CONTENTS. 



Page. 

 CHAPTER IV Continued. 



Discussion of experimental data 130 



Scope and method of discussion 130 



Sensitiveness and the index of relative vari- 

 ation 130 



Control of constants by slope 131 



Control of constants by discharge 132 



Control of constants by fineness 133 



Special group of observations 134 



Summary as to control by conditions 134 



The optimum form ratio 135 



Summary 136 



CHAPTER V. Relation of capacity to discharge 137 



Formulation and reduction 137 



Measures of precision and their interpretation . . 142 



Control of relative variation by conditions 143 



Duty and efficiency 144 



Comparison of the controlsof discharge and slope . 145 



Controls of capacity 145 



Controls of duty 147 



Controls of efficiency 148 



Summary 149 



CHAPTER VI. Relation of capacity to fineness of 



debris 150 



Formulation 150 



Precision 151 



Variation of the constant <f> 153 



Index of relative variation 153 



Duty and efficiency ' 154 



Summary 154 



CHAPTER VII. Relation of capacity to velocity 155 



Preliminary considerations 155 



The synthetic index when discharge is constant. 157 



Mean velocity versus slope 158 



The synthetic index when slope is constant 159 



The synthetic index when depth is constant. . . 160 



The three indexes 160 



Relative sensitiveness to controls 162 



Competent velocity 162 



CHAPTER VIII. Relation of capacity to depth 164 



Introduction 164 



When discharge is constant 164 



When slope is constant 164 



Depth versus discharge 165 



When velocity is constant 165 



The three conditions compared 166 



Comparison of controls by slope, discharge, and 



mean velocity 167 



CHAPTER IX. Experiments with mixed grades 169 



Adjustment and notation 169 



Mixtures of two grades 172 



Control by slope and discharge 175 



Mixtures of more than two grades 176 



A natural grade 177 



Causes of superior mobility of mixtures 178 



Voids 179 



Fineness 180 



Relation of capacity to fineness, for natural 



grades 180 



Definition and measurement of mean fineness.. 182 



Summary 184 



Page. 



CHAPTER X. Review of controls of capacity 186 



Introduction 186 



Formulation based on competence 186 



The form-ratio factor 190 



Duty and efficiency 192 



The formula of Lechalas 193 



The formula 193 



Discussion 194 



CHAPTER XI. Experiments with crooked chan- 

 nels 196 



Experiments 196 



Slope determinations 196 



Forms and slopes 197 



Features caused by curvature 198 



CHAPTER XII. Flume traction 199 



The observations 199 



Scope 199 



Grades of debris 199 



Apparatus and methods 199 



Processes of flume traction 200 



Movement of individual particles. . . . 200 



Collective movement 201 



Table of observations 202 



Adjustment of observations 203 



Formulation 203 



Precision 206 



Discussion 206 



Capacity and channel bed 206 



Capacity and slope 208 



Capacity and discharge 209 



Capacity and fineness 210 



Mixtures 212 



Capacity and form ratio 213 



Trough of semicircular cross section 214 



Summary 215 



Competence 215 



W'ork of Overstrom and Blue 216 



CHAPTER XIII. Application to natural streams. ... 219 



Introduction 219 



Features distinguishing natural streams 219 



Kinds of streams 219 



Features connected with curvature of 



channel 220 



Features connected with diversity of dis- 

 charge 221 



Sections of channel 222 



The suspended load 223 



The two loads 230 



Availability of laboratory results 233 



The slope factor 233 



The discharge factor 233 



The fineness factor 235 



The form-ratio factor 236 



The four factors collectively 236 



The hypothesis of similar streams 236 



Summary 240 



Conclusion 240 



CHAPTER XIV. Problems associated with rhythm.. 241 



Rhythm in stream transportation 241 



Rhythm in the flow of water 242 



