinder gate. Figs. 322 and 323 show a section through one of the main units and a plan of the power house and turbines of The Soiuthern Wis- consin Power Company now under construction at Kilbourn, Wis- consin, on the designs and under the supervision of the writer. This plant consists of four main units, each generator having a capacity, at full load, of 1650 kilow r atts and an overload capacitv of 25 per cent. Each unit is direct-connected to six 57" turbines now under construction by The Wellman-Seaver-Morgan Com- Arrangement of the Reaction Wheel, Soir.e Installations of Horizontal Water Wheels. 519 520 Arrangement of the Reaction Wheel. pany of Cleveland, Ohiou Each turbine unit is set in a separate penstock controlled by three independent sets of gates. The four center wheels discharge in pairs into common draft-tubes, while the two end wheels have independent draft-tubes. All of the bearings within the flume are accessible by independent wrought iron man- hole casings. Fig. 324 shows four pairs of 45" Samson horizontal turbines man- ufactured by The James Leffel and Company of Springfield, Ohio. These wheels have been installed for The Penn Iron Mining Com- pany of Vulcan, Michigan, where two such units are now in opera- tion. Eight similar units, designed -to deliver 1400 H. P. under 14 foot head, are now under construction by The James Leffel and Company and are to be installed in the plant designed by the writer for The Economy Light and Power Company at Dresden Heights, Illinois, the general arrangement of which is shown by Fig. 350. When the head increases above 20 or 30 feet, it may become de- sirable to convey the water from the head-work by means of a closed penstock as shown in the case of the plant of The Winnipeg Electric Railway Company (See Fig. 340). In this plant are shown four wheels in tandem, direct connected to a generator. The bell-mouthed entrance to the penstock should be noticed, also the air inlet pipe which is designed to admit the air into the penstock when the same is to be emptied, and to admit the water gradually and without shock when it is again filled. When the head becomes still higher the closed penstock .becomes imperative as in the case with The Shawinigan Water and Power Company's plant shown in Fig. 338 where a head of 135" is utilized. Similar arrangements and connections for single and double wheels with penstock are those of The Dodgeville Electric Light and Power Company, shown in Fig. 337, and that of The Hudson River Power Company's plant at Spier's Falls, as shown in Fig. 335. The plant of The Nevada Power and Mining Company shown in Fig. 341, involves tangential wheels operating with needle nozzle and discharging freely into the tail race below. In the selection and installation of reaction wheels a con- siderable latitude in the choice and details of arrangement is possi- ble and it is only after a careful examination and consideration of all the conditions of installation that the correct size, speed, and arrangement of the wheels can be obtained. Numerous failures, more or less serious, in the past have fully shown the fact that Some Installations of Horizontal Water Wheels. ' 521 CM CM CO bo B 5 22 Arrangement of the Reaction Wheel. i 1 r t: ^ y~r^ if i :> '. ^3 1 T-$ ' - Some Installations of Horizontal Water Wheels. 523 524 Arrangement of the Reaction Wheel. this work demands the most careful attention and investigation of the engineer and should be attempted only after the most thor- ough study and mature deliberation. 258. Unbalanced Wheels. In installing horizontal wheels it is usually desirable to use them in pairs with two, four, six or eight turbines in tandem. It is, of course, possible to introduce an odd number of wheels and this is frequently done where it seems to be desirable. There is an advantage is an even number of wheels for in this case the wheels may be, and should be, so arranged as to balance the thrust by the union of a right hand and left hand wheel in each pair. Where an odd number of wheels is introduced, an unbalanced condition arises which can only be taken care of by a thrust-bearing which, at the best, is an additional complication often unsatisfactory and should be avoided if possible. There is another cause of unbalanced condition which may be here mentioned. If a pair of wheels is so joined together as to use a common draft-tube then, on starting the wheel, the vacuum formed in the draft-tube is co-mmon to both wheels and therefore balanced. If, on the other hand, the wheels have separate draft- tubes, when the wheels are started a partial vacuum is commonly created in one of the draft-tubes in advance of the other, or even when the wheels are in operation the vacuum in one draft-tube is not as great as in the other, creating thereby a thrust in one di- rection or the other which must be balanced by the connection of the two draft-tubes by an air pipe or must be taken up by a thrust- bearing as in the case of a single wheel. CHAPTER XXI. THE SELECTION OF MACHINERY AND DESIGN OF PLANT. 259. Plant Capacity. The selection of machinery for a power plant depends upon numerous conditions. In the first place, for permanent and constant operation, the machinery must be so selected that its total capacity shall be great enough to take care of the maximum load and have at least one unit in reserve so that if it becomes necessary to shut down one unit for examination or repairs, the plant will still be capable of carrying the maximum load for which it was designed. The desirable reserve capacity of any plant depends on the con- tingencies of the service or the degree of liability to disabling acci- dent involved in the operation of any plant, and on the relative cost of such reserve capacity and the damages which might be sus- tained if the plant should at any time become disabled as a whole or in part and incapable of furnishing all or any part of the power for which it was designed. In many manfacturing plants the occa- sional delays caused by the entire suspension of power on account of high or low water, or for the necessary repair to machinery, are not serious if cheap power is available for the remainder of the year. For the operation of public utilities, and the furnishing of light and power for diverse municipal and manufacturing purposes, the matter becomes more serious and necessitates a sufficient du- plication of units to practically assure continuous operation. For paper mills and other manufacturing purposes water powers are utilized in which the head and consequent power is practically destroyed during high water conditions. For continuous and un- interrupted service such powers are available only with auxiliary power that can be used during such periods. In the same manner reserve capacity may be unnecessary, desirable or absolutely essen- tial as the importance of maintaining uninterrupted power in- creases. 260. Influence of Choice of Machinery on Total Capacity. A study of the week day load curve of The Hartford Electric Light 32 526 The Selection of Machinery and Design of Plant. Company as shown by Fig. 257, page 422, will show that the load for December, 1901, represents the maximum load which that plant was called upon to carry during the year, and, consequently, was the maximum load for which the machinery must have been se- lected. A considerable variety of unit sizes would be possible which would- fill the requirements of this load curve to a greater or less extent. The maximum or peak load shown in December, 1901, was about 3,000 k. w. If a single machine were selected of 3,000 k w. capacity for regular operation, then, in order to have one unit in reserve, it would be necessary to purchase two 3,000 k. w. machines or a total capacity of about 6,000 k. w. If, on the other hand, machinery should be purchased with units of 500 k. w. capacity each, it would be necessary to have six of such units in order to carry the maximum load of 3,000 k. w., and a seventh unit of 500 k. w. capacity would be all that would be needed for the reserve. This would give a total capacity to the plant of 3,500 k. w., giving the capacity of the machine purchased some 2,500 k. w. less than the plant first discussed. 261. Effect of Size of Units on Cost. The cost of machinery is not in direct proportion to its capacity. The larger machinery is somewhat less in price per kilowatt capacity than the smaller ma- chinery. Hence the cost of the last plant suggested would be more than 35/60 of the cost of the first plant. On the other hand, the in- stallation of such a large number of units complicates the plant and is undesirable. For this plant it would therefore be desirable to select five units of 750 k. w. capacity each, or four units of 1,000 k. w. capacity each, giving in one case a total plant capacity of 3,750 k. w. and in the other case of 4,000 k. w. A plant having units of 750 k. w. or 1,000 k- w. capacity each would have a less total kilowatt capacity and, consequently, a less first cost compared with a plant having units of 3,000 k. w. capacity. Such a plant would also have a less number of units and conse- quently less complication in the arrangement than a plant having units of 500 k. w. capacity. 262. Overload. In the above consideration no mention is made of overload capacity. The ordinary direct-current machinery can be operated at about 25 per cent, overload for short periods of per- haps one hour at a time without danger to the machinery. Alter- nating machinery can be operated at 50 per cent, overload at similar times or at 25 per cent, overload for two hour periods. In conse- quence of this condition it is frequently possible to purchase ma- Economy in Operation. 527 chinery of considerable less capacity than the total load would in- dicate, depending on the overload capacity of the machine for short periods of maximum load. Unless, however, the estimated load curve covers all possible contingencies for maximum power it is desirable to retain this overload capacity as a provision for a second condition which has not been fully covered in the estimate of the daily load curve ; or, in other words, it is desirable to retain the overload capacity as a factor of safety. 263. Economy in Operation. A second matter that needs the careful consideration of the engineer in the selection of machinery is the question of economic operation under variation in load. A reference to the efficiency curve of most machines will show that the machine will operate most efficiently at some particular load, usually some .75 to full load, and will perhaps give the best results at from .75 to 1.25 load, or to 25 per cent, overload. It therefore becomes important to so select machinery that it will operate effi- ciently at all conditions of Joad. An examination of the load curve of The Hartford Electric Light Company for the full week day load in March, June, September and December, will show that for securing the most efficient results at all times in the day, and at all times in the season, units of 500 k. w. capacity would apparently be the best. Such units would take care, efficiently, of the minimum loads that occur at 6 :oo A. M., between 12:00 and I :oo P. M., and at about 7:00 P. M. At such times one of these units would operate efficiently; but in most cases the period at which it could be operated singly would be for a few minutes only, or perhaps for an hour at the most, when the additional unit would have to be cut in. A 750 k. w. generator would operate with almost as great an efficiency at these times and it would, with its overload capacity, take care of the load for a much greater period of time each day. The 1,000 k. w. machine would perhaps fulfill these requirements even to a greater degree. While it would be less efficient at the minimum point of the load, it would have the advantage of operating singly for a much wider range of load and the additional advantage that, as a rule, the larger the ma- chine the higher the full load efficiency curve. The complications resulting from the numerous machines, and the losses entailed thereby, have also to be considered and must be carefully weighed in this connection. The circumstances of operation and many local conditions, which appertain particularly to the plant in question, must be weighed in 528 The Selection of Machinery and Design of Plant. connection with the selection of this machinery. There is no defi- nite law by which the selection of machinery for any plant can be reduced to an exact science, and several combinations of ma- chinery are possible in almost any plant and will give reasonable satisfaction. In the above discussion only units of a uniform capacity have been considered and it is usually desirable, other things being equal, to have similar machines so that a minimum number of repairs and duplicate parts may be kept in stock. On the other hand, if a long, low night load is probable, it may be desirable to install one or more units of a capacity suitable to carry such load efficiently. 264. Possibilities in Prime Movers. A third matter for the careful consideration of the designing engineer is the possibility of a prime mover that is to be used for operating the machines in question. If a steam or gas engine is to be used as the motive power, there is a wide range of selection in speed, capacity, and economy of such machinery, and, as a general rule, the prime mover may be selected to conform to the generator or other machine that is to be operated thereby. In the selection of water wheels for prime movers the conditions are radically different and the selection of the size and capacity of the units to be operated is "often modi- fied or controlled by the waterwheels and the conditions under which they will be obliged to operate. In the selection of the water wheel one of the most important matters is the head and the range of heads under which the wheel will be called upon to operate. While it is possible to select a wheel so that it will operate at almost any reasonable speed under a con- siderable head, yet the capacity or power of the wheel rapidly de- creases in amount with the speed, and if the speed be too high it will be necessary to join two or more wheels in tandem in order to furnish the power necessary to operate the machinery selected. This is perfectly feasible and is done in a great many cases. 265. Capacity of Prime Movers. It is important to note that if the generator or other machinery to be operated is to be operated under overload conditions, the maximum power to be generated must be kept fully in mind in the selection of a prime mover. In the case of steam engines, these engines can be commonly operated under overload conditions. They are usually rated at their most efficient capacity and can sometimes be operated to 50 per cent. above their normal rating, although their economy under such con- ditions is apt to materially decrease. Gas engines, on the other Power Connection. 529 hand, are commonly rated at very nearly their full capacity and hence the machinery which they are to operate can be operated only to about the normal rated capacity of the engine. Water wheels are commonly rated in the catalogues of manu- facturers at very nearly full gate and consequently at full power. In some cases they are rated at about seventh-eighths gate so that a small margin of additional power is availalble. In the selection of a water wheel, therefore, it is important that a careful study be made of the actual power that the wheel can generate under full gate and at minimum head. This should be sufficient to operate the machinery at its maximum load. 266. The Installation of Tandem Water Wheels. The installa- tion of two wheels set tandem, either horizontally or vertically, and directly connected with the machine by a common shaft, is very common and this may be increased to four, six, or occasionally to eight turbines. Every additional machine, however, involves the introduction of increased diameter in the shaft, of additional bear- ings which must be set and held in alignment, and a complica- tion in the design and construction of the machinery which should be avoided wherever possible. The excuse for the attachment of a number of turbines in tandem arrangement, and the com- plexity of the plant of water wheels installed, lies in the sim- plification of the machinery to be operated by them, and in the de- sign and arrangement of other portions of the plant. The extent to which the application of any principle is to be carried is a matter of judgment and can be answered only by experience and the con- sideration of all of the conditions involved in each particular case. 267. Power Connection. -With the turbine, as with every other prime mover, it is important to convey the power to the machine or machinery to be operated as directly as possible. The turbines should be connected as directly as possible to the machinery to be driven without any unnecessary intervention of gearing, shafting, bearings, belts, cables, or other still more complicated methods of power transmission. Every shaft, every gear, every belt, every bearing and every other means of transmission that intervenes be- tween the power generated in the wheel and the machine in which the power is to be utilized means an extra loss and a decrease in the efficiency of the plant. The machine to be operated should, therefore, whenever practicable, be direct connected to the shaft of the turbine instead of being connected with the turbine by any intermediate mechanical means. (See Figs. 310, 314 and 322 530 The Selection of Machinery and Design of Plant. Various Methods of Connection. 531 Direct connection of machinery and turbine involves a careful selec- tion of both machinery and turbine so that both will work satis- factorily at the same number of revolutions per minute. This frequently involves extra expense that may not be justified in plants for many purposes. Other methods of connection or of power transmission are, therefore, frequently necessary. With many low head installations direct connections are impracticable for a number of reasons. Sometimes various machines with diverse revolutions are to be driven by the same wheel and the revolutions of the turbines in- stalled must differ from some or all of the machinery to be operated and some form of connection other than the direct must be used. Even where the importance of the plant makes it desirable to use di- rect connection, it frequently happens that a single turbine gives an insufficient power at the speed desirable for connection to a machine of the desired capacity. Under such conditions it is nec- essary to unite two or more turbines in order to generate sufficient power for the purposes for which the plant is to be designed. The necessity of using a large number of turbines in a single unit may give rise to very long shafts and a large number of bearings, and the loss due to such an arrangement is sometimes considerable, and if poorly arranged will be almost or quite as inefficient as gearings and shafting well maintained. 268. Various Methods of Connection in Use. The most common form of turbine used is a single vertical turbine, connected by a beveled crown gear and pinion to a horizontal shaft. Several of such turbines are commonly coupled up to the same shaft and may be set in a single or in separate wheel pits. Such types of installa- tion are shown in Figs. 329 to 334. Fig. 325 shows the turbine harness in the plant of The Oliver Plow Works at South Bend, Indiana, installed by The Dodge Manufacturing Company. The arrangement of the wheel is quite similar to that illustrated by Fig. 334. Three or four vertical wheels are here each connected by a gear and pinon with a horizontal shaft, which, in turn, is con- nected to an electric generator. In all such cases more or less energy is lost in transmitting the power through the gearing and numerous bearings to the generator. Sometimes it is found desir- able not to connect the generators directly with the main shaft, but to connect the generator or other machines to be operated by the power plant by belting them to driving pulleys attached to the same horizontal shaft, as shown by Fig. 326, which shows the power 53 2 The Selection of Machinery and Design of Plant. Various Methods of Connection. 533 plant of The Trade Dollar Mining-Company near Silver City, Idaho. This, however, introduces another source of loss through these belts but possesses a certain flexibility due to the ability to thereby drive various small units at a variety of speeds by the simple process of changing the diameter of the pulleys used to drive such machin- ery. Sometimes rope drives can be used to advantage in place of Fig. 327. Harness and Driving Sheaves, Southwest Missouri Light Co., Joplin, Mo.* belts. This is especially true where the distance is great or the alignment other than direct. Examples of such connections are shown by Figs. 327 and 328. Direct connected plants are shown in Figs. 310, 314, 322, 335, etc. 269. Use of Shafting. A shaft connecting a machine to a prime mover, or imposed in any manner in any power transmission, must be carefully designed and constructed. It must be carefully aligned and have its bearings carefully adjusted. Each bearing may be con- sidered as a point in the alignment of a shaft, and, as two points determine the direction of a straight line, it will be seen that each additional bearing is objectionable for it increases the difficulty of obtaining and maintaining a satisfactory alignment. When more than two bearings are used each must be brought and maintained in * Dodge Manufacturing Co., . Mishawaka, Ind. 534 Th e Selection of Machinery and Design of Plant. the best practicable alignment, both horizonally and vertically. All bearings must be of sufficient size that the limit of bearing pres- sure shall not exceed good practice and they must be sufficiently adjustable so that the shaft shall have as complete and uniform bear- Fig. 328. Plan Showing Harness, Rope Drive and Jackshaft. Southwest Missouri Light Co.* ing as possible over the entire surface of the box. Boxes and bear- ings must be arranged for satisfactory lubrication so that under the hardest service they will not become unduly heated. In order to secure good results the best class of workmanship is necessary and it is also necessary that the plant shall be carefully and prop- *Dodge Manufacturing Co. The Wheel Pit. 535 erly maintained. A poor shaft, running in poor boxes, poorly aligned, may consume most of the power generated. Shafting, to be reasonably satisfactory, demands frequent and proper inspection, constant lubrication, and proper maintenance or it will soon become a source of great energy loss. 270. The Wheel Pit. The wheel is usually set in a chamber called the wheel pit, flume, or sometimes the penstock, which is connected with the head-race from which it can be separated by suitable gates. The wheel pit in the smaller plants has commonly been con- structed of timber but in the larger plants is usually built of a more substantial character, of concrete, plain or reinforced, stone or iron. Open pits are commonly used for heads up to 18 or 20 feet, and may be used for considerably higher heads ; however, for higher heads, closed flumes of reinforced concrete or steel are commonly used, and such construction is usually connected with the head- race by metal, wood or reinforced pipes, to which the term penstock is commonly applied. This latter form of construction admits of the use of wheels with heads of almost any height. A number of wheels can be set in the same wheel pit, and are commonly so set, especially where they are used together to operate one machine. It is frequently desirable, however, to sep- arate the turbines and set them in separate pits so that one or more wheels can be shut down at any time without interfering with the operation of the plant. The exent to which this arrange- ment is carried is a matter of policy and depends upon a variety of conditions which the engineer must settle for each particular case. 271. Turbine Support. The arrangement and construction of the wheel pit must be such as to furnish a proper support for the tur- bine in order to secure satisfactory operation. In many of the earlier plants, the wheel pits were built of timber, with the turbine case resting direc.tly on the timber floor, which was often improp- erly supported. The result of such conditon has been that the tur- bines settle out of alignment and much energy is expended in un- due friction in the transmitting mechanism. The floor or founda- tion on which the wheel case rests should be of a substantial char- acter and of such a nature that it will not readily deteriorate and allow the wheel to settle. It is usually desirable to support the wheel by a column directly below the wheel case, which should rest upon substantial foundations below the bottom of the tail-race, 536 The Selection of Machinery and Design of Plant. (See Fig. 331) In all events settlements and vibrations must be prevented or reduced to a minimum in order to eliminate one of the very important causes of loss which is frequently encountered in water power plants. In many cases, due to defects of this kind, water power plants are giving efficiencies of 50 per cent, and below, where 75 or 80 per cent, should be obtained. 272. Trash Racks. The water entering the wheel pit from the head-race commonly passes through a trash rack consisting of nar- row bars of iron, usually y" by 3" in dimension, spaced i 1 /^" to 2" between and reaching from above the head-waters to the bottom of the wheel pit, the purpose of which is to strain out such floating matter as may be brought by the current down the head-race and which, if not taken out at this point, might float into the wheels and if large and heavy enough, might seriously injure the same. These racks 'have to be raked or cleaned out at intervals depending on the amount of leaves, grass, barks, ice or other floating matter in the stream. In water power plants on some streams where large amounts of such floating matter occurs at certain seasons, it is sometimes necessary to keep a large number of men constantly at work keeping the racks clear. The accumulation of material on the racks will sometimes shut off the entire flow of water if attention is not given to keeping them clear; hence it is sometimes necessary to so design the racks and their supports that they may sustain the entire head of water. The racks are usually made of barb wire held apart by spools be- tween each pair of bars and held together by bolts passing through the spools and joining together such a number of bars as may be convenient for handling. The spools should usually be placed near the back of the bar so as to allow the rake teeth to pass readily. .The rack should be situated at an angle so as to afford facilities for raking. The deeper the water, the greater should be the in- clination, as with long racks, and especially with high velocities, the clearing of the racks becomes more difficult. Chain racks and automatic mechanical racks have been attempted but without satisfactory results. Where trouble occurs from ice, involving much winter work, it is frequently desirable to cover the racks with a house in order to protect the workmen. CHAPTER XXII. EXAMPLES OF WATER POWER PLANTS. 273. Sterling Plant. A rear elevation (Fig. 329) of the plant which was designed by the writer for The Sterling Gas and Electric Company of Sterling, Illinois, shows three 50" vertical Lefrel wheels connected to a common shaft by beveled gearings. The general type of harness used is fully shown in the plan and elevation and needs no further description. This plant is located on the Sterling race and is next to the last plant on the race on the Sterling side of Rock River. (See Fig. 345.) The head developed at this plant is about 8 feet, and the power of each wheel is about 115 horse power. Each wheel is set in an inde- pendent wheel pit which can be closed by means of a gate, as shown in Fig. 332. In order to make repairs on any wheel without inter- fering with the other wheels, the wheels and harness are well sup- ported from the foundation, a very essential condition for perma- nently maintaining a high efficiency. The discharge pit is of ample size, so that the velocity with which the escaping waters leave the draft tube is reduced to a practical minimum. A rack, to keep coarse floating material from the wheel, is placed in front of the penstock and is shown in Fig. 331, in section, and in Fig- 332, in partial elevation. The shaft ojf this plant is extended into the adjacent building and to it are belted the generators which supply electric current for light and power purposes in the city of Sterling. An engine is also connected to this main shaft and may be utilized in case of extreme low water conditions, where sufficient water for power is not available, or for flood conditions where the head is practically destroyed. 274. Plant of York-Haven Water Power Company. Figure 333 shows the arrangement of the power station of the York-Haven Water Power Company on the Susquehanna River at York, Pa. The power house is 478 ft. long and 51 ft- wide. The head-race is 500 ft. long and of an average depth of 20 ft. The wheel pits are 19 ft. deep and extend the entire width of the power house, open- 538 Examples of Water Power Plants. o o S bfi J O > E , otherwise, through a tunnel to a point immediately above the site of the power station. From the end of the tail-race or tunnel the water is carried to the plant through a metallic penstock. Fourth : The fourth type is similar to the third except that where the head-race or tunnel is used (the ground being unfavorable to such construction or the expense of the same being unwarranted) a long penstock of metal is provided to conduct tlie water from the head works to the station. Fifth : The fifth type is the tunnel tail-race type and involves con- ducting the water through metallic penstock direct to the wheels located at the minimum level and, after the water is discharged therefrom, the provison of a tunnel tail-race for conducting the water from the turbine to the point where it is to be discharged back into the stream. It is important to note in this case, as in the case of all other classifications attempted, that such a classification is for the pur- pose of systematizing the consideration of numerous diversified types and bringing them to a similar basis for examination. In the actual adaptation of plans of development, it is seldom any sin- gle type will be found in its simplicity ; in most cases modifications of the same become desirable or essential. Classification of Types of Development. 563 Fig. 343. 564 The Relation of Dam and Power Station. 285. Concentrated Fall. In most of the low head water powers the portion of the fall of the river which can be utilized is distrib- uted over minor rapids and small falls and occupies a considerable length of the stream. Where the head is small and the expense of a dam to concentrate the head entirely at one point is permissible, the power house may sometimes be located to advantage in the dam itself. In this case the power house will constitute a part of the dam itself. This is possible only where the length of the spillway remaining is sufficient to pass maximum flood without an undue rise in the head of the water .above the dam. In many such cases this plan, which is represented by Diagram C, Fig. 343, meets economical construction as it may both cheapen the cost of the dam and reduce the excavation necessary for the wheel pit and tail- race. The power house built at such point is, however, usually directly in the line of the current and must be so constructed and protected as to prevent its injury or destruction by floods, ice or other contingencies of river flow. In other cases, where the spillway available by the above plan is not sufficient or where the plant is not properly protected by such forms of construction, the plant may be constructed on one side of the dam, receiving its waters from a head-race which joins the river above the dam and discharges it into the river below, as shown by Diagrams C and D, Fig. 343. Or, where the capacity is suitable, the plant itself may receive the water directly from its head gate from the river above the dam and discharge it through a tail-race which will enter the river at some point below the dam, as shown in Diagram A, Fig. 343. In other cases, where the power is to be distributed to a number of independent plants, raceways may be constructed on either or both sides of the stream and from the dam, following the stream downward along the bank and more or less approximately parallel thereto as the nature of the conditions demand. The plant drawing the water from this head-race may be distrbuted at various points along the same, and from these plants the water will be discharged after use either directly into the stream itself or into a tail race con- necting such plants with a lower point farther down the stream, as shown in Diagram E, Fig. 343. 286. Divided Fall. An independent tail-race is usually con- structed to advantage where the dam concentrates only a portion of the head or fall, leaving certain additional portions to be developed by the use of the tail-race, which may, if desirable, enter the stream Classification of Types of Development, 565 Fig. 344. 566 The Relation of Dam and Power Station. at a point much farther down the river and at the foot of the rapids. Where the fall of the stream is considerable, and the expense of construction of the dam to suitable height to concentrate the entire fall at a single point is inadvisable, it is often desirable to build a dam to less height at perhaps considerably less expense and develop at the dam only a portion of the total fall. From this dam a head- race may extend to some considerable distance, and the water from this head-race may be delivered to the power plant a mile or two lower down the stream. From this head race, the water, after pass- ing through the wheels, is carried directly into the stream at the lower point, as shown in Diagram G, Fig. 344. Under other conditions, where the topography of the country is suitable, the head-race may be much less in extent, and a tail-race substituted for receiving the waters after they have been used in the wheel and then conducted to the river at or near the end of the rapids, as shown in Diagram F, Fig. 344. Under still other conditions the plant itself may be located imme- diately at the dam and the tail waters may be conducted from the turbine to a tail-race or tail-water tunnel to the lower end of the rapids, as in Diagram H, Fig. 344. The relation of head-race and tail-race is merely a question of developing the power plant at the least cost and securing the max- imum head, and the topographical conditions at the power site will therefore determine which line of development will be best. In a number of cases, where the head or fall is considerable and the power development is large, and where the cost of land for head- races would be almost or quite prohibitive, the stations have been located in the immediate vicinity of the river and have delivered the water into a tail-race tunnel, which frequently empties at a con- siderable distance down the stream and at the lowest point of deliv- ery that is practicable. In other cases it is more economical to run open raceways for a portion of the distance and then conduct the water under pressure by closed pipes to the wheels at the lower point. This last method is used particularly under high head and where the water must be conducted for a reasonable distance over an irreg- ular profile. The quantity of water to be used, the head available, and the value of power modify the arrangements which must be carefully studied in view of the financial, topographical, and other modifying conditions. Distribution of Water at Various Plants. 287. Examples of the Distribution of Water at Various Plants. Fig. 345 is a plan of the power development on the Rock River at Sterling, Illinois. The dam at this point is about 940 feet in length. The power is owned by various corporations and private individuals who have combined their interests in the dam and raceways and ROCK Sterling Hydraulic Company. have organized The Sterling Hydraulic Company, whose function is to maintain the same. The individual plants are owned, installed, and operated by the various owners or by manufacturers who lease the power. At this location races have been constructed at the foot of the rapids, but these rapids continue to a point near the lower end of the tail-race, and the plants farthest from the dam have the highest falls. The fall varies from about 8 to 9% feet. The Relation of Dam and Power Station. Fig. 346 shows the general arrangement of the canal of The Hoi- yoke Water Power Company at Holyoke, Mass. The total fall of the river at this point, from the head water above the dam to the tail water at the lowest point down the stream, is about sixty feet. The fall is divided into three levels by the various canals, marked : ist level canal, 2nd level canal, and 3rd level canal. Fig. 346. Canals of Holyoke Water Power Company. The first level canal, which has a length of about 6,000 feet, is con- structed as a chord across the bend of the river and is approximately some 3,000 feet from the bend. The canal is about 150' wide near the bulkhead and decreases to about 100' at the lo>wer end. The water depth is about 20' at the upper end and about 10' at the lower. The canals are all walled throughout their length to a height two or three feet above the maximum water surface. The fall from the first level to the second is about 20'. Various mills draw their water supply from the first level as a head-race, and discharge into the second canal as a tail-race. Near the upper end of the canal are a few factories that draw water from the first level and discharge the same into the river with a head of some 35 or 40 feet. The second level canal is built parallel to the first and at a dis- tance of about 400 feet nearer the river. The main canal is about 6,500 feet in length, but near the left hand of the map is shown to Distribution of Water at Various Plants. 569 Rear devotion of Fig. 347. Kilboura Plant of Southern Wisconsin Power Co. 57o The Relation of Dam and Power Station. sweep round towards the river and attain a reach of about 3,000 feet in length parallel thereto. The mills drawing their supply from this canal discharge either directly into the third level or into the river. The water supply from each of the lower levels is the tail water from the next level above, but is also supplemented by over- flows when the mills fed from the level above are not discharging Fig. 348. Plant of The Lake Superior Power Co. sufficient water to maintain the quantity needed in the lower level. The fall from the third level of the river is essentially the same for all the mills drawing water therefrom, but according to the stage of the river ranges from 15 to 27 feet. The flow of water in the first level is controlled by gates and its height limited by an overflow of about 200 feet in length which acts as a safety overflow and prevents any great rise in the head water during times of flood. 288. Head-Races Only. Fig. 347 illustrates the general plan of the hydraulic power development of The Southern Wisconsin Power Company at Kilbourn, Wisconsin. Here the entire cross-section of the stream is necessary in order to pass the maximum volume of Distribution of Water at Various Plants. 571 572 The Relation of Dam and Power Station, Distribution of Water at Various Plants. 573 water, which amounts to about 80,000 second-feet. The plant has therefore been constructed at one side of the river, receives the flow through a series of gates built just above the dam, and discharges the water into the river just below the bend in the river, as shown. The plant now under construction is only a portion of that which it is designed to ultimately install. The proposed future extension of the power plant is shown by the dotted lines. TWIN FALLS Fig. 351. Possible Canal for Peshtigo River Development. Fig. 348 shows the water power plant of The Lake Superior Power Company at St. Mary's Falls, Michigan. The canal on the American side begins just above the entrance to the American ship canal and above the Soo rapids. The water is conducted through this canal to a power house located below the rapids at the point shown on the map. On account of the value of the land this canal was designed for a velocity of flow of about 7%' per second with full load of the plant, which was designed for about 40,000 h. p. requiring a capacity with available head of 16.2 feet, of about 4,200 cubic feet per second. (See Engineering News of August 4th, 1898.) 35 574 The Relation of Dam and Power Station. Fig. 349 shows the plan of the hydraulic development of The Economy Light and Power Company at Joliet, Illinois. The entire installation as shown is owned by this company. The fall available is about ii feet and is developed by a concrete dam which creates the upper basin along which the power plant has been constructed. The water flows through the flume gates directly on to the wheels and is discharged into a tail-race built parallel with the river- A 49 SO 51 52 S3 54 55 MILES Fig. 352. Profile of Peshtigo River. certain amount of water is necessary for feeding the lower level of the canal and this is supplied by a by-pass tunnel shown in dotted line above the dam. This by-pass, which is slightly higher than the elevation of the tail-race, is fed by the discharge of one of the wheels, which operates under a less head than the other wheels in the installation. 289. Plant Located in Dam. In Fig. 350 is shown the general plan and elevation of the hydraulic plant at Dresden Heights on the Des Plaines River just above its.junction with the Kankakee River. These two streams unite at this point to form the Illinois River. In this case the dam is built across a very wide valley and the length of the dam is much greater than necessary or desirable to High Head Developments. 575 \ S V, accommodate the flood flow of the stream which is approximately 25,000 second-feet. In consequence, the pres- ent power plant, as well as the pro- posed extension to the power station, will form a part of the 'dam itself and the spillway will occupy only a portion of the entire length of the structure and is so designed as to maintain a sat- isfactory head at times of flood flow The head of the water above the dam is controlled both by the length of spillway and by six tainter gates by means of which the level of the water above the dam can be controlled at all stages of flow. 290. High Head Developments. Fig. 351 illustrates the general plan of a possible method of development of the Peshtigo River for The Northern Hydro-Electric Company. The fall available is shown by the profile, Fig. 352. It is proposed to construct a dam above High Falls of sufficient height to back the water over Twin Falls, and to either develop the. power at High Falls and Johnson' s Falls independently or conduct the water by a canal to Mud Lake, thence to Perch Lake, thence to the head work to be be built above Johnson's Falls, where a head of about 110' will be available. If a single de- velopment is chosen the water will be be conducted from the head works through penstocks to the power plant to be built at the base of the bluff below Johnson's Falls. The canal in this case will conduct the head waters with very little fall to the immediate site of the plant, thence by penstocks to the tur- bine located in the gorge below. 576 The Relation of Dam and Power Station. Fig. 354, Niagara Falls Power Development. Head Developments. 577 Fig. 353 is a plant of the power development at Trenton Falls, New York. The upper portion of the fall is developed by a dam about 60' in height, which is connected by an 84" pipe line with the turbine located in the power house about two miles below. The turbines used in this development are the Fourneyron turbines, which are described in Chap. XIX, and are illustrated by Fig. 311. Fig. 354 is a general plan of the water power developments at Niagara Falls. The first development was that of The Niagara Fig. 355. Falls Hydraulic and Manufacturing Company. By means of a canal the water is taken from the upper end of the rapids and con- ducted to the lower bluff on the American side, and distributed, by open canals, to various plants located along this bluff.. The second plant constructed was chat of The Niagara Falls Power Company, in which power is developed by the vertical shafts connecting with a tail-water tunnel which discharges into the river just below the new suspension bridge. 578 The Relation of Dam and Power Station. On the Canadian side are shown three plants. The Ontario Power Company secures its water supply from the upper portion of the rapids, conducting it through steel conduits to a point above the power house and thence by penstocks to the wheel, located in the gorge below the falls. In the plants of The Toronto and Niagara Power Company and The Canadian-Niagara Power Company, the water is taken from above the Falls and discharges through penstocks to wheels located at the base of a shaft and thence into tunnels, discharging into the river at a point below the Falls. Fig. 355 illustrates the plant of The Niagara Falls Hydraulic and Manufacturing Company, which is supplied by water from the hydraulic canal above mentioned. The water is conducted from the forebay by a vertical penstock to which is attached several wheels which deliver the water into a tail-race tunnel and thence into the gorge below. The plant arrangements above described are typical of many now in use both in this country and in Europe. It is at once obvious that in considering this subject each particular location is a problem by itself which must be considered in all its bearings ; but an under- standing of the designs and arrangements already in use forms a satisfactory basis fromi which a judicious selection can be made with suitable modifications to take care of all the conditions of topography and other controlling conditions. CHAPTER XXIV. PRINCIPLES OF CONSTRUCTION OF DAMS. 291. Object of Construction. A dam is a structure constructed with the object of holding back or obstructing the flow and elevat- ing the surface of water. Such structures may be built for the fol- lowing purposes : First : To concentrate the fall of a stream so as to admit of the economical development of power. Second : To deepen the water of a stream so as to facilitate nav- igation and to so concentrate the fall that vessels may be safely raised from a lower to an upper level by means of locks. Third : To impound or store water so that it may be utilized as desired for water supply, water power, navigation, irrigation, or other uses. Fourth : In the form of mine dams or bulk heads to hold back the flow of water which would otherwise flood mines or shafts or cause excessive expense for its removal. Fifth: As coffer-dams for the purpose of making accessible, usually for construction purposes, submerged areas otherwise inac- cessible. 292. Dams for Water Power Purposes. The primary object of a dam constructed for water power purposes is to concentrate the fall of the stream so that it can be developed to advantage at one point and so that the water thus raised can more readily be delivered to the motors through raceways and penstocks of reasonable length. This object is sometimes accomplished in rivers with steep slopes or high velocities by the construction of wing dams which occupy only a portion of the cross-section of the stream, but cause a head- ing up of the water and direct a certain portion of the flow into the channel or raceway through which it flows to the wheels. Usually in streams of moderate slope the dam must extend entirely across the stream in order to concentrate sufficient head to be of practical utility. 580 Principles of Construction of Dams. Wing dams can be used at the head of high falls where only a portion of the volume of flow can be utilized, as at Niagara Falls, or in rapid rivers w r here a portion of the flow is to be directed into a narrow channel for utilizing low heads by means of undershot or float wheels as is frequently done for irrigation purposes. Where the full benefit of both head and volume is to be utilized the dam must extend from bank to bank and be constructed of as great a height as possible. 293. Height of Dam. To utilize a river to the maximum extent the highest dam practicable must be constructed. The height of a dam may be limited by the following factors : First : The overflow of valuable lands. Second: The interference with water power rights above the point of development. Third : The interference with other vested or public rights. Fourth : The cost of the structure. The value of the power that can be developed by means of a pro- posed dam will limit the amount that can be expended in the pur- chase or condemnation of property affected by backwater from the dam and the cost of its construction. These are among the ele- ments of the cost of the project and must be considered together with other financial elements before a water power project can be considered practicable. In considering backwater and its effect on riparian rights both high and moderate conditions of flow must be considered. The former condition gives rise to temporary interference, often of little importance when affecting purely farming property, and the real or fancied damages from which can commonly be liquidated by re- leases at small expense. The latter condition will permanently inundate certain low lands which must be secured by purchase or condemnation. In many states where the laws of eminent domain do not apply to the condemnation of property for such purposes it is necessary to secure such property by private purchases before the work is undertaken, and usually before the project becomes known publicly, for in such cases the owner of a single piece of land may delay the project by a demand for exorbitant remuneration, from which demand there is in such cases no escape- In every case it is desirable that riparian and property rights be fully covered before the construction of the project actually begins. The Foundation of Dams. 581 294. Available Head. Beside the question of backwater the ques- tion of head at the dam is important both in relation to the question of interference and in relation to the question of power. In relation to interference it is an easy matter with a known length and height of dam to determine by calculation from a properly selected weir formula the height of water above the dam under any condition of flow. To determine the head available under all conditions of flow the weir curve must be studied in connection with the rating curve as discussed in Chapter V. Two conditions of flow often require consideration in this con- nection : First : Where a considerable portion of the flow is being utilized by the wheels and therefore does not affect the head of the dam. Second: Where the water is not being used by the wheels and consequently affects the head of the dam. Both of these conditions should be studied and determined in rela- tion to their influence on both backwater conditions and power. 295. The Principles of Construction of Dams. The general prin- ciples for the construction of all dams are similar, and are as fol- lows : First : They must have suitable foundations to sustain the pres- sure transmitted through them, which must be either impervious or rendered practically so. Second : They must be stable against overturning. Third : They must be safe against sliding. Fourth : They must have a sufficient strength to withstand the strains and shocks to which they are subjected. Fifth : They must be practically water-tight. Sixth : They must have essentially water-tight connections with their beds and banks, and, if bed or banks are pervious, with some impervious stratum below the bed and within the banks of the stream. Seventh : They must be so constructed as to prevent injurious scouring of the bed and banks below them. The application of the above principles depends on the material .from which the dam is to be built and on local conditions- 296. The Foundation of Dams. The materials used for the con- struction of dams may be masonry, which includes stone-work and concrete-work, reinforced concrete, timber, steel, loose rock, and earth. Each may be used independently or in combination. Masonry and concrete dams must be built upon foundations which 582 Principles of Construction of Dams. are practically free from possible settlement. Small masonry struc- tures may sometimes be safely constructed on piles or grillage foundation based on softer materials ; but the larger and more im- portant structures, if constructed of masonry, can be safely built only upon solid rock. Reinforced concrete is now being extensively used for small structures and is not as seriously affected by slight settlement as in the case of dams of solid masonry. There is, how- ever, little flexibility in structures of this kind, and the foundation Fig. 356. Timber Crib Dam at Janes ville, Wis. must be selected in accordance with this fact. Timber and steel possess a flexibility not possible in concrete construction and are much better adapted to locations where the foundation may be sub- ject to settlement. In construction on rock foundation it is usually desirable to exca- vate trenches therein in order to give a bond between the structure of the dam and its foundation. It is also essential with rock foun- dations to determine whether cracks or fissures in the foundation extend below the structure, and if such are found, they must be completely cut off. On earth, sand or gravel foundations, when such must be used, the flow which would take place through these materials and under the structure of the dam must be completely cut off by the use of steel or timber sheet piling, which, if possible, should be driven from the structure to the rock or to some other impervious stratum. If no impervious stratum is accessible, the sheet piling must be Strength of Dams. 583 driven to such a distance below the base of the dam that the friction of the flow of water under it will reduce or destroy the head and consequently reduce the flow of water to an inappreciable quantity. 297. Strength of Dams. A dam to be built in a flowing stream should be designed with a full appreciation of all the stresses to which it may be subjected. Of these, stresses that are due to static pressure can be readily estimated from the known conditions. The strains due to dynamic forces are not so fully understood or easily Fig. 357. Janesville Dam with Moderate Water. calculated. Where the structure is constructed to retain a definite head of water without overflow, as in the case of reservoir embank- ments, the problem becomes one largely of statics and the only other stresses to be considered are those due to ice action and the action of waves on the structure. When a dam is constructed in a running stream and is subject to the passage of extensive floods of water over it, frequently accompanied by large masses of floating ice, logs or other material which in many cases may strike the crest of the dam, and bring unknown and violent strains, the prob- lem becomes largely one of experience and judgment. 298. Flood Flows. The passage of great volumes of water over a dam involves the expenditure of the power so generated upon or immediately adjoining the structure, and unless preparations are made for properly taking care of this immense expenditure of power, the power may be exerted in the destruction of the structure itself. 584 Principles of Construction of Dams. Figs. 356 to 358 show three views of the timber to in ^t n ON033S U3d 133J DI8R3 Nl 33UVH3SIQ Effect of Limited Storage. 629 feet of the Sunday shut-down on the stream flow is well shown in the hydrograph and is evident even during flood periods. 315. Effect of Limited Storage. When the pondage 'available is more than sufficient to carry the night flow of the low water period over for day use, it becomes possible to equalize, to a greater or less extent, the variation in daily flow and to utilize excess flow to in- crease deficient flows, thus raising the quantity of available contin- uous power. The extent of this equalization depends on the quan- tity of storage and can readily be investigated graphically. Fig. 390 shows the estimated daily flow of the Wisconsin River at Kilbourn for July, August, and September, the low water period) 1904. From this hydrograph it will be seen that the lowest flow is 3,000 cubic feet per second. From Sec. 312 it is seen that in order to utilize the night flow during the twelve hours of day, a pondage of 3,000 acre feet must be available. With such a pondage the 16,000 14,000 12,000 10,000 8,000 6,000 4.0OO 2,000 O JULY AUGUST SEPTEMBER Fig. 390. Low Water Flow at Kilbourn and Storage Capacity Necessary to Augment it to Various Amounts. night flow can ordinarily be distributed so as to be available either for twelve hour constant power or to furnish power for any equiv- alent load curve. In Fig. 390 the horizontal spaces each represent a flow of 1,000 cubic feet per second, and the vertical spaces, one day. The area of each space therefore, represents 86,400,000 cubic feet, or ap- proximately 2,000 acre-feet. To increase the low water flow of the river to 4,000 second feet will require a storage capacity equivalent to that represented by ap- proximately three spaces, or a storage of 6,000 acre-feet in addition to the pondage, or a total storage of about 9,000 acre feet. To in- 630 Pondage and Storage. crease the flow to 5,000 second feet, a total storage of 28,000 acre- feet in addition to the pondage would be required; and a flow of 6,000 second feet, will require a storage of 90,000 acre feet in addi- tion to the pondage. In this latter case the conditions to Sept. 6th must be considered, for the increased flow from August I2th to I7th is not sufficient to fill the reservoir, although it will reduce the capacity required, as will also the increased flow of August 2oth. The reservoir capacity represented by 90,000 acre feet is shown on the diagram both by the curved hatched area above the flow- line and by the rectangular shaded area as well. If the reservoir capacity is known, and its equivalent repre- sented on the drawing, its effect on the hydrograph can readily be determined by trial. (See also Fig. 393.) 316. Effect of Large Storage. When large storage is available, the daily flow of a stream can be equalized and its variations there- fore becomes less important. In such cases the power of a plant depends on the average weekly or monthly flow of the stream and the possible storage capacity. S. B. Hill, C. E., has suggested a method of discussing the effect of storage on the flow and power of a stream which is well illus- trated by Figs. 391 and 392. These hydrographs were prepared by the writer to illustrate a report on the probable power of a pro- posed hydraulic development in the South. Figs. 391 represent the mean monthly flow of the river in question for the years 1893 to 1906 inclusive. In this case the scale above the zero line shofws both the mean monthly flow of the stream in cubic feet per sec- ond and the mean monthly power of the stream in horse power hours per day with the head available. The available storage is here 51,000 acre feet or 2,221,560,000 cubic feet. This storage is equivalent to a flow of 857 second feet for thirty days, or a stor- age of energy, with the available head, of about 5,000,000 horse power hours. The maximum daily continuous power (see A-A, Fig. 391) is determined by the effect of the driest year (viz. 1904) on the stor- age. The effect of the dry periods on the storage is shown by the incisions into the lower or storage line of trie diagram. In the year 1904 the reservoir capacity would have been just exhausted in order to maintain the power during the low flows of September, October and November of that year. The amount of available con- tinuous energy (i. e. the position of the line A-A) is determined Effect of Auxiliary Power. 631 by equalizing the deficiency in flow during the dry months with the total reservoir capacity. It is important in the study of storage to see that in the inter- vening periods of excessive flow, such flows are sufficient to supply the deficiency occasioned by previous demands on the res- ervoir, otherwise the effect of one dry period must be considered in its relation to subsequent periods in determining the available continuous power (see Fig. 391, 1897 and 1898). The daily flow of this river for the year 1904 is shown by the hydrograph, Fig. 393, from which it will be seen that with pondage, but without storage, the available power of this stream would be limited to a minimum of 27,000 horse power hours per day. 317. Effect of Auxiliary Power. In order to maintain a con- tinuous power greater than that due to the minimum flow of the stream plus the pondage, some source of auxiliary power must be available. If it is desired to increase the power of the stream rep- resented in Fig. 391 by 50,000 horse power hours per day, making the total horse power hours delivered 163,400 (represented by line B-B, Fig. 392), auxiliary power, as represented by the shaded areas on this diagram, would be needed. As at all other times water power would be available, the addition of steam auxiliary power would apparently be warranted. The size of the plant needed to furnish such excess power would depend on the method of power utilization. It is evident that during the dry periods in 1899, 1904 and 1905, if the water power was first used to its maximum, and the storage exhausted, an auxiliary plant would be needed of a capacity almost equal to the maximum demand on the plant, and that a plant of less capacity could be utilized satisfactorily only by operat- ing it to a considerable capacity whenever a considerable draft be- gan to be made on the storage. As the extent of the drought, or deficiency of water, could not be anticipated such a use of the auxiliary plant would require a greater expenditure of auxiliary horse power hours than is represented by the shaded areas in Fig. 392. An investigation of the capacity and amount of auxiliary power needed, without pondage or storage, to maintain a given continu- ous power, can be readily made from the hydrograph of daily flow as shown by Figs. 394 and 395 which represent such a study of the Rock River at Sterling, Illinois, before the diversion of water for use in the Illinois and Mississippi canal, and the probable addi- Fig. 391. Mean Monthly Flow of a Southern Rive Fig. 392. Amount of Auxiliary Power Nec< I3SOOQ 08000 81000 54000 27000 U) id Effect Thereon of a Given Reservoir Capacity 2000 135000 108000 81000 54000 27000 ry to Increase Output by 50,000 H. P. H. 634 Pondage and Storage. O cn ~ QNOD3S Uld 133J Nl 39tiVH3SIQ Calculations for Storage. 635 tional auxiliary power required to maintain the same power after such diversion. 318. Effect of Maximum Storage. As the head increases the quantity of water needed to develop a given amount of power de- creases, and storage becomes of much greater relative value. The storage of comparatively small quantities of water also becomes a more simple matter, but conditions which need little consideration with larger flows and lower heads, then become more important- In such cases, relatively, large reservoir capacity sometimes becomes Fig. 394. Hydrograph Showing Auxiliary Power Necessary to Maintain 4450 Ten-hour Horse Power at Sterling, 111. Fig. 395. Hydrograph Showing Auxiliary Power Needed to Maintain Ca- pacity of Wheels and Probable Increase Due to Diversion of Water for Illinois and Mississippi Canal. possible and only the questions of desirability and cost limit the extent to which such storage may be carried. 319. Calculations for Storage. Rippl has outlined a method of coimputing storage which may occasionally be used to advantage under high head conditions, when- it is desired to utilize the average flow of a series of dry months or years by extensive storage. This method consists in graphically representing the net yield of the 6 3 6 Pondage and Storage. stream during the period of low flow and from the curve of the net flow estimating the quantity of storage necssary for its full utiliza- tion. The method suggested may be illustrated as follows : From a study of the hydrographic conditions on the water shed for a considerable term of year, the period of extreme low flow is selected. For this period the observed or estimated flow of the stream for each month is reduced by the loss due to evaporation, 800,000 700,000 SCALE OF MONTHS Fig. 396. Diagram Illustrating Rippl Method of Calculating Storage. seepage, etc. The remainder represents the net quantity of water available for power purposes, The summation of these monthly balances, added one to the other consecutively can be platted in a curve in which the abscissa of each point represents the total time from the beginning of the period ; and the ordinate, the total quan- tity of water available during the same interval. The scale may represent inches on the drainage areas, cubic feet, acre feet, or such other unit as may be desired. Such a curve is represented in Fig. 396 by the irregular curve A-B-OD-E-F. The inclination of Lhe curve at any point indicates the rate of the net flow at that par- Calculations for Storage. 637 ticular time. When the curve is parallel to the horizontal axis, the flow at that time will just balance the losses caused by evapora- tion, seepage, etc. A negative inclination of the supply line shows that a loss from the reservoir is taking place. In a similar manner the curve of consumption can be platted. For most purposes this can be considered a straight line as the var- iation in the use of power from season to season is a refinement not usually warranted, unless the uses to which the power is to be put at various times of the year are well established. In Fig. 396 a series of straight lines of consumption are drawn, representing the use of water at rates of 100 to 600 acre feet per day. These rates correspond essentially to rates of from 50 to 300 cubic feet per sec- ond. The ordinate between the supply and any demand line represents the total surplus from the beginning of the period considered, and when inclination of the supply line is less than that of the demand line, the yield of the drainage area is less than the demand and a reservoir is necessary. The deficiency occurring during dry periods is found by drawing lines parallel to the demand line, or lines, and tangent to the curve at the various summits of the supply curve, as at B. The maximum deficiency in the supply, and the necessary capac- ity of the reservoir to maintain the demand during the period, is shown by the maximum ordinate drawn from the tangent to the curve itself. The period during which the reservoir would be drawn below the high water line is represented by the horizontal distance between the tangent point and the first point of inter- section of the curve. If the tangent from any summit parallel to any demand line fails to intersect the cu,rve, it indicates that, during that period, the supply is inadequate for the demand. To insure a full reservoir it is necessary that a parallel tangent drawn backward from the low points on the supply curve shall intersect the curve at some point below. For example: The line B-7, representing a daily consumption of 700 acre feet, does not again intersect the curve and is therefore beyond the capacity of the stream. The line B-6 intersects the curve at E and is the limit of the stream capacity. Such a consumption will be provided by a storage of about 150,000 acre feet as represented by the length of the line 6-D, and such a reservoir will be below the flow line for about twenty-two months during the dry period illustrated in this diagram. That this reser- voir will fill is shown by the intersection of the lower tangent D-A 6 3 S Pondage and Storage. with the curve near A. The conditions necessary to maintain capacities of 500, 400 and 300 second feet are shown respectively by the tangents B-5, B-4 and B-3, and the verticals 5-D, 4-C and 3-C. If the amount of storage is known, and it is desired to ascertain the maximum demand, that can be satisfied by such fixed capacity, ORYEST FIVE CONSEC 1MT 1M0 IBM Fig. 397. Diagram Showing Annual Run-off from Tohickon Creek. the rate is determined by drawing various tangent lines from the summits, having the maximum ordinates equal to the fixed storage. 320. Method of Storage Calculations. The results of calcula- tions, as outlined in Sec. 319 for various conditions of storage on Tohickon Creek, are shown in Table XXXIX and Fig. 398. To- hickon Creek is one of the possible sources of water supply which has been investigated by the City of Philadelphia for a considerable period. The observed monthly rainfalls and stream flows from the drainage area of this stream (in inches on the drainage area) are given in Tables XL and XLI. The five year period of minimum flow is found by inspection to run from December, 1893, to Novem- ber, 1898, as shown by Fig. 397. The approximate evaporation dur- ing the period is taken from Appendix F. The calculations of the mass curves are based on the extreme variations in reservoir area of o to 100 per cent ; that is, on the as- Method of Storage Calculations. 639 O O O O O O O O O I -onoorNtom^ni S3HONI Ml JJO-Nna Q3J.ViniAinOOV 640 Pondage and Storage. B9JB JlOAiaSdJ #001 WAV 75# r are ? jo rans ranooy II jo rans ranooy 91 P" 91 jo rang g jo *es rHCOCDCDl^-CD-^rHaCCOlOCD O CO CO CO Cl CO t^- rH rH rH rH rH rH C 1 CM 'N CM TO ^ CO GOlOl>-CO rH CO CO rH CO O CO CO CO CO HH rH rH COCO CO CO CO CO O O GO rH t^ rH CO CO CO CO CO HH rH CO CO rHrHrH +++II+III+++ ++I++I 3 GO Ol ^ CO -. rH O 81 jo rans oanooy 1>- CO rH 1C rH CD CO h- OS -H TfH CO OS C^l CD 1C 1C ico -c^ocoii.^t x COOOCOlCOt^T it^ 5 CO 1C 00 CO 1C Tfi CO C* cS^ 1> 1C + + + i I+T77 + + + ++ i ++ i i 'z jo Ml 2 1 -I 3 I g jo rans oanooy COCOrHi iCl ic Oi co HH co rN co co CO (MCOCOOOH^-tiTtl 8PU13Z jo rang i O X O GO GO CO O l> CD t^ i>- 1C 1C CD GO O t^ 1C .COiCCOCDCDCOGOt^COOrH HHt^c- CC IO HH. rH !>. IO r^Ico co co" co lOlOlOrHrHrHrHt^CMHHCCOS CM . Q^i <^) rH HH ^^ CO CO CO HH HH ' " OS O CO O CO OS HH CO r^ co rH i co co co co OS OS rH CM OS 00 t^ CM CM O5 CMCMCOCOCOCOCOCOCOCOCOCO CO CO CO HH HH 'HH CO O 1C 1C i CO CO CO CM COOCCMHHCOCOrHCOCOCQCO ' CM CM rH ' HH CO CN O rH I>- O O CO CO CO CO rH CO ID r4 'CM II CO CO CX| rH i 1 CO CO 1 + 1 + + rH rH CM rH rH I I + I + I + CN CX| rH iO ^O *O to iO CO CO CO iO CO CO CO l> t^ t^- i>- I>- 1 + i + + + + i i i +7 + i + I+++++I+I 1 1 + + + + 1 r^ooi^ioost^-oscpcoi^- 'M CM OSCOtOlOt^COCOCOOSCMOSrH ' d OSOrH-HHiOCOrHT^lOCMCOkO OS IO O CM rH CM CO O CO t^ CO O O CO OCOOlOCO( Tj-i O t- t> rH IO OS O - "* CO iO CO CM CO rH O I I I + I CO O OS CO 00 CO CO t^ CO iO (MCOCNCOCOlOCCCO rH.rH CO^CiOCOOCOHHGCCXlO^ CDlClO^ft-COrHlOrHrHOCO rH CMOS!OiO-HCCCO- i i CO C^J oo cr. Tt o o i>. t^- rf CC -^ CO kiOjOjO_JJD 'O '91 PUB ci jo rang ^^^0 T-H T-H 00 rH l f C. * O O CO O 01 (M With 25$ reservoir arear. '6 jo rans uinaoy o gSSSS s^iis '8 pu^ Z jo mng - r^ co cc oo 00 1 1 + + fi J fe as o o * co CO B8.re JIOAI9 -S9J ou qijAY g jo rans uinooy OS CO ~ O Cl CO O t-- I-H co Ci CO o: OCQ lO .... 7 ^t ^ M c CS S s_' CU < >* o3 *^ 0; d H^ 1-5 hb < "a. ^ 8 1 d 1 .& 8 tj pHpii-- 1886 4.15 4.24 5.31 4.23 2.82 6.14 5 49 6.01 5.47 4.34 2.37 4.73 4.58 1.23 5.88 3.96 .96 7.90 3.10 3.38 4.75 4.08 4.76 3.07 5.23 3.67 6.77 4.79 4.13 2.46 1.65 3.11 5.44 2.46 2.84 6.60 4.04 3.42 2.42 4.08 4.90 2.48 1.97 1.95 4.96 2.91 5.50 1.48 3.20 3.73 2.19 3.33 7.14 2.59 3.03 5.41 6.30 2.83 5.55 4.98 13.50 2.99 3.18 8.90 7.62 9 93 174 4.53 5.77 1.69 6.94 3.93 3.38 3.20 4.05 2.63 4.49 4.07 5.10 .76 2.74 3.95 5.47 8.13 3.20 12.33 5.81 7.49 4.27 2.10 2.28 3.53 8.06 8.47 4.00 3.29 5.42 1.08 5.30 8.07 4.63 5.75 8.90 3.76 8.67 2.03 4.43 1.63 4.75 6.05 5.05 4.93 1.30 3.36 8.32 7.92 2.98 1.37 2.91 3.20 9.44 .68 5.83 1.92 2.03 6.70 4.16 2.59 1.93 4.06 4.57 6.31 3.81 .64 3.72 5.18 3.86 2.67 1.83 5.21 1.39 3.71 5.16 1.42 3.66 8.86 1.07 1.97 7.10 4.37 3.01 2.11 4.08 5.02 3.56 2.55 3.33 3.83 6.53 4.35 1.99 2.75 5.09 1.57 3.17 4.60 2.57 .94 4.64 3.49 2.34 3:78 49.45 50.22 55.34 68.04 51.60 52.32 41.80 50.52 53.01 38.24 46.46 50.59 46.92 43.51 49.11 1887 1888 1889 1890 1891 1892 1893 2.96 1.82 4.19 1.18 2.20 4.19 3.68 3.64 1894 1895 1896 1897 1898 1899 Average TABLE XLI. Tohickon Creek Monthly Discharge in Inches on Drainage Area. Year. oS 1-5 J3 OS 6 G >-5 >> -5 hi> < <5 & 4^ 6 to cj & t-& .2* ^P-g 1886 1887 1888 1889 4.36 5.04 6.38 4.38 2.06 6.15 6.53 2.22 .80 3.95 .54 1.81 3.70 4 7?, 9.19 5.25 6.72 1.51 3.78 5.68 1.19 6.64 3.80 1.70 i.59 2.92 4.05 5.56 4.25 4.28 3.84 6.27 3 86 6.37 5.03 4.87 4.54 3.09 5.37 5.48 2.19 1.83 8.99 4.70 4.75 1.02 4.28 2.88 1.79 1.58 .84 3.22 2.28 4.65 .73 1.55 2.50 1.57 2.50 3.43 .93 .52 1.70 3.09 .28 2.05 3.79 8.58 .66 .30 4.63 5.04 .25 2.08 1.41 1.21 .15 2.29 .75 .17 .70 .45 .53 .27 .18 1.71 .19 .07 .76 .77 1.63 .06 6.41 .87 .90 .51 .10 .19 .80 2.54 2.68 .07 .08 1.15 .09 1.96 1.77 3.75 .92 8.92 .30 1.56 .12 37 .19 .73 .74 1.02 1.19 .03 .40 5.50 3.40 1.22 .94 .19 .83 3.37 .03 1.12 .12 .08 2.26 1.36 .05 .25 1.54 2.33 3.54 .46 .09 .60 2.10 .09 1.06 .07 .60 .19 1.20 1.91 .25 3.11 7.97 .69 .63 3.19 2.62 2.67 .13 2.34 1.79 4.50 1.02 1.89 2.38 3.20 3.47 1.92 1:51 4.27 1.67 3.10 3.57 .67 .80 4.08 4.23 1.28 2 89 32.65 24.98 39.77 42.40 26.59 30.01 22.13 29.67 31.10 18.69 19.87 24.28 27.53 27.01 27.58 1890 1891 1892 1893 1894. 1895 .,.. 1896 1897 1898 1899 Average 3.59 sumption that the reservoir may occupy from nothing to the en- tire drainage area. The conditions on the reservoir area are those due to the equal- ization of the rainfall with the evaporation, seepage and other 644 Pondage and Storage. losses. The conditions on the balance of the water shed are given by the run-off and its summation. Table XXXIX shows these calculations in detail and the mass curves drawn from columns 6, 10, 14, 18 and 19 are platted in Fig. 398. The maximum continuous power which could be maintained throughout this period without storage is shown by the lowest slopes of the zero per cent, mass curve. The possible maximum de- velopment of the stream with various percentages of reservoir area can be determined by an analysis of the lower curves similar to that described in Sec. 319. 321. Analytical Methods. Graphical methods o;f computation have been heretofore suggested as a means of investigating pondage and storage conditions. Such methods are believed to be advanta- geous in most cases on account of presenting visible evidence which can usually be more clearly understood than an abstract analysis. Analytical methods for the consideration of these questions are usually obvious after the graphical methods discussed are under- stood, and such methods should usually be used to check up the graphical deductions. Such methods may be illustrated by the fol- lowing analysis of the effect of low water conditions on- a proposed water power on a Western river on which the writer recently fur- nished a report. In this case daily guage readings were available for about ten years, and the rainfall records were available for a considerably longer period. From these records it appeared that the year 1905 was the driest year on record, and that the power available during the low water period of that year would have been equalled at least at all times during every year in the past twenty years, and with a probable like result in the future. At the proposed plant each cubic foot per second, flowing during a day of twenty-four hours, will, at 80 per cent, efficiency, produce 3.63 continuous horse power. In order to develop 8,000 twenty-four hour horse power, it would be necessary, therefore, to have avail- able a continuous flow of 2,200 second feet, while the minimum flow in 1905 was only 1240 second feet. An examination of the gaug- ings shows that during the dry period of 1905 the water was defi- ient in quantity for sixty-eight days. The average flow for this pe- riod was 1,700 second feet, causing an average deficiency of 500 second feet. To impound sufficient water to maintain 2,200 second feet would require, therefore, a storage capacity of about 1,000 acre Literature. 645 feet for each day of the dry period, or a total reservoir capacity of about 68,000 acre feet. Above the proposed dam site is a lake hav- ing an area of about 60 square miles or 38,400 acres. By raising the level of this lake two feet a storage of 76,800 acre feet would be at- tainable which, with careful manipulation would be sufficient to maintain the desired power. If no storage were possible, and auxiliary power was to be es- tablished, the maximum capacity of the auxiliary plant would be determined by the day of lowest flow. During this day there was a deficiency of 960 second feet, equivalent to about 3,500 horse power The average deficiency for the period was 500 second feet, rep- resenting a necessary average of auxiliary power of 1815 horse power, or 43,560 horse power hours per day. The total auxiliary power for this period (68 days) would therefore be about 3,000,000 horse power hours. In the same manner the total amount of auxiliary power neces- sary during each year could be estimated and the interest and de- preciation on the cost of the plant, plus the average annual operating expenses of the auxiliary plant, when considered in connection with similar elements of the water power installation, would furnish the basis for an estimate of the first cost and operating expenses of the combined plant to develop the required power. LITERATURE. 1. Rippl, W. The Capacity of Storage-Reservoirs for Water Supply. Insti- tute of Civil Engineers, vol. 71, p. 270. 2. Fitzgerald, Desmond. Report on Capacity of the Sudbury River and Lake Cochituate Water Sheds in Time of Drought. New Eng. Water Works Asso. 3. Fitzgerald, Desmond. Methods Used to Determine the Best Capacity to Give to Basin No. 5, Boston Water Works. Asso. of Eng. Soc. Vol. X, p. 431. 4. Greenleaf, J. L. A Method for Determining the Supply from a Given Water Shed. Eng. News, vol. 33, p. 238. 5. Horton, Theodore. A Form of Mass Diagram for Studying the Yield of Water Sheds. Eng. Rec. Vol. 36, p. 185. 6. Turneaure and Russell. Public Water Supplies. Chapter XV. John Wiley & Sons. 7. Mead, Daniel W. Report on the Water Power of the Rock River at Ster- ling and Rock Falls, 111. 1904. CHAPTER XXVII. COST, VALUE AND SALE OF POWER. 322. Financial Considerations. Every engineer who is called upon to advise as to the commercial feasibility of a proposed water power development must carefully consider all financial aspects of the project, for on its financial feasibility the entire commercial suc- cess depends. It is not enough that^the power be constant and suffi- cient in quantity, that the plant be well designed, and that the cost of the same be reasonable ; but there must also be a market in which the power can be utilized to advantage and the price at which the power can be sold in competition with all other sources of power must be sufficient to pay all expenses involved in the construction and operation of the plant and afford a fair return to those who as- sume the risk of the undertaking. It is a common belief that any water power development must be profitable. Knowing that an undeveloped water power is a contin- ual waste of energy, it is commonly assumed that the saving of this waste is bound to result in a profit to those who acquire the prop- erty and develop the power. That many water powrs can not be de- veloped at a profit under present conditions is a fact which in many instances is learned by its owner only after a large and unwarranted expense is entailed. 323. Purpose of Development. Any water power project must be examined in the light of the purposes for which it is to be used or the market it is to supply. The supply must be constant and con- tinuous not only for every day in the year but for every year of its operation unless its use will permit of the discontinuation of the power during droughts, high water, or other contingencies that will decrease or temporarily suspend the generation of power by the plant. If its use or market will permit of such interruption, a temporary power may sometimes be developed to advantage. Where the power furnished must be continuous in order to avoid losses or great inconvenience, precautions must be taken to so design the plant with duplication of parts, extra units and suitable pondage or Cost of Development. 647 storage or with such sufficient auxiliary sources of power that in- terruptions shall be essentially obviated. In some cases considerable losses have been entailed by hydraulic developments constructed without sufficient study or consideration of these questions. In such cases, the plants after completion, were unable to maintain continuous power, without the installation of auxiliary steam plants for use during the temporary interruptions to which the plant was subject, and the income from the sale of power would not warrant the extra expense and hence the plants were commercial failures. 324. Cost of Water Power, The cost of water power depends on : . First: The investment in real estate, water rights, power plant and equipment, transmision lines, sub-stations, distribution system, etc., and the interest which must be paid thereon. Second : On the loss from the depreciation of the various elements of the plant, the cost of maintenance and repairs, the cost of con- tingent damages from floods or other accidents. Third : The operating expenses, including labor, oil, waste, and other station supplies and expenses, including also in, hydro-electic plants, the patroling and maintenance of the transmission lines and distribution system. Fourth : The expenses for taxes, insurance, etc. The total annual cost due to the above sources of expense is the annual cost of the power to be furnished by the plant, be the quan- tity of that power much or little. The investment charge should be liberally estimated and should include the entire expense of development including auxiliary power plant, if needed. All contingencies should be carefully considered and estimated. A serious error in the estimate of cost caused by large and unexpected contingencies in construction may mean a commercial failure of the enterprise. The same consideration should be given to the estimate of contingent expenses, deprecia- tion and operating expenses, and each other factor on which the financial life of the plant depends. 325. Cost of Development. The various conditions under which water power is developed greatly affect the cost of development. As a general rule, other things being comparatively equal, the larger the power developed the smaller the cost of development per unit capacity. This is particularly true when developments of various capacities are considered on the same stream. Many of the features 6 4 8 Cost, Value and Sale of Power. of the development must be essentially the same regardless of the ultimate capacity of the plant. This is especially true of dams and river protection work. The variation in cost per unit capacity of various sized plants is well illustrated by Table XLII. TABLE XLII. Estimate of the cost of a Hydro- Electric Plant at Niagara Falls.* ITEMS. 24-HouR POWER CAPACITY. 50,000 H. P. Development. 75, 000 H. P. Development. 100,000 H.P. Develop- ment. Tunnel tail-race $1,250,000 450,000 500, 000 300,000 1,080,000 760,000 350,000 100,000 75,000 $1,250,000 450,000 700, 000 450,000 1,440,000 910,000 525,000 100, 000 75, 000 $1,250,000 450,000 700, 000 600,000 1,980,000 1,400,000 700, 000 100, 000 75,000 Headworks and canal Wheel pit. Power house Hydraulic equipment Electric eouipment Transformer station and equipment. . Office building and machine shop. . . . Miscellao eous Engineering and contingencies 10 per cent. . . . $4,865,000 485,000 $5,900,000 - 590,000 $7,255,000 725,000 Interest, 2 years at 4 per cent Total capital cost $5,350,000 436, 560 $6,490,000 529,584 $7,980,000 651,168 $5,786,560 $7,019,584 $8,631,168 Per horse-power $114 $94 $86 * First report of Hydro-Electric Power Commission of the Province of Ontario, page 15. Other things being comparatively equal, the cost of development varies inversely, although not in the same ratio, as the head. The reason of this is evident from the fact that while the power of a stream is directly proportional to the head, the capacity of a turbine increases as the three-halves power of the head. With double the head the power of a wheel is increased almost three times. For moderate changes in head, the cost of the turbines will vary in proportion to their size and not their capacity ; so that the cost per unit of capacity will usually decrease considerably with the head. The cost per unit of capacity of other features of water power plants will also frequently decrease as the head increases. This is Cost of Development. 649 particularly true of pondage capacity which increases in value directly as the head increases, although the cost per unit of land overflowed may remain constant. The relative cost of high and low head developments may be illustrated by the comparative cost of two plants recently designed by the writer which were of ap- proximately the same capacity but working under different heads. The comparison is as follows: TABLE XLIII Comparative Cost of Water Power Plants. COST OF WATER POWER DEVELOPMENT. Capacity. Head. Without dam. With dain. With dam and electrical equipment. With dam, electrical equipment and transmission line. 8,000 18 63.50 86 115 150 8,000 80 21 39 60 90 TABLE XLIV. Estimates of the cost of developing various Comachian power from Reports of Ontario Hydro- Electric Power Commission. Location of Proposed Development. Natur- al head. Avail- able head. Power develop- ed, H. P. Estimated capital cost. Cost ?. Cost per H. P. per ft. head. (1) Healey's Falls, Lower Trent River . 00 8000 $675000 84 38 Middle Falls, Lower Trent River 30 5200 475000 91 37 Rauney's Fall 35 6000 425000 69 67 Rapids above Glen Miller . . 18 3200 3500CO 109 38 Rapids above Trenton 18 3200 370000 115 63 (2) Maitland River 80 (5) 1600 325000 203 12 40 1333 250000 187 53 Beaver River (Eugenia Falls) 420 2267 291000 128 28 Severn River (Big Chute) 52 (6) 4000 350000 87 50 South River 85 750 115000 153 33 <3) St. Lawrence River, Iroquois, Ont. 12 1200 179000 149 16 Mississippi River,-High Falls, Ont. A 78 (7) 2400 195000 81 25 Mississippi River, High Falls. Ont. B 78 1100 123000 181 82 * Montreal River, Fountain Falls, Ont. 27 2400 214000 89.16 (4) Dog Lake, Kaministiquia River 347 310 (8) 13676 832000 61.00 Cameron rapids 347 39 310 6840 16350 619700 815000 91.00 50 00 39 8250 600000 73 00 Slate Falls 31 40 3686 357600 97 00 31 40 1843 260000 141.00 Third Report; (5) Dam rather expensive. (6) Head works and canal less expensive than ordin- ary. (7) With storage developed. (8) Including 3500 feet of head water tunnel. 650 Cost, Value and Sale of Power. t i OO-Ot^ 10 O CO iO -^ i I Ol CO r- 10 C O1 O CO i i iO - O O CO 1C CO CO O 10" cTcTcxT co'io'co' i I i i CM i O CO O 1C i i CXI CO O O CO CO O ^ co O5 o "- cxi co Cost of Development. 651 f ft c<>-. e * G,Q C C ,0^3 C C!,a S c rt o3 SO O 1 O O 1 ^^ O 3 O O O O ^O iO CO i iOGC"fOiCO O (M co O r i t-^ O*l O t^ 1-1 i I OOCOGCCCi ikOO ' T-T r-T ^-T (>r crT co" C CO CO "^ i I O GO CC -^ ; co co G t> O ll I 0) 0) ft Jj gf ^ e-W W 1 feC T2 2 -Si I s^ I Si C ^ -S oc ft ft ft ' '0; -g # f6(Sop 6 6w GO S Sl^c.S.lo S .S-2 x 3fl3,r5oa^ .2 .H i i! i* i i II 1 !i i !!! Ml it 1 II il lllllg^ Sfeteg-sw s^ Sliff^ -2^.0 s:S,8s=. ^2P of of of n eq t of on eq ly 12- ltage re cli favo iles e e cos e cos statio e cos statio ost vo ver ery 5 Th Th Th Th Mo Se V 652 Cost, Value and Sale of Power. The estimates of The Ontario Hydro-Electric Power Commission of the cost of various hydro-electric plants proposed in Ontario, furnish a good example of the variations in the cost, per unit of power, of various plants under various conditions. These estimates are shown in Table XLIV. The actual costs per horse power capacity of various complete American and foreign plants are shown in Tables XLV and XLVI, respectively. 326. Depreciation. In every operating plant there is in the course of time a certain deterioration or reduction in value due to ordinary operation and the effect of the elements. In the considera- tion of any power plant as an investment, allowance must be made in the annual charges for a sum sufficient to keep the original in- vestment intact. In order to accomplish this an allowance should be made on each feature of the plant for the annual reduction in value or deterioration. The amount of depreciation will vary with the character and use of the machinery or structure and shou,ld be estimated with the best possible knoweldge of the conditions under which the plant will be operated, fully in mind. Such estimates should be sufficiently large to fully cover this item in order that the feasibility of the project may be correctly estimated. The allowance for depreciation in an operating plant should be placed in a sinking fund which should be used to replace the vari- ous portions of the plant at the expiration of their useful life. 327. Annual Cost of Developed Power. As already pointed out the annual cost of operating a plant includes : a. Administration and operating expense. b. Maintenance and repairs. c. Depreciation. d. Interest, insurance and taxes. Each of these items will vary with the duration and the condi- tions under which the power plant is installed and operated. The method of estimating these charges in shown in the following esti- mates of the cost of operation of the Chicago Sanitary District Hydro-Electric Plant (see Electric World, Feb. 28, 1906). Total cost of development and transmission $3, 500, 000.00 ESTIMATE OF COST. Interest on investment at 4 per cent $140,000.00 Taxes on real estate buildings, etc 7 260 00 Depreciation on buildings at 1 per cent 3, 650 . 00 Cost of Distribution. 653 Depreciation on water wheels at 2 per cent 2,027.32 Depreciation on generators at 2 per cent 1, 824 . 60 Depreciation on pole line at 3 per cent 2,020.50 Depreciation on other electrical appliances at 3 per ct. 3,995.52 Total fixed charges , $161, 137.94 OPERATING EXPENSES. Power and sub-station labor 63, 240.00 Repairs to machinery and buildings 3, 700.00 Incidental expenses 1,200.00 Operating Lawrence avenue pumping station 43, 960.00 Operating 39th avenue pumping station 120, 380.00 Interest on investment 39th avenue pumping station. . 15, 599 . 76 248,079.76 Total cost to sanitary district , $409, 217.70 Capacity 15, 500 H. P. Cost per H. P. per annum $26 . 40 An interesting comparison of the estimated yearly cost of various Hydro-Electric generating plants is given in the various reports of the Ontario Hydro-Electric Power Commission which are repro- duced in Table XLVII- 328. Cost of Distribution. Having estimated the annual cost of the development of power at the plant, the cost of distributing the power to the customer must also be considered. In many power plants the power is generated at or near the point where it is to be used and the transmission losses and costs will include its trans- mission through shafting, cables, and belts, or by electrical means, to the machine or appliances in which it is to be utilized. In other cases the power has to be transmitted for miles by high voltage electric currents. The units of power for which the power com- pany will receive compensation may or may not include these various transmission losses. Where the power is distributed to a factory, the losses in transmission though shafting, belting, etc., is usually at the consumer's expense ; but the transmission loss in long distance lines is ordinarily assumed by the power company and must be taken into account in the determination of the cost of furnishing power to the consumer. The losses in any system of distribution are a considerable element of the cost of the delivered power and must be carefully estimated. (Sec. 20, page 24, et seq.) The losses in the distribution of power in various mills, factories, etc., as determined by Prof. C. H. Benjamin, are given in Table XLVIII. The reports of The Ontario Hydro-Electric Power Com- mission, to which references have already been made, furnish nu- merous clear analyses of the cost of electrical distribution. Table 6 54 Cost, Value and Sale of Power. XLIX shows such an estimate for the delivery of power from a proposed Niagara plant to a proposed sub-station at Hamilton, Ontario. Table L shows the estimate of the Commission on the cost of distributing power from a sub-station to an individual con- sumer not within the local distribution. The variations in the cost of power from the generating plant to the consumer is also well shown by Table LI, taken from the same source. TABLE XLVIL Estimated yearly operating expenses of generating plant from Reports of Ontario Hydro-Electric Power Commission. Location of Plant. Horse-power. Net H. P. trans- formed for transmisson. Operating expen- ses including - administration. Maintenance and repairs. d .0 a Q Interest at 4 per cent. Water rental. 1 JO o j>> cS o> N Yearly cost of transformed 24-hour power. 1 1 (1) Niagara plant r>oooo 48750 $57900 $115700 $86800 $231400 Sfi^OOn fijXM'.JAA fill 1C (2) Middle Falls. . . 5000 100000 5200 73125 97500 4990 70200 86300 11875 140400 172600 9500 105300 129500 9500 280800 345200 19000 6oOOO 77500 661700 811100 4W5 9.05 8.32 10 00 Healev's Falls 8000 7680 16875 13500 13500 27000 . . ... 7087^ 9 10 Two above combined 13200 12670 23000 23000 23000 46000 115000 9 08 (3) Maitland River 1600 5665 2754 2755 13000 24174 Saugeen River 1333 4840 3247 3->47 9984 21318 Soutb River . 750 4100 2620 2620 Severn River (Big Chute) Severn and Beaver Rivers combined 4000 6267 17483 23713 8571 13968 8571 14000 14000 25640 485T5 77000 (4) St. Lawrence River 1200 6864 5119 5118 Mississippi River High Falls 2400 9391 3840 3841 7777 9AQAQ Mississippi River High Falls 1100 6390 2491 2491 4908 J0280 Montreal River Fount- tain Falls 2400 9850 3903 *21622 cxqq (5) Dog Lake 13675 13760 16127 1 SQ?" 6840 13296 1063 -> 10 13'^ 04707 Cameron Rapids 16350 16375 173'^7 16727 82.30 14390 11478 10978 24008 60854 Slate Falls 368(5 6000 H634 1 &'W)'i 1843 6000 3868 3669 10400 23957 ( "Including 10-year sinking fund. To make the delivered current available for power, a motor must be installed. This is commonly furnished by the consumer. Table LIT shows the estimated cost of induction motor service per horse power per year. 329. Effect of Partial Load on Cost of Power. The maximum amount of work that any plant can accomplish will be done only when the plant works to its full capacity for twenty-four hours per Cost of Distribution. 655 liaq jad J8A\Od aSJOH CO 00 t- Tfl O i 1 - CO rjn )O Ttn -^ ^t 1 o o; co oo T^I o "^ C5 i rH O IO CO lO O Tt< CO Ttl CO rjl CO CO rH . t>- Satj'eaq aad jaMOd 8SJOH t TjH O CO CO i 1 O t^ ^^ O~~ l^- iO CO CO OS CO 10 CO 1C t- 10 HH Ci O 1-^ CO CO X O CC Hr Ci O CO O O t <* O t^- rn ^^g S 55 5 cii^ samqo'Bia jo aaquin^ GO CO Ol CO CO Tf CO CO (M rH O OO CC 't Gi CO LO ii O iO l- C^l (N CC O O !> CO t^- HH (M rH sSnuttaq jo jaqum^[ S S j CO (M O Tf Tfl rt< rH i I rH rH rH S ?t 3 rH rH (M TH rH CO HH Oi 1^- O5 t^ rH CO a^nmra jad suoi^niOAaa i 1 Ci SO OrHO rH O5 lO rH rH rH O rH rH i i^ 1 rHrHTtli iOrHO O rH lO (M CO !' H rH rH H ^^--^ s rH lO O 1>- IO t^ O CO t^ LO rH .aqoai '}jqs ami ja^auiBia MM< r-l|M (N CO CO Hc^ W -f CO CO CO CO rHlC^HlN (M C^J -f CO (M 't 1 JTt< Ml^f H^. rH CO CO rH CO CO (M OO HN r4?> PH|N ii C laaj 'Sutjswqs 9uq qiSuai i^ox CO CO i i O O O iO CO tO - OO CO !> CO O5 i (N M 6C be q . : : $ : ' "3 ; o 2 S . . ^2J2S > ;? ' OQ P 02 *"-; -* : : : ! o 0^2 h "13 NATURE OF Wire drawing and poll Steel stamping and po Average . . Boiler and machine we Bridge machinery .... Heavy machine work Heavy machine work Average.. Light machine work . Manufacture of small 1 Manufacture of small 1 Sewing machines and Sewing machines. .... Screw machines an 1 sc Average Steel wood-screws. Manufacture of steel n Planing mill Light machine work . 656 Cost, Value and Sale of Power. TABLE XLIX. Showing investments, annual charges, and cost of low tension power at sub- station. (Sub-station included.} Full load. % load. M load. Total horse' power distributed. 16,000 12,000 8 000 Total investment, including step-down stations and interswitching. $450,879 $404, 879 $358,379 Investment per H P delivered 28 18 33 73 44 80- Total annual repairs, depreciation, pa- trolling and operation 22, 496 19,092 15,651 Administration, 10 per cent of repairs, etc. Annual interest, 4 per cent of investment 2,250 18,035 1,909 16, 195 , 1,565 14, 335 Total annual charges $42, 781 $37,196 $31,551 Cost of 24-hour power, including line and step-down sub-station losses $12 69 $12 49 $12 35- Cost of transmitting and transforming. . . . 2 67 3 10 3 94 Total cost of power $15 36 $15 59 $16 29- The above costs of power are based on an assumed rate of $12.00 per 24-hour horse-power per annum for high-tension power at Niagara Falls. TABLE L. Showing cost of distribution from municipal sub-station to an individual consumer, not covered by local distribution. Distance in miles from municipal sub-station. COST PER HORSE- POWER PER ANNUM FOR THE DELIVERY OF VARIOUS AMOUNTS OF POWER. 50 H. P. 75 H. P. 100 H.P. 150 H.P. 200 H.P. 250 H.P. 300 H. P. 2 $5 58 6 89 7 92 8 87 10 20 14 10 16 12 18 76 . 22 74 $4 20 5 20 6 18 7 18 8 24 10 14 12 13 14 03 17 08 $3 53 4 41 5 20 5 98 6 77 8 40 9 54 11 12 13 48 $2 92 3 60 4 27 4 96 5 38 6 97 8 31 $2 74. 3 25 3 93 4 55 5 13 6 24 $2 60 3 10 3 72 4 32 4 60 5 79 6 96 7 96 $2 511 3 03 | o ; 3 86^-g 4 17 | g 4 43J SKJffs 6 17 ) 7 22 ) 8% 8 32 ) 1 3 4... 5 6 . 8... 10 7 68 8 42 9 35 12 10 12 10 89 15 8 84 Cost of Distribution. 657 TABLE LI. COST OF 24-HouR POWER PER H. P. PER ANNUM. AMOUNT OF POWER DELIVERED. At Niagara Falls includ- - ing line and At At step- down sub-station. customer. sub station losses. Full load 2 000 H P $18 54 $21 89 $26 03 ^ load 1 500 H P 13 18 23 54 29 06 * load 1 000 H P 12 85 27 21 34 48 TABLE LII. Capital cost and annual charges on motor installations. Polyphase 25-cycle, induction motors. CAPACITY H. P. Capital cost per H. P. installed. ANNUAL CHARGES. Interest 5 per cent. Deprecia- tion and repairs, 6 per cent. Oil, care and operation. Total per H. P. per annum. 5 $41 00 39 00 35 00 28 00 25 00 24 00 21 00 20 00 17 00 16 00 $2 05 1 95 1 75 1 40 1 25 1 20 1 05 1 00 85 80 $2 46 2 34 2 10 1 88 1 50 1 44 1 26 1 20 1*02 96 $4 00 3 00 2 50 2 00 1 75 1 50 1 25 1 00 80 70 $8 51 7 29 6 35 5 28 4 50 4 14 3 56 3 20 2 67 2 46 10 15 25 35 50 75 100 150 200 . day. Thus, if a plant has a capacity of one thousand horse power and is operated continuously during the twenty-four hours, the total output will be twenty-four thousand horse power hours of work. Under such conditions the plant can be built at a minimum expense per unit of output and the cost of operation, fixed charges, interest, etc., will be less per unit of work done than under any other condition of operation. 40 658 Cost, Value and Sale of Power. For example : If a plant of one thousand horse power be installed at a cost of one hundred thousand dolars, the annual cost of opera- tion, including fixed charges and all other legitimate expenses, may be estimated as follows : Interest on $100, 000 at 6 per cent $ 6, 000 Repairs and depreciation ~.l 5, 300 Operating expenses 10, 000 Miscellaneous and contingent expenses 4, 250 Total annual cost of power $25, 550 On the above basis the annual cost for each horse power of maxi- mum load will be $25.55. If the plant works at its maximum capac- ity for twenty-four hours per day, the cost per horse power hour will be .292 cts. If, however, the plant is operated to its full capac- ity for 12 hours per day only, the total Cost of power may be reduced to say $23,000 per annum. In this case the cost per horse power of maximum load will be reduced to $23.00 per year, but the cost per horse power hour of energy generated will be increased to .526 cts. In many cases the plant will be used for ten hours per day and for six days per week. Its maximum capacity may be utilized only occasionally, and the demand for power will vary greatly from haur to hour resulting in a load factor of perhaps 50 per cent, or less. In this case the annual cost per maximum horse power will still not exceed twenty-three dollars ($23)) per year, .but the annual cost of average ten hour power will be forty-six dollars ($46), and the cost per horse power hour of useful work will be increased approximately to 1.5 cents. The cost of each unit of power under the last condition is over five times as great as in the first case mentioned, and about three times as great as in the second case discussed. It is therefore obvious that unless the conditions of use are carefully studied and conservatively estimated, they may lead to unfortunate investments and financial losses. 330. Cost of Auxiliary Power, or Power Generated From Other than Water Power Sources. It frequently becomes necessary to es- timate the cost of power plants and of power developed from other than water power sources. This is necessary in order to determine the probable cost of auxiliary power plants and such auxiliary power as may be needed to assist a water power plant at times when the hydraulic power is deficient. It is also necessary to deter- mine the cost of power with which the hydraulic plant may be called upon to compete. Cost of Auxiliary Power. 659 For a correct estimate of such cost, it is necessary to determine the efficiency of the various parts of the plant (see page 31) under all conditions o or that obtained by closing the gate instantly. Were it not for the elasticity of water and pipe, instan- taneous gate closure would produce an infinite rate of retardation, dv -fa> and hence infinite pressure. In reality the water near the gate first compresses and the surrounding pipe expands, due to the water hammer pressure, the flow meanwhile continuing undiminished in the remainder of the pipe in order to fill the additional space thus obtained. The point up to which this compression of the water has taken place, as shown by Joukowsky * travels along the pipe from gate to reservoir as a wave with a velocity, A,f equal to that of * See the "Memoires of the Imperial Acadainemy of Sciences of St. Peters- burg," vol. IX, No. 5. Ueber den Hydraulipchen Stoss in Wasserleitungsrohren, by N. Joukowsky; published in German and Russian. See also the synopsis of same by O. Simin in The Trans, of the American W. W. Ass'n, 1904. t A. varies from about 4,500 to 3,000 feet per second as the size uf the pipe- increases, and can always be obtained by the formula (due to Joukowsky) : 12 _ _ _d_ where: A = velocity of the wave in feet per second. K = volumnar modulus of elasticity of the water = 294, 000 s pounds per square inch, e = thickness of the pipe walls in inches. E = modulus of elasticity of the material of the pipe, w, g, and d = as previously defined in Chapter XVIII. 686 Water Hammer. sound in the same column of water. The water has not all been brought to rest until the wave reaches the reservoir, which evi- dently requires a timey. Although only an elementary length of the water column is brought to rest at a time, the effect upon the pressure is the same as would result from retarding the whole col- umn as a unit in a time^-. The maximum possible rate of retar- dation is hence dv 1 Max ' dF = v -*- T From Equation (i) (2) H m = maximum h a . -T- = The pressure-head given by this formula varies from about 140 to 100 feet per foot of extinguished velocity as the pipe increases in size from 2!' upwards. If the gate is only partially closed by this instantaneous motion, the pressure head is given by the same for- mula in which case v represents the amount of the velocity which is instantaneously extinguished. Thus, in the case of instantaneous gate movement, the pressure is not produced at the same instant along the entire pipe, but travels as a wave with a velocity A from the gate to the origin of the pipe and back again to the gate. It then reverses and becomes a wave of rarefaction which travels twice the length of the pipe in the same manner. This continues until the energy of the moving column of water has been dissipated by friction, and the wave gradually sub- sides. This phenomenon is identical with that of the vibrating sound wave in an organ pipe. Although equation (2) gives the maximum possible pressure head which can result from the extinction of a given velocity v in a pipe it does not, however, represent the maximum pressure which could be obtained as the result of several successive gate move- ments ; in fact, no limit can be assigned to the pressure which might result in case several water hammer waves were to be produced at intervals differing approximately by multiples of the vibration * This formula is the same as that obtained by Joukowsky by two other methods of analysis. His discussion of water hammer phenomena includes all that is known upon the subject and it, or Simin's spnopsis, should be read es- pecially by every engineer interested in high head developments as the subject can only briefly be touched in this book. Water Hammer. 687 period of the water column, in which case they are known to "pile up" to enormous indeterminable pressures. When the flow in a pipe is shut off by the gradual closure of a gate then equation (i) and also the following equation from Chapter XIX, sections 213 and 217, apply as before except that in this case not only v but also V is a variable, its value being differ- ent for each successive position of the gate, and its law of variation depending upon the law and rate of gate movement- The integra- tion of equation (3) in its general form, to obtain the velocity curve is then very difficult if not impossible. An approximate curve of v, and hence also of h can be plotted by assuming the gate closure to take place by means of a great many small instantaneous movements, according to any law which may be chosen. The value of.V for each of the many gate positions can then be computed from the known hydraulic data of the wheels and penstock. Now, in equation (3), substitute for v the initial velocity in the pipe, and for V the normal velocity (above determined), after the gate has received its first small instantaneous movement. The re- dv suit will be the initial slope of the v-t curve =^r. Assume this at rate of decrease in velocity to continue constant for the short in- terval between successive gate movements ; then the actual velocity, v, at the instant of the next gate movement will be (4) >.. T -T- J where i is the interval between the two movements. Assume this new value of v, to be v and using the value of V for the corresponding (or second) gate position, again apply equations (3) and (4), until the gate is completely shut. Having thus determined the v-t curve, the head curve can be readily found from equation (i), which gives the excess of head above static or so called water hammer head. dv Substituting the value of r from (3) in (1) gives (5) h a = : Church has investigated this problem by a method described in the Journal of the Franklin Institute for April and May, 1890. APPENDIX-B. SPEED REGULATION, A MORE DETAILED ANALYSIS THAN IN CHAPTER XVIII. In Chapter XVIII, Section 217, the following equation was shown to express the rate of acceleration of water in the penstock subse- quent to an instantaneous change in gate opening of the wheel. dF^V 1 IT* Separating the variables v and t, gives d t = lvs dv gH ' V 2 -v 2 Integrating we have: To determine the constant of integration, C, assume that v v when t = 0, hence C = - log e V ~ VO Let (3) (4) B=^ V-vo Substituting these values of C, B and k in (2), gives, From the definition of a logarithm: if X = log e N, then e x = N hence Solving for v we obtain: (7) ^ Be kt 4-l From the principles of logarithms we have: kt ** k/t e =10 *-3 = 10 Change of Penstock Velocity. 689 hence (8-) v = V BX antilogk't 1 ' B X antilog k ' t + 1 Equation (8) is very readily applied to finding the curve of velocity increase or decrease in any pipe line subsequent to a sudden change of gate opening. It has been experimentally demonstrated I L 2 3 TIME: - SECONDS Fig. 403. Curve Showing the Acceleration of Water in a Pipe Line After a Sudden Opening of the Gate. for the acceleration of water in the drive pipe of an hydraulic ram, as shown by Fig. 403 which is taken from Bulletin No. 205, Uni- versity of Wisconsin, Engineering Series, Vol. 4, No. 3, "An Investi- gation of the Hydraulic Ram," by the writer. The curve is the plot of equation (8) and the experimental points were determined by an especially designed instrument. The fact that they fall commonly below the theoretical curve is due to a systematic friction error in the instrument. The agreement is suf- ficiently close, however, to entirely verify the form of equation (8). Fig. 404 shows the curves determined from equation (8) for 42 690 Speed Regulation. the wheel used for illustrative problems in Chap. XVIII, Section 228. Acceleration curves are shown for changes from o to the ve- locities of %, %> -9 and full loads ; retardation curves from an initial velocity of 5' per sec. to the above velocities. It will be observed that in each case the actual velocity approaches, but theoretically never equals, the normal value, V, for the given gate position. The values of the constants used in computing these v-t curves are given below. B, for accelerating from an initial velocity of zero, is: V + v V TIME IN SECONDS Fig. 404. Curves of Acceleration and Retardation of Water in Penstock for Various Gate Movements. The other constants are: H = 50', 1 = 500', and v = 5' for re- tardation curves ; also for the retardation curves B is negative, since v is greater than V. If we always use the positive value of V o we will obtain two equations: For increasing velocities or acceleration (9) antilogk't-1 antilog k't + 1 For decreasing or retarding velocities, (10) _ y B antilog k't+1 Bantilogk't- 1 Change of Penstock Velocity. From equations (3) and (4) we obtain the table, 691 Load. 1.0 .9 .5 .25 V. 4.77 4.49 2.88 1.94 B 41.3 19.1 3.71 2.27 k' .585 .623 .975 1.444 The computations of v, by equations (9) and (10), for various assumed values of t is very simple if tabulated as below. The computation of the curve of acceleration and retardation of water in the penstock from 0, and from 5 feet per second, respectively, to its value 2.88 ft. per sec. for % load is shown. It is assumed that the gate opens instantly from to its position at % load, and closes to this position instantly when the velocity is 5' per sec., giving the values of velocity in columns v and v', (4) and (6) , respectively. Computation of v-t curve.* H = 50', 1 = 500', d = 8', k' = .975, B = 3.71, v = and 5', V = 2.88', (1) (2) (3) (4) =v (5) (6X.-V 1 t k't antilog of k't <3)-l oo (3) X3.71 (5) + 1 S8 <3) + l- (5)-l~ .0 .0 1. .0 3.71 5.0 .1 .0973 1.261 .321 4.64 4.17 o .1946 1.565 .635 5.81 4.077 .4 .3892 2.45 1.210 9.10 3.59 .6 .5838 3.835 1.690 14.23 3.31 .8 .7784 6.003 2.055 22.27 3.15 1.0 .973 9.397 2.327 34.85 3.05 1.2 1.168 14.72 2.513 54.70 2.99 1.4 1.362 23.01 2.64 85.5 -.95 1.7 1.654 45.08 2.753 167.3 2.91 2.0 1.946 88.31 2.81 328.0 2.897 * A number enclosed in parenthesis refers to the value given in the column of that number. Referring again to Figure 404 we see that the acceleration curves thus computed all have a common tangent at the origin showing an initial rate of acceleration in each case of, dv _ gH ~dtT : ~T~ The initial rate of retardation, however, depends upon the gate opening. 692 Speed Regulation. As shown by equations (9), (10) and the curves in Figure 404 the velocity never equals, but approaches indefinitely near, to its normal value, V, for a given gate opening. To show the application of the foregoing discussion to the change of penstock velocity, power, speed, etc., at a change of load, refer to Figure 405. Here the line A B represents J load, line C C repre- sents full load, line D D .8 load and line H H 45 per cent load for the same wheel discussed above. Lines A 7 B', C' C' and D' D' represent the corresponding hydraulic power input lines. Line abccba represents the line of gate movement from its initial position at 14 to its position at full load and back again to % load. Line O C v C is copied from Figure (404) and represents the curve of velocity increase which would result from a sudden complete opening of the gate. At b the gate begins to open, and the velocity to increase along an estimated curve B v C v . This curve could be more accu- rately determined by the process outlined in Appendix A, but was not so determined here. In the same way curve F B x v A^ w r as taken from Figure 404 and the velocity curve during gate movement, C' v B"' v . was estimated. Having thus obtained the velocity curve A v B v C v C-C' V B' v A v , the curve of effective head at the wheel can be readily determined from equation (11) Chapter XVIII, or (H) h=^H' While the gate is in motion from b to c the valve of V changes, but can be readily estimated by interpolation from the values at !/4 and full gates. From c to c (gate curve) V is constant, and equal to 4.77 ft. per second. Since the friction loss in the pen- stock is slight in the problem under discussion H' is assumed to equal H = 50'. The resulting curve for h is A h B h C h C h C' h B'h A h . The curve of hydraulic horse power or input was then determined by applying the equation below to several points along the v and h curves obtaining curve A' B' G Y' X'. p _ 9h _ A v h 8.8 ~ 8.8 The output power curve A B C Y X was then computed by ghE 8.8 E or efficiency for each point was obtained from the characteristic curve of the wheel, Figure 245, by first computing from the known Graphical Analysis. 693 values of q, h, and S (= 180) at each point the values of the dis- charge under one foot head and . Many interesting facts can now be seen from a study of Figure 405 It will be seen that the opening or closing of the gate in order to in- crease, or decrease, the power of the wheel has an 'immediate effect directly opposite to that intended and that in the output curve the Fig, 405. Graphical Analysis of Speed Regulation. power reduces to practically, if not quite, zero for nearly one-half second. The effective head drops very greatly during acceleration, and rises during retardation. It is evident that the rate of gate movement here used (% second) is too fast for closure, since the head rises to about 165 feet, over three times its normal value. Now, since the product of power and time gives energy or work, it is evident that the areas of the figures generated by the ordinates to the various load curves are proportional to the demand for en- 694 Speed Regulation. ergy and the areas of the output curves are proportional to the supply. The area between the two curves, therefore, represents a deficiency or excess of work accomplished by the wheel, and can be measured by means of a planimeter or otherwise. The value of one square is % X 200=50 horse power seconds = to Y zzo 27,500 foot pounds. It was found in this way that the deficient hydraulic energy sup- plied to the wheel, assuming the load demand to increase from 14 to full is 27,500 X areaB' O Y' X' C' B' = 27,500 X 36 = 990,000 foot pounds. The deficient load output is 27,500 X areaB C YXCB = 27,500 X 35 = 963,000 foot pounds. This deficiency of input over output must be supplied from the energy stored in the rotating parts, or from the fly-wheel effect, and can be accomplished only by a drop in speed of the power unit. Furthermore, in the case considered, the speed can never return to normal as long as the load remains at full value, but suffers a per- manent drop due to the fact that v, q, h and power theoretically approach, but never equal the normal values for the new gate opening. The excess energy, when the load again drops to its ^4 value is, 27, 500 X area C E F A B C or 27,500 X 18 = 495,000 foot pounds. It is evident that this excess energy at decreasing load will al- ways be less than the deficient energy at time of increasing load, since the low efficiency of the wheel during the velocity-change tends to decrease the former and increase the latter. It is also possible to dissipate the excess energy through a by- pass or relief valve, while no method is available for supplying the deficiency during load increase except at a sacrifice of the kinetic energy of the rotating parts and consequent reduction of speed. In Section 226, Chap. XVIII, it was shown that the percentage departure of the speed from normal is * = 294,000 R * K Since the deficient energy AK is actually measured in this case, the estimated co-efficient R becomes unity. The normal speed, S, of the wheel is 180, and I will be assumed as 1,000,000 ft. 2 Ibs., or 1,000,000 pounds at one foot radius, then Numerical Example. 695 d - 294 ooo 963 ' 00 1,000, 000 X ISO 2 = 8.7 per cent. This is a permanent drop in speed. In order for the speed to pick up again to normal, the gate must therefore overrun. The condition then is best illustrated by assum- ing in Figure 405 that the load increases only to 0.8 of full load value, following the line A B D D, while the gate movement follows the same line as before. In this case the v, h, wheel imput, and wheel output curves will be unchanged. The deficiency of input or of energy in the delivered water is then (by means of planimeter) represented by area B' D' Y' Q B' or = 27,500 X 21.8 = 600,000 foot pounds. The deficiency of output, represented by area B D Y C B, is 27,500 X 21.3 = 586,000 foot pounds, giving a speed regulation of The two quantities will probably always agree as closely as the accuracy of the problem demands, and much labor can be saved in an analysis if hydraulic horse power, or input, only is considered. At Y the power curve crosses the demand line, D D, and the speed begins to pick up, due to an excess of developed power. The time required for return to normal can be obtained by continuing the two curves until the excess area equals the former deficiency. In this case 8% seconds is required. By the successive application of equation (41) Chapter XVIII to narrow vertical strips of the excess or deficient energy area, we may plat the speed curve of the unit. In this way curve MSS , Figure 405, for increase from !/4 to Ml load; curve MSS 2 for in- crease from 14 to .8 load but simultaneous full gate opening ; curve S' S^ for decrease from full to 14 loaci > and curve S' S 2 for decrease from full to 45 per cent, load, were platted. Curves MSS X and S' Si never returned to normal (180 R. P. M.), but curve MSS 2 re- turns in 8!/2 seconds, and curve S' S 2 in 4 seconds- It is the belief of the writer that this method of analysis is not too long for a problem in practice and, if not, is therefore better than the method given in Chapter XVIII since the conditions before and during gate movement can be readily included. APPENDIX C. THE STAND-PIPE. It was shown in Section 223, Chapter XVIII that the following equations apply to the operation of a plant with standpipe : d.V ' ST 2T (1) -r- =-y (accelerating head) -y- h a (<2\ d dh Av ~ dt dt F The value of h a in a plant with penstock, is h a = y h f 1 v 3 Hence = y (1 -j- f ~r -h etc.) = y cv 2 Equation (2) gives the instantaneous rate of fluctuations of water level in the stand-pipe. Equation (3) gives the rate of increase of penstock velocity in terms of the then existing values of y and v. The quantity, q, in equation (2), represents the water used by the wheel. This may remain practically constant if the head fluctua- tion is not too large, in which case the speed of the wheel will suffer ; or, by means of an ideal action of the governor, it may be made to fluctuate inversely as the head h, thus maintaining a constant value of the product, qh, and hence of the power input of the wheel. In case this latter assumption is made, then : qh =q t h, or q(H-y)=Av 1 (H-cv 1 2 ) Substituting this value of q in equation (2) gives : (4) dy_A r YI (H - o v r * n dt~FL V (H-y) J The solution of the two simultaneous differential equations 2 and 3, or 3 and 4, depending upon which assumption is made, is nec- essary in order to determine the exact curve of variation of head and velocity. Their general solution is however, very difficult if not impossible in this form. The equations may be applied successively to short portions of the arc by considering the curves to consist of Graphical Analysis. 697 a great many short straight lines. This method is not too long for application to a problem in practice, and will assist in obtaining ap- proximate formulas which will be seen to coincide very closely with the true curves. Assume an installation where d = 8', 1 = 500' H = 50, F = 8A. Let the velocities on the penstock at fractional loads be the same as given in the problem considered in Section 228, Chapter XVIII. If the load suddenly increases from *4 to full, the velocity in the pen- stock must accelerate from 1.94 to 4.77 feet per second, or q from 97.8 to 240 cu. ft. per sec. Estimating f = .018, equation (3) gives dv 32.15 F . 500. (5) - = .0643 (y .0331 v 2 ) Qt and equation (4) gives : dy_ _ dh _ v 4 . 77 X 49 . 25 "cfiT ~ dt ~~ 8(H y) <*}L = _ 29 ' 4 dt. 8 H y Curves A v and A h , Figure 406, show the curves of velocity, v, and head, h, respectively, obtained by applying equations (5) and (6) alternating to the two curves, considering them to remain straight for the time interval between consecutive points which were taken from % to one second apart depending upon the curvature. The closer these points are taken the more accurate would be the result- ing curves. If friction in the penstock, and the action of the governor, in compensating for the fluctuations of h, be neglected then equations (i) and (2) become (8) = v,-v Dividing (8) by (7): dy _ Al[ v, y dv ~~ Fg' y Integrating: To determine the constant of integration, C ; let v = v when y =^= o, whence : 698 The Stand-pipe. Substituting this value in (9) gives : (10) y 2 - -- [(v, - v ) 2 - ( Vl - v)*] Substituting this value of y in (7) and solving for dt gives - y (Tl _ Vo _ fVl _ v) . The integral of (n) is: When t = o, v = v 0f hence c = after which (12) becomes: t= V T v Solving this equation for v gives: (13) v - Vl - ( Vl - v ) cos - If this value of v be now substituted in equation (8) the equation for y in terms of t can be obtained as follows : When y = o, t = o, hence C o and ^ 04) ' ' v = Since this equation is that of a true sine curve it will be readily seen that the maximum ordinate and hence the maximum de- parture of the head from normal is (15) Y = - (Vl ~ Vo) ' and return to normal head occurs when Whence (16) T = Fluctuations of Head and Velocity. 699 Equations 13 and 14 may now be revised to read (17) (18) i v ) cos t and fr* These equations, (17) and (18), are shown for a particular prob- lem, by the dotted lines B v and B h in Figure 406. The closeness of their agreement with the curves A v and A h which involve the effect of both friction and governor action shows that the values IN FEET PENSTOCK VELOCITY IN FEET PER SECOND o-iuu*>uia>Njco . T I -- + 6 + 4 X s 0(0 UJ * 2 < > -4 -B ^5" ^ ^ i i ^ X N 2 ^ ^> -F s k m ^ s^ i ; N Of _M \L y EL DC :IT Y/ OR N :w L DA D j \u D / vx s ^ s, DF BIN E C UF W _ ^x s ^ s ^ ff X ^ ^ v^. > < x ^v . X v, Nl m ^_A L - _y EL QC LT. Y_. P_R 3fi GL NA L _L Of Q k -. ^ ! ^ ev rf "~- ^ EFFECTIVE HEAD Cv fc Ul Ul ^ en CD a ru ^ &f ^ Y "-^ 5; S ~. - _N_C R ^A L 1 HEAD X ^N D ;<- t L xx X S DF S IN E C 3U =IV E ^5 k^ ^> ^ ^ v , x / < OO CC ?O ^J< IOO O H > O ^ ' i o o TH 01 <*< t^ O5 (N co co-g; xo i >ft2lOWU3 CO CO *<'<< Tj< ^ r}< Ji-5^*'c4t^*J 1 > o> r- * 3 s o i > rf 10 lA GO oi 10 c ' ^ t^- 1~ t- t~ t- 1 t>- oo o eo o o o oo n o o oo M o i- Victor Turbine. 705 OC' 3 ooooo aoaooocsoaJcScj o ' t^-t>- o P t> r-- 1> t>- r- r- ( o o o KggS82 SSsHlli l| e '*^Si i o _ i-i in | = . = s S. ..... s jjj. . . - . . , 43 7o6 Turbine Test Data. TABLE LXI. Test of a 96-inch Fourneyron Turbine Built in 1851 for the Tremont Mills, Lowell, Mass., after designs by James B. Francis. Number of experi- ment. Gate opening (propor- tional part. Proportional discharge (discharge at full gate with highest efficiency =1). Mean head in feet. Duration of test in minutes Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 1 1 1 01 12 86 8 53 62 139 42 161 4 78 4 2 1 1 01 12 86 10 53 5 139 42 159 2 78 3 3 1 1 01 12 87 10 53 6 139 47 159 5 78 4 4 1 1 13 12 55 6 95 8 156 65 60 6 27 2 5 ,.. 1 1 12 12 61 8 91 9 154 39 77 9 35 3 6 1 1 10 J2 6-"> 7 87 7 152 27 94 43 7 1 1 08 12 70 8;j () 149 46 109 2 50 7 g o 1 07 12 72 5 78 5 147 29 l''l 5 57 2 9 o 1 OB 12 18 5 77 4 146 02 131 7 62 2 10 o 1 05 12 80 g 71 144 81 140 2 66 7 11 o 1 04 12 82 9 67 5 143 91 147 2 70 3 12 o 9 107 13 .... o 1 18 12 51 9 lo7 o 163 43 14 o 1 03 12 86 9 6t 142 52 152 6 73 5 15 o 1 03 12 89 9 61 4 142 04 155 8 75 16 o 1 03 12 89 | 60 141 98 157 75 6 17 o 1 02 12 90 9 58 2 141 28 158 3 76 6 18 .... Q ] (J2 12 8^ 56 7 140 47 158 9 77 4 19 o 1 01 12 88 10 55 4 140 OS 159 5 77 9 20 o 1 01 12 87 9 54 7 140 01 159 7 78 21 22 .0 o 1.01 1 01 J2.90 12 90 10 14 54.1 53 8 139.90 139 67 160.0 "160 2 78.1 78 4 23 (J 1 17 12 43 9 106 8 161 69 24 o 1 01 12 90 9 53 6 139 01 160 5 78 9 25 26 .0 o 1.01 1 12.90 12 89 13 5 53.1 52 5 139.03 138 76 160.4 159 5 78.8 78 6 27 28 .0 o 1.0 1 12.90 12 91 14 13 5^.8 52 4 138.85 138 87 160.5 160 5 79.0 78 9 29... o 1 12 91 12 52 138 51 160 6 79 2 30 31 .0 o 1.0 1 17 12.90 12 54 ]2 y 51.1 106 8 138! 19 162 32 160.5 79.4 32 (J 1 12 91 6 2 138 27 160 6 79 3 33 o 1 12 93 10 48 8 138 23 160 6 79 2 34 1 1 12 94 jj 47 1 38 09 160 78 Q 35 1 1 12 94 11 44 5 137 71 158 4 78 3 36 1 99 12 96 jl 41 7 136 49 156 2 77 9 37 1 98 12 94 10 38 7 135 14 152 6 77 38 1 1 17 12 5 9 107 1 161 69 39 1 98 12 96 12 38 8 135 34 153 76 9 40 41 1.0 1 0.97 97 12.97 12 98 8 11 36.0 31 9 134.80 133 75 149.3 142 7 75.3 72 5 42 1 97 12 95 9 27 3 133 43 133 67 9 43 44 1.0 I 0.9* 98 12.80 12 77 1.5 2 5 0.0 135.65 135 62 0.0 0.0 45 1 I 17 12 47 9 106 9 162 02 46 47 1.0 1 1.00 1 00 12.95 )> 93 11 10 49.9 4Q 138.62 1 'Itf nfl 161.1 IfiO 7 79.1 TQ 1 48 1 1 00 12 95 11 48 2 138 47 160 5 78 9 49 1 1 00 12 95 12 47 4- ifta 07 160 3 78 9 50 51 1.0 75 1.00 1 fl-t 12.95 12 7fi 11 j 46.2 138.16 159.8 78.7 52 75 1 111 !'* 87 g 7* A -IQQ 01 120 fi K.Q A 53 75 1 00 12 91 9 K7 ^ 54. . 75 1 00 12 Q4. 55 56 0.75 7") 0.99 OQH 12.95 8 61.4 137.00 145.9 72.5 75 58 75 97 JO QQ 59 75 96 iq An 60 75 61 75 OQK 148.7 Francis' Tremont Turbine. 707 TABLE LXL Continued. Test of a 96-inch Fourneyron Turbine Built in 1851 for the Tremont Lowell, Mass., after designs by James B. Francis. Mills, Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficienc3' = l). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 91 3 4 5 6 7 8 9 62... 75 95 13 04 9 46 3 130 99 147 9 76 4 63 U 75 95 13 03 8 42 5 13(1 89 145 1 75 64 75 1 08 12 72 U 103 fl fl n (I 65 49 88 13 17 H 92 9 121 97 66 67. .. 0.49 49 0.86 8t 13.08 14 13 6 6 81.1 73 1 118.55 116 1 52.8 78 3 30.0 45 3 68 49 83 13 18 g 65 114 26 96 6 69 49 82 13 21 60 2 113 24 103 3 60 9 70 49 81 13 25 y 55 4 111 52 63 7 71 49 79 13 2d 50 6 109 71 107 8 65 2 72 73 0.49 49 0.78 78 13.31 13 31 II 6 46.5 46 5 108.05 107 95 106.8 107 65.5 65 6 74 49 76 13 33 9 41 2 105 53 102 3 64 1 75 49 75 13 36 ( s 36 9 103 85 97 3 61 9 76 49 73 13 41 27 4 100 54 83 7 54 8 77... 87 99 12 88 51 3 137 36 156 8 78 1 78 79 0.87 87 0.99 99 12.90 12 91 7 7 49.3 47 4 136.97 136 55 157.0 156 6 78.4 78 3 80 81 0.25 25 0.58 57 13.35 13 37 5 6 74.9 68 8 80.45 78 84 0.0 168 2 0.0 14 i 82 83 0.25 U 25 0.56 0.54 13.40 13 43 6 6 57.6 46 3 76.62 74 06 38.6 49 7 33.2 44 84 85 0.2.') 0.25 0.52 51 13.48 13 51 8 8 40.3 33 6 71.87 70 01 50.9 48 8 46.3 45 5 86. .'.. 25 49 13 56 27 7 67 82 44 4 42 7 87 0.25 0.47 13.56 H 18 64.51 32 7 33 o 88 25 44 13 52 60 36 U 89 90 91 0.25 0.087 0.087 0.44 0.28 0.28 13.53 13.98 14.00 7 7 0.0 37.2 41.3 60.42 38.22 38 57 0.0 9.09 6 23 0.0 15.0 10 2 92 ... O.U87 0.27 14 02 17 23 3 37 17 14 21 24 7o8 Turbine Test' Data. TABLE LXII. Test of a 57-inch Left Hand McCormick Turbine. Built by J. and W. Jolly, Holyoke, Mass. Testing Flume of the Holyoke Water Power Co. Tested on Conical Draft Tube. Test No. 1156. Oct. 31 and Nov. 1, 1898. With the flume empty a strain of IT Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = l). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 40 000 1 Oil 13 77 4 79 87 244 50 305 SO 80 10 39 OUO 1 007 13 86 4 83.25 244 34 309 12 49 38 37 .000 OUO 1.004 1 001 13.92 13 93 4 4 86.75 HO. 25 244.16 243.38 311.49 311.78 80 82 81.10 36 OUO 994 14 03 4 94 62 242 58 312 08 80 86 35 3J .000 770 0.934 890 14.10 14 69 4 4 99.87 79 37 240.66 222 19 305.63 299 03 79 43 80 81 33 32 31 0.770 0.770 770 0.886 0.883 881 14.72 14.73 14 75 4 4 4 82.87 85.75 88 75 221.41 220.81 220 38 302.63 303.24 '303 58 81.89 82.22 82 36 30 29 28 0.770 0.770 770 0.876 0.868 857 14.76 14.82 14 86 4 4 5 92.00 95.50 98 90 219.17 217.65 215 23 302.19 298.75 292 57 82.38 81.68 80 67 27 770 847 14 94 5 101 50 213 41 283 (JO 78 28 26... 615 762 15 36 4 77 75 194 56 261 73 77 23 25 24 0.615 615 0.761 757 15.36 15 40 4 5 81.87 86 20 194.25 193 52 266.69 269 07 78.82 79 62 23 615 753 15 39 4 89 62 192 50 267 55 79 64 22 21 20 0.615 0.615 615 0.745 0.739 729 15.45 15.47 15 52 4 4 4 92.37 95.62 98 75 190.92 189.30 187 15 262.57 257.51 251 16 78.50 77.51 76 26 19 18... 17... 0.615 0.483 483 0.719 0.632 630 15.63 15.90 15 87 4 4 4 102.25 78.12 82 37 185.14 164.25 163 42 243.37 215.69 218 46 74.17 72.83 74 28 16 483 626 15 85 4 8(3 37 162 32 17 32 74 49 15 14 13 12 0.483 0.483 0.483 483 0.621 0.615 0.609 603 15.81 15.81 15.74 15 75 4 4 4 4 89.50 93.00 96.00 99 25 160.80 159.31 157.40 156 03 213.03 208.71 20-3.38 195 74 73.90 73.07 72.04 70 y 4 11 483 598 15 7 4 102 37 154 55 187*97 68 23 10 483 59'{ 15 76 105 50 153 45 179 36 65 41 9 8 0.360 360 0.500 498 16.27 16 37 4 4 74. 7o 79 62 131.52 131 26 161.14 163 52 66.41 67 11 7 6 5 4 0.360 0.360 0.360 360 0.495 0.492 0.488 OAQZ 16.42 16.41 16.43 Ifi 4? 4 4 4 83.75 87.12 90.37 130.63 129.75 128.87 163.46 161.15 157.94 67.20 66.74 65.78 R4. 49 3 360 481 16 45 96 62 127 21 14Q -IK 62 86 2 360 479 Ifi ^4. -IAA OX 128 K^ 611 19 1 0.360 0.474 16 59 4 104.37 125.70 134.86 57.03 Samson Turbine. 709 TABLE LXIII. Test of 56-inch Right Hand Samson Turbine, built by James Leffel Co.', Spring- field, O. Testing Flume of the Holyoke Water Power Co. Test No. 1257. June 20, 1900. Tested on Conical Cylinder. With the flume empty a strain of 22 Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). 4 Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 9 82.29 83.26 83. 5* 82.79 81.68 78.94 83.75 84.60 83. ',13 82.50 80.63 78 94 84.32 85.01 84.24 83 .14 8:4.10 80.41 78.75 84.08 83.56 82.40 81 46 K).56 79.78 80.74 81.06 80.99 80.31 79.29 80.06 80.36 79.85 78.70 77.01 78.29 78.33 78.09 77.40 75.99 73.62 75.00 74.20 73.11 71.85 70.20 66.96 1 3 4 it C 7 8 19... 1.000 1.000 1.000 1.000 1.000 1. 000 0.919 919 0.919 0.919 0.919 0.919 0.846 0.846 0.846 0.846 0.846 0.846 0.846 0.771 0.771 0.771 0.771 771 0.771 0.696 0.696 0.696 0.696 696 0.626 0.626 0.626 0.626 0.626 0.564 0.564 0.564 0.564 564 564 0.497 0.497 0.497 0.497 0.497 0.497 0.995 0.996 1.001 0.999 0.992 0.980 0.945 0.947 0.943, 0.936 0.928 0.916 0>'85 0.888 0.882 0.876 0.868 0.855 843 0.824 0.819 0.812 0.802 0.794 0.786 0.736 0.727 0.725 0.717 0.715 0.663 (1.660 0.655 0.651 0.647 0.603 0.600 0.598 0.592 0.587 0.581 0.537 0.532 0.527 0.522 0.520 0.517 13.27 13.27 13.27 13.30 13.33 13.50 13.52 13.50 13.52 13.56 13.63 .13.71 13.80 13.79 13.80 13.82 13.91 14.09 14.11 14.15 14.18 14.21 14.24 14.27 14.33 14.63 14.69 14.70 14.76 14.81 15.11 15.12 15.16 15.13 15.17 15.45 15.44 15.46 15.49 15. 5t 15.56 15.91 15.95 16.00 16.04 16.04 16.07 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 4 4 4 99.67 104.00 108.62 111.75 113.50 117.00 99.37 104.25 107.75 110.12 132.37 115.12 96.62 101.00 103.12 105.00 107.80 110.87 113.50 97.50 1(10.37 102.12 104.00 106.25 109.67 97.50 100.37 103.75 106.87 110.50 98 25 102.00 105.00 107 37 110.75 95.50 98.62 102.25 105.75 109.87 114.00 101.25 105.12 109.20 113.37 117.50 125.75 245.41 245.75 246 86 246.69 245.26 243.81 2:35.43 235.56 234.80 2X3.37 231.98 229.82 222.77 223.37 2<21.99 220.47 219.26 217.31 214.58 210.02 208.95 207.29 205.01 203.03 201.51 190.73 188.70 188.28 186.67 166.38 174.50 173.83 172.83 171.55 170.70 160.63 159.54 159.11 157.75 156.65 155.30 145.14 143.93 142.87 141.70 140.91 140.27 303.28 307.27 309.85 307.40 302.19 294.03 301.69 304.47 301.52 295.43 *88.50 281.48 293.34 296.35 292.06 286.69 283.35 278.62 269.81 282.77 280.18 274.66 269.13 264.12 260.71 254.95 254.28 253.68 250.42 247.67 238.90 239.01 236.77 231.17 225.66 219.89 218.36 217.37 214.04 208.95 201.31 195.99 192.77 189.13 184.80 179.56 170.82 18 17 }(j 15 14 25 24 23 22 21 5>0 32 31 30 29 28 27 26 54 53 52 51 50 49 48 47 46 .. . 45 44 43 42 41. 40 39 38 37 36 35 34 33 6 5 4 3 2 \ Turbine Test Data. TABLE LXIV. Test of a 54-inch Right Hand Special Hercules Turbine. Built by the Holyoke Machine Co., Holyoke, Mass. Testing Flume of the Holyoke Water Power Co. No. 1051. Date Nov. 12, 1897. Number of experi- ment. Gate opening (propor- tional part). Proportional (discharge discharge at full gate with highest efficiency =1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet, Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 42 41 1.000 1 000 1.004 997 13.98 14 07 5 4 80.40 84 12 230.06 228 98 305 38 306 94 83.72 84 00 40 39 l.OUO 1 000 .989 881 14.13 14 22 4 4 87.00 90 50 227.80 26 71 305.62 305 62 83.71 83 58 38 1 000 974 14 26 4 94 00 225 30 303 89 83 26 37 36 1.000 1 000 .964 956 14.29 14 34 4 4 98.00 101 50 223.16 221 65 299.65 293 11 82.83 81 31 35 1 000 944 14 38 4 104 87 219 38 285 03 79 66 34 800 881 14 69 4 80 00 206 93 287 01 83 25 33 800 875 14 73 5 83 20 205 72 287 19 83 56 32 31 .800 800 .868 859 14.80 14 87 4 4 86. 6 J 90 25 204.66 202 ^8 V87.16 286 38 83.59 83 65 30 800 852 14 94 4 93 75 201 77 284 75 83 28 29 800 844 15 01 4 97 12 200 41 281 78 82 59 28 800 836 15 07 4 101 00 198 92 277 94 81 75 27 SOU 829 15 09 4 104 87 197 26 270 78 80 20 26 800 820 15 15 108 40 195 46 261 48 77 85 25 650 749 15 38 5 77 oo 179 88 246 9") 78 70 24 650 745 15 40 fj 81 00 179 02 250 4'' 80 09 23 22 .650 650 .739 734 15.45 15 48 o 5 84.60 88 60 177.87 176 85 251.78 252 85 8(1.78 81 43 21 20 iy .650 .650 650 .728 .722 714 15.49 15.47 15 50 5 92.80 95.80 99 25 175.59 173.91 172 09 252.22 248.01 ''4'* 10 81.76 81.28 80 02 18 17 16 .650 .650 527 .705 .696 622 15.53 15.57 15 97 5 4 4 102.40 105.75 74 50 170.10 168.14 ic9 97 234.48 226.34 20 49 78.26 76.23 7Q 40 15 .527 618 16 01 4 78 87 151 47 205 79 74 82 14 13 .527 527 .612 606 16.03 16 09 4 4 83.12 87 25 150.12 207.28 207 50 75.94 12 527 597 16 12 7tt J.7 11 527 591 16 15 95 37 145 60 200 89 75 32 10 527 584 16 22 4 99 25 14S 98 195 57 70 04. y 527 578 16 23 irvj nn 79 01 8 410 4QQ 410 494 16 63 Sl '" ifiO t;i 6. .. . 410 489 Ifi t'A 5 4 .410 410 .483 478 16.68 16 66 4 90.50 04. 7& 120.82 159.88 69.95 3 2 .410 410 .472 467 16.68 Ifi 7i 5 99.10 118.20 148.14 66.25 1 .410 .460 16.79 5 109.30 115.53 129.97 59.07 McCormick Turbine. 711 TABLE LXV. Test of a 51-inch Left Hand McCormick Turbine. Built by J. and Holyoke, Mass. Testing Flume of the Holyoke Water Power Co. 1444, Feb. 19 and 20, 1903. Tested on Conical Draft Tube. W. Jolly, Test No. With the flume empty a strain of 37 Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 3 4 5 6 7 8 9 57 55 l.QOO 1 000 1.007 1 001 15.20 14 71 4 4 98.50 101 12 196.58 192 30 293.50 278 13 86.61 86 70 54 1 ODO ij; is 14 70 4 105 50 191 60 277 38 86 84 53 1 000 995 14 68 4 110 00 191 02 274 38 86 28 52 1 (100 989 14 65 4 113 75 189 58 268.40 85 21 51 50 1.000 1 000 0.974 948 14.74 14 86 4 4 118.25 124 25 187.26 183 09 ','55.10 234 54 81.49 76 01 49 1 000 922 15 04 4 130 25 179 05 210 74 69 00 48 1 000 897 15 15 4 136 00 174 79 183 37 61 06 75.''!!.'.'!!.'! 0.760 0.760 0.879 876 15.65 15 65 4 4 90.50 96 50 174.22 173 55 259.30 263 47 83.86 85 54 74 73 0.760 0.760 0.871 0.861 15.67 15.76 4 .4 101.75 106 00 172.71 171 13 264.09 260 83 86.04 85 28 72 71 0.710 76d 0.850 840 15.83 15 94 4 4 110.75 114 25 169.47 168 07 257.58 250 32 84.66 82 39 70 69 68 0.760 0.760 0.760 0.826 0.813 0.795 16.04 16.16 16.29 4 6 3 118.50 123.17 129 00 165.73 163.65 160 65 239.66 228.35 208 72 79.50 76.14 70 32 67 760 778 15 74 4 132 25 154 65 178 31 64 59 85 0.624 0.767 15.63 4 90.00 151 93 218 42 81 11 84 83 0.624 0.624 0.764 0.756 15.61 15.64 4 4 94.75 100.25 151.12 149.67 219.73 218 97 82.13 82 48 82 0.624 0.742 15.67 4 104 25 147 07 213 65 81 75 81 80 0.624 0.6.'4 0.735 0.7^4 15.73 15.78 4 4 108.75 114.25 145.93 144.08 206.74 200 26 79.42 77 67 79 624 0.712 15.86 4 119 75 141 98 189 71 74 29 78 0.624 0.698 15.96 4 127.50 139 76 171.91 67 96 77 0.624 0.684 16.12 4 134.75 137.55 145 35 57 80 47 500 656 15 93 . 4 87 00 131 12 178 30 75 27 46 0.500 0.653 15.96 ft 91.83 13H.61 179 53 75 94 45 500 0.648 16 05 4 97 12 130 11 180 05 76 03 44 0.5110 0.640 16.14 4 101.62 128.70 178.12 75 61 43 .. . . 0.500 0.632 16.19 4 106.00 127 55 175 08 74 76 42 0.500 0.624 16.25 4 111.50 126.04 169.13 72 81 41 0.500 0.615 16.27 5 118.20 124.29 159.37 69 49 40 39 0.500 0.500 0.605 0.59t 16.30 16.36 4 5 124.00 129.80 122.26 120.27 146.29 131.26 64.73 58.82 38 0.5UO U.585 16.41 6 135.50 118 65 114.18 51 71 712 Turbine Test Data. TABLE LXVI. Test of a 45-inch Right Hand Victor Turbine. Built by the Plait Iron Works Co., Dayton, Ohio. Testing Flume of the Holyoke Water Power Co. Test No. 1177, March 13 and 14, 1899. Tested on Conical Draft Tube. With the flume empty a strain of 10 Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency =1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi clency. . 1 2 3 4 5 6 7 8 9 48 47 .000 o;K) 1.012 1.000 15.22 15.21 4 4 102.37 107.50 180.69 180.24 252.39 254.82 80.92 81.96 46 000 1 004 15.20 4 111.50 179.26 253.70 82.10 45 44 .000 000 0.997 0.986 15.2(5 15.31 4 5 116.67 121.60 178.26 176.54 253.57 *51.08 82.19 81.91 43 000 972 15.35 4 126.25 174.41 246.10 81 .05 42 .000 0.954 15.36 5 128.40 171.19 235.46 78.96 41 1 000 0.934 15.44 4 131.50 167.98 223.29 75.91 40... 0.900 0.959 15.32 4 98.37 171.76 239.19 80.15 39 0.900 0.955 15.32 4 103.37 171.19 241.52 81.20 38 37 36 0.900 0.900 900 0.949 0.942 929 15.36 15.39 15.50 4 5 5 107.25 111.30 115.80 170.19 169.23 167.41 240.39 239.64 238.31 81.08 81.13 80.98 35 900 917 15 54 4 119 00 165 39 234.39 80.41 34 33 0.900 900 0.907 896 15.58 15.73 4 4 122.50 127.50 163.86 162.75 230.47 225.15 79.60 77.55 32 30 0.900 800 0.890 888 15.73 15.90 4 4 133.50 97.25 161.52 162.07 217.62 228.54 75.52 78.20 29 28 27 0.800 0.800 800 0.886 0.878 867 16.04 16.20 16 34 5 4 4 105.70 111.00 118.00 162.46 161.79 lliO.41 238.35 239.74 241.24 80.65 80.65 81 15 31 800 873 1(5 80 4 113 37 158 91 231 00 81 12 26 25 0.800 800 0.861 838 16.24 16 28 4 4 131.35 125 25 157.14 154 81 232.71 225.44 80.32 78 87 24 0.800 0.826 16.20 4 131.87 152.24 214.96 76.85 23. . 700 802 16 16 4 99 00 147 56 205.08 75.83 22 700 799 16 15 4 104 12 147 04 207 20 76 94 21 0.700 794 16.17 4 109.62 146.23 208 47 77.74 20 . 700 781 16 12 4 114 50 143 56 206.09 78 52 19 700 768 16 18 4 118 00 141 49 200 36 77 17 18 17 0.700 700 0.758 747 16.19 16 23 4 3 122.75 130 00 139.54 137 72 184.26 185 42 75.82 73 14 16 0.600 0.701 16 39 4 96 00 129.89 169.53 70.21 15 600 702 16 39 4 101 37 130.02 172 13 71 22 14 13 0.600 0.600 0.696 0.683 16.38 16.44 4 4 106.75 111.62 128.88 126.85 173.29 172.85 72.38 73.08 12 600 676 16 44 4 115 50 125 45 170 23 72-78 11 10 0.600 0.600 0.669 0.662 16.42 16.43 4 4 118.87 124.50 124.06 122.81 165.94 160.66 71.82 70.21 9 8 0.600 502 0.656 607 16.44 16 60 4 4 131.25 95 25 121.81 113 21 151.55 139 09 66.73 65 26 7 0.502 0.603 16 60 4 100.62 112.49 140.10 66.15 6 502 594 16 64 4 104 62 110 91 139 27 66 54 5 4 0.502 502 586 580 16.62 16 62 4 5 109.75 114 80 109.32 108 25 138.65 136 45 67.29 66 87 3 0.502 576 16 65 4 120 00 107 66 132 85 65 35 2 502 574 16 68 4 125 50 107 30 127 86 62 99 1. . 502 570 16 68 4 131 50 106 59 120 58 59 80 Samson Turbine. 713 TABLE LXVII. Tent of a 45-inch Right Hand Samson Turbine. Built by The James Leffel Co., Springfield, Ohio. Testing Flume of the Holyoke Water Power Co. Test No. 979. Jan. 25 and 26, 1897. Tested with Conical Cylinder With the flume empty a strain of 15 Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- ;ions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 3 4 5 6 7 8 9 8 1 000 992 14 94 5 127.60 171.24 233 49 80.48 1 000 1 000 14 88 5 133.40 172.12 236 84 81 54 6 1.000 0.998 14.92 4 138.12 172.12 238.65 81.94 5 4 1.000 1 000 0.999 ' 1 001 15.00 15 02 4 4 144.00 148 75 172.69 173 23 240.97 240 82 82.03 81 61 3 1 000 1.002 15.03 3 153.33 173.38 239.89 81 18 2 1 000 998 15 04 4 157 75 172 81 236 08 80 09 1 18 17 1.000 0.832 832 0.986 0.887 892 15.11 14.99 15.02 3 4 4 169.33 112.50 119.75 171.11 153.24 154.34 218.85 208.16 215.05 74.64 79.90 81 80 16 15 0.832 0.832 0.896 897 15.04 15.03 4 4 126.12 132.25 155.04 155.27 219.62 223.11 83.05 84 30 14 832 896 15.04 4 134.12 155 03 223.61 84 55 13 0.832 0.893 15.06 4 143.00 154.74 221.79 83.92 12 832 888 15 09 4 148.12 153.93 219.65 83 38 11 10 9 27 0.832 0.832 0.832 684 0.881 0.874 0.847 0.766 15.16 15.21 15.32 15.19 4 4 4 3 151.25 155.00 160.50 112.67 153.12 152 15 148.02 133.24 214 01 208.77 196.52 183.94 81.29 79.55 76.42 80.14 26 25... 0.684 684 0.769 0.768 15.12 15.11 3 4 121 33 127.67 133.52 133.24 189.83 191.06 82.91 83 6S 24 23 22 0.684 0.684 0.684 0.762 0.756 0.745 15.14 15.20 15.28 4 4 4 131.50 135.50 133 00 132.34 131.58 130.06 187 85 185.27 182 49 82.67 81.68 80.97 21 20 19 57 .. 0.684 0.684 0.684 0.568 0.732 0.728 0.719 0.641 15.33 15.39 15.43 15.85 4 4 4 5 141.75 147.00 156.00 125.80 128.02 127.52 125. b9 113.89 178.39 176.99 169.79 162.59 80.15 79.52 77.01 79.42 58 59 0.568 0.568 0.633 0.630 15.88 15 85 4 4 131.50 135.75 112.65 112.04 162.80 160.68 HO. 25 79 78 60 568 0.629 15.83 4 139 75 111.68 157.81 78 71 61 62 0.568 568 0.622 0.613 15.84 15.85 4 4 143.25 148.25 110.45 109.02 152.99 146.23 77.11 74 62 46 424 0.500 16.50 4 112.50 90 70 123 97 73 05 45 424 0.499 16.53 4 121.25 90.59 127.84 75.28 47 424 0.499 16.49 4 124.00 9U.37 127.79 75 61 44 49 0.424 424 0.497 497 16.55 16.47 4 4 127 00 126 >7 90.24 90.04 127.86 127.73 75.49 75 95 43 424 0.494 16.55 4 131.75 89.69 125.47 74 53 48 4' 0.424 424 0.487 0.479 16.50 16.58 4 4 135.50 151 25 88.24 87 01 121.67 113 ig 73.69 69 18 Turbine Test Data. TABLE LXVIII. Test of a 44-inch Left Hand Improved New American Turbine. Built by the Dayton Globe Iron Works Co., Dayton, Ohio. Testing Flume of the Holyoke Water Power Co. Test. No. 1609. March 21, 1904. Tested on Long Conical Draft Tube. Balanced Gate. With the flume empty a strain of 7 Ibs. applied 3.5 feet from the center of the shaft, sufficed to start the -wheel. Number of experi- ment. Gate opening (propor- tional part.) Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 4 5 6 7 8 9 8 .. 1.000 1.000 .000 .000 .000 .000 .000 .000 .000 .000 0.907 0.907 0.907 0.907 0.907 0.907 0.823 0.823 0.823 0.823 0.823 0.823 0.823 823 0.823 0.823 0.823 0.684 0.684 0.64 0.684 0.684 0.684 0.684 0.684 0.684 0.581 0.581 0.581 0.581 0.581 0.581 0.581 0.459 0.459 0.459 0.459 0.4.7.t 0.459 0.986 0.988 0.992 1.001 1.014 1.011 0.999 0.98H 0.976 0.772 0.944 0.948 0.949 0.952 0.945 0.935 0.878 0.882 0.884 0.830 0.871 0.863 0.855 0.848 0.838 0.821 0.796 0.729 0.739 0.746 0.741 0.736 0.725 0.70.5 C.6K) 0.66v> 0.628 0.633 0.633 0.614 0.58ti 0.566 0.551 0.496 0.493 0.488 0.468 0.4.50 0.441 15.31 15.24 15.23 15.22 15.19 15.18 15.23 15.32 15.37 16.15 15.42 15.42 15.42 15.39 15.47 15.52 15.61 13.59 13.56 15.57 15.61 15.67 15.79 15.75 15.74 15.82 15.94 16.31 16.24 16.19 16.19 16.16 16.17 16.24 16.35 16.41 16,54 16.55 16.56 16.63 16.75 16.87 16.97 17.02 17.03 17.04 17.10 17.11 17.08 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 132.25 137.75 141.75 146.50 150.50 155.00 159.00 161.75 165.40 210.25 '131.50 136.00 139.00 143.50 147.75 151.00 115.75 121.00 131.00 135.25 138.50 142.50 147.50 151.50 156.75 161.00 164.00 98.00 109.00 117.75 122.75 125.50 132.00 139.25 145.00 151.50 108.50 112.00 114.50 124.25 134.50 145.00 156.25 99.75 107.25 112.50 128.75 143.00 152.00 172.28 172.13 172.89 174.40 176.35 175.81 174.09 172 57 170.73 138.47 165.47 166.15 166.27 166. 70 165.87 164.50 154.80 155.32 155.60 155.05 153.55 152.60 151.67 150.20 146.45 145.80 141.85 131.50 132.91 134.05 133.15 132.00 130.22 126.92 122.77 119.79 114.06 115.00 114.90 111.84 107.13 103.84 101 26 91.31 90.75 89.87 86.39 82.01 81.30 228.61 231.64 233.60 236.50 237.89 234.58 20 19 18 17. .. . 16 15 14 ... 13 12 11 29... 30 28 S>7 26 25 24 23... 22 36 37 35 34 33 32 31. . 43 42 41 40 ... 39 38 Victor Turbine. 715 TABLE LXIX. Test of a 43-inch Right Hand Victor Turbine. Built by the Plat Iron Works Co., Dayton, Ohio. Testing Flume of the Holyoke Water Power Co. Test No. 1707. Tested on Conical Draft Tube. Swing Gate. Nov. 20, 1907. With the flume empty a strain of 20 Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full pate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 3 4 6 6 7 8 9 1 1.000 0.852 16 19 3 Still 154 79 15 1 000 946 15 98 2 100 00 170 72 203 27 65 69 14 1 000 969 15 93 H 122 00 174 gg i!31 46 73 35 13 1 000 985 15 79 3 143 00 176 80 247 08 78 03 11 1 000 989 15 75 3 151 33 177 23 251 22 79 35 10 1 000 9^8 15 74 3 159 67 178 78 254 24 79 66 12 000 1 002 15 70 3 165 00 179 22 254 91 79 87 9 g .000 000 1.006 1 005 15.82 15 86 4 4 172.25 178 75 180.64 180 79 256.77 954 35 79.22 78 21 7 000 979 16 01 4 178 75 176 80 ''36 18 73 57 6 5 .001) 000 0.956 93-1 16.10 16 23 4 3 183.25 189 67 173.26 169 33 217 29 192 77 68.68 61 85 4 3 .000 000 0.878 808 16.39 16 60 3 4 202.67 214 25 160.52 148 59 137.33 72 59 46.02 25 95 2 .000 0.762 16.67 3 224.00 140 43 28 27 26 0.900 0.900 900 0.874 0.901 908 15.98 15.93 15 90 4 4 4 89.75 111.75 127 00 157.76 162.30 163 54 182.44 215.80 232 34 63.80 73.59 78 78 25. . . 900 911 15 84 4 138 50 163 67 239 SO 81 38 24 900 918 15 81 4 150 5 164 76 244 34 82 70 23 UOO 915 15 81 4 158 50 164 22 241 64 82 06 22 21 0.900 900 0.894 877 15.88 15 94 4 4 160.25 164 00 160.79 158 15 228.02 216 69 78.74 75 79 20.. 900 862 15 94 4 168 50 155 31 205 51 73 19 19 900 839 16 02 4 174 00 151 68 188 64 68 45 18 900 798 16 21 4 184 25 145 14 156 OD 58 48 16.......... 0.900 900 0.743 690 16.38 16 59 3 2 199.00 218 50 135.86 126 81 101.13 40.07 38 800 783 16 32 3 60 33 142 88 130 34 49 9 8 37 800 837 16 15 119 25 151 91 218 16 78 40 36 35 0.800 800 0.847 847 16.14 16 13 135.50 146 00 153 56 153 56 234.12 237 42 as. 29 84 51 34 33 0.800 800 0.824 807 16.23 16. bO 148.00 151 75 149.80 147 12 225.63 215 93 81.82 79 39 32 S( 773 16 42 161 50 141 45 196 97 74 77 31 800 726 16 56 173 75 133 30 164 82 65 83 30 800 690 16 67' 4 187 00 127 18 126 71 5'' 69 29 800 627 16.86 3 215 00 116 21 47... 700 717 16 57 3 89 33 131 75 157 37 63 56 48 46 45 0.700 0.700 700 0.738 0.754 752 16.51 16.42 16 38 R 3 8 110.67 126.00 133 00 135.45 137.95 137 41 189.72 209.17 21 1 78 74.80 81.42 82 96 44 43 42 41 40 0.700 0.700 0.700 0.700 700 0.732 0.708 0.678 0.650 618 16.44 16.53 16.63 16.70 16 82 8 4 4 4 4 136.00 142.25 150.50 160.00 179 50 133.93 129.98 124.90 120.02 114 42 203.73 192.77 178.46 162.62 121 63 81.18 79.10 75.75 71.53 55 72 39 700 0.568 17.02 3 209 00 105 73 58 600 623 16 94 3 94 67 115 74 147 54 66 35 57 56 0.600 600 0.634 643 16.89 16 83 3 3 105.00 116 00 117.55 119 02 169.08 172 Q2 71.09 7fi 11 55 HOO 645 16 80 4 122 50 119 28 178 46 78 52 54 53 0.600 600 0.625 601 16.81 16 90 4 4 126.50 134 'iO 115.74 111 4T 171.43 77.66 52 600 582 16 97 4 144 5 108 20 ]56 38 75 09 51 50 0.600 600 O.fi60 543 17.04 17 14 4 4 160.25 182 50 104.44 135.73 qo 74 67.23 49 o.'eoo 0.501 17.28 3 204' 00 94.03 Turbine Test Data. TABLE LXIX.- Continued. Test of a 42-inch Right Hand Victor Turbine. Built by the Plait Iron Works Co., Dai/ton, Ohio. Testing Flume of the Holyoke Water Power Co. Test No. 1707. Nov. 20, 1907. Tested on Conical Draft Tube. Siving Gate. With the flume empty a strain of 20 Ibs. applied 3.6 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- ' feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 67 500 542 17 32 3 94 33 101 82 132 31 66 15 66 65 64 0.500 500 0.500 0.553 0.556 0.539 17.24 17.19 17.25 3 4 3 106.67 116.35 122.00 103.59 104.06 101.02 144.56 149.66 144 66 71.37 73.77 73 19 63 62. 0.500 500 0.515 509 17.28 17.29 4 4 135.75 150 50 96.66 95 61 137.97 127 47 72.83 67 99 61 0.500 0.499 17.31 4 163.00 93.69 110 45 60 04 60 500 0.476 17.39 8 184 33 89 63 62 45 35 33 59 5UO 451 17 50 3 198 33 85 20 NOTE For experiments 2, 16, 29, 39, 49, 59, Jacket Loose. McCormick Turbine. 717 TABLE LXX. Test of a 39-inch Left Hand McCormick Turbine. Built by the S. Morgan Smith Co., York, Penn. Testing Flume of the Holyoke Water Power Co* Tested on Conical Draft Tube. Test No. 1191. May 29, 1899. With the flume empty a strain of 6 Ibs. applied 3.2 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 3 4 5 6 7 8 9 8 . . 1 000 1 009 15 79 I 126 00 117 83 177 36 84 15 1.000 1.006 15 79 4 131 75 117 46 178.98 85.19 6 1 000 1 001 15 82 4 138 00 116 98 179 84 85 78 5 4 '6 1.000 1.000 1 000 0.998 0.990 977 15.85 15.87 15 91 4 4 143.00 150.00 154 60 116.73 115.89 114 53 179.32 177.03 171 06 85.56 84.27 82.87 2 1 000 961 15 96 4 160 25 112 80 162 53 79 70 1 1 000 945 15 98 4 185 75 110 99 152 83 76 07 43 796 903 15 95 4 118.25 105.98 159.91 83 51 42 41 0.796 0.796 0.8H9 0.896 15.97 15.97 4 4 123.75 129.25 105.51 105.02 161.27 162.08 84.49 85 31 40 796 889 15 99 4 133.00 104 44 160 24 84 70 39 796 882 15 98 5 136 60 103 62 157 86 84 11 38 796 874 16 03 4 140.50 102.78 155.46 83.29 37 36 0.796 796 0.864 853 16.08 16.06 4 4 145.00 149.00 101.72 100.45 151.52 146.54 81.78 80.19 35 796 843 16.11 4 153 25 9i).4l 141 30 77 89 34 33 32 0.621 0.621 621 0.760 0.754 748 16.26 10.29 16.29 4 4 5 123.75 127.25 130.80 89.97 89.41 88. '(3 136.92 135.32 133.47 82.62 82.02 81.51 31.. 621 742 16 30 4 134 00 87 94 130.97 80 66 30 621 734 16 34 4 138 25 87 18 129 17 80 05 29 621 728 16.35 4 142.25 86.51 126.79 79.13 28 27 0.621 621 0.716 703 16.37 16.40 4 4 147.75 156.25 85.09 83.65 122.61 115.26 77.70 74.17 26... 0.498 615 16.55 3 115.00 77.10 109.57 75.80 25 498 640 16.55 4 120.25 76.47 110.14 76.82 24 23 0.498 0.498 0.636 0.63U 16.55 16.56 5 4 123.60 127.75 7o.95 75.31 108.65 107.58 76.30 76.15 22 0.498 625 16.59 4 131.75 74.77 106.09 75.50 21 0.498 0.619 16.60 4 136.25 74.12 104.69 75.11 20 498 0.611 16.69 4 143.00 73.30 101.09 72.94 19 18 17 0.498 0.498 390 0.600 0.588 527 16.71 16.78 16 72 4 4 4 150.25 157.75 116.75 72.03 70.71 63.25 86.13 87.27. 83.97 69.77 64.93 70 09 16 15 0.390 390 0.522 0.516 16.73 16.75 4 4 121.50 125.50 62.66 62.06 82.90 81.77 69.81 69.44 14 13 0.390 0.390 0.512 0.509 16.78 16.77 4 4 129.50 133.00 61.66 61.28 80.40 78.48 68.60 67.42 12 390 0.506 16.76 4 135.50 60.86 76.63 66.32 11 10 0.390 390 0.502 0.495 16.75 16.77 4 4 139.75 145.00 60.38 59.60 73.88 70.41 64.48 62.19 9 390 0.489 16.77 5 150.60 58.81 64 80 58 00 7 i8 Turbine Test Data. TABLE LXXI. Test of a 3ff-mch Right Hand Swain Turbine. Built by the Swain Turbine and Mfg. Co., Lowell, Mass. Testing Flume of the Holyoke Water Power Co. No. 977. Date Jan. 20-21. 1807. Number of experi- ment* Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 64 63 1.000 1 000 1.004 995 IS. 16 15 25 3 4 130.33 135 00 76.49 75 98 111.57 111 47 84 84 84 83 62 1 000 984 15 40 3 140 83 75 52 111 61 84 62 61 60 1.000 l.UOO .973 .966 15.42 15.43 3 4 144.00 146.50 74.74 74.19 110.16 108.51 84.28 83 58 59 1.000 954 15 48 4 150 75 73 45 107 08 83 04 58 57 1.000 1 000 .945 934 15.47 15 44 4 3 154.00 158 00 72.73 71 7t> 104.72 101 68 82.07 80 92 56 1 000 922 15 33 4 161 37 70 58 97 97 79 84 55 54 .875 875 .932 925 15.16 15 15 3 4 132.00 135 75 70.95 70 42 102.58 102 20 P4.10 84 47 53 .. 875 916 15 28 4 140 75 70 01 102 54 84 52 52 51 .875 875 .907 896 15.41 15 50 4 4 147.00 153 50 69.61 68 99 102.63 101 58 84.37 83 75 50 49 .875 750 .877 866 15.60 15 66 3 4 162.33 130 00 67.75 67 03 98.55 100 24 82.22 84 20 48 750 857 15 74 4 136 00 66 52 100 73 84 83 47 46 .750 750 .849 844 15.76 15 70 4 2 141.00 146 00 65.96 65 41 100.16 99 28 84.96 85 24 45 44 43 .750 .750 750 .838 .829 826 15.54 15.62 15 16 4 3 4 149.75 157.33 156 75 64.64 64.09 62 88 97.28 96.47 91 36 85.39 84.97 84 51 42 750 814 15 20 4 162 75 6;i 06 88 ^3 83 13 41 625 783 15 30 127 50 59 90 85 Q 2 82 7 40 625 775 15 38 4 134 75 59 45 86 72 83 63 3tt 38 .625 625 .767 758 15.43 15 47 4 4. 142.12 149 50 58.95 58 30 87.15 86 23 84.48 84 30 37 625 749 15 51 4 154 50 57 70 84 42 83 18 36. 625 733 15 58 4 162*75 56 62 81 02 80 99 35 625 715 "15 K5 IRQ -Vl 55 32 7fi TS 77 cc 34.. 500 683 15 74 123 20 52 93 74 PO 79 09 33 500 676 15 78 1 m 2^ 5 9 54 75 70 XO ^1 32 31 30 .500 .500 500 .668 .660 652 15.83 15.85 1 C01 4 4 137.50 144.00 ICf) OC 51.98 51.42 50 87 75.13 74.31 72 98 80.51 80.40 79 ^,1 29 28 .50J 500 .644 635 15.95 15 96 4 157.50 163 33 50.31 49 6'-* 71.72 69 41 78.81 71* oq 26 375 CR7 -ion 07 4.2 50 T.4 08 70 7- 25 24. .375 375 .552 545 15.19 IK O1 4 127.50 >oq cr 42.06 41 58 54.19 CO AG 74.78 74. *S8 23 375 538 15 1 4 130 00 41 06 5>> 33 73 87 22 21. .375 375 .531 *>24 15.22 3 145.67 40.53 51.30 49 94 73.32 70 qc 20 27 .375 375 .514 504 15.30 1C Of) 4 160.25 167 20 39.36 38 57 48.65 45 68 71.23 68 25 19 18 .250 250 .420 416 15.53 15 54 113.50 120 25 32.40 3'' 11 36.52 36 50 64.00 64 50 17 250 412 ic C7 noc en qi QQ 36 10 64 22 16... 250 407 01 AR 35 60 cq qi 15 250 401 15 60 1^9 50 '31 00 34 72 63 31 14 13 12.. .250 .250 250 .396 .386 378 15 61 15 66 146.25 155.75 30.59 29.91 33.74 32.15 on 7u 62.31 60.52 11. 250 qfi7 10... .250 AZK 1* 70 A 170 KH 97 KA_ 91 KO J.J fU Swain Turbine. 719 TABLE LXXL Continued. Test of a 36-inch Right Hand Swain Turbine. Built by the Swain Turbine and Mfg. Co., Lowell, Mass. Testing Flume of the Holyoke Water Power Co. No. 977. Date Jan. 20-21, 1897. Number of experi- ment. Gate opening (propor- tional part) Proportional discharge (discharge at full gate with hignest efficiency =1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 9 125 257 16 03 4 111 50 20 06 16 92 46 41 8 125 254 16 01 4 119 00 19 89 16 62 46 01 7 125 252 16 07 4 126 75 19 76 16 16 44 88 6 125 249 16 17 4 134 12 19 62 15 47 43 00 125 247 16 23 4 141 00 19 45 14 55 40 65 4 135 245 16 18 4 146 25 19 24 13 32 37 73 3..., .125 125 .242 239 16.22 16 11 4 4 152.25 159 50 19.07 18 73 12.02 9 68 34.26 28 30 1 . 067 161 16 49 4 153 25 12 80 720 Turbine Test Data. TABLE LXXII. Test of a 36-inch Eight Hand Victor Turbine. Built by the Platt Iron Works Co., Dayton, Ohio. Testing Flume of the Holyoke Water Power Co. Test No. 1061, December 14, 1897. Tested on Conical Draft Tube. Cylinder Gate. With the flume empty a strain of 8 Ibs, applied 3.2 feet from center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part). Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 12 11 10 1.000 1.000 1.000 1.010 1.009 1.009 16.75 16.76 16.74 3 4 4 133.33 139.25 144.87 116.38 116.38 116.27 175.20 176.99 177.91 79.24 80.01 80 59 9 1 000 1 002 16 79 4 150 75 115 63 177 73 80 71 8 6 1.000 ooo 0.997 992 16.80 16 73 4 4 155.00 156 50 115.04 114 30 176.07 172 97 80.33 79 75 5.'.'.'. .'..'.'.. 4 .'ooo .000 .000 0.982 0.975 965 16.82 16.69 16.58 4 4 4 161.75 162.75 167.00 113.46 112.21 110 63 173.81 169.89 164 07 80.30 79.98 78 87 3 000 953 16 59 4 172 25 109 31 158 65 77 14 2 1 53 .000 .000 .000 0.941 0.923 0.748 16.65 16.70 17.33 4 4 4 177.25 184.00 240.50 108.09 106.21 87 70 152.37 141.23 74.65 70.20 52 0.900 967 16 92 4 133 75 112 07 172 47 80 19 51 50 49 0.900 0.900 0.900 0.965 0.959 953 16.99 17.01 17 04 4 4 4 139.50 144.00 148 50 112.07 111.37 110 76 174.74 174.19 173 25 80.92 81.07 80 93 48 47 46 0.900 0.900 0.900 0.947 0.939 925 17.03 17.04 17 05 4 4 4 152.00 157.00 164 00 110 03 108.19 107 62 " 171.73 170.63 168 17 80.81 80.86 80 81 45 900 914 17 06 2 170 00 106 32 161 80 78 65 44 0.801 900 17 10 3 132 33 104 79 160 07 78 76 & 42 41 0.801 0.801 801 0.900 0.899 892 17.07 17.02 17 02 4 4 4 137.75 142.25 147 00 104.67 104.32 103 61 162.40 162.46 161 57 80.14 80.64 80 78 40 801 884 17 02 4 151 25 102 68 159 74 80 59 39 38 0.801 0.801 0.870 863 17.02 16 97 4 4 155.25 159 25 101.04 100 09 157.29 154 50 80.64 80 ' J 37 80 I 816 16 92 4 163 50 99 18 150 59 79 1 36 35... 34.. . . 0.801 0.701 701 0.845 0.814 814 16.89 16.89 16 90 4 3 4 168.25 125.67 133 25 97.79 94.25 94 25 144.64 134.27 139 09 77.21 74.37 76 99 33 0.701 812 16 89 4 138 75 94 03 140 58 78 04 32 701 807 16 92 4 144 25 93 47 140 83 78 51 31 701 7'94 17 00 92 20 130 75 78 61 30. 29 0.701 701 0.787 776 17.07 17 15 5 153.60 158 75 91.54 90 52 137.70 134 52 77.70 76 40 28 0.701 601 0.768 717 17.15 17 24 4 4 163.25 129 00 89.52 83 87 130.31 117 23 74.84 71 49 26 601 714 17 29 137 00 CO ce 120 29 73 33 25. 601 705 17 36 oo 77 73 04 24 601 6% 17 41 4 148 00 81 91 119 05 73 48 23 601 685 17 47 CM (.) 116 12 7 69 22 21 0.601 601 0.676 17.53 4 159.00 79.77 112.28 70.79 fi8 3Q 20 502 622 17 60 1OO 00 96 93 66 00 19 18 0.502 502 0.617 609 17.55 17 55 3 3 131.07 138 00 72.85 71 81 98.64 98 29 68.02 68 77 17 502 598 17 56 3 W'V? 68 41 10 502 592 17 55 fiQ 87 OQ 1Q 15 14 0.502 502 0.588 580 17.56 17 56 4 3 155.37 IpO RA 69.34 90.63 85 34 65.63 62 61 13 502 573 17 55 fi7 R1 78 4O 58 26 For experiment 53, the jacket was removed from the dynamometer. Special Smith Turbine. 721 TABLE LXXIII. Test of a 33-inch Special Left Hand Turbine. Built by the S. Morgan Smith Co., York. Penn. Testing Flume of the Holyoke Water Power Co. Test No. 1511. March 25 and 26, 1904. Tested on Conical Draft Tube. Bal- anced Gate. With the flume empty a strain of 9 Ibs. applied 3.3 feet from the center, sufficedto start the wheel Number of experi- ment. Gate opening (propor- tional part. Proportional discharge (discharge at full gate with highest efficiency=l). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 3 4 5 6 7 8 9 15 1 000 995 17 01 4 196 00 112 81 178 22 81 s'( 14 13 1.000 1 000 0.998 1 000 16.99 16 98 5 4 203.80 208 75 113.05 113 20 178.92 179 34 82.14 GO 97 12 1 000 1 003 16 99 4 21'i 50 113 55 179 40 09 nn 11 10 1.000 1 000 1.004 995 16.95 16 94 4 4 220.00 221 50 113.55 112 5" 177.97 173 62 81.53 Of) 00 9 1.000 948 0.984 964 17.00 17 05 4 4 223.50 194 75 111.46 109 42 168.18 mOK 78.27 GO 7/) 5 6 0.948 948 0.967 969 , 17.11 17 08 4 4 201.50 204 75 109.90 110 02 179.43 179 75 84.13 QA QK 4 948 968 17 14 4 209 75 110 14 ISO 20 84. 17 3 948 959 17 19 4 211 75 109 30 175 ''8 82 26 2 948 952 17 17 4 9 13 00 108 45 170 97 on QA 1 948 949 17 19 4 214. 7*1 -inu 11 ICQ 00 8 948 939 17 09 5 216 40 106 69 162 84 78 7^ 71 70 0.883 883 0.909 910 17.29 17 25 4 4 181.75 185 75 103.84 103 84 173.24 173 56 85.08 ftS 44 69 883 914 17 93 4 193 00 104 20 17^ 4Q 0(1 1Q 68 883 909 17 24 4 197 00 103 71 172 95 85 29 67 66 0.883 883 0.901 . 893 17.28 17 31 4 5 199.25 202 00 102.90 102 09 168.68 164 67 83.65 82 17 64 883 876 17 36 4 208 50 100 34 iKt; on 7Q 42 54... 851 894 17 15 4 191 00 101 72 170 08 OK Q7 53 851 883 17 19 4 193 50 100 58 166 24 Q4 ITU 52 851 875 17 20 4 196 50 99 77 162 65 83 58 51 851 868 17 27 4 200 25 99 07 159 48 82 19 50 851 858 17 29 4 203 25 98 02 IKK KA of) qr\ 49 851 851 17 32 4 20(5 25 97 35 152 62 79 81 48 47 0.851 851 0.842 836 17.38 17 37 4 4 210.25 212 67 96.50 95 74 150.30 146 70 79 02 77 78 46 .... 851 827 17 42 4 215 50 94 82 141 90 75 75 45 0.851 813 17 44 4 218 25 93 34 136 86 74 13 44 43 0.765 765 0.836 823 17.37 17 38 4 4 169.25 172 75 95.73 94 25 161.32 160 33 85.55 86 30 42 765 818 17 41 5 177 60 93 79 159 26 86 00 41 0.765 803 17 45 4 181 75 92 2o 153 86 84 33 40 765 778 17 48 4 192 75 89 41 145 04 81 83 39 63 0.765 702 0.736 764 17.55 17 33 4 3 206.25 159 00 84.77 87 39 129.34 144 57 76.66 84 17 62 702 765 17 33 3 166 67 87 50 147 37 85 69 61 , 702 763 17 35 4 168 50 87 28 145 82 84 91 60 702 750 17 37 3 172 00 85 95 143 45 84 73 59 58 0.702 702 0.739 729 17.38 17 42 3 4 175.67 180 25 84.66 83 56 139.90 136 77 83.84 82 85 57 702 720 17 44 4 185 00 82 57 133 41 81 69 56 55 0.702 702 0.707 690 17.48 17 50 4 4 189.00 197 75 81.18 79 34 130.37 124 01 81.01 78 75 31 30 0.636 636 0.711 705 17.71 17 69 4 4 162.50 166 25 82.24 81 51 137.57 135 53 83.28 82 Kft 29 636 696 17 71 4 170 50 80 43 133 65 82 73 28 636 689 17 69 4 173 58 79 58 131 65 82 46 27 26 0.636 636 0.680 670 17.70 17 72 4 4 176.50 180 25 78.60 77 54 129.50 126 60 82.08 81 24 25 636 658 17 74 4 187 50 76 15 123 46 80 58 24 0.636 0!659 17! 73 4 209.50 76^28 118.24 77.09 44 722 Turbine Test Data. TABLE LXXIIL Continued. Test of a 33-inch Special Left Hand Turbine. Built by the S. Morgan Smith Co., York, Penn. Testing Flume of the Holyoke Water Power Co. Test No. 1511. March 25 and 26, 190 1*. Tested on Conical Draft Tube Bal- anced Gate. With the flume empty a strain of 9 Ibs. applied 3.3 feet from the center, sufficed to start the wheel. Number of experi- ment. Gate opening (propor- tional part. Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 22 556 616 17 77 4 126 25 71 40 102 92 71 53 23 21 0.556 556 0.638 632 17.75 17 74 5 4 153.00 156 00 73.82 73 20 120.89 119 35 81. 35 81 04 20 556 619 17 78 4 161 00 71 73 116 10 80 27 19 18 0.556 556 0.605 589 17.79 17 80 4 4 184.50 205 75 70.10 68 33 109.91 103 2 77.71 74 83 17 556 564 17 83 4 ^35 00 65 4 -> 73 68 55 70 Victor Turbine. 723 TABLE LXXIV. Test of a 33-inch Right Hand Victor Turbine. Built by the Platt Iron Works Co., Dayton, Ohio. Testing Flume of the Holyoke Water Power Co. Test No. 1250, May 29 and 31, 1900. Tested on Conical Cylinder, Wicket or Swing Gate. With the flume empty a strain of 12 Ibs. applied 3.2 feet from the center of the shaft, sufficed to start the wheel. Number of experi- ment. Gate opening (propor tional part). Proportional discharge (discharge at full gate with highest efficiency =1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 3 3 4 5 6 7 8 9 6 1 000 998 16 95 4 156 50 114 36 146 64 66 76 1 000 999 16 99 4 161 25 114 61 148 13 67 13 5 1 000 1 001 16 96 4 163 00 114 74 147 74 67 00 4 1 000 1 002 16 95 4 169 37 114 86 147 29 66 77 ;{ i oon 1 004 16 93 4 174.25 114 99 146 20 66 27 2 1 000 1 005 16 93 4 181 50 115 11 144 50 65 44 1 1 000 1 Oj6 16 98 5 191 20 1 15 34 140 51 63 32 19 18 0.878 878 0.977 980 16.96 16.93 4 4 155.75 160.87 112.02 112 27 150.71 151 72 70.01 70 44 17 878 981 16 95 5 167 00 112 40 152 39 70 59 16 878 983 16.94 4 173.00 112 63 15150 70 08 15 878 982 16.98 5 101.20 112 63 149 81 69 10 24... 23 0.785 II 785 .937 938 .02 03 5 4 159.20 163.25 107.56 107 70 155.99 155 96 75.20 75 04 22 7H5 936 .08 4 169.75 107 70 156 9 75 31 ''1 78o 935 .07 4 177.75 107 56 156 75 75 35 20 785 935 .06 4 191.25 107.44 152.26 73 31 30 29 0.688 688 .872 872 .15 .15 3 5 162.00 167.00 100.51 100.51 154.77 155 46 79.24 79 59 28 X7 0.688 6^8 .870 867 .16 .18 4 4 171.50 175.50 100.27 100.04 155.44 154.77 79.73 79.47 26 688 863 .20 4 181.00 99 57 152 97 78 83 25 688 858 .22 4 187.75 98.53 149 47 77.75 38 37 0.595 595 .796 793 .53 .50 4 4 152.75 158.50 92.81 92.35 147 80 148.51 80.17 81.10 36 595 791 48 4 163.50 92.02 148 19 81 31 35 34 0.595 595 .784 779 .47 .43 4 4 169.00 173.50 91.24 90.57 146.97 145.57 81.37 81 38 33 595 773 .39 4 178.25 89.68 143 00 80 92 32 595 .765 .38 4 181.50 88.75 138.94 79.50 31 14 0.595 472 .756 677 1 .40 1 .63 5 4 184.60 148.00 87.76 79.15 135.66 126.89 78.40 80.25 13 472 670 1 .67 4 155.25 78.41 128 35 81 76 12 11 10 0.472 0.472 472 .662 .654 .646 1 .69 1 .68 5 4 4 160.80 164.50 170.00 77.45 76.50 75.64 128.02 125.93 123.89 82.46 82.17 81.71 9 472 .639 1 .68 4 177.00 74.80 121.40 81.02 8 472 633 1 .70 4 184.00 74.17 118.32 79 54 51 386 .555 1 .92 4 150.25 65.43 101.22 76 18 50 49 48 0.386 0.386 386 .548 .547 .542 1 .94 1 .95 1 97 5 4 4 156.40 161.25 167.75 64.63 64.44 63.93 100.57 99.74 98.62 76.55 76.10 75 76 47 0.386 .539 17.97 4 175.25 63.54 96.59 74.66 46 45 44 0.386 0.304 0.304 .531 .450 .447 18.00 18.17 18.17 4 4 4 188.00 146.25 151.25 62.74 53.41 53.01 92.11 78.82 77.81 71.98 71.68 71.29 43 . 304 .445 18.14 4 156.50 52.74 76.67 70.73 42 41 40 0.304 0.304 (1 304 .443 .442 .439 18.14 18.13 18.15 4 4 4 162.50 168.50 17'6.75 52.54 52. 35 52.10 75.63 74.30 71.44 70.03 69.09 66 67 39 0.304 .435 18.15 4 187.75 51.63 66.69 62.81 724 Turbine Test Data. TABLE LXXV. Test of a 30-inch Special Chase Jonval Turbine. Built by the Chase Turbine Mfg. Co., Orange, Mass. Testing Flume of the Holyoke Water Power Co. No. 256. June 7, 1884. With the flume empty a strain of 4 Ibs. applied 2.4 feet from the center of the shaft sufficed to start the wheel. Number of experi- ment. Gate opening BSKT part. Proportional discharge (discharge at full gate with highest efficiency = 1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse- power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 B 1 :.... 8 7 6 1.000 1.000 1.000 1 000 0.960 1.008 1.004 1 004 14.72 14.51 14.43 14 61 3 3 8 3 Still. 169.67 181.67 196.33 39.74 41.42 41.16 41.42 49.66 50.68 52 08 72.98 75.36 76.00 5 1 000 998 14 57 4 204 75 41 1(1 51.50 75 96 4 1 000 999 14 41 3 215.00 40.91 51.13 76.60 8 2 1.000 1 000 1.001 998 14.41 14.49 3 5 225.00 244. 41.02 40.99 ^50.42 50 38 75.34 74.91 22... 930 922 14 68 4 185 75 38 12 49.27 77.76 21... 930 920 14.72 6 194.17 38.07 49.73 78.37 23 930 919 14 78 4 203.75 38.12 50 32 78.88 24 25 17... 0.930 0.930 837 0.916 0.913 831 14.87 14.95 15 28 4 4 3 213.00 226.00 180.00 38.13 38.07 35 07 50.66 50.65 46 10 78.90 78.59 75.98 16.. 837 827 15 42 4 191 00 35 03 47 17 77.12 15 837 826 15 42 3 199 67 35 00 47.49 77.71 18 837 823 15 33 3 207 00 34 75 47 34 78.47 19 837 822 15 28 4 215 00 34.65 47.20 78.73 20 14... 0.837 674 0.818 666 15.26 16 13 4 4 228.25 163.50 34.49 28.85 46 98 35.15 78.82 66.70 13 12.... 0.674 674 ' 0.663 661 16.14 16 07 4 174.25 185 33 28.75 28.61! a=>.86 36 45 68.25 70.04 11 6 674 669 16.11 4 195 50 28.52 36.66 70.46 10 674 655 16 14 4 206 50 28.40 36.83 70.97 9 67 i 650 16.20 4 217.00 28.25 36.72 70.86 30... '0 488 462 17 10 4 142.25 20 62 16.26 40.74 29 488 460 17 11 4 158 50 20 55 16 67 41.88 28 48S 458 17 08 3 174 33 20.43 16.74 42.38 27 488 459 17 02 4 182 50 20 43 16.69 42.40 26 !-- lf>s 17.07 3 190.67 20.43 16.57 41.96 31 488 457 17 09 5 206 20 20 37 10.03 40.67 Chase Jonval Turbine. 725 TABLE LXXVI. Test of a 30-inch Regular Chase Jonval Turbine. Built by the Chase Turbine Mfg. Co., Orange, Mass. Testing Flume of the Holyoke Water Power Co. June 10, 1884. With the flume empty a strain of 33 Ibs. applied 2.4 feet from the center of the shaft, sufficed to start the wheel. Xumber of experi- ment. Gate opening (propor- tional part; . Proportional discharge (discharge at full gate with highest efficiency =1). Mean head in feet. Duration of test in minutes. Revolu- tions per minute. Dis- charge in sec- ond- feet. Horse power devel- oped. Percent- age of effi- ciency. 1 2 3 4 5 6 7 8 9 1 000 938 15.62 3 Still. 33 33 6 5 .OOU 000 0.993 995 15.32 15.29 3 3 194.CO 201.67 34.93 34.96 43.48 43.35 71.70 71.58 4 000 996 15 30 5 211 14 35 00 43 46 71 62 3 29 .000 .000 889 1.001 1.007 894 15.27 15.26 15 78 3 3 4 222.33 237.00 174 75 35.14 35.34 31 93 43.72 43.36 41 56 71.92 70.96 72 80 2S 889 897 15.77 4 190 25 32 01 42 64 74 55 27 20 0.888 889 0.897 0.898 15.75 15 80 4 4 200.25 211.25 32.01 32.10 43.05 43.48 75.36 75.66 23 889 901 15 77 3 220 67 32.17 43 40 75 50 24 0.889 0.903 15.74 4 232.00 32.20 43.50 75.76 25 889 907 15.72 3 242.67 32.33 43 29 75.17 22 733 0.756 16.30 4 184.50 27.43 36.28 71.63 o* 733 0.757 16.24 4 195.25 27.41 36 61 72 59 20 9.733 0.75S. 16.27 4 .'Or.OO 27.47 36.92 72.91 18 19 0.733 733 0.756 757 16.28 16.32 H 4 218.67 230.50 27.43 2i'.47 37.00 36.90 73.14 72 64 14 13 12 15 0.611 0.611 O.S11 611 0.644 0.644 0.641 0.644 16.65 16.65 16.68 16.77 5 4 3 3 175.80 188.75 202.00 209. as 23.63 23.60 23.54 23 63 27.34 27.62 27.72 27 76 61.33 62.05 62.16 62 21 ]H 11.811 0.644 16.67 3 221.33 23.64 27.33 61 21 17 611 0.647 16.61 3 236.33 23.71 27.02 60 56 7 411 0.469 17.14 3 141 33 17 47 12 93 38 10 8 411 469 17.20 4 157.00 17.47 12.92 37 96 LI 411 0.468 17.17 4 166.00 17.43 12 91 38 06 ]ti 0.411 0.469 17.13 4 184. (HI 17.43 12.62 36.46 11 411 0.471 17.16 3 201). 00 17.53 11.89 34 89 APPENDIX E. EFFECT OF AN "UMBRELLA" UPON THE FORMATION OF VORTICES. Report of Test Made on 30-Inch Horizontal Wheel With "Umbrella" at -the Holyoke Water Power Company's Flume, April 25th to 27th, 1907, by F. Moeller, Engineer Power and Mining Department of the Wellman, Seaver, Morgan Co. for The Southern Wisconsin Power Company. The general arrangement of the wheel and testing apparatus is shown by Fig. 407. Before begin^ng the test it was desired to note the action of the water without umbrella in place. The penstock was filled, the level of the water being 8' above the center of the shaft, making the total head of water 16.2'. Under this condition, with the head stationary and the wicket gates wide open, a large vortex was formed immediately above the wheel. Fig. 407. Formation of Vortices. 727 The umbrella which was first made T in diameter and dished 11", was lowered into the penstock until the edge was 3.1' above the center of the shaft, with the level of the water the same as before. With this arrangement no vortex was formed immediately above the wheel, but there were vortices near the edge of the umbrella, (see Fig. 408). The umbrella was then re- moved and a raft 8' square was built of matched pine about l 1 /^" thick, tongued and grooved and placed as nearly as possible over the center of the wheel on the surface of the water. This did not prevent the formation of vortices. The raft was then increased from 8'x8' to 8'xl2', and placed in po- sition as shown in Figure 409. This entirely prevented the formation of vortices under the same condition of head as before and under all the run- ning conditions of the wheel. Regarding these vortices it was observed that all of them were formed at the right hand side of the wheel (standing at the point marked "A," Fig. 408) and towards the upper face of the penstock. The water enters the penstock A Fig. 408. from the left hand side, flows through the wheel and draft tube and off at the right hand side. The most reasonable explanation of this tendency for the vortices to form at the place mentioned was that the wheel, being right hand, the gates at the right hand side of the wheel pointed upward (see Fig- ure 410) and formed a comparatively direct path for the vortex into the wheel, while the gates on the right hand side pointing downward, formed an effectual barrier. An examination of Figure 409 shows that the left hand edge of the large raft does not project beyond the gates so that there was every chance for the vortices to form at this point, yet none formed on this side in any of the experiments. As a result of these preliminary trials it was decided to increase the um- brella to 10^' in diameter, and meanwhile a test was run off at full gate and three-quarter gate opening, with the large raft in place, to determine the efficiency of the wheel under this condition. These efficiencies are shown on the report of the Holyoke Water Power Company and are numbered 1 to 18. It may be here noted that the Holyoke Water Power Company finds it necessary to use a raft on practically all of the horizontal tests made by 728 Effect of "Umbrella" Upon Vortices. them, the exceptions being only in the case of the smallest wheels, and it is the opinion of the Hydraulic Engineer of that Company, as a result of his observations on the various tests, that the employment of rafts to prevent the formation of vortices does not affect the efficiency of the wheels. This is verified in at least one instance, in the test made of two 33" runners built for the 3.4 4.1 3.8 / 5 2.6 4.0 2.4 2.6 3 3 2.3 3.4 1.5 2.4 2.0 2.7 2.6 3.3 3.4 4.4 2.4 5.1 4.2 5.2 3.5 6.4 2.5 3.8 3 * 3 4.8 5 4 4 3.8 46 4.5 2.5 1.8 3.8 25 3.1 1.8 1.8 1.8 2.7 2.8 4.5 2.2 4.1 3.3 3.9 4.3 4.8 4.3 4.6 3.8 4.5 4.4 2.7 3.3 5.0 3.4 4.7 2.1 2.7 2.6 4.1 4.0 4.5 4.6 5.7 3.6 5.( 6.0 5.6 4.2 5.8 3.0 5. 4.3 4.4 5.4 5.0 4.6 5.3 4.3 5.1 4.8 =^28 kSS 3 QC fl) GO >!>- co 3 CO ~ GO 4.5 5.0 4.1 4-1 4.9 5.6 5 4 4.4 5.3 5.8 6.6 6.9 4.0 4.3 4.9 4.9 5.5 6.8 7.7 6.5 6.9 6.6 4.9 5.5 5.2 5.4 6.0 5.9 3.4 4.6 5.4 4.8 5.6 3.9 4.7 5.4 4.6 4.5 5.0 4.3 5.2 4 6 5.9 4.3 5.2 4.6 5.8 7.0 4.1 5.o 5.0 5.4 6.3 7.4 6.9 6.6 6.4 5.6 5.2 5.2 3.7 3.8 3.9 3.3 4.2 5.3 3.7 4.2 3.4 5.8 5.2 4.6 5.7 4.7 4.4 5.0 4.7 5. 4.3 5.2 4.8 5.2 5.2 3.3 5.4 4.9 5.5 5.9 6.4 5.2 6.1 5.1 4.9 3.9 3.6 3.8 3.1 3.8 3.7 3.7 3.4 2.8 2.7 2.4 3.1 3.2 4.1 3.4 3.0 3.0 4.6 4.5 4 1 4.6 3.4 4.6 4.1 5.9 5.2 4.1 4.7 4.4 5.4 4.9 3.0 4.2 4.0 4.9 4.1 4.7 4.0 3.4 2.8 2.7 2.6 2.5 3.4 3.4 3.4 2.8 2.2 2.6 1.9 2.2 2.5 3.2 2.9 2.4 2.5 Hi! 4.2 3.6 3.4 4.3 4.0 3.7 3.4 3.9 4.3 3.0 4.2 4.0 4.2 3.6 2.6 3.9 3.8 4.1 3.1 3.3 2.6 2.8 1.9 2.2 2.2 1.9 2.4 2.2 2.4 2.0 1.5 1.7 1.4 1.3 1.7 2.3 1.9 1.9 1.2 2.5 2.4 2.2 3.1 2.2 9 s oi.o 48.8 42.1 56.6 1 45.4 247 2.445.6 2.249.6 2.35L.7 2.338.8 2.4146.0 2.1 3.1 3.1 47.1 52.4 53.1 1.946.4 2.1 45.9 2.4 50.0 50.1 1J54.8 1.648.6 2.1 52.0 1.847.8 2.344.5 1.632.9 T028.9 435.7 336.6 338.6 1.336.0 28.6 027.6 24,5 029.3 236.8 29.0 9 28 . 2 23.0 Evaporation Tables. 733 Depth of evaporation, in Inches, at signal service stations Continued. Stations and Districts. o! GO 1 Si il 30 >>GC 11 3 fi i| si 1 l| 00 CO ! "~ 5 i ** Extreme Northwest: Moorhead Saint Vincent Bismarck Fort Buford Fort Totten Upper Mississippi Valley: St. Paul LaCrosse Davenport DesMoines Dubuque Keokuk .... 0.2 0.3 0.4 1.4 0.2 0.7 0.4 0.5 0.6 0.7 0.8 1.6 0.8 1.3 1.1 1.1 0.9 1.1 0.8 0.7 1.2 0.6 3 1.4 0.3 0.6 0.7 0.3 0.7 1.2 1.0 1.0 1.0 1.1 2.1 1.1 1.6 1.6 1.7 1.5 1.2 1.5 1.1 1.6 0.9 0.7 0.5 0.5 0.6 0.6 0.4 2.2 1.4 1.8 1.5 1.4 2.1 2.9 2.0 2.5 2.4 2.4 2. 2. 1. 1. 1. 1. 2.1 1.8 3.0 3.0 2.2 2.0 3.3 3.8 3.7 2.2 4.2 5.8 4.6 5.5 4.4 5.0 4.6 4.0 4.4 3.5 5.0 4.4 3 7 3.6 3.8 4.3 4.7 4.6 2.3 3.5 3.4 3.1 2.9 3.7 4.4 3.8 4.7 3.8 4.8 4.5 4.1 3.8 3.3 3.2 4.1 3 7 3.8 3.9 4.1 5.0 3.8 4.1 4.4 4.6 4.2 4.2 4.3 4.3 4.3 5.0 4.0 4.0 5.0 4.1 5.2 4.5 5.3 5.2 4 1 3.7 3.1 5.6 6.2 4.2 5.0 5.4 6.9 6.6 6.2 7.0 5.6 5.4 7.5 6.0 5.0 6.3 6.3 6.2 5.6 6.9 7.7 5 7 3.3 2.6 4.2 4.9 3.7 3.7 4.7 6.2 4.7 4.8 6.8 6.5 6.5 8.0 4.6 3.4 4.5 3.5 5.2 4.7 5.0 4.9 4 9 3.5 2.6 4.0 4.8 3.7 2.8 3.0 4.4 4.1 3.3 5.0 5.1 4.5 5.9 3.7 3.4 4.0 3.2 4.3 3.8 5.2 5.7 4 1 2.4 2.0 2.6 3-0 2.3 2.4 3.0 3.0 3.3 2.8 3.8 4.5 3.5 4.9 3.6 3.5 3.9 3.0 4.3 3.6 3.8 3.6 3 1 1.3 0.9 1.2 1.7 1.4 1.5 1.8 2.3 2.3 1.8 2.9 3.8 2.9 3.9 2.9 3.1 2.7 2.2 3.0 2.4 3.3 2.8 ?, 4 0.5 0.3 0.4 0.5 0.4 0.7 0.8 1.1 0.9 0.9 1.2 2.3 1.4 1.4 1.5 1.4 A .4 .4 .1 .5 0.7 7 26.3 22.1 31.0 35.5 27.2 28.1 32.9 39.0 36.0 33.2 42.9 48.9 40.8 52.2 39.6 38.3 41.6 36.1 41.7 35.5 43.8 41.9 33 Cairo . . ... Springfield, 111. . . . St. Louis Missouri Valley: Lamar Springfield, Mo. . . Leaven worth Topeka Omaha Crete Valentine Fort Sully Huron Yankton 0.4 0.8 0.6 1.1 1.4 1.2 1.5 1.4 3 6 1. 1. 1. 1.1 2 1 3.3 3.8 5.4 3.3 6 1 3.1 4.1 6.8 3.2 4 3 4.4 4.2 4.9 4.6 5 5 4.6 6.8 9.6 6.8 7.2 6.0 8.0 6.0 6.7 8.3 3.0 7.3 8.3 7.6 4.8 9.5 11.4 9.4 3.7 5.5 8.0 4.6 7.7 4.8 7.7 4.8 7.2 8.5 4.0 5.2 6.6 6.2 7.5 7.5 9.0 11.6 2.9 4.8 6.1 3.8 6.4 4.4 8.6 3.7 6.8 6.1 3.0 4.3 5.5 5.4 5.1 6.2 5.9 3.9 3.0 3.5 3.4 2.8 4.3 2.5 5.8 2.8 4.6 4.9 2.3 4.5 5.2 4.7 4.2 4.5 5.2 4.0 2.2 2.5 2.9 2.0 3.0 1.7 6.1 2.3 4.2 4.2 2.8 3.4 4.2 4.2 4.1 3.4 5.7 3.6 0.8 1.1 1.5 1.1 2.1 0.7 3.5 1.1 2.9 3.1 1.0 1.8 2.1 2.2 2.0 1.7 4.9 3.8 31.0 39.5 52.0 35.8 53.4 35.4 76.5 41.3 59.4 69.0 26.8 47.2 54.6 55.4 46.1 54.4 96.4 76.0 Northern Slope: Fort Assimboine.. Fort Custer Fort Maginnis .... Poplar River 0.4 3.3 0.8 3-0 2.8 2.1 1.3 1.4 1.3 1.6 1.8 5.4 3.9 0.8 5.7 1.8 3.3 3.7 1.3 2.8 2.4 1.9 2.0 1.7 5.7 3.9 0.8 4.0 1.8 4.1 3.5 1.5 1.8 2.8 3.2 3!l 6.7 5.2 2.7 8.2 5.4 6.7 7.6 2.1 4.8 4.1 5.1 3.8 4.2 8.5 7.3 4.9 5.2 3.9 5.6 5.8 1.8 4.3 4.6 5.4 4.0 5.0 11.0 9.5 5.7 10.4 6.9 4.3 10.5 1.9 5.7 7.4 8.2 4.4 5.8 12.0 10.9 Cheyenne North Platte Middle Slope: Colorado Springs. Denver Pike's Peak Concordia Dodge City Fort Elliott Southern Slope; Fort Sill Abilene Fort Davis Fort Stanton 734 Evaporation Tables. Depth of evaporation, in inches, at signal service stations Continued. Stations and Districts. if m *i _ 11 B co I*! ?i II |i si 11 I r* Southern Plateau: El Paso 4.0 3.9 6.0 8.4 10.7 13.6 9.4 7.7 5.6 5.2 4.6 2.9 82.0 Santa Fe 3.0 3.4 4.2 6.8 8.8 12.9 9.2 9.8 6.6 6.7 5.7 2.7 79.8 Fort Apache .... 2.6 3.0 3.6 6.8 9.4 9.1 7.1 6.7 5.3 5.2 4.1 2.6 65.5 Fort Grant 5.2 4.8 6.4 9.2 10.2 13.8 12.4 10.5 9.0 7.9 7.2 4.6 101.2 Prescott 1.4 2.8 3.6 5.4 6.2 8.1 6,6 6.5 4.7 4.9 3.6 2.2 56.0 Yuma 4.4 5.2 6.6 9.6 9.6 12.6 11.0 10.2 8.2 8.2 5.5 4.6* 95.7 Keeler 3.0 4.6 6.3 8.7 9.3 11.9 12.8 13.9 10.6 8.8 5.9 4.8 100.6 Middle Plateau: Fort Bidwell .... 0.8 1.8 1.8 4.6 5.2 4.0 8.8 8.1 5.0 4.6 2.4 1.3 48.9 Winnemucca .... 0.9 2.8 6.2 9.1 9.3 10.1 11.5 12.0 9.9 6.6 3.7 1.8 83.9 Salt Lake City. . . 1.8 2.7 3.6 7.2 6.9 8.9 9.2 10.7 9.6 6.5 5.0 2.3 7.44 Montrose 1.8 2.7 3.7 6.2 7.0 11.1 10.2 8.3 6.9 5.2 3.4 2.0 68.3 Fort Bridger 1.6 2.5 2.7 4.3 4.3 6.5 7.7 6.8 5.6 4-2 5.2 4.7 56.1 Northern Pleat eau: Boise City 1.6 2.5 3.8 6.1 6.5 6.6 10.0 9.2 7.4 5.2 3.2 1.8 63.9 Spokane Falls. . . 0.7 1.7 2.7 4.4 5.4 4.4 7.7 6.4 3.8 2.5 1.7 1.4 42.8 Walla Walla.... 1.1 2.9 3.6 6.2 7.7 5.7 9.9 7.9 5.1 3.4 1.8 2.4 57.7 No. Pacific Coast:. Fort Canby 1.2 1.1 1.8 2.1 2.8 2.3 1.8 2.9 1.8 1.8 1.5 0.9 21.1 Olynipia 1.3 1.2 1.8 2.5 4.1 3.3 3.2 3.1 2.4 1.5 1.3 1.1 26.8 Port Angeles .... 1.0 0.9 1.8 1.8 2.5 2.1 2.1 1.8 1.5 1.2 1.3 1.1 19.1 Tatoosh Island. . 1.2 1.1 1.8 1.4 1.8 1.8 1.4 1.4 1.4 1.6 1.8 1.4 18.1 Astoria 1.1 1.0 1.6 2.1 3.0 2.7 3.0 2.9 2.6 2.3 1.8 1.2 25.3 Portland 0.9 1.1 2.4 3.4 5.0 3.2 5.4 4.2 3.4 2.7 1.8 1.2 34.7 Roseburg 1.2 1.6 2.7 3.9 4.7 3.5 5.4 4.7 5.0 3.2 1.7 1.6 39.2 Middle Pacific Coast: "Red Bluff 3.0 4.6 5.4 6.1 7.0 6.9 11.0 10.7 10.1 10.5 5.9 3.6 84.8 Sacramento 1.8 3.1 3.7 4.3 4.2 5.6 5.9 5.6 6.5 7.3 3.9 2.4 54.3 San Francisco. . . 2.7 2.7 3.3 3.1 2.8 3.1 2.4 2.5 3.3 5.0 2.8 3.0 36.7 So. Pacific Coast: Fresno 1.8 2.8 3.0 5.6 6.0 7.0 9.1 10.2 7.6 6.7 3.8 2.2 65.8 Los Angeles 2.3 2.0 2.8 3.4 3.0 3.8 3.2 3.5 3.1 4.1 3.0 3.0 37.2 San Diego 2.9 2.7 2.5 2.7 3.3 2.8 3.2 3.3 2.9 4.3 3.2 3.7 37.5 APPENDIX. G. TWO NEW WATER WHEEL GOVERNORS. The Glocker- White Turbine Governor. The I. P. Morris Com- pany has built a governor for the Electrical Development Company of Ontario., Canada, which has one novel feature-* A cross section of its distinctive feature is shown in Fig. 411. The governor ball is hollow and contains two chambers, a and b, communicating with each other through a small opening, c. The balls are partially filled with mercury which, when running at normal speed, the axis of the ball being vertical, is divided be- tween the two chambers. When an increase of speed throws the balls outward, centrifugal force causes a flow of mercury from chamber, a, to chamber, b. This raises the center of gravity of the ball and increases its lever-arm about the knife edge, j, thus increas- ing its effectiveness by making its movement increase in a greater ratio than the speed increases. Similarly a reduction in speed causes the balls to incline inward and the mercury therefore to flow from chamber, b, to chamber, a, which tends to cause a still greater in- ward inclination. The charge of mercury hence increases the sensitiveness of the governor balls to small changes in speed. The centrifugal force of the balls is resisted through knife edges, K, K, by a spiral spring. This movement is transmitted by levers to a small pilot valve which controls a larger relay valve admitting oil under 250 pounds pressure to the cylinder. The gate to be moved is a cylinder gate opening upward, a force of 15,000 pounds being required for the purpose. The weight of the gate is sufficient to close it and the power-cylinder of the governor is therefore made single acting. The entire governor is not shown as there are no other unusual features. The Allis-Chaimers Governor. This Company has recently de- veloped a water wheel governor, the following description of which is taken from their bulletin No. 1612: * See "The Glocker-White Turbine Governor" by W. M. White and L. F. Moody in "Power," Aug. 4, 1908. 736 Two New Water Wheel Governors. Fig. 411. Cross-Section of the Glocker-White Governor Head. The Allis-Chalmers Governors. 737 ''The Allis-Chalmers Governor is of the oil pressure type and con- sists of three distinct elements : "First Governor Stand (see Fig. 4i2) containing the apparatus 10 DISCHARGE Fig. 412. View of the Governor Stand of the Allis Chalmer Governor. for controlling the time of application of energy for actuating the gates- "Second Regulating Cylinder for applying energy. "Third Pressure System for supplying energy. 45 738 Two New Water Wheel Governor. "The Governor Head (i), designed to be a highly sensitive yet stable apparatus and driven from the Turbine Shaft by Pulley (2), forms the basic governing element. Any change in its position moves the Governor Collar (18), thereby shifting the Floating Lever (3), and through it and its connection with the Relay (4) (which momentarily acts as a stationary fulcrum) actuates the Reg- ulating Valve (9). Any movement of this Regulating Valve admits oil from the Pressure System to either the opening or closing side of the Regulating Cylinder and thereby actuates the Turbine gates. The Relay (4) forms a mechanical connection between the Regu- lating Cylinder Piston and the Floating Lever (3), constituting what may be termed a moving fulcrum, so that every movement of the Regulating Piston shifts the fulcrum point and brings the Regu- lating Valve (9) back to mid position, thereby making* the mechan- ism "dead beat." If this movement is adjusted so that the position of these parts have the proper relation, the Governor Collar will practically retain a fixed position. 'The Regulating Cylinder cannot however, fully open or close the turbine gates instantaneously and the above result can only be obtained within certain limits, a difference of speed occurring be- tween no load and full load that requires a certain movement or travel of the Governor Collar (18). Consequently, the speed of the Turbine at different gate openings will vary slightly and depend upon the speed of the Governor at corresponding positions of the Regulating Piston Stroke. "Under favorable conditions (open flume and short penstocks) the opening and closing time of the gates depends solely upon the inertia of the moving masses and "aperiodical regulation" can be obtained; i. e., the stroke of the Regulating Piston and the travel of the Governor Collar correspond in time. Under favorable con- ditions (long penstocks) the closing time is often so influenced by the "critical time," already mentioned, and by other considerations that "aperiodical regulation" is no longer practicable since a travel of Governor Collar would be required that would cause a greater difference in speed between no load and full load than is commer- cially allowable. To meet such conditions, the '"Compensating Dash Pot" (7) is utilized. "In the diagram, Fig. 413, the full travel of the Governor Collar is shown as corresponding to a speed change "x"- The Relay Stroke, however, is designed so that only a portion of this travel corresponding to a speed change "y" is utilized; i. e./ within this The Allis-Chalmers Governor. 739 limit the Governor, without other mechanism than the Relay, is ''dead beat" and the Regulating Valve by relay action is returned to mid-position after each movement. The Compensating Dash Pot, (7), consists of a cylinder having an adjustable bypass and containing a compound piston, with auxiliary spring device, the rod of which is connected through a suitable lever to the Governor Col- lar. Arranged so that its piston takes motion from the Relay actu- ating shaft, is a positive displacement pump connected by a pipe to the "Compensating Dash Pot" cylinder. For slight changes of Fig. 413. Diagram of Allis-Chalmers Governor. load, a negligible displacement of oil takes place and the Dash Pot has a slight damping action only on the governor head, but when any load change occurs of sufficient magnitude to produce a speed variation greater than "y" as shown on the diagram, enough oil dis- placement takes place to bring the auxiliary spring effect of the Dash Pot piston strongly into action until the fluctuation is con- trolled and the Governor Collar is again brought within the limits corresponding to "y" speed variation when action ceases. By this means, a governing element of maximum sensitiveness can be used and the regulation of ordinary slight fluctuations made "aperiodical", even under the most unfavorable conditions. These elements in design, therefore, result in the Allis-Chalmers Governor operating with great quickness and holding the speed variation, due to ordi- nary fluctuations, within the narrowest limits, yet being absolutely safe from hunting or overtravel after heavy load fluctuation, even under the most difficult operating conditions." APPENDIX H. MISCELLANEOUS TABLES. TABLE LXXVIIL EQUIVALENT MEASURES AND WEIGHTS OF WATER AT 4 CENTIGRADE 39.2 FAHRENHEIT. u. s. Gallons Imperial Gallons Liters Cubic Meters Pounds Cubic Feet Cubic Inches Circular Inch 1 Foot Long- 1 .83321 3.7853 .0037853 8.34112 .13368 231 24.5096 1.20017 1 4.54303 .004543 10.0108 .160439 277.274 29.4116 .264179 .22012 1 .001 2.20355 .035316 61.0254 6.4754 264.179 220.117 1000 1 2203.55 35.31563 61025.4 6475.44 .119888 .099892 .453813 .0004538 1 .0160266 27.694 2.9411 7.48055 6.23287 28.3161 .0283101 62.3961 1 1728 183.346 .0043^9 .003607 .0163866 .0000164 .0361089 .0005787 1 .10613 .0408 .034 .1544306 .0001544 .340008 .005454 9.4224 1 TABLE LXXIX. EQUIVALENT UNITS OF ENERGY WORK HEAT ELEC- TRIC HYDRAULICS 'S II Foot Ton 2240 Lbs. Kilogram Meter is EHS * 65 il e "c S wg 'E^ bt Sti.2 oc3 Volt Columb d ^3 8* feO si S.8 11 11 PL|O ^rtf 10 PnU 1 .000446 1383 .000138 .001285 .000324 .000377 .12 .016 .0519 .0069 2240. 1 309.688 .3097 2.8785 .7262 .8439 268.817 35.906 116.414 15.456 7.233 .00323 1 .001 .0093 .00235 .00272 .8673 .1159 .3755 .0499 7233.18 3.2291 1000 1 9.302 2.3452 2.7241 867.303 115.928 375.516 49.90 778. .3474 107.562 .1076 1 .2520 .2929 93.28 12.448 40.394 5.368 3085.34 1.3774 426-394 .4264 3.9683 1 1.1623 370.17 49.396 160.29 21 . 221 2655.4 1.1854 371.123 .3671 3.414 .8603 1 318.39 42-486 137.87 183.23 8.341 .00372 1.1532 .00115 .1072 .0027 .00314 1 .1334 .4as .05754 62.39 .02785 8.6257 .00863 .0803 .00202 .02353 7.48 1 3.245 .4312 19.259 .00859 2.6626 .00266 .0248 .00624 .00726 2.309 .3082 1 .13-9 144.92 .0647 20.036 .02004 .1863 .04712 .05457 17.37 2.318 7.524 1 Theoretical Jet Velocities. 74 1 TABLE LXXX. Velocities, in feet per second, due to Heads from to 50 feet. Head in feet. .0 .1 .2 .3 .4 .5 .6 .7 .8 .9 0.000 2.536 3.587 4.393 5.072 5.671 6.212 6.710 7.178 7.609 1 8.020 8.412 8.786 9.144 9.490 9.823 10.145 10.457 10.760 11.055 2 11.342 11.622 11.896 12.163 12.425 12.681 12.932 13.179 13.420 13.658 3 13.891 14.121 14.347 14.569 14.789 15.004 15.217 15.427 15.634 15.839 4 16.040 16.240 16.437 16.631 16.823 17.013 17.201 17.387 17.571 17.753 5 17.934 18.112 18.289 18.464 18.637 18.809 18.979 19.148 19.315 19.481 6 19.645 19.808 19.970 20.131 20.290 20.448 20.604 20.760 20.914 21.067 7 21.219 21.370 21.520 21.669 21.817 21.964 22.110 22.255 22.399 22.542 8.'.'.'.'. 22.685 22.826 22.966 23.106 23.245 23.383 23.520 23.656 23.792 23.927 9 24.061 24.194 24.326 24.458 24.589 24.720 24.850 24.979 25.107 25.235 10 25.362 25.489 25.614 25.740 25.864 25.988 26.112 26.235 26.357 26.479 11 26.600 26.721 26.841 26.960 27.079 27.198 27.316 27.433 27.550 27.667 12 27.783 27.898 28.013 28.128 28.242 28.356 28.469 28.582 28.694 28.806 18 28.917 29.028 29.139 29.249 29.359 29.468 29.577 29.686 29.794 29.901 14 30.009 30.116 30.222 .30.329 30.435 30.540 30.645 30.750 30.854 30.958 15 31.062 31.165 31.268 31.371 31.474 31.576 31.677 31.779 31.880 31.980 16 32.081 32.181 32.281 32.380 32.480 32.579 32.677 32.775 32.873 32.971 17 33.068 33.165 33.262 83.359 33.455 33.551 33.647 33.742 33.837 33.932 18 34.027 34.121 34.215 34.309 34.403 34.496 34.589 34.682 34.775 34.867 19 34.959 35.051 35.143 35.234 35.325 35.416 35.507 35.597 35.688 35.778 20 35.867 35.957 36.046 36.135 36.224 36.313 36.401 36.490 36.578 36.666 21 36.753 36.841 36.928 37.015 37.102 37.188 37.275 37.361 37.447 37.532 22 37.618 37.703 37.789 37.874 37.959 38.043 38.128 38.212 38.296 38.380 23 38.464 38.547 38.630 38.714 38.797 38.879 38.962 39.014 39.127 39.209 24 39.291 39.373 39.454 39.536 39.617 39.698 39.779 39.860 39.940 40.021 25 40.101 40.181 40.261 40.341 40.421 40.500 40.579 40.659 40.738 40.816 26 40.895 40.974 41.052 41.130 41.209 41.287 41.364 41 .442 41.520 41.597 27 41.674 41.751 41.828 41.905 41.982 42.058 42.135 42.211 42.287 42.363 28 42.439 42.515 42.590 42.666 42.741 42.816 42.891 42.966 43.041 43.116 29 43.190 43.264 43.839 43.413 43.487 43.561 43.635 43.708 43.782 43.855 30 43.928 44.002 44.075 44.148 44.220 44.293 44.366 44.438 44.510 44.582 31 44.655 44.727 44.798 44.870 44.942 45.013 45.085 45.156 45.227 45.298 3-2 45.369 45.440 45.511 4?,. 581 45.652 45.722 45.792 45.863 45.933 46.003 33 46.073 46.142 46.212 46.281 46.351 46.420 46.489 46.559 46.628 46.697 31 46.765 46.834 46.903 46.971 47.040 47.108 47.176 47.244 47.312 47.380 85 47.448 47.516 47.584 47.651 47.719 47.786 47.853 47.920 47.987 48.054 36 48.121 48.188 48.255 48.321 48.388 48.454 48.521 48.487 48.653 48.719 37 48.785 48.851 48.917 48.982 49.048 49.113 49.179 49.244 49.310 49.375 38 49.440 49.505 49.570 49.635 49.699 49.764 49.829 49.893 49.958 50.022 39 50.086 50.150 50.214 50.278 50.342 5D.406 50.470 50.534 50.597 50.661 40 50.724 50.788 50.851 50.914 50.977 51.040 51.103 51.166 51.229 51.292 41 51.354 51.417 51.479 51.542 51.604 51.667 51.729 51.791 51.858 51.915 42 51.977 52.039 52.100 52.162 52.224 52.285 52.347 52.408 52.470 52.531 43 52.592 52.653 52.714 52.775 52.836 fi2.87 w.958 53.018 53.079 53.134 44 53.200 53.26U 53.321 53.381 53.441 53.501 53.561 53.621 53.681 53.741 4) 53.801 53.861 53.921 53.980 54.040 54.099 54.159 54.218 54.277 54.336 46 54.396 54.455 54.514 54.573 54.632 54.690 54.749 54.808 54.867 54.925 47 54.984 55.042 55.101 55.159 55.217 55.275 55.334 55.392 55.450 55.508 48 55.56H 55.623 55.681 55.739 55.797 55.854 55.912 55.969 56.027 56.084 49 56.141 56.199 56.256 56.313 56.370 56.427 56.484 56.541 56.598 56.655 742 Miscellaneous Tables. TABLE LXXXI. Table of three-halves (f ) power of. number.* Head in .0. .1 .2 .3 .4 .5 .6 .7 .8 .9 feet. 0... 0.0000 0.0316 0.0894 0.1643 0.2530 0.3536 0.4648 0.5857 0.7155 0.8538 1.... 1.0000 1.1537 1.3145 1.4822 1.6565 1.8371 2.0238 2.2165 2.4150 2.6190 2 2.8284 3.0432 3.2531 3.4881 3.7181 3.9529 4.1924 4.4366 4.6853 4.9385 3.... 5.1962 5.4581 5.7243 5.9947 6.2693 6.5479 6.8305 7.1171 7.4070 7.7019 4 8.0000 8.3019 8.6074 8.9167 9.2295 9.5459 9.8659 10.1894 10.5163 10.8466 5.... 11.1803 11.5174 11 8578 12.2015 12.5485 12.8986 13.2520 13.6086 13.9682 14.3311 6.... 14.6960 15.0659 15.4379 15.8129 16.1909 16.5718 16.9557 17.3425 17.7322 18.1248 18.5203 18.9185 19.3196 19.7235 20.1302 20.5396 20.9518 2i.;i66 21.7842 22.2045 s'.'.'. 22.6274 23.0530 23.4812 23.9121 24 3455 24.7815 25.2202 25.6613 26.1050 26.5.123 9.... 27.0000 27.4512 27.9050 28.3612 28.8199 29.2810 29.7445 30.2105 30.6789 31.1496 10.... 31.6228 32.0983 32.5762 33.0564 33.5390 31.0239 34.5111 35.0006 35.4924 35.9865 11.... 36.4829 36 9815 37.4824 37.9855 38.4908 38.9984 39 5082 40.0202 40.5343 41 0507 1*.... 41.5692 42.0910 42.6128 43.138 s * 43.6648 44.1952 44.7256 45.2600 45.7944 46.3332 13.... 4S.8720 47.4148 47.9576 48.5048 49.0520 49.6032 50.1544 50.7096 51.2648 51.*240 14 52.3832 52.9464 53.5096 54.0768 54.6440 55.2152 55.7864 56.3616 56. 9368 57.5156 15. . . . 58.C944 58.6776 59.^608 59.8472 60.4336 61.0244 61.6152 62.2096 62.8040 63.4020 16.... 64.0000 64.6020 65.2040 65.8096 6B.4152 67.0244 67.6336 68.2464 H8.S592 69.4760 17 70.0928 70.7132 71.3336 71.9572 75.5808 73.2084 73.H360 74.4672 75.0984 75.7328 18.... 76.3672 77.0056 77.6440 78.2856 78.9272 79.5724 80.2176 80.8684 81.5152 82.1672 19.... 82.8192 83.4748 84 . 1304 84.7892 85.4480 86.1104 86.7728 87.43^4 88.104(1 88.7732 20.... 89.4424 90.1152 90.7880 91.4636 92.1392 92.8184 93.4976 94.180a 94.8624 95.5484 21.... 96.2344 96 9232 97.6120 98.3044 98.9968 99.6924 100.3880 101.0868 101.7856 102.4872 22.... 103.1883 103.8940 104.600S 105.3076 106.0160 106.7276 107.4392 108.1540 108 8688 109 .58(54 23. . . . 110.3040 111.0248 111.7456 112.4700 113.1944 113 9216 114.6488 115.3788 116.1088 116.8420 24.... 117. 5752 118.3128 119 0496 119.7876 1^0.5272 121.2696 122.0120 122.7576 123.5032 124.2516 25.... 125.0000 125.7516 126 5032 127.2576 128.0120 128.7706 129.5292 130.2876 131.0480 131.8112 26.... 132.5744 133.3408 134.1072 134.8764 135.6456 136.4180 13,' 1904 137.965-2 188. 7400 139.5180 27.... 140.2960 141.0768 I41.a576 142.6416 143.4256 144 2120 144.9984 145.7880 146.5776 147 3700 28.... 148.1624 148.9572 149.7520 150.5500 151. 34H) 152.1488 152.9496 153.7532 154.556* 155.3632 29.... 156.1696 156.9788 157.7880 158.6000 159.4120 160.2268 161.0416 161.858K 162.6760 163.4W4 30.... 164.3168 165.1396 165.9624 166.7884 167.6144 168.4428 169.2712 170.1020 170.9328 171.7668 81.... 172.6008 173.4372 174.2736 175.1128 175.9520 176.7940 177.6360 178.4804 179.3-.MH 180.1720 32.... 181.0192 181.8692 182.7192 183.5716 184.4240 185.2792 186.1344 186.99:iO 187.8496 188.7100 33.... 189.5701 1 90. 4336 191.2968 192.1624 93.0280 193.8960 194.7640 195.6318 19H.5056 197.3788 34.... 198.2520 199.1460 200.04dO 200 9008 201.7616 24B.H424 20:5.5232 204.4068 205.29H4 206.1764 35.... 207.0624 207.9512 208.8400 209.7312 210.6224 211.5204 212.4184 213.3104 214.2U24 2:5.1012 36.... 216.0000 216.9012 217.8024 218.7060 219.6096 220.5760 221.4224 222.3312 223.2400 224.1512 37. . . . 225.0624 225.976(1 226.8896 227.8056 228.7216 299.6404 230.5592 231.4MX) 232.40(1* 233.3244 38.... 234.2480 235.1736 236.0992 237.0276 237.9560 2*38.8868 239.8176 240.7508 241.^840 242.6HI6 39.... 243.5552 244.4932 245.4312 ^46.3712 247.3112 248.2540 249.196S 250.1420 251.0S7 2 252. OH 18 40.... 252.9824 253.9320 254.8816 255.8340 256.7864 257.7412 258.6960 259.6528 260.KOJ6 261. SOS* 41.... 262.5280 263.4896 264.4512 265.41521 266 3792 ?R7.345li 268.3120 269.2804 27'0.24H8 271 2200 42.... 272.1912 273.1644 274.1316 275.1132 276.0888 277.0672 278.0456 279 6252 2*0.0048 280. VJ87 2 43.... 281.9696 282.9544 283.93*2 284.^264 285.9136 286.9028 287.8920 288 8836 289.8752 29.8453 386.9343 3H8.0301 389.1219 390.2205 391.3150 392.4163 393.5136 394.6122 395.7122 54.... 396.8136 397. 9163 399.0204 40 J. 1258 401.2326 402.3408 403.4448 404.5557 405.6679 406.7759 55. . . . 407.8855 409.0017 410.1139 411.2273 412.3477 413.4639 414.5814 415.7002 416.8204 417.9419 56. . . . 419.0648 420.1833 421.3089 422.4257 423.5583 424.6879 425.8131 426.9453 428.0732 429.2080 57. . . . 430.3386 431.4704 432.6036 433.7380 434.8738 436.0110 437.1494 438.2892 439.4302 440.5726 58.... 441.7106 442.8556 443.9961 445.1438 446.2869 447.4372 448.5830 449.7300 450.8842 452.0359 59.... 454.0849 455.3271 455.4907 456.6455 457.8017 458.9592 460.1179 4*1.2720 462.4334 463.5960 60.... 464.7540 465.919,' 467.0797 468.2475 469.4106 470.5750 471.7467 472.9J37 474.0819 475.2514 61.... 476.4222 477.3942 478.7676 479.9422 481.1181 482.2891 483.4676 484.6473 485.8222 487.0044 62.... 488.1880 489.3666 490.5465 491.7339 492.9163 494.1000 495.2912 496.4774 497.6648 498.8536 83.... 500.0436 501.2348 502.4273 503.6211 504.8161 506. 00*51 507.2036 508.4024 509.5961 510.7974 64.... 512.0000 513.1974 514.3960 515.6024 516. 8035 518.0059 519.2160 520.4209 521.6270 522.8344 (55. . . . 524.0430 525.2528 526.4639 527.6762 528.8898 530.1046 531 3120 532.5313 533.7498 534.9630 66.... 536.1840 537.2996 538.6230 539.8411 541.0870 542.2875 543.5092 544.7389 545.9630 547.18 C 4 H7 548.4151 549.6429 550.8720 552.1022 553.3337 554.56r>5 555.6179 557.0356 558.2652 559.5027 68.... 560.7416 501.974H 563.2160 564.4516 56 >. 6953 56(5.9334 568.1795 r>69.4199 570.6616 571.9113 69.... 573.1554 574.4006 575.6473 576.8947 578.1436 579.3937 580.6449 581.8974 583.1510 584.4059 70.... 585.6620 586.9122 588.1707 589.4303 590.6841 591.9462 593.2023 594.4668 595.7253 596.9921 71.... 598.2531 599.5152 600.7856 602.0500 603.3157 604.5825 605.8505 607.1197 608.3901 609.6616 72.... 610.9344 612.2083 613.4340 614.7596 616.0371 617.3085 618.5883 619.8692 621.0841 622.4274 73.... 623. 71 20 624.9903 626.2699 627.5579 628.8398 630.1302 631.4144 632.6997 633.9862 635.2813 74.... 636.5702 637.8602 639.1513 640.4437 641.7372 643.0318 644.3276 645.6246 646.9152 648 2145 75.... 649.5150 6.50.8166 652.1118 653.4157 654.7208 656.0195 657.3268 658.6278 659.9375 661.2408 76 662.5452 663.8583 665.1650 666.4728 667.7894 669.0996 670.4108 671.7131 673.0368 674.3514 675.6673 676.9*42 677.2043 679.6216 680.9419 682.26&J 683.5784 684.9021 686.2271 687.5454 78!!! WR.8788 690.2009 691.5226 692.8532 694.1771 695.5100 696.8361 698.8361 699.1713 700.8292 79.... 702.1599 703.4995 704.8324 706.1665 707.5016 708.8379 710.1752 711.. '137 712.8534 714.1941 80.... 715.5360 716.8789 718.2230 719.5683 720.9146 722.2540 723.602ti 724.9523 726.2950 727.6496 81.... 729.0000 730.3460 731.7613 733.0495 7^4.3989 735.7575 737.1091 738.4699 739.8237 741.1876 742.5340 743.K998 745.2580 746.6173 747.9776 749.3392 750.7018 752.0655 753.4303 754.1962 83!!! 756.1632 757. 53 12 758.9004 760.2624 761.6338 763.01)63 764.3798 765.7461 767.1219 768.4904 84.... T.iQ.8684 771.2474 772.6192 774.0004 775.3743 776.7493 778.1338 779.5110 780.8892 782.2770 85.... 783.6575 785.0389 686.4215 787.8052 789.1984 790.5843 791.9712 793.3591 794.7482 796.1383 86.... 797.5296 798.9219 800.3066 801.7011 803.0966 804.4932 805.8909 807.2810 808.680* 810.0833 87. . . . 811.47'51 812.8781 814.2736 815.6788 817.0763 818.4837 819.8834 821.2929 822.6947 824.1064 88.... H25.5704 826.9154 828.3-214 829.7374 831.1456 S: .V>4<) 833.9652 835.3765 836.7890 838.2025 89.... 839.6171 S41. 0327 842.4494 843.8671 845.2859 846.7058 848.1267 849.5487 850.9627 X52.3868 90. . . . 853.8120 855.2382 856.6564 858.0847 859.5051 860.9355 862.3670 863.7905 865.2241 8B6.6496 91.... 868.0763 869.5130 870.9417 872.3806 873.8114 875.2432 876.6761 878.1192 879.5541 880.9901 92.... 882.4272 883.8652 885.3044 886.7445 888.1857 889.6280 891.0712 892.5156 893.9609 895.4073 93 896.8518 898.3032 899.7528 901.1946 902.6456 904.09X2 905.5519 906.9972 908.4530 909.9097 94.... 911.3582 912.8170 914.2675 915.7284 917.1809 918.643'J 920.0985 9-21.5541 923.0202 924.4778 95.... 925.9365 927.4056 928.8664 930.3281 931.7908 933.2642 934.7290 936.1948 937.6616 939.1295 98.... 940.5984 942.0683 943.5392 945.0111 946.4841 947.9581 949.4:131 950.9091 952.3764 953.8545 97 955.3336 956.8136 958.2948 959.7672 961.2503 962.734-> 964.2099 965 6961 967.1 73^ 968.6617 98.... 970.1412 971.6314 973.1129 974.6051 976.0886 977. 582^ 979.0684 980.5548 98-2.0522 983.5407 93. . . . 9&J.0302 986.5206 988.0220 989.5145 991.0080 992.51(25 993.9980 995.4945 996.9920 998.4905 100 1 OOO.OUOO 744 Miscellaneous Tables. TABLE LXXXII. Table of Jive-halves (|) powers of number*. Head in .0 .1 .2 .3 .4 .5 .6 .7 .8 .9 feet. i 000 .003 .018 .049 .101 .177 .279 .410 .572 .768 1 1.000 1.269 1.578 1.927 2.319 2.756 3.238 3.769 4.347 4.976 2 5.657 6.390 7.179 8.0*2 8.923 9.883 10.90 11.880 13.118 14.320 3 15.589 16.920 18.317 19.784 21.315 22.918 24.588 26.333 28.150 30.038 4 32.000 34.038 36.149 38.343 40.612 42.957 45.384 47.888 50.477 53.150 5 55.901 58.736 61.662 64.671 67.765 70.945 74.211 77.671 81.014 84.553 6... 88.182 91.903 95.716 99.622 103.622 107.718 111.910 116.198 120.578 125.063 7 129.642 134.325 139.104 149.086 148.962 154.050 159.235 164.526 169.915 175.420 8 181.019 186.729 192.544 198.470 204.506 210.647 216.892 123.251 229.724 236.313 9 243.000 249.804 256.726 263.757 270.908 278.170 286.452 293.047 300.654 308.385 10 316.228 324.190 332.275 340.477 343.806 357.252 365.817 374.511 383.314 392.258 11... 401.311 410.500 419.798 429.242 438.797 448.477 458.293 468.234 478.301 488.507 18 49H.820 509.301 519.879 530.610 541.446 552.438 563.548 574.802 586.163 597.696 13 6U9.336 621.137 633.046 645.170 657.297 (569.641 682.094 694.727 707.457 720.354 14 733.365 746.539 759.842 773.301 786.873 800.618 814.476 828.521 842.668 856.988 15 871.416 886.038 900.767 915.659 930.684 945.872 961.194 976.697 992.303 1008.092 16 1024.000 1040.092 1056.305 1072.703 1089.200 1105.896 1122.724 1139.708 1156.831 1174.144 17 1191.578 1209.192 1226.945 1244.856 1262.909 1281.140 1299.514 1318.066 1336.744 1355.621 18 1374.606 1393.809 1413.121 1432.634 1452.257 1472 082 1492.055 1512.194 1532.482 1552.956 19 1573.561 1594.373 1615.296 1636.428 1657.691 1679.145 1700.751 1722.529 1744.459 1766.583 20 1788.840 1811.312 1833.918 1856.719 1879.636 1902.769 1926.059 1949.526 1973.130 1996.953 21 2020.914 2045.075 2069.374 2093.875 2118.536 2143.378 2168.381 2193.588 2218.935 2244.465 22 2270.136 2296.057 2322.142 2348. 3fi8 2374.758 2401.380 2428.121 2455.096 2482.213 2509.519 23 2536.992 2564.678 2592.507 2620.551 2648.740 2677.167 2705.716 2734.482 2763.394 2792.524 24 282 1. 800 2851.343 2881.010 2910.848 2940.859 2971.115 3001.495 3032.123 3062.874 3093.875 25 3125.000 3156.375 3187.876 3219.627 3251.505 3283.661 3315.942 3348.402 3381.038 3413.905 26.... 3446.924 3480.200 3513.603 3547.239 3581.054 3615.077 3649.254 3683.666 3718.232 3753.034 27 3787.992 3823.187 3858.538 3894.127 3929.872 3985.830 4001.945 4038.328 4074.868 4111.623 28 4148.536 4ia5.692 4223.006 4260.565 4298.283 4336.247 4374.370 4412 711 4451.242 4489.991 29 4528.930 4568.089 4607.410 4646.980 4686.713 4726.697 4766.843 4807.212 4847.745 4888.530 30 4929.510 4970.714 5012.052 5053.676 5095.466 5137.512 5179.693 5222.131 5264.736 5307.600 31... 32 5350.631 5792.608 5303.891 5887.995 5137.349 5883.552 5481 .037 i 5929.376' 5524.893 5075.888 5569.011 6021 .568 5613.298 6067. 9f,8 5&57.816 6114.638 5702.535 6161.480 5747.487 6208., 559 33 6255.810 6303.365 6351.060 6398.995 6447.135 6495.516 6544.070 6592.899 6641.903 6691.148 34 6740.568 6790.879 6841.368 6890.904 6940.613 6991.149 7041.896 7092.923 7144.092 7195.542 35 7247.170 7299.080 7351.168 7403.504 7456.019 750S.960 7562.081 7615.167 7668.432 7722.126 3f, 777rt.OOO 7830.133 7884.447 7939.028 7993.789 8051 .024 8104.060 8159.555 8215.232 8271.179 37 8327.309 8383.709 8440.293 8497.149 8554.188 8611.515 8669.026 8726.796 8784.750 8842.995 3H 8901.424 8960.114 9018.989 9078.157 9137.510 9197.142 9256.959 9317.056 9377.339 9437.902 39 9498 653 9559.684 9620.903 9682.388 9744.061 9806.033 9868.193 9930.637 9993.271 0056.189 40 10119.296 0182.673 0246.240 0310.110 10374.171 10438.519 0503.058 0567.869 0632.872 0698.164 41 10763.648 0829.423 089.",. 389 0961.648 11028.099 11094.842 1161.779 1228.993 1296.340 1364.118 4-.' 11432.030 1502.221 1568.607 1637.288 11706.165 11775.356 1844.743 1939.996 1984.205 2054.351 43 12124.693 2195.835 2266.173 2337.313 12408.650 12480.272 2552.091 2624.213 2696.634 2769.197 44 .... 12841.761 2915.113 2988.340 3062.014 13135.829 13209.950 3284.271 3358.8*1 3433.692 3508.794 45 13584.096 3659.726 3735.557 3811.680 13888.005 13964.623 4041.444 4118.576 4195.912 4273.560 46 14351.411 4429.558 4507.909 4-86.574 14665.444 14744.578 4823.982 4899.897 4976.000 5059. C65 47 15144.152 5224.849 5305.752 5386.974 15468.402 15550.151 5632.107 5714.?64 5796.829 5879.597 48 15962.573 6045.809 6129.325 6203.457 16297.190 16381.302 64H5.928 65*2.036 6635.7^3 6722.212 49 50. 16807.000 17677.500 6892.786 6978.851 7065.195 17152.070 17238.979 7326.168 7413.647 7501.893 7589.181 1 Relation of Rainfall to Stream Flow. 745 TABLE LXXXIIL Showing relation of mean rainfall to the maximum and minimum discharge of various rivers. DRAINAGE AREA, 500 TO 1,000 SQUARE MILES Drainage Mean Annual Discharge Ca Ft STREAM AND LOCALITY. Area, Rainfall, pef Sec. Sq. Miles Inches per Sq. Mile I. AMERICAN STREAMS. MAX. Mw. Broad river at Carlton, Ga 762 47.73 22.21 .394 Coosawattee river at Carters, Ga 532 52.73 15.17 .588 Des Plaines river at Riverside, 111 630 29.75 14.23 .000 Etowah river at Canton, Ga 604 52.73 31.50 .405 Flint river at Molina, Ga 892 52.73 7.37 .062 French Broad river at Asheville, N. C 987 7 . S8 .660 Greenbriar river, mouth Howard's cr., W. Va. 810 40.70 .120 Housatonic river, Massachusetts 790 . 165 Little Tennessee river at Judson, N. C 675 56.40 .408 Mahoning river at Warren,* 596 .017 Mahoning river 967 .026 Monocacy river at Frederick, ,Md 665 38.77 16.98 .116 North river at Port Republic, Va 804 38.77 29.78 .220 North river at Glasgow, Va... 831 38.77 44.80 .180 Olentangy river at Columbus, 523 .014 Passaic river at Paterson, N. J 791 45.00 .190 Potomac river, no. branch at Cumberland, Md. 891 38.77 22.82 .045 Potomac river at Cumberland, Md 920 38.77 19.46 .022 Raritan river at Bound Brook, N. J , 879 45.94 59.30 .140 Schoharie creek at Fort Hunter, N. Y 948 39.25 44.00 Shenandoah river at Fort Republic, Va 770 38.77 .167 Tuckasagee river at Bryson, N. C 662 45.30 .603 II. FRENCH STREAMS. Armancon river at Aisy 575 49.20 .011 Armancon river at Tonnerre 853 .034 Marne river at St. Pizier 915 30.70 7.73 .101 Meuse river at Pagny-la-Blanchecote 573 .039 Meuse river at Chalaines 607 31.51 .041 Meuse river at Pagny-sur-Meuse 734 .056 Meuse river at Vignot 817 .085 Meuse river at Mt. Mihiel 914 .078 III. GERMAN STREAMS. Ihna river at Stargard 672 26.60 15.50 .137 Jagst river at its mouth 708 29.50 .200 Kocher river at its mouth - 768 29.50 .221 Lippe river at Hamm 965 9.75 .235 Malapane river at Czarnowanz 773 25 . 04 14 35 .274 Oppa river at Strebowitz 805 24.40 21.95 .256 Stober river at its mouth.. 620 22.70 3. 05 *From paper on Water Supply for New York State Canals, Report of State Engineer on Barge Canal, 1901. 746 Miscellaneous Tables. TABLE LXXXIIL-Continued. DRAINAGE AREA, 1,000 TO 2,500 SQUARE MILES. Drainage Mean Annual Discharge Cu. Ft. STREAM AND LOCALITY. Area, Rainfall, per Sec. Sq. Mile. Inches per Sq. M lie. I. AMERICAN STREAMS. MAY. MIN. Androscoggin river at Rumford Falls, Me. . . Broad river at Gaffney, S. C 2,220 1,435 40.39 47.73 25.00 13.05 .475 .550 Catawba river at Catawba, N . C . 1,535 34.30 .553 Chattahoochee river at Oakdale, Ga 1,560 48.91 21.75 .432 Genesee river at Mt. Morris, N. Y 1,070 38.09 39.20 .094 Greenbriar river at Aederson, W. Va 1,344 44.86 41.55 .041 James river at Buchanan, Va 2,058 40.83 15 56 .146 Neuse river at Raleigh, N. C 1,000 .193 Neuse river at Selma, N. C 1,175 6.70 .064 2,425 49.23 14.92 .157 Oconee river at Carey, Ga 1,346 49.31 7.44 .283 Oostannala river at Resaca, Ga 1,527 52.47 14.50 .389 Potomac river at Cumberland, Md 1,364 35.28 .018 Saluda river at Waterloo, S. C 1,056 12.08 .275 Schuylkill river at Philadelphia, Pa 1,800 .170 Schuylkill river at Fairmount, Pa 1,915 12.17 .013 Scioto river at Columbus, O 1,07.0 .004 Scioto river at Shadeville, O 1,670 .015 Tar river at Tarboro, N. C 2,290 6.38 .074 Youghiogheny river at Ohio Pyle, Pa 1,775 .060 II. FRENCH STREAMS. Aisne river at Biermes 1,341 - .085 Aisne river at Berry-au-Bac 2,120 .092 Aisne river at Berry-au-Bac 2,120 7.58 Loing river at its junction with the Seine. . ^ 1,785 28.40 .046 Lys river , 1,420 1.74 .099 Marne river -at La Chaussee 2,297 .010 Marne river at Chalons 2,497 .010 Meuse river at Verdun 1,219 28.33 .110 Oise river at Chauny 1,575 .-104 Seine river at Troyes 1,314 .051 III. GERMAN STREAMS. Bober river at Sagan 1,638 39.20 17.40 .389 Drage river at its mouth 1,234 2.11 .356 Ill river at Strasburg 1,294 9.15 .327 Kuddow river at Usch 1,830 18.90 19.30 .405 Lahn river at Diez 2,008 25.60 12 80 .123 Lippe river at Wesel 1,890 11.62 .198 Main river above mouth of the Regnitz river 1,725 27.44 .224 Netze river at Antonsdorf 1,086 .063 Netze river above Eicbhorst 1,130 .046 Oder river at Hoschialkowitz 1,440 21.60 .155 Oder river at Annaberg 1,800 24.60 27.00 .219 Oder river at Olsau 2,250 24.60 43.90 .274 Obra river at Moschin 1,325 .101 Ruhu river at Mulheim 1,728 33.80 .176 Saale river at its junction with the Main 1,070 27.76 .081 Welna river at Kowanowko, near mouth . . . 1,013 3.14 .077 Relation of Rainfall to Stream Flow. 747 TABLE LXXX1IL Continued. DRAINAGE AREA, 2,500 TO 5,000 SQUARE MILES. Drainage Mean Annual Discharge Cii. Ft. STREAM AND LOCALITY. Area, Rainfall, per Sec Sq. Miles. Inches. per Sq. Mi ile. I. AMERICAN STREAMS. MAX. Mi*. Black Warrior river at Tuscaloosa, Ala. . . . 4,900 38.80 .018 Broad river at Alston, S. C r 4,609 10.26 .394 Cape Fear river at Fayetteville, W. Va 4,493 1.17 .076 Catawba river at Rock Hill, S. C 2,987 21.96 .445 Chattahoochee river at West Point, Ga. . . . 3,300 52.92 17.37 .252 Connecticut river at Dartmouth, N. H 3,287 .306 Coosa river at Rome, Ga 4,001 52.73 11.42 .225 Crow Wing river, Minnesota 3576 30.84 2.84 .250 Dan river at Clarksville, Va 3,749 38.28 8.80 .107 Hudson river at Mechanicsville, N. Y 4,500 41.61 15.50 .189 Kennebec river at Waterville, Me 4,410 25.20 .006 4,085 19.83 .310 *Merrimac river at Lawrence, Mass 4,551 20.00 .27 Mohawk river at Rexford Flats, N. Y 3,384 23.10 Mohawk river at Cohoes, N. Y. 3,444 38.65 .232 Ocanee river at Dublin, Ga 4,182 49.31 6.69 .021 Potomac river at Dam No. 5, Md 4,640 38.77 22.15 .078 Savannah river at Calhoun Falls, Ga 2,712 47.73 .96 .518 Shenandoah river at Millville, W. Va 2,995 39.56 11.44 .203 Staunton river at Clarksville, Va 3,546 38.28 10.30 .157 Susquehanna river, w. br., Williamsport.Pa. 4,500 11.60 .178 Tallapoosa river at Milstead, Ala 3,840 9.50 .091 Yadkin river at Salisbury, N. C 3,399 23.55 .225 Yadkin river at Norwood, N. C 4,614 13.70 .284 II. FRENCH STREAMS. Aisne river at Soissons 3,040 6.43 .081 Aisne river, above junction with the Oise rivei 3,285 23.50 5.95 .096 Eure rivei* at its mouth 2,980 22.30 2.72 .076 Isere river at its mouth 4,300 21.00 .780 Marne river at Chateau Thierry 3,333 .127 Meuse river at Sedan 2,560 28.33 8.05 .194 Meuse river at Fumay 3,700 28.33 4.04 .191 Seine river at Bray 3,750 4.05 .003 Seine river at Nogent-sur-Seine 3,594 .103 Yonne river at Sens 4,270 9.09 .106 Yonne river at Nogent-sur-Seine -. 4,300 30.80 6.37 .140 III. GERMAN STREAMS. Main river, below mouth of the Regnitz river 4,650 27.44 .186 3 550 29.48 14.92 .199 Mur river at Graz 2,959 12.98 .243 Neckar river at Heilbronn , 3,155 .146 Neckar river at Offenau 4,770 33.35 .167 Oder river at Ratibor 2,580 S4.60 21.20 .306 Oder river at Kosel 3 520 24.60 14.10 .128 Oder river at Krappitz 4,150 24.60 3.86 .187 Regnitz river at its juhc. with the Main river 2,920 25.60 .164 '"Figurrs supplied by Mr. Rich. A. Hale, Lawrence. Mass. 748 Miscellaneous Tables. TABLE LXXXIII.- Continued. DRAINAGE AREA, 5,000 AND OVER SQUARE MILES. Drainage Mean Annual Discnarge Cu. Ft. STREAM AND LOCALITY. Area, Rainfall, per Sec. Sq. Miles. Inches. per Sq. Mile. I. AMERICAN STREAMS. MAX. MlN. Connecticut river at Holyoke, Mass 8,660 13.26 .029 Connecticut river at Hartford, Conn 10,234 44.53 .310 Connecticut river at Hartford, Conn 10,234 44.53 20.27 .510 Coosa river at Riverside, Ala 6,850 48.08 10.53 .197 Delaware river, New Jersey 6,750 50.00 .300 Delaware river at Stockton, N. J 6,790 45.29 37.50 .170 Delaware river at Lambertsville, N. J 6,855 45.29 9.71 .364 James river at Richmond, Va 6,800 40.83 .191 Kanawha river at Charleston, W. Va 8,900 40.70 13.49 .123 Mississippi river 7,283 32.64 1.49 .261 36,085 25.75 19.73 .045 Mississippi river 164,534 .190 Mississippi river 526,500 .050 Mississippi river 1 ,214,000 .210 Missouri river 17,615 15.70 .100 New river at Fayette. W. Va 6,200 40.70 13.49 .189 Ohio river at Pittsburg, Pa 19,990 .114 Ohio river 200,000 41.50 .270 Os.wego river at Oswego, N. Y 5,013 37.69 230 Potomac river at Point of Rocks, Md 9,654 39.35 19.40 ,083 Potomac river 11,043 38.77 42.60 .170 Potomac river at Georgetown, D. C 11,124 38.77 15.70 Potomac river at Great Falls, Md 11,427 45.36 41.15 215 Potomac river at Great Falls, Md 11,476 45.36 15:25 .093 Potomac river at Chain Bridge, D. C 11,545 38.77 17.16 .165 Red river, Arkansas 97,000 39.00 2.32 Roanoke river at Neal, N. C 8,717 38.21 7.38 ,229 St. Croix river, Minnesota 5,950 32.58 6.00 ,424 Savannah river at Augusta, Ga 7,294 47.73 42.50 272 Susquehanna, w. branch, at Northumberland 6,800 17.53 ,074 Susquehanna river at Harrisburg, Pa .24,030 18.88 .092 Tennessee river at Chattanooga, Tenn 21,418 20.78 .199 II. FRENCH STREAMS. Loire river at Nevers 6,560 23.10 070 Loire river, between Maine and Vienne rivers 9,950 255 Marne river at Charenton 5,657 016 Marne river at its junction with the Seine. . . 5,295 30.70 4.67 | .080 Meuse river at Maestricht 8,240 42.50 5.51 , 146 Meuse river at Maeseyck 8,480 42.50 7.36 244 Meuse river above Ruremond 8,750 3.01 317 Oise river at Creil 5 622 3 14 194 Rhone river at Lyons 18,000 36.32 11.83 333 Seine river at Port a 1' Anglais 17,624 046 Seine river at Paris 20,000 21.27 5.80 085 Seine river at Mantes 25,135 3.09 091 Seine river at mouth of the Eure river.. . 28 583 3 09 III. GERMAN STREAMS. Elbe river at Torgau 22,000 27.09 2.89 144 Main river above mouth of Saale river 5 820 18 Main river below mouth of Saale river 6,900 166 Main river above mouth of Tauber river 7,290 167 Main river below mouth of Tauber river 8,000 167 Main river at Frankfort. . . 9,610 12.50 1^1 Memel river art Tilsit 38,600 4 02 813 Moselle river at Kochem. 10,253 8 52 174 Moselle river at Coblenz 10,840 24.76 13.04 .166 Relation of Rainfall to Stream Flow. 749 TABLE LXXXIII. -Continued. DRAINAGE AREA, 5,000 AND OVER SQUARE MILES. Drainage Mean Annual Discharge Cu. Ft STREAM AND LOCALITY Area Rainfall Per Sec. Sq. Miles. Inches. Per S*q. Mile, III. GERMAN STREAMS. MAX. MIN. Neckar river at Heidelberg 5,321 32. 17 .215 Neckar river at Mannheim 5,395 31.02 Oder river at Ohlau 7,750 24.60 4.17 .215 Oder river at Breslau, below the Ohle river. 8,330 24.60 10.40 .209 Oder river at Steinau 11,412 24.02 .95 .229 Oder river below mouth of the Warthe river 28,319 23.62 .61 .212 Saale river at Rothenburg 7,282 27.76 5.41 .120 Warthe river at Pogorzelice ... 7,900 .164 Warthe river at Posen 9,620 6.37 .100 Warthe river at Landsberg t 20, 020 21 . 65 2 . 56 .192 750 Miscellaneous Tables. TABLE LXXXIV. Mean average rainfall, run-off, and evaporation for storage, growing and re- plenishing periods for 12 streams of the United States.* Period. Muskingum River, from 1888 to 1895, eight years. Catch- ment area, 5,828 square miles. Genesee River, from 1890 to 1898. nine years. Catchment area, 1,070 square toiles. Croton River, from 1877 to 1899, twenty- three years. Catch- ment area, 338.8 square miles. Rain. Run- off. Evap- ora- tion. Rain. Run- off. Evap- ora- tion. Rain. Run- off. Evap- ora- tion. Storage 18.8 11.6 9.3 9.6 1.7 1.8 9.2 9.-9 7.5 19.4 11.5 9.4 10,5 1.7 2.0 8.9 9.8 7.4 23.7 13.6 12.1 16.8 2.6 3.4 6.9 11.0 8.7 Growing Replenishing Year 39.7 13.1 26.6 40.3 14.2 26.1 49.4 22.8 26.6 Period. Lake Cochituate, from 1863 to 1900, thirty-eight years. Catchment area, 18.9 square miles. Sttdbu 18751 six 3 men squa Rain. ry River, from o 1900, twenty - r ears. Catch- ,t area, 78.2 re miles. Mystic Lake, from 1878 to 1895, eighteen years. Catchment area, 26.9 square miles. Rain. sg- Evap- ora- tion. Run- off. Evap- ora- tion. Rain. Run- off. Evap- ora- tion. 7.3 8.6 8.2 Storage 23.1 11.6 12.4 14.9 2.1 3.3 8.2 9.5 9.1 23.6 10.7 11.9 17.9 1.7 3,0 5.6 fl.O 8.9 22.4 10.9 10.8 15.1 2.8 2.6 Growing Replenishing Year 47.1 20.3 26.8 46.1 22.6 23.5 44.1 20.0 24.1 Period. Neshaminy Creek, from!884to 1899, six- teen years. Catch- ment area, 139.3 square miles. Perkiomen Creek, from 1884 to 1899, six- teen years. Catch- in e n t area, 152 square miles. Tohickon Creek, from 1884 to 1898, fifteen years. Catchment area, 102.2 square miles. Rain. Run- off. Evap- ora- tion. Rain. Run- off. Evap- ora- tion. Rain. Run- off. Evap- ora- tion. Storage 23.1 13.4 11.1 17.2 2.7 !! 5.9 10.7 7.9 23.2 13.7 11.1 16.7 3.1 3.8 6.5 10.6 7.3 24.2 14.6 11.3 20.5 3.5 4.4 3.7 1L1 6.9 Growing Replenishing ; Year 47.6 23.1 24.5 48.0 23.6 24.4 50.1 38.4 i 21.7 Period. Hudson River, from 1888 to 1901, four- teen years. Catch- ment area, 4,500 square miles. Pequannock River, from 1891 to 1899, nine years. Catch- ment area, 33.7 square miles. Connecticut River, from 1872 to 185, eleven years. Catchment area, 10,234 square miles. Rain. Run off. Evap- ora- tion. 4.5 9.2 7.2 Rain. Run- off. Evap- ora- tion. Rain. Run- off. Evap- ora- tion. Storage 20.6 12.7 10.9 16.1 3.5 3.7 33.0 12.7 11.1 19.7 3.1 4.0 3.3 9.6 7.1 18.9 13.8 10.3 15.1 3.3 3.6 3.8 10.5 6.7 Growing Replenishing Year .... 44.2 23.3 20.9 46.8 26.8 20.0 43.0 22,0 21.0 *From W. p. and I. Pap?r No. so. Rafter. Rainfall, Run-off and Evaporation. TABLE LXXXV Croton River, 1868-1899, inclusive. L Catchment area=-338,8 square miles.] 1868. 1869. 1870. Period. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Storage 23.24 17 25 5 99 21 89 15 75 6 14 28 42 19 01 9 41 Growing 13.64 5 75 7 89 7 77 2 01 5 76 10 59 1 56 9 03 Replenishing 1 14.85 11 06 3 79 15 09 4 39 10 70 10 09 96 9 13 Year 51.78 34.06 17 67 44.75 22 15 22 60 49 10 21 53 27 57 1871. 1872. 1873. Storage 19.83 9 72 10 11 14 57 10 31 4 26 22 19 18 52 3 67 Growing. 16.04 2.61 13.43 14.33 3.01 11 32 8 65 1 54 7 11 Beplen i sh in g 11 95 5 65 6 30 10 75 4 38 6 37 12 58 3 20 9 38 Year 47 82 17 98 29 84 39 65 17 70 21 95 43 42 23 26 20 16 1874. 1875. 1876. Storage 23.74 22.86 0.88 17 10 14 81 2 29 22 64 19 89 2 75 Growing 12.30 2.77 9 53 16 45 5 86 10 59 7 14 1 07 6 07 Replenishing 8.68 1 60 7 08 10 33 3 41 6 92 10 11 1 35 8 76 Year 44.72 27.23 17 49 43 88 24 08 19 80 39 89 22 31 17 58 1877. 1878., 1879. Storage . . 17.49 12.36 5.13 20.99 14.19 6 80 25.17 20 81 4 36 Growing 13.17 .96 12.21 11.29 2 57 8 72 18 09 2 63 15 46 Replenishing 18.46 5 49 12.97 16.72 5 01 11 71 6 96 1 88 5 08 Year 49.12 18.81 30.31 49.00 21.77 27 23 50 22 25 32 24 90 1880. 1881. 1882. Storage 19.78 12.19 7.59 24.53 14 79 9 74 27 91 16 85 11 06 Growing 11.42 .68 10.74 9 61 1 95 7 66 9 03 2/06 6 97 Replenishing . . 7.57 .84 6.73 8 96 97 7 99 19 10 6 21 12 89 Year 38.77 13.71 25.06 43.10 17.71 25 39 56 04 25 12 30 92 1883. 1884. 1865. Stora go . .. . .. 19.03 11.37 7.66 24.81 16 85 7 96 21 86 15 36 6 50 -Growing. . . .. 12.10 1.09 11.01 15.72 2 34 13 38 12 89 88 12 01 Replenishing 10.41 1.28 9.13 8.01 1 87 6 14 12 23 2 92 9 31 Year 41 54 13 74 27 80 48 54 21 06 27 48 46 98 19 16 27 82 1886. 1887. 1888. Storage 25 45 18.16 7.29 23 05 16 44 6 61 30 33 21 74 8 59 Growing 11 68 1 53 10 15 24 76 6 71 18 1)4 11 25 2 63 8 62 Replenishing 9 82 1 23 8 59 7 78 2 60 5 18 18 76 8 23 10 53 Year 46 95 20.92 26 08 55 58 25 75 29 83 60 34 32 60 27.74 752 Miscellaneous Tables. TABLE LXXXV Continued. Croton River, 1868-1899, inclusive. Period. 1889. law. 1891. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run_- off. Evapo- ration. Storage - -- 22.40 17.37 18.83 16.86 6.49 8.70 5.54- 10.88 10.13 25.31 13.31 14.60 19.10 2.51 7.02 6.21 10.80 7.68 26.66 11.26 7.78 21.22 1.14 1.11 5.44 10.12 6.67 Replenishing Year r 58.60 32.05 26.55 53.22 28.63 24.59 46.70 23.47 22.23 1892. 1893. 1894. Storage 22.93 15.37 10.30 12.87 2.60 2.31 10.06 12.77 7.99 27.34 12.39 11.08 21.41 1.84 3.51 6.93 10.56 7.67 23.24 7.96 17.06 15.65 1.88 4.41 7.60 6.18 12.64 Growing Replenishing Year 48.60 17.78 30.82 50.81 26.76 24.06 48.24 21.88 26,,% 1895. 1896. 1897. Storage 19.55 11.19 9.54 14.78 1.06 1.27 4.77 10.14 8.27 23.18 24.84 12.25 11.27 18.01 2.03 3.13 6.88 10.22 8.14 20.55 20.79 8.76 14.64 6.93 2.78 6.91 13.86 6.08 25.80 Growing Replenishing Year 40.28 17.10 48.36 23.17 25. W 50.10 24.30 1898. 1899. Storage 28.81 17.17 13.36 20.08 4.83 3.99 8.73 12.34 9.37 22.66 12.19 10.37 21,38 1.67 1.96 1.2ft 10.02 8.41 Growing Replenishing Year 59.34 28.90 30.44 45.22 24.91 20.31 Mean 1868-1876, in- clusive. Mean 1877-1899, in- clusive. Storage . 21.51 11.88 11.61 16.46 2.91 4.00 5.05 8.97 ^T.61 28.68 13.68 12.08 16.83 2.57 3.42 C.85 11.01 8.66 Growing -- Replenishing Year 45.00 23.37 21.63 49.33 22.81 26.52 Rainfall, Run-off and Evaporation. 753 TABLE LXXXVI Lake Cochituate, 1863-1900, inclusive. [Catchment area=18.9 square miles, not including catchment of Dudley Pond.] 1863. 1864. 1865. Period. * Rain fall. Run off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Storage 29.49 16.31 13.18 24. 70 14.44 10.26 29. 63 17.28 12.35 Growing 21.71 5.15 16 56 5.20 1.58 3.62 7.37 1.27 6.10 R eplenishing 16 49 5 25 11 24 13.47 3.17 10.30 13.43 2.15 11.28 Year * 67 69 26 "71 40 98 43 37 19 19 24 18 50 43 20 70 29 73 1866. 1867. 1868. Storage 22.87 9.38 13.49 27.02 16.47 10.55 23.02 16.95 6.07 Growing 22.13 2.94 19.19 :20.67 3.34 17.33 12.49 8.22 9c27 Replenishing 16. 31 3.26 13.05 10.98 2.43 8.55 15.65 4.76 10.89 Year 61 31 15 58 45 73 58 67 22 44 36 43 51 16 24 93 26 23 . 1869. 1870. 1871. Storage. .. 28.91 12.83 16.08 36.50 23.72 12.78 19.77 10.19 9 58 Growing 8.65 2.39 6.26 9.18 1.91 7.27 11.72 2.15 9 57 Replenishin g 21.25 4.77 16.48 13.00 2.85 10.15 13. 85 2 38 11 47 Year 58.81 19.99 38.82 68.68 28.48 30.20 45.34 14.72 dO 62 1872. 1873. 1874. Storage 14.51 8.88 5.63 20.00 18.51 1.49 20.76 16 23 4 53 Growing 19.58 2.95 16.63 11.63 2.47 9.16 12 78 3 83 8 95 Replenishing - * 14.20 6.39 8.81 13.27 4.68 8.59 4 64 1 63 8 01 Year 48.29 17.22 31.07 44.90 25.66 19/24 38.18 21.69 16.49 1875. 1876. 1877. Storage 17.80 10.76 7.04 20.45 14.91 5.54 21.61 15.65 5 96 Growing 15.34 2 35 12.99 13.28 1.64 11.64 8.76 2.24 6 52 Replenishing 13 11 3.75 9.36 12.57 3.22 9.35 15.54 4 31 11 23 Year 46.25 16.86 29.39 46.30 19.77 26.53 45.91 22.20 23 71 1878. 1879. 1880. Storage 23.38 19.08 4.30 19.96 16.83 3.13 18.47 8.55 9 92 Growing 13.74 2.07 11.67 13.95 2.05 11.90 12.06 .62 11 44 Replenishing 12.36 3.09 9.27 5.62 1.93 3.69 6.34 1.56 4 78 Year 49.48 24.24 25.24 39.53 20.81 18.72 36.87 10.73 26.14 1881. 1882. 1883. Storage 22.23 12.74 9.49 23.10 12.39 10.71 16.62 8.31 8.31 Growing 8.74 1.56 7.18 6.50 .75 5.75 5.08 .16 4.92 Replenishing . 8.85 1.25 '7.60 12.35 2.39 9.96 8.53 1.62 6.91 Year 39 82 15 55 24 27 41 95 15 53 26 42 30 23 10 09 20 14 46 754 Miscellaneous Tables. TABLE LXXXVL Continued. Lake Cochituate, 1863-1900, inclusive. Period. 1884. 1885. 1886. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration . Rain- fall. Run- off. Evapo- ration. Storage 24.79 12.79 5.82 15.70 1.54 1.09 9.09 11.25 4.73 22.80 11.70 12.15 11.90 .76 3.09 10.90 10.94 9.06 24.14 8.26 11.12 18.97 .57 1.92 5.17 7.69 9.20 Growing Replenishing Year . 43.40 18.33 25.07 46.65 15.75 30.90 43.52 21.46 22.06 1887. 1888. 1889. Storage 26.97 10.05 6.53 19.91 2.87 1.83 7.06 7.18 4.70 24.22 10.06 20.79 15.44 1.94 9.09 8.78 8.12 11.70 21.79 16.84 14.56 17.26 6.24 6.65 4.53 10.60 7.91 Growing Replenishing T Year ,.... 43.55 24.61 18.94 55.07 .26.47 28.60 53.19 30.15 23.04 1890. 1891. 1892. Storage 23.42 7.48 17.82 17.17 2.20 6.29 6.25 5.23 11.53 27.73 11.68 9.10 28.21 1.99 2.88 -0.48 9.69 6.72 21.11 10.49 9.43 12.47 1.38 2.26 16.11 8.64 9.11 __UT 24.92 Growing Replenishing Year. . 48.67 25.66 23.01 48.51 32.58 15.93 41.03 1893. 1894. 1895. Storage * 22.84 11.01 7.58 12.40 1.90 2.51 10.44 9.11 5.07 21.00 7.79 10.94 39.73 10.25 1.24 2.04 13.63 10.76 6.65 8.90 20.18 11.79 18.66 11.29 1.45 6.17 8.89 10.34 12.49 Growing Replenishing Year . 41.43 16.81 24.62 26.20 50.63 18.91 31.72 1896. 1897. 18k Storage .. 20.91 7.69 14.74 15.96 1.55 3.70 4.95 6.14 11.04 19.87 12.34 9.92 11.05 2.57 2.58 8.82 9.77 7.34 26.61 12.71 16.76 16.15 245 4.26 10.46 10.26 12.50 Growing Replenishing Year . . . 43.34 21.21 22.13 42.13 16.20 25.93 56.08 22.86 33.22 1899. 1900. Storage. . , 22.31 8.16 10.01 18.38 .23 1.63 3.93 7.93 8.38 28.30 9.25 13.01 14.09 1.49 2.72 14.21 7.76 10.29 Growing . Replenishing.. . Year _ 40.48 20.24 20.24 50.56 18.30 32.26 Mean for 5 years, 1896-1900, inclusive. , Mean for 38 years 1863-1900, inclusive. Storage 23.60 10.03 12.89 15. 13 1.66 2.98 8.47 8.37 9.91 23.15 11.59 12.38 14.92 2.08 3.32 8.23 ' 9.51 9.05 Growing Replenishing Year 46.52 19.77 20.75 47. 13 20.32 26.81 Rainfall, Run-off and Evaporation. 755 TABLE LXXXVII Neshaminy Creek, 1884-1899, inclusive. [Catchment area=139.3 square miles.] 1884 1885. 1886. Period. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run-v, off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Storage . 25 77 25 61 16 20 13 17 85 2 28 26 61 21 45 5 16 Growing 13.71 1.85 11.86 10.25 1.08 9.17 12.67 1.87 10.80 Replenishing 7.05 .45 6.60 11.22 1.73 9.49 7.60 .66 6.94 Year 46.53 27.91 18.62 41.60 20.66 20.94 46.88 23.98 22.90 1887. 1888. 1889. Storage 21.88 15.92 5.96 26.48 21.17 5.31 22.32 13.44 8.88 Growing 19.26 4.44 14.82 11.83 1.01 10.82 22.42 10.00 12.42 Replenishing 7.59 1.03 6.58 14.18 6.02 8.16 22.18 12.37 9.81 Year 48 73 21 39 27 34 52 49 28 20 24 29 66 92 35 8l 31 11 . 1890. 1891. 1892. Storage 22.06 14.85 7.21 23.48 17.74 5.74 22.55 15.01 7.54 Growing. 14.28 2.15 12.13 15.90 2. 53 13.37 11.58 1.31 10.27 Replenishing . . . 10.23 3.33 6.93 8.08 2. ay 5.70 10.13 1.94 8.19 Year . 46.57 20.33 26.24 47.46 22.65 24.81 44.26 18.86 26.00 1893. 1894. 1885. Storage 22 16 18 52 3 64 26 68 18 16 8 52 20 97 15 84 5' 13 Growing 12.21 1.70 10.51 8.95 1.82 7.13 11.41 2.07 9.34 Replenishing 11.07 3.74 7.33 16.45 6.12 10.33 6.21 .24 5.97 Year 45.44 23.98 21.48 52.06 26.10 25.98 38.59 18.15 20.44 1896. 1897. Storage 20.52 11.54 8.98 19.28 10.60 8.68 Growing 10.80 1.65 9.15 17.70 6.50 11.20 Replenishing 12 65 3 41 9 24 9 06 3 11 6 95 Year 43.97 16.60 27.37 46.04 19.21 26 83 1898. 1899. Storage 25.68 16.87 8.81 33.09 20.60 2 59 Growing 12.34 1.69 10.65 9.41 1.76 7.66 Replenishing 12.80 3.33 9.47 10.91 1 96 895 Year 50. 82 21.89 28.93 43.41 24.22 19.19 756 Miscellaneous Tables. TABLE LXXXVIII Perkiomen Creek, 1884-1899, inclusive. [Catchment area=152 square miles.] 1884. 1885. 1886. Period. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration. Storage 25.25 25.19 0.06 20.47 15.29 5.18 26.03 19.74 6.29 Growing 15.53 4.07 11.46 9.83 1.68 8.15 11.76 3.35 8.41 Replenish! ng 7.54 1.59 5.95 9.49 2.3& 7.11 9.00 2.02 6.98 Year 48.32 30.85 17.47 39.79 19.35 20.44 46.79 25.11 21.68 1887. 1888. 1889. Storage 21.63 14.66 6.97 27.48 19.67 7.81 22.99 14.28 8,71 Growing 17.28 4.26 13.00 12.42 2.17 10.25 23.38 10.02 13.36 Replenishing 6.70 1.45 5.25 14.18 7.40 6.78 20.45 11.81 8.64 Year 45.59 20.37 25.22 54.08 29,24 24.84 66*82 36.11 30.71 1890. 1891. 1892. Storage .. 24.68 18.15 6.53 22.89 17.35 5.54 23.64 15.89 7.75 Growing 14 35 3 11 11 24 18 32 &25 15 07 11 06 2 3a 8 68 Replenishing 10 31 4 52 5 79 8 15 2 69 5 46 9 33 2 66 6 67 Year 49.34 25.78 23.56 49.36 23.29 26.07 44.03 20.93 23.10 1893. 1894. 1896. Storage 22 16 17 21 4 95 24 37 15 77 8 60 23 22 15 51 7 71 Growing 12 20 1 82 10 38 8 77 2 05 6 72 10 88 1 32 9 56 Replenishing 10 18 3 33 6 85 15 40 5 18 10 22 6 25 75 5 50 Year 44 54 22 36 22 18 48 54 23 00 25 54 40 35 17 58 22 77 1896. 1897. Storage 19 99 10 26 9 73 20 00 12 37 7 63 Growing 15 05 2 83 12 22 13 69 3 08 10 61 Replenishing . 14 62 4 19 10 43 10 07 2 26 7 81 Year 49 66 17 28 32 38 43 76 17 71 26 05 1898. 1899. Storage 24 24 15 74 8 50 22 79 20 49 2 30 Growing 9 98 1 39 8 59 14 12 2 46 11 66 Replenishing ,. 13.85 3 90 9 95 11 36 4 01 7 35 Year , 48 07 21 03 27 04 48 27 26 96 21 31 Rainfall, Run-off and Evaporation. 757 TABLE LXXXIX Tohickon Creek, 18S4-1898, inclusive. [Catchment area=102.2 square miles.] 1884. 1885. 1886. Period. Rain- fall. Run- off. Evapo- ration. Rain- fall. Run- off. Evapo- ration Rain- fall.' Run- off. Evapo- ration. Storage 26.06 27.27 -1.21 21.86 19.45 2.41 28.54 27.79 0.75 Growing 17.52 6.53 10.99 11.31 1.54 0.7? 11.10 2.27 8.83 Replenishing 7.97 1.35 6.62 10 2.94 7.06 9.05 2.04 7.01 Year 51 55 35 15 16.40 43 17 23 93 19 24 48 69 32 10 16 59 1887. 1888. 1889. Storage . . . , > 21.60 18.44 3.16 28.52 27. i7 1.15 25.13 17.82 7.31 Growing 19."19 4.80 14.39 12.96 1.99 10.97 23.90 12.45 11.45 Replenishing 6.71 .91 5.80 16.04 10.14 5.90 21.34 18.70 7.64 Year 47,50 24.15 23.35 57.52 39.50 18.02 70.37 43 97 26.40 1890. 1891. 1892. Storage 25.09 19.01 6.08 23.07 20.23 2.84 23 43 19 76 3 67 Growing 15.49 2.54 12.95 19.77 4.99 14.78 11 22 1 52 9 70 Replenishing 10.20 5.45 4.75 7.16 2.03 5.13 10 65 3 47 7 18 Year 50.78 27 23.78 50 27.25 22.75 45.30 24.75 20.55 1893. 1894. 1895. Storage ... 22.82 22.05 0,77 27.04 21.65 5.39 21.35 19.91 1 44 Growing 14.82 2.10 12.72 6.95 .84 6.11 12.45 1.46 10 99 Replenishing 11.81 4.06 7.25 17.63 8.11 9.52 6.63 .28 6 35 Year 48.95 28.21 20.74 51.62 30.60 21.02 40.43 21.65 18.78 1896. 1897. 1898. Storage 21.69 12.30 9.39 20.82 13.93 6.89 26.40 21 30 5 20 Growing 13.76 2.91 10.85 17.32 5.12 12.20 10.87 1 9 87 Replenishing . ^ 12.58 4.52 8.06 8.78 1.98 6.80 13.80 5.19 8 61 Year 48 03 19 73 28 30 46 92 21 03 25 89 51 07 27 39 23 68 \ INDEX PAGE Abbe, evaporation relations 141 Acceleration, and retardation of water in penstock 690 curve of 689 effect of, on water supplied to wheel 455 of gravity 06 Action, turbines (see Impulse Turbines) 244 Adam's, A. L., Values of coeffi- cients for wood stave pipe .... 60 Air chamber 461 Air, energy in 22 Allis Chalmers Co., Sewalls Falls turbines 512 turbine governor 735 Turner's Falls power plant.. 514 Altitude, effect of on rainfall ... 124 American turbines. 11, 13, 249, 256, 266 buckets of 275 Fourneyron 250 Francis 2 48 impulse 275 Jonval 252 practice of various manufac- turers in measuring the di- ameter of 28G reaction, type, efficiency of. . 247 catalogue relations of diam- eter and speed of 326 relations of diameter and discharge of 339 relation of power and diam- eter of 342 relation of speed and dis- charge in 346 ! American Turbines Con. PAGE relation of speed and power in 350 specific speed of 350 Ampere 33 Aprons for dams, preliminary study of, for dam at Kilbourn. . 585 Archibald, E. M., discussion of effect of load factor on cost of power 622 Atkins' wheel and case 273 Atlantic drainage, hydrographs. . 190 Auxiliary power, cost of 65S effects of 631 hydrograph showing amount of, necessary to maintain power at Sterling, 111 635 necessary to maintain fixed power on a southern river 633 study of, for report on water power 680 B. Back water curve 58 literature on 78 study of, for report on water power 678 Barker's mill 5, 239 Bazin's formula 50, 69 diagram for solution of. ... 51 Bearings, Geylin glass suspension 290 horizontal lignum vitae 295 hydraulic balancing piston of Niagara Falls Power Co. 293, 294 of horizontal turbines 292 760 Index. Bearings Con. PAGE vertical cross or hanging bearings of Niagara Falls Power Co 293 vertical turbine 289 Belt losses 30 Bends in a stream, effect of on distribution of velocity 212 Betiva Dam, India, automatic drop shutter for 610 Bmn and 329 Electric lighting load curve 424 Electric lighting, losses in hy- draulic plant for 25 Electric units 32 Emerson, James, testing of turbines by 361 tests by 364 Energy 23 conservation, laws of 21 definition of 19 differentiation of 20 equivalent units of 740 exertion of by, momentum 41 weight ; 41 pressure 41 in the air. . 22 Energy Con. PAGE literature of 39 losses in an hydraulic plant 25 losses in a pumping plant.. 25 losses in steam power plant. 24 mathematical expression of 40 no waste of in nature 20 of fuel 19 potential and kinetic 3'J potential 20 thermal 20 required to change penstock velocity 446, 456 transmission and transforma- tion of 23 units, conversion of 33 units of 32 Enlargements, sudden 42 Entrance head 42 Equivalent measures and weights of water 740 Equivalents of energy 740 Escher, Wyss and Company:.... 280 double turbines at Chivres near Geneva 282 Jonval turbine at Geneva Water Works 281 Estimate of cost, for report on water power 682 European practice in, turbine construction 280 water wheel design 278 European type of turbine 249 European vertical turbine, steps of 290 Evaporation, 137 and temperature on Lake Cochituate, relations of. . 150 annual in the United States 138-139 from water surface in inches, Chestnut Hill reservoir... 143 literature on 144 monthly from free water sur- faces, Augusta, Ga., Cincinnati, Ohio, Des Moines, Iowa, Detroit, Mich., Helena, Mont., Little Rock, Ark., Index. 765 Evaporation Con. PAGE monthly from free water sur- facesCon. Montgomery, Ala., New Haven, Conn., Olympia, Wash., Palestine, Texas, Sacramento, Cal., Spo- kane, Wash., Topeka, Kans., Winnemucca, Nev., Yuma, Ariz., and at vari- ious points in the U. S.. . 140 of water 20 precipitation, run-off and temperature, relations of on upper Hudson, River... 154 rainfall and run-off for vari- ous periods 750 relation to precipitation, run- off and temperature, on Lake Cochituate 149 tables ... .732 F. Factory friction tests, data an^d results of 655 Factory load curves 424, 42S Faesch and Picard 252 Failures of Dams, literature on. . 601 Fairbairn 3 Fairmont pumping station 252 Falling stream, effects of on gra- dient 201 Fanning, J. T 15 Financial considerations of water power development 646 Fishways : 614 in dam at Danville, Illinois,.. 618 in timber dam at Sterling, 111 619 of Fish Commission State of Wisconsin 619 literature on 632 Fitzgerald, Desmond. On evap- oration 137 Fitz Water Wheel Company. overshot water wheels of 243 Five-halves powers of numbers.. 744 Flash boards, 100, 609 Flash Boards Con. PAGE adjustable at Eau Claire, Wis 611 and supports, Rockford Wa- ter Power Company 609 literature on 622 Float Measurements 226 at Lowell by Francis 229 Float Wheels, 1-3 London water works 1 Flood discharge, American and European rivers 168 of rivers, relation to rainfall 745 Flood Flow, study of for report on water power 678 Flood flows, data on 583 Flood gates 606 Flood over Holyoke dam 592 Flow, comparative mean monthly of Wisconsin and Rock Rivers 178 distribution of velocity dur- ing various conditions of. . 212 effects of low water 107 estimates of, from cross sections and slope 219 by weirs 219 in open channels, methods for the estimate of 219 in open; channels, literature of 198 in reaction wheels 317-320 in tangential wheels 316 measurements of by the de- termination of velocity . . . 221 mean monthly of various Eastern streams, in chron- ological order 172 mean monthly of various streams, arranged in order of magnitude 173 of water in pipes 59 of water through orifices. ... 64 over weirs 64 power of a stream as affected by 79 relations of guage height to 208 766 Index. PAGE Flow and head, relations of 83 Fly-ball governor, first used . . 3 Fly wheel 457 Foot pound 32 Foot, cubic foot per minute, equivalents of 36 Foot, cubic foot per second, equivalents of 35 Foot gallon, equivalents of 34 Foot pound, equivalents of. ... 34 Foot pounds per minute, equiva- lents of 35 Forests, effect on, evaporation .... 136 Foster, H. A., tests of steam power plant 660 Foundations of dams... 581 Fourneyron turbine, 11, 239, 250, 305 characteristic curve of 409 data of 706 diagram of double turbine of the Niagara Falls Water Power Company 253 efficiency of 247 Fox River, hydrograph at Rapid Croche 628 Francis, J. B 11, 378 float measurements at Low- ell 229 formula for dam on the Mer- rimac River 69 inward flow wheel 256 tests by 359 turbine at Boott Mills, test data of 703 turbine, original 12 Fraser River, high water dis- charge at Mission Bridge 170 Friction loss 44 in asphalt coated pipe 02 in lap-riveted pipe 63 in wood stave pipe 63 Friction in pipes, conduits and channels, first principles 44 Friction loads in factories 655 Friction of reaction wheels, losses by ' 315 Frizell's formula for sharp cres- ted weirs PAGE Fuel, energy of 19 Furnace efficiency 22 G. Ganguillet and Kutter's formula 47 Garratt, A. C., discussion of connec- tion of governors to gates.... 493 Gas plant, estimate of capital cost and annual cost 665 Gate hoists and head gates. . 611, 617 Gate movement, permissible rate of 451 Gate opening, discharge of a tur- bine at various 332 Gates and guides of Girard Im- pulse turbine 306 Gates, cylinder 300 details and operating devices of Snoqualmie Falls tur- bine 303 flood 606 for overshot and breast wheels 3 register 301 wicket 300-301 Guage heights, and heads available at Kil- bourn, Wis 99 fluctuations in 200 relations at various stations on the Wisconsin river. . . . 206 relation of to flow 208 Gears and shafting, losses in. ... 2i) Generators and motors, ordinary efficiency of 31 Generation and transmission of energy, power losses in 27 Generation of power from poten- tial source 26 Genesee River, run-off diagram.. 155 Geneva, Switzerland, 280 water works, Jonval turbine at 281 Geological conditions, effects on run-off 177 study of for report on water power . . 677 Index. 767 PAGE Geylin Glass suspension bearing 290 Geylin-Jonval turbine 249, 254, 290, 299 of Niagara Falls Paper Mill Company 256 Girard turbines, current 239 Gates and guides of 306 general view of 280 impulse 278 longitudinal section of.. 279 runners of 284 with draft tube 278 runner of 280 Girard type for partial tur- bine 273 type of water wheels 269, 276, 307 Glocker-White turbine governor 735 Governing, impulse wheels with deflect- ing nozzles 470 regulation with variable speed and resistance 441 water wheels, present status of 443 Governor, Allis Chalmers hydraulic 735 anti-racing mechanical 473 calculations, nomenclature for 447 connections, by cable 477, 495 by draw rods 492 by shaft and sectors. . . . 494 control from switchboard. . . . 492 details and application of Woodward 477 diagram of Lombard-Replogle mechanical 479 effect of sensitiveness and rapidity of 457 essential features of an hy- draulic 481 for water wheels first used 3 general consideration of.... 491 Glocker-White . . 735 Governor Con. PAGE Lombard-Replogle mechan- ical 478 Lombard type "N" hydraulic 480 operating results with Lom- bard 485 problem of water wheel 445 section and plans of Wood- ward 476 section of Woodward vertical compensating mechanical 475 simple mechanical 472 Sturgess hydraulic 486 the ideal 443 Woodward compensating. . . . 474 Woodward standard 471 specifications 467 Grade, effect of change in 205 Gradient, effect of channel con- ditions on 203 effects of rising or falling stream on 201 Granid River, at Lansing Mich- igan 165 Graphical, analysis of relation of power, head and flow at Kilbourn, Wisconsin 105 determination of stream flow from measurements 230 investigation of the rela- tions of power to head and and flow 103 relation of energy and veloc- ity in reaction turbines... 321 representation of head 97 representation of the laws of motion 38 study of head 104 study of power at Kilbourn 104 Gravity wheels 237, 233 Great Lakes, hydrograph of dis- charge of the 180 Growing period 157 Guides and buckets of Tremont turbine 251 Gulf drainage, hydrographs of.. 190, 192 768 Index. H. PAGE Hand of water wheels 289 Hanging bearing, the Niagara Falls Power Company 293 Harness and driving sheaves, Southwestern Missouri Light Co 533 Harper, John L., tests of Leffel turbines at Niagara 380 Harrington, N. W., effect of for- ests on rainfall and evapora- tion 133 Hartford Electric Light Co., increase in sale of energy of 423 load curve of 422 Head, at Kilbourn dam 581 showing changes in.... 99 under various conditions 97 effect of design of dam on available 100 entrance 42 friction 44 graphical representation of . . 97 graphical study of 104 measurements of 373 on turbines, relation to speed and diameter 324 study of for report on water power 67S variations in 93 velocity 41 velocity in feet per second due to 741 Head and flow, importance of for power pur- poses 79 relations of 83 variations of 83 Head and power, effect of number of wheels on 108 selection of turbine for uni- form 38? Head gates, at Constantine, Michigan 612, 613 details of for Mr. Wait Tal- cott, Rockford, Illinois.. . 616 Head Gates Con. PAGE rear view of, at Constantine, Michigan 613 Head race, plants with 570 Head water curve 96 Heat, solar, 20 units of, 32 Heights of dams, limit of 580 Henry, Professor, conclusions on the reliability of rainfall rec- ords 125 Henschel turbine 233 Hercules turbine, test of a 54 inch 710 High head developments 575 High head or type "B" runner.. 268 High water, Fraser River at Mis- sion, Bridge, B. C 170 History of water power develop- ment 1, 14, 16 Hoist for tainter gates 606 Holyoke Machine Company, test of a 54 inch turbine 710 Holyoke testing flume, 364, 370 arranged for horizontal tur- bines 367 plan of 366 Holyoke Water Power Company, canals of 568 view of dam during flood. . . . 591 view of masonry dam of.... 590 Horse power, 32 and efficiency of proposed tur- bines for McCall Ferry Power Company 418 equivalents of 34 speed relation of from tests 415 Horse power hour 33 Houck Falls power station, test of Victor high pressure turbine at 382 Howd-Francis turbine 249 Howd, Sanruel B 11 wheel of 256 Hudson River, discharge arranged in chrono- ical order 172 arranged in order of magnitude 174 Index. 769 Hudson River Con. PAGE run-off diagram of 155 table showing relation of rainfall to runoff for the storage, growing and re- plenishing period 158 Hudson River Power Transmis- sion Company, speed records from plant of 48G Spier's Falls plant of 546 Hug bucket 274 Hunking, A. W., notes on water power equipment 338 Hunting or racing of water wheels 447 Hunt-McCormick runner 267 Hunt runner of The Rodney Hunt Machine Company 269 Hurdy-Gurdy wheel 241 Hydraulics, general literature on 75 Hydraulic governor, Allis Chalmers 735 details of Lombard 481 essential features of 481 Glocker-White 735 Sturgess type "N" 488 Sturgess, the 486 Hydraulic gradient, effects of channel grade and obstructions on 204 effects of variable flow on... 200 of a stream, after construction of dam 94 effects of variable flow on 202 under various conditions of flow 93 Hydraulic plant, energy losses in 25 Hydraulics, 40 of the turbine... 309 Hydraulic type of relay 471 Hydro-electric plant, efficiency of 24 losses in 26 Hydrographs, 80 as power curves 89 available at some other point on the river 82 available on other rivers 83 47 Hydrographs Con. PAGE comparative from different hydrological divisions of the U. S 184, 189 continuous 24 hour theoreti- cal power at Kilbourn .... 88 for full range of conditions of rainfall and temperature 82 when none are available 85 of, Alcovy River 191 Atlantic and Eastern Gulf Drainage 190 Ausable River 186 Bear River, Utah 193 Chittenango River 191 Clear Creek 192 Coosa River 190 Discharge of Great Lakes 180 Fox River 628 Grand River at Grand Rapids... 186, 191 at North Lansing.. 186 Hood River 193 Iron River, Michigan... 191 Kalamazoo River 186 Kalawa River 193 Kennebec River 19$ Kern River 193 Licking River 190 Meramec River 192 Mississippi Valley and Gulf Drainage 191 Niobrara River 192 Ohio Valley and St. Law- rence Drainage 191 Otter Creek 192 Passaic River 1^82-183 Perkiomen Creek 190 Rio Grande River 192 Salt River 192 San Gabriel River 193 Seneca River 190 Spokane River 193 St. Joseph River 186 Tennessee River 191 Thunder Bay River 186 Walker River, California 193 770 Index. Hydrographs Con. PAGE Western drainage 193 Wisconsin River, at Kilbourn, based on measurements at Necedah 86 at Necedah, Wis. 81,192 Yadkin River 190 Yellowstone River 192 power hydrographs at, Kilbourn 90-91 Sterling, Illinois 623 reliability of comparative. .. 87 showing continuous power at Kilbourn, with actual head 101 showing power of plant as influenced by variable head 110 study of a stream from 181 use of comparative 83 use of local 83 when none are available 87 when available 82 Hydrological divisions of the U. S., comparative hydro- graphs from 189 I. Ice conditions, maximum velocities in a ver- tical plane 217 rating curve for... 217 with overshot and breast wheels 3 Ice covering, effects of, on distri- bution of velocity 215 Illinois River basin, comparison of mean monthly rainfall and run-off 147 Improved New American tur- bine 257, 259, 300 calculations from character- istic curves of 407 characteristic curve of 406 sectional plan of 262 Impulse and reaction turbines.. 311 relative advantage of 245 conditions of operations of. . 215 PAGE Impulse turbines (see also Tan- gential Wheels) 237,241,244,246,301,313 angle of discharge 310 early development of 261) efficiency of 247 governing of 470 regulation of 452 J. James Leffel and Company 266 characteristic curve of a 45 inch Samson wheel... 410-411 curve showing efficiency, power and discharge, un- der various heads, calcu- lated from characteristic curves 412 double horizontal turbine. . . . 517 double horizontal turbine manufactured by 265 double runner of 26'i four pairs of 45 inch Samson horizontal turbines 523 tests of wheel at Niagara. . . . 380 Janesville, Wisconsin : dam during high water 583 dam during moderate flow.. 583 dam showing low water 582 Joliet plant of Economy Light and Power Company 571 Joliet, water power at 22 Jolly, J. & W., Holyoke, Mass.,.. 248 test of a 57 inch turbine. . . . 70S test of a 51 inch turbine 711 Jonval, 8 turbine, 239-255 efficiency of 247 at the Geneva Water Works 281 tests of a 30 inch 725 tests of a 30 inch special 724 the American . . 252 K. Kennebec River discharge, arranged in order of magni- tude 17.! chronologically arranged... 172 Index. 771 Kilbourn dam, diagram showing changes in head at 99 head under various condi- tions of flow 97 Kilbourn, Wisconsin: guage heights and head available at 99 graphical study of power at 104 head gate hoists at 617 hydrograph showing continu- ous power with actual head 101 hydrograph showing 24 hour horse power 88 hydrograph of Wisconsin River based on flow at Ne- cedah, Wis 86 plant of Southern Wisconsin Power Company 521, 569 power hydrograph 90 power hydrograph, H. P. hours with pondage 10, 19 power of the wheels under variations in flow 106 rainfall above 129 Kilowatt hour 33 Kinetic energy 33, 34, 36 Knight bucket 274 Koechlin 8 Kuichling, Emil: discussion of rainfall and run-off 162 graphical relations of dis charge area for maximum flood, American and Euro- pean rivers 168 Kutter's coefficient "n" 47 Kutter's formula 47 diagrams for the solution of 48-49 L. Lake Cochituate, rainfall, run-off and evaporation 763 Lake Superior Power Company, pJant of 570 Lap-riveied pipe, friction losses 63 Laws: of energy conservation... 21 of motion, graphical repre- sentation of . . 38 Laws Con. PAGE of motion, Newton's 36 Laxy overshot water wheels (see frontispiece) 14 Leffel and Company, the James (See also James Leffel & Co) 13 tests of a 56 inch turbine... 709 test of a 45 inch Samson tur- bine 713 Leffel turbine, 249 diagram of efficiency, dis- charge and power at Niagara 380 tests of, at Logan, Utah 379 Lighting, losses in generation and transmission of power for.... 30 Limit turbines. 244 Lippincott, J. B. and S. G. Ben- nett, relations of rainfall to run-off in California 177 Literature: back water and interference 78 causes of rainfall 131 concerning dams 595 descriptive of hydraulic and hydro-ejectric plants 556 disposal of rainfall 144 effect of altitude on rainfall 132 evaporation 144 floods 190 flow of water over weirs. ... 77 flow of water through pipes 76 general hydraulic. 75 measurement of rainfall 132 power and energy 39 percolation 144- relations of rainfall and stream flow 195 results of stream flow meas- urements 194 stream gauging 233 turbines 353 turbine testing 383 water power development . . 16 Lloyd, E. W., data concerning the power load on various central stations, due to various classes of consumers . 667 772 Index. PAGE Load conditions for maximum re- turns 431 Load curve 420 factory 424 for sharp thunder storm peak 426 in relation to machine selec- tion 433 New York Edison Company, for day of maximum load. . 425 of Hartford Electric Light Company 422 of light and power plant 421 literature on 439 maximum days of pumping, London Hydraulic Co 429 Pennsylvania railroad shops 427 relation of power, supply and demand, diagrams of 435 relation of, to stream flow and auxiliary power 434 study of, for report on water power 679 typical factory 42S typical railway 430 Load factor, definition of 433 effect of on cost of power, Ar- chibald 662 effect of on cost of steam- generated electric power to the consumer 669 influence of on operating ex- penses 662 literature on 439 Logan, Utah, tests of Leffel tur- bines at 370 Log way 621 at Lower Dam, Minneapolis, Minn 62 1 in the Chesuncook timber dam 620 Lombard governor, operating results with 485 details of 481 type "R" 484 type "N" 480 Lombard hydraulic relief valves 496 Lombard relay valve. . . 483 PACK Lombard-Replogle mechanical governor 478, 479 London Hydraulic Supply Com- pany, maximum days of pump- ing 429 London water wheels, float wheels 1 London Water Works, undershot wheel used in 14 Losses, in an hydro-electric plant. ... 26 in belts 30 in\ machinery 23 in turbines 27,371 Low heads, vertical shaft tur- bine for 509 Low water flow, effects of 107 Machine factor, definition of.... 433 Machine, ideally perfect 23 Machine selection, load curve in relation, to 433 Machinery, losses in 23 Madison, Wisconsin, diagram of fluctuations of monthly rain- fall at 122 Manchester, England, sharp thun- der storm peak 426 Maps of, average annual rainfall in the United States 112-113 average annual rainfall in Wisconsin 115 rainfall conditions in the United States, July 16-17 118 weekly distribution of rain- fall in Wisconsin 117 Manufacturing purposes, losses in utilization of energy for 30 Market price of water power.... 663 Masonry dams, literature on 597 stability of 586 Mass 36 Mass diagram showing run-off from Tochickon Creek 639 Mathon, DeCour 5 McCall's Ferry dam, section of . . . 592 McCormick, John B 13,266 Index. 773 PAGE McCormick turbine, 267, 269 test of a 57 inch 708 test of a 51 inch 711 test of a 39 inch 717 Mechanical governor, anti-racing, Woodward 473 Lombard-Replogle 478 simple, Woodward 472 Mechanical type of relay 471 Merrill, Wisconsin, rainfall above 129 Merrimac River discharge, arranged in chronological order 172 arranged in order of magni- tude 174 Meter, the wheel as a 365 Michigan drainage area 185 Michigan rivers, comparative hydrographs of various 186 discharge in cubic feet per second per square mile of drainage area 18<8 Mississippi Valley Drainage, hy- drographs of 192 Missouri River, variations in the cross-section of, near Omaha, Neb 210 Momentum, exertion of, energy by 41 Moore bucket 274 Morin, tests in 1838 359 Morris Company, I. P 252, 268 diagram of double Fourney- ron turbine 253 estimate for turbine for Mc- Call-Ferry Power Co 412 graphical diagram of rela- tions of power and head. . . 413 graphical diagram of test of wheel of The Shawinigan Power Company 382 Shawinigan Falls turbine... 270 Trenton Falls plant of The Utica Gas and Electric Co. 511 Morris, Elwood, 9 first systematic tests of tur- bines in U. S.. . . 359 PAGE Morris plant of Economy Light and Power Co 572 Motion, compound 37 laws of 36 uniform 37 uniformly varied 37 Motor installation, capital cost and annual charge on ..... 657 ordinary efficiency of 31 Movable crest for dam at Kil- bourn, Wisconsin 608 Movable dams 100, 603 at McMechan, W. Va 603 literature on 622 Mullin's formula (used by East India engineers) 69 Murphy, E. C., methods of current meter computation 227 Muskingum River, run-off dia- gram of 156 table showing relations of rainfall to run-off for vari- ious periods 156 Necedah, Wisconsin, hydrograph of the Wiscon- sin River at 96 rainfall above 129 rating curve of Wisconsin River at 96 Needle nozzle, Doble, cross section of 306 Neshaminy Creek, 167 rainfall, run-off and evapora- tion 754 Nevada Mining and Milling Com- pany, plant of 555 New American turbine 257 test of a 44 inch 714 runner of 260 Newell, F. H., estimates of rela- tion of rainfall to run,'-off 174 Newton's laws of motion 36, 38 Niagara Falls, estimate of the cost of hydro- electric plant at 643 774 Index. Niagara Falls Con. PAGE first power at 15 power development 576 water power at 22 Niagara Falls Hydraulic Power and Manufacturing Company 255, 266 Niagara Falls Paper Company. . . 254 Niagara Falls Power Company, the vertical bearing used by 291 double horizontal Leffel tur- bine of the 265 tests of wheels of 380 Niagara River, hydrograph of dis- charge of 179 Niagara Falls Water Power Com- pany 252 Niagara Fourneyron turbine 290 Nomenclature for, governor .calculations 447 turbine discussion 310 Nora, Chinese 1 Northern Hydro-Electric Power Company, hoists for tainter gates for 606 Northern rivers, monthly rainfall and run-off 165 Nunn, P. N., turbine tests at Lo- gan, Utah 379 O. Oberchain, Matthew and John.. 267 Obstructions, effect of change in 205 effects on channel grade, and on the hydraulic gradient 204 Ogden pipe line, experiments on 60 Ohio Valley drainage, hydro- graphs of 191 Oliver Power Plant, wheel har- ness of 530 Ontario Hydro-Electric Power Commission, estimates by 648, 649, 654, 656, 657, 664 Open channels, flow in, literature of 198 Open penstocks, application of method to 465 predetermination of speed Open Penstocks Con. PAGE regulation for wheels set in 461 Operation, economy in 527 Operating expenses, effect of load factor on...,. 662 estimate of for various pro- posed Canadian plants.... 654 ratio of individual items to total 660 Orifices, flow of water through 01 submerged 43 Oscillatory waves in long pen- stock 451 Outward radial flow turbines... 244 Overload 526 Overshot water wheels 3, 243 Laxy 14 P. Pacific Coast, development of wheels on 275 Paddle wheels 241 Paris water works, undershot wheel used in 14 Partial load, effect of on cost of power 651 Partial turbines 244 Passaic River, hydrographs of 182-18S rainfall on drainage area of 182-18a relations of rainfall to ruii'- off 182-183 rim-off diagrams of 155 Pel ton, bucket 274 tangential water wheel run- ner 27d Water Wheel Company 275-276 wheel 276, 307 Penstock velocity, change of 453 energy required to change 446-456 Percolation, literature on 144 Periods, growing 15? Index. 775 Periods Con. PAGE replenishing 157 storage 157 Pcrkiomen Creek,,. 167 rainfall, run-off and evapora- tion 75G Peshtigo River development, pro- file of 574 Philadelphia, water wheel tests in 1860 at 360 Pile foundations for dams.. 603, 608 Piobert and Tardy 8 Pipe> Chezy's formula 60 Darcy's formula 60 flow of water in 59 literature on flow of water in 76 losses in asphalt coated 62 Plant capacity 525 Plant design, study of for report on water power 681 Plant of, Columbus Power Company.. 546 Hudson River Transmission Company at Spier's Falls 546 Nevada Mining and Milling Company 555 South Bend Electric Company 546 Sterling Gas and Electric Company 537 The Concord Electric Com- pany 553 The Dolgeville Electric Light and Power Company 548 The Lake Superior Power Company 570 The Niagara Falls Paper Company 257 The Shawinigan Water and Power Company 550 Winnipeg Electric Railway Company 553 York Haven Water Power Company 537 Plants, Located in dams 574 with concentrated fall 564 with divided fall 564 with head race only.. . 570 PAGE Platt Iron Works Company . . .267, 268, 276, 295, 300, 301, 308 characteristic curves of a Vic- tor turbine 402-403 graphical diagram of test of 25 inch Victor high pres- sure turbine 382 relations of efficiency to dis- charge at various revolu- tions 405 the Snoqualmie Falls reac- tion turbine 272-273 test data of 48 inch turbine 704 test of a 42 inch turbine 715 test of a 45 inch turbine 712 tests of a 36 inch turbine 720 tests of a 33 inch turbine 723 Poncelet's wheel 4, 241 Pondage, effect of limited, on the power curve 624 effect of on power 624 hydrograph on Fox River showing effect of Sunday shutdown of hydraulic plants 628 hydrograph showing effect of 626 study of for report on water power 679 Pondage and storage, analytical method for calcu- lating 644 Potential energy, 20, 33 development of 19 generation of power from. ... 26 Potomac River, discharge arranged in chronr ological order 172 discharge arranged in order magnitude 174 discharge, velocity and area curve of 232 Power, actual conditions under which same is furnished to consumers from central stations . 668 776 Index. Power Con. PAGE at Kilbourn, graphical study of .104 charges for by Cataract Power and Conduit Co. of Buffalo 670 conversion of 26 development of at Niagara Falls 576 study of for report on water power 680 effect of on pondage 624 from municipal sub-station, estimated cost of 656 literature on 672 measurment of 375 of the Kilbourn wheels un- der variations in; flow 106 of plant as influenced by var- iable head, hydrograph showing 110 of plant, effect of head on . . 100 of steam 33 of stream as affected by flow 79 of turbine, 325 expression for 336 of homogeneous design . . 341 proportional to hi 8v>5 of water 33 relation of to head in a 12 inch Smith-McCormick tur- bine 33G sale of 666 transmission of 26 utilization of 26 Power and diameter, graphical relations of in tur- bines of homogeneous de- sign 341 of various American turbines 342 Power and energy, literature on.. 39 Power and speed of turbines, relations of 347 various American 350 Power curve, effects of limited pondage 624 hydrograph as a 89 Power, head, and flow, relation of at Three Rivers, Michigan 103 PACK Power hydrograph at Kilbourn 91 Power hydrograph at Sterling, Illinois C25 Power losses in generation and transmission of energy 27 Power plant at Turner's Falls. . . . 514 Power station, and dam, relation of 561 study of site of for report on water power 681 Power transmission, estimate of investment, an- nual charges and costs. . . . 656 literature on 673 Precipitation, in United States, types of monthly distribution 123 relation of evaporation, run- off and temperature to, on Lake Cochituate 140 run-off, evaporation and tem- perature, relations on Siid- bury River basin 151 run-off, evaporation and tem- perature, relations of on Upper Hudson River 154 variations at stations closely adjoining 125 Pressure, exertion of energy by. . 41 Pressure or reaction turbines. . . . 244 Price's electric current meter. . . . 222 Prime movers, possibilities of. ... 528 Prony brake, W. O. Weber 377 Pumping engine, efficiency of. ... 23 Pumping plant, at Connorsville, Indiana, reg- ulation of 441 energy losses in steam and electric 25 R. Raceways, of Holyoke Water Power Company 56S of Sterling Hydraulic Com- pany 567 Racing or hunting of water wheels , 447 Index. 777 PAGE Racing, value of 456 Racks, trash 536 Rafter and Williams, experi- ments of. 65 Rafter, George W., discussion of rain fall 125 discussion of Vermuele's for- mula 148 graphical comparison of dis- charge over weirs 68, 69 graphical diagram showing discharge over weirs with irregular crest 72-73 report to the Board of Engi- neers on Deep Waterways 65 Railway load curve, typical 430 Rainfall, accuracy of records of ........ 122 at Merrill, Wis ,120 annual at, Augusta, Ga 120 Cincinnati, 120 Des Moines, Iowa 120 Detroit, Mich 120 Helena, Mont 120 Little Rock, Ark 120 Madison, Wis 120 Montgomery, Ala 120 Moorhead. Minn 120 New Haven, Conn 120 Phoenix, Ariz 120 Sacremento, Cal 120 San Antonio, Texas 120 Spokane, Wash 120 Tacoma, Wash 120 Topeka, Kans 120 Winnemucca, Nev 120 annual, local variations and periodic distribution of 121 conditions in the United States 118 data, availability of 87 disposal of 133 distribution of Ill in United States, types of monthly distribution of... 123 literature on 130 literature on disposal of.. . 144 Rainfall Con. PAGE maps and records, accuracy of 122 monthly mean at, Augusta, Ga 127 Cincinnati, 127 Des Moints, Iowa. 127 Detroit, Mich... 127 Helena, Mont 127 Little Rock, Ark 127 Montgomery, Ala 127 Moorhead, Minn 127 New Haven, Conn 127 Sacramento, Cal 127 San Antonio, Tex 127 Spokane, Wash 127 Tacoma, W r ash 127 Topeka, Kans 127 Tucson, Ariz 127 various points in United States 127 Winnemucca, Nev 127 observations, accuracy in... 126 on the drainage area of the Wisconsin river 129 records, value of extended.. 124 relations of annual to run off 177 study of, Ill as affecting run-off 126 for report on water power 677 rate or intensity of 133 relation to river discharge.. 745 run-off and evaporation, for various periods 750 variations of at stations closely adjoining 125 Rainfall and Altitude 124 Rainfall to run-off monthly relation of 162 on southern rivers 166 on Northern rivers 165 on Sudbury River for each period of the water year. . 161 on upper Hudson River for each period of the water year 160 relations between monthly depth of 161 77 8 Index. Rainfall to run-off Con. PAGE relations between, on the Passaic river 182-183 relation of, for various per- iods on the Connecticut River 159 relations of, for various per- iods on the Hudson River 158 relations of, on the Hudson and Genesee River, dia- gram of 155 relation of periodic 159 Rating curve, changes in head due to changes in cross section.. 96 current meter 221 for Wallkill River, ice and open conditions 217 for Wisconsin River at Kil- bourn, Wisconsin 209 influence of stream cross sec- tion on 95 Rating or discharge curve 95 Rating station for current meters, Denver, Colorado 223 Reaction and impulse turbines.. 311 relative advantages of 245 Reaction turbine, 237, 239, 316 American type 256 arrangement of 500 condition of operation of.... 245 diagrams of 240 economical operation of 31$ friction of 318 general conditions of opera- tion 500 graphical relation of energy and velocity in. . 321 graphical relation of velocity and energy in flow through 320 minimum residual velocity of water in leaving buckets 319 necessary submergence of... 501 path of jet 317 relative velocity of the bucket 318 residual velocity of water from 31S Snoqualmie Falls 272,273 PAGE: Register gates 301, 301 diagram showing eddying caused by 305- Regulation of impulse wheels... 452: Regulation of turbines, compara- tive 487 Reinforced concrete dams, litera- ture on 601 Relay, hydraulic type of 471 mechanical type of 471 Relay Valve, Lombard 483" Relief valves, 495-498- Lombard hydraulic 49ft on end of penstock 49f> Sturgess 49S Rennie 3- Replenishing period 15T Report of water power, general outline of 683 Resistance and speed, relation of 44ft Retardation of water in penstock 690 of on gradient 201 Rising or falling stream, effects Risler, M. E., estimate of daily consumption of water by differ- erent kinds of crops 135 Rivers, comparative hydrograph of various in Michigan 18f> hydrographs of, Alcovy River 190 Bear River, Utah 19S Clear Creek 192 Chittenango Creek 191 Coosa River 19ft Grand River at Grand Rapids 191 Hood River 193 Iron River 193" Kalawa River 193 Kennebec River 19ft Kern River 193 Licking River 191 Meramec River 192 Niobrara River 192 Otter Creek.. . 192 Index. 779 Rivers, hydrographs of Con. PAGE Perkiomen Creek 191 Rio Grande River 192 Salt River 192 San Gabriel River 193 Seneca River 191 Spokane River 193 Tennessee River 191 Walker River 19;! Wisconsin River at Ne- cedah, Wis 192 Yadkin River 190 Yellowstone River 192 monthly discharges in cub. ft. per sec. per square mile, Ausable River 183 Grand River at Grand Rapids 188 Grand River at Lansing, Mich 1S8 Kalamazoo River 1 88 Manistee River 188 Muskegon River 188 St. Joseph River 18S Thunder Bay River 188 White River 188 relation of rainfall and run- off on 165 Reek-fill dams, literature on 597 Rockford, Illinois, details of head gates for Mr. Wait Talcott 610 flashboards and supports at. . 609 Rock River, at Rockton, Illinois 165 comparison of mean monthly flow with Wisconsin River 178 Rodney Hunt Machine Company 267-268 Rome, water wheels in 14 Rotary converters, losses in 29 Rotation of water wheels, direc- tion of 289 Rou6 a Cuves 8 Rou6 Volant 8 Runner, details of 28C its material and manufacture 2j84 Improved New American.... 261 Runner Con. PAGE of Girard turbine 280 Run-off (see also Stream Flow), relations between monthly depth 164 study of for report on water power 676 and rainfall, monthly rela- tion of 162 and rainfall, monthly rela- tions on Southern Rivers.. 16(5 and rainfall, monthly rela- tions of on Northern Rivers left diagrams of Hudson and Genesee River 155 of the Muskingum River 156 of the Passaic River.... 155 effects of area on 179 effects of geological condi- tions on 177 effects of rainfall on 126 influence of storage on the distribution, of 179 influen.ce of various factors on 14S mean annual of the rivers of the U. S 152-153 precipitation, evaporation and temperature, relations of on Upper Hudson River.. 154 precipitation, run-off and tem- perature, on Sudbury River basin, relations of 151 rainfall, and evaporation, for various periods 750 relation of periodic rainfall to 159 relation of annual rainfall to 175-177 relation to precipitation, eva- poration and temperature on Lake Cochituate.. . 149 S. Sale of power, 646-666 an equitable basis for 669 literature on?. . . 673 Index. PAGE Saline River, cross section at guaging station 225 Samson turbine, 265 section and plan of 263 test of a 56 inch. . : 709 test of a 45 inch 713 top and outside view of run- ner of 261 characteristic curve of a 45 inch 410-411 Schiele turbine 239 Science of hydraulics 40 Scotch turbine 7, 239 Seattle and Tacoma Power Com- pany, The 268 Sewall's Falls, vertical turbines for 512 Shafting, efficiency of 24 use of 533 Shawinigan Falls turbine... 268, 270 runner of 271 efficiency and discharge dia- gram of 381 Shawinigan) Water and Power Company, plant of 550 Shock, due to sudden changes in velocity 449 Shutter, automatic drop at Ba- tavia, India 610 Site of dam for power station, study of for report on. water power ' 681 Slope, estimates of flow from 210 Smeaton's experiments on water wheels 357 Smith, Hamilton, Jr's., coefficients of discharge for weirs 74 Smith-McCormick turbine, relations of head to discharge of 334 relations of power to head in, a 12 inch 336 runner- of 267 Smith turbine 267 S. Morgan Smith Company, 267 curve of relations of dis- charge and speed from ac- tual tests. . . .393 S. Morgan Smith Co. Con. PAGE curve of turbine from actual t(ysts 399 relation of efficiency to speed in a 33 inch wheel 395 relation of power ami speed from actual turbine tests.. 396 test of a 33 inch turbine 717 tests of a 33 inch special tur- bine 7.21 turbine, relations of speed and efficiency in 329 turbines for Contcord Electric Co 513 two pairs of turbine units in tandem 519 Snoqualmie Falls reaction tur- bine 272, 273 diagram showing relation of gate guides and buckets.. 303 diagram showing rigging for opening and operating . gates : 303 thrust bearing of 296 Solar energy 19, 20 South Bend Electric Company's plant 546 Southern Wisconsin Power Com- pany, dam with.. movable crest at Kilbourn, Wis 60S head gate hoists for 617 Kilbourn plant of 521-569 preliminary study of dam for 585 Southwestern Missouri Light Co., harness and sheaves of. ... 533 Special New American runner. . 261 Specifications for governor 467 Specific speed or system curve of turbines 349 Speed, economical speed of any wheel 329 relation) necessary for con- stant 442 relation of turbine speed to diameter and head 324 Speed and discharge of various American turbines. . .... 34J Index. 7 8i PAGE Speed and power of turbines, relation of 347 Speed and power, selection of a turbine for, under fixed heads. . 387 Speed and power of various Am- erican turbiixes 350 Speed and resistance, relation of 440 Speed, cp and horse power, ex- perimental curve showing rela- tion of 415 Speed of rotation, measurements of 373 Speed of turbines, relation of discharge to 345 Speed records from Hudson, River Power Transmission Co 486 Speed regulation, detailed analysis of 688 for plant with open penstock, predetermination of 461 plant with closed penstock.. 462 plant with stand pipe 463 graphical analysis of '. 693 influences opposing 453 Speed relations, graphical expres- sion, of 329,331 Special New American turbine. . . 257 Spier's Falls plant of Hudson River Power Transmission Co. 546 Spouting velocities of water 741 Stability of masonry dams, litera- ture on 505 Stand pipe, 453 discussion of relative speed regulation 696 fluctuation of head in 699 numerical problem 466 predetermination of speed regulation with 463 St Clair River, drainage and guage heights on 200 hydrograph of discharge of the 180 variations in velocity in the cross section of 211 Steam and electric pumping plant, energy losses in 25 PAGE Steam engine, efficiency of 24 Steam plant, capital cost and an- nual cost of per brake H. P... 664 Steam power 33 Steam power plant, energy losses in 24 Steel dams, literature on 601 Sterling Gas and Electric Com- pany plant 537 Hydraulic Company, race- ways of 567 power hydrograph.... 625 tainter gates in U. S. dam at 604 timber fishway in dam at... 619 St. Lawrence drainage, hydro- graphs of 179, 191 St. Mary's River, hydrographs of discharge of the 180 Storage, 624 calculations for 635, 636 diagram showing effect of large storage capacity 633 effects of limited 629 effect of maximum 635 influence of on distribution of run-off 179 limited, effect on low water flow at Kilbourn 629 literature on 645 study of for report on water power 67$ period of 157 Stout, Mills and Temple 13, 25G Strabo, reference on water wheels 14 Stream flow, broad knowledge of neces- sary for water power pur- poses SO estimates of 169 factors of 79 graphical determination of, from measurements 230 literature on 19S maximum 16:> measurements, necessity of. . 21S relation of load curve to 434 value of single observations 80 782 Index. Stream flow Con. PAGE variation of from year to year 82 Stream guaging, application of 231 cable station for 228 Stream, study of from its hydro- graphs 181 Sturgess governor, test results with 491 hydraulic governor 486 Type N, section of 489 relief valves 498 Submerged orifices 43 Submergence of reaction wheel.. 501 Sub-stations, estimated cost of power from 65C Sudbury River, rainfall and run- off of for each period of the water year 161 Sudden enlargements 42 Swain turbine 13, 249 test of a 36 inch 718 Switchboard, control of governors from m 492 Tailwater curve 9.3 Tainter Gates, for Morris Plant of Economy Light and Power Co 605 in U. S. dams at Appleton, Wis 607 in U. S. dam at Sterling, Il- linois 604 Talladega Creek 166 Tangential wheels (see also Im- pulse Wheels) 241 angle of discharge from buck- ets of 3H Atkin's wheel and case...,. 273 early forms of g effect of angle of discharge on efficiency 315 efficiency of 247 maximum work... 314 path of jet 316 runners of 284 Tangential wheels Con. PAGE Telluride double, 2,000 H. P. 275 Tate, Professor Thomas, on evap- oration 141 Taylor, J. W., turbine 300 Telluride double tangential wheel 275 Telluride transmission plant, the 276 Temperature an/i evaporation, re- lations of on Lake Cochituate basin 150 Temperature, precipitation, run- off and evaporation, rela- tions of, on Sudbury River basin 151 on the Upper Hudson River 154 on Lake Cochituate 149 Test data of turbine water wheels 703 Testing turbines 355 purpose of 370 flumes for at Holyoke 364 machinery for, importance of 355 by James Emerson. 361 early methods 359 literature on 383 plan of apparatus for by James B. Francis 374 illustration of methods and apparatus 378 Test results with Sturgess gov- ernor 491 Tests, curve showing discharge and speed of wheel from actual 398 factors that influence the re- sults of 371 of water wheels, at Philadelphia in 1860. . 360 by Messrs. Samuel Weber and T.' G. Ellis 362 in place 379 the value of 369 Thermal energy 20 Thermal units, British 32 Thompson's turbine 239 Three-halves powers of numbers. 742 Three Rivers, Michigan, variation in power at 103 Thrust bearing at Snoqualmie Falls . . 295 Index. PAGE Thunder Bay River 165 Thurso, J. W 279 Tidal mill..... 14 Timber dam, at Janesville 582 at Sewell's Falls 594 of the Montana Power Com- pany, near Butte 593 Timber fishway, of Fish Commission State of Wisconsin 619 in dam at Sterling, Illinois.. 619 Tohickon Creek 167 diagram showing annual run- off from 638 mass curve of run-off of 639 monthly discharge from drainage area of 643 monthly rainfall in inches on drainage area of 643 rainfall, run-off and evapora- tion 757 Topographical condition, relation of run-off to 175 study of for report on water power 677 Traction purposes, transmission of power for 26 Trade Dollar Mining Company, power plant of 532 Transformation of energy 23-33 Transformers, losses in 29 Transmission of energy 23 losses in 27 for traction purposes 26 literature on 673 Transverse curves of mean veloc- ity in stream cross sections... 211 Trash racks 53C Tremont-Fourneyron wheel, characteristic curve of 409 diagram of 21 efficiency of 247 guides and buckets of 251 Trenton Falls, N. Y., plan of power development at 575 Tub wheel . . 8 PAGE Turbines, American, Francis 11 Cadiats, Fourneyron, Fran- cis, Girard Current, Hen- schel, Jonval, Schiele, Scotch, Thompson's 239 advantages of 9 arrangement of, horizontal 504 reaction 500 vertical shaft 501 axial flow 244 bearings of, horizontal 292 vertical 239 calculation of, a more exact graphical method for 396 graphical method, effi- ciency and speed at various heads and gates 395 diagram of estimated power at various heads 397 to estimate operating re- sults under one head from test results at another head 389 to estimate results of one diameter from tests of another 391 capacity of, power and speed of a 40" wheel under 16' head 260 characteristic curve of 400 classification of 243,506 complete 244 connection of, to load 531 conditions of operation of 245,384 constants of 310, 351 design of, first principles. . . . 311 details and appurtenances.. 284 development of 4 in Europe 277 in United States.. 24S discharge, measurement of.. . 372 784 Index. Turbines Con. PAGE at fixed gate opening 332 fundamental ideas of 5 gates of 290 history of 8,9 horizontal 244 horizontal, multiple tandem. 517 hydraulics of, practical o09 impulse or action^ 244 installations of, horizontal 513 tandem 529 vertical 507, 510 inward radial flow 244 limit 244 literature on 353 mixed flow 244 number of, effect on head and power 108 partial 244 outward radial flow 244 power of modern, increase in 13 power of 335 practice, modern changes in 13 radial flow 244 reaction, or pressure 244 regulation, comparative 487 relations 321 of discharge to diameter in various wheels 339 of diameter and speed.. 326 of discharge to diameter 337 of efficiency and speed of 33" turbine, graphical. 395 of efficiency and speed of a 48" Victor, curve of 322 of

potential energy 34 University of Wisconsin, experiments on 12" S. Mor- gan-Smith wheel 329 experiments on submerged orifices at 43 Unwin, Professor . . . 26 Upadachee River 166 Utica Gas and Electric Co., Tren- ton Falls plant of 511 V. Valves, relief 498 Velocities, position of mean and maximum in a vertical plane under ice .- 217 48 Velocity, PAGE changes of penstock. ....... 453 effects of ice covering on dis- tribution, of.. , ... 215 energy required to change penstock 446, 456 measurements of flow by the determination of. 221 relative, of the bucket in re- action wheels. 318 residual, in reaction wheels 318 shock due to sudden changes in 449 variations in the cross sec- tion of a stream. 210 Velocity curves, for open and ice covered streams, comparative mean vertical 216 ideal vertical 213 of Potomac River. .. . ... 232 Velocity head ;..,... -It Vermuele, C. C. 148 formula for the relation be- tween annual evaporation, precipitation and run-off. . 148 Vertical Geylin-Jonval turbine, diagram of 251 Vertical turbine, arrangement of 501 for low heads 509 for Sewall's Falls... 512 bearings of 289 Vertical thrust or hanging bear- ing of The Niagara Falls Power Co 293 Vertical turbines, some installa- tions of 507 Vertical turbines and their con- nection ......... 507 Vertical turbines in series, some installations of 510 Vertical suspension, ball bearing 291 Vertical suspension oil pressure bearing 292 Vertical velocity curves, in streams 211, 213, 214, 215 Victor turbine, characteristic curves of. .402-405 Index. Victor turbine Con. efficiency-speed curve of a 48" 322 relation of efficiency to the number of revolutions 405 runner of 267,268 teats of, data of a 48* 704 test of a 45" 712 of a 42" 713 f *36" 720 of a 33" 723 VitruvUw' description of water wheels 14 Volt 33 Volt, coulomb, equivalents of 34 Vortices, effect of an umbrella up- on the formation of . . 72 tf W. River, rating curve for 217 Warren. H. B., ou predetermina- tion of spaed regulation 462 Waste of energy, none in nature 20 Water, circulation of 20 evaporation of 20 Water hammer 685 due to sudden changes in ve- locity 449 Water power 33-79 chronological development of 15 sort of development 647 development in the U. S 14 market price of 663 sources of 79 Water power development, examples of 537 financial consideration of... 646 history of 1-14-16 investigation of 675 purposes of 646 relation of capacity to cost. . 648 classification of types 562 costs of various, American $50 Canadian $49 Foreign 651 Water power property, value of. 671 PAGE Water power purposes, dams for 580 Water supplied to wheel, effect of slow acceleration on 455 wheels (.see also Turbines) 237 Barker's Mill 5 breast 3 Chinese Nora 1 classification of L 10 .7 current 1 early types of 1 float 1-3 horizontal, some installations of installation of ta.ndem W Laxy overshot ou Isle of Man 14 overshot I, M3 Poncelet 4 Roue* a Cuves 8 Rou6 Volant 8 Smeaton's experiments on. . . :r>7 testing of 3 "HI tests at Philadelphia in, IS- tub 8 undershot 2 use of 241 wry fly 6 Water wheel governors t see Governors) 470-735 problem of 445 types of 470 Water year, the MR rainfall and runoff of the Hudson River for each period of 1*0 rainfall and run-off of the Sudbury River for each period of 161 rainfall and run-off of vari- ous rivers 7o< Waters, W. A., graphical analysis as proposed by 412 Watt, the equivalents of Weber, Samuel 13 and T. O. Ellis, turbine tests by Weber, W. a, plan of brake wheel 576 plan of prony brake 377 Index. 787 PAGE Weekly rainfall in Wisconsin, distribution of 117 Weight, exertion of energy by. . 41 Weights of water, equivalent measures and 740 Weirs, coefficients 65 et seq. formulas for 64 measurements of flow by 219 comparative discharge over 68-69 comparative discharge with irregular crest 72-73 flow over 64 literature on flow of water over 77 Wellmari-Seaver-Morgan C o m- pany 299-300 characteristic curve of 51" wheel 408 Western drainage, hydrograph of 193 Wheeler, L. L., design of fish way by 614 tainter gates designed by... 606 Wheel harness of Oliver power plant 530 Wheel pit 535 Wheels (see Turbines), Atkins' wheel and case 273 effects of number on head and power 108 gravity 237 impulse 237-301-313 other American 266 reaction 237 Whitlaw, James 6 Wicket gate 300-301 diagram showing condition of flow through open and par- tially closed 304 Winnipeg Electric Railway Com- pany, plant of 553 Wisconsin, diagram of fluctuations of monthly rainfall at Madi- Wisconsin Con. PAGE son 122 distribution of average an- nual rainfall in 116 distribution of total annual rainfall in lltJ distribution of weekly rain- fall in 117 maps of annual rainfall in 114-115 rainfall on drainage area of Wisconsin River 129 Wisconsin River, comparative flow of 85 comparison of mean monthly flow with Rock River 173 drainage area of 84 hydrograph at Kilbourn, based on observations at Necedah 86 hydrograph in 1904 81 monthly rainfall and run-off 165 rainfall on the drainage area of 129 rating curve at Kilbourn . . . 209 rating curve at Necedah .... 96 relations of coefficient to hy- draulic radius 199 relations of gauge heights at various stations on 206 Wood, R. D., and Company 254 Geylin-Jonval turbine 266 Wood stave pipe friction losses.. 63 Woodward governors, compensating 474 details and applications of. . 477 standard 471 Work 32 Wry fly wheel 6 Y. York Haven Water Power Com- pany, plant of .537 BOOK IS DUE ON THE LAST DATE STAMPED BELOW 25 CENTS 1 L i- ^ ^ ^\ \ YC 67946 A rx ' V V