CONTENTS. 



Page. 



CHAPTER XIV Continued. 



The vertical velocity curve 244 



The moving field 249 



APPENDIX A. The Pitot-Darcy gage 251 



Scope of appendix 251 



Form of instrument 251 



Rating methods 252 



Rating formula 253 



Page. 

 APPENDIX B. The discharge-measuring gate and its 



rating 257 



The gate 257 



Plan of rating 258 



Calibration of measuring reservoir 258 



The observations 259 



INDEX.. 261 



TABLES. 



J'age. 

 TABLE 1. Grades of de'bris 21 



2. Gate readings and corresponding dis- 



charges 23 



3. Data connected with changes in mode 



of transportation 33 



4. Observations on load, slope, and depth.. 38 



5. Values of capacity generalized from Table 



4(G) 61 



6. Data for the construction of curves in 



figures 20 and 21 62 



7. Values of a in C=6,(S-<T) B 66 



8. Values of a, arranged to show variation 



in relation to fineness of debris 68 



9. Experimental data on competent slope.. 69 



10. Experimental data on competent dis- 



charge 70 



11. Values of a, as adjusted for use in inter- 



polation equations 72 



12. Adjusted values of capacity, duty, and 



efficiency 



75 

 89 



13. Values of n l in d= 



14. Adjusted values of depth of current, with 



values of mean velocity and form ratio . 89 



15. Values of i\ in relation to slope 100 



16. Valuesof j, in C=cS>i 109 



17. Values of i, for mixtures of two or more 



grades 114 



18. Comparison of values of ^ for mixtures 



and their components 115 



19. Values of i l associated with the smooth 



mode of traction 115 



20. Relations of i l to discharge, de'bris grade, 



and channel width 116 



21. Selected data showing the relation of ca- 



pacity to slope when the form ratio is 

 constant 117 



22. Values of a corresponding to data in 



Table 21 118 



23. Values of synthetic index under condi- 



tion that R is constant, and under con- 

 dition that w is constant 119 



23a. Comparison of parameters in C=5, 



(S-<j)and E=B 1 (S-a) nn 123 



24. Relation of capacity to width when 



slope and depth are constant 126 



25. Values of capacity and depth for grade 



(C), width 0.66 foot, and slope 1.0 per 

 cent . . 128 



TABLE 26. Values of m l , in Coc d 1 * 1 , when slope is 

 constant 



27. Quantities illustrating the influence of 



slope on the relation of capacity to form 

 ratio 



28. Quantities illustrating the influence of 



discharge on the relation of capacity 

 to form ratio 



29. Quantities illustrating the influence of 



fineness on the relation of capacity to 

 form ratio 



30. Quantities illustrating the influence of 



slope and discharge on the relation of 

 capacity to form ratio 



31. Estimated ratios of depth to width to 



enable a given discharge, on a given 

 slope, to transport its maximum load. 



32. Data on the relation of capacity to dis- 



charge 



33. Values of K, computed from data of 



Table 32 



34. Adjusted system of values of K 



35. Values of i 3 , arranged to show variation 



in relation to fineness 



36. Comparison of i l with ig 



37. Variations of i, arid ig in relation to dis- 



charge 



38. Variations of i, and i 3 in relation to width . 



39. Variations of i l andt' 3 in relation to fine- 



ness 



40. Variations of f, and i, 3 in relation toslope. 



41. Variationsof the ratio -^- . 



42. Variations of the ratio -J 



1 



Page. 



128 



132 

 133 

 133 

 134 



135 

 137 



140 

 141 



144 



145 



146 

 146 



147 

 147 



148 

 148 



43 



Values of capacity, arranged to illustrate 

 the relation of capacity to grades of 

 de'bris 150 



Data connected with the plots in fig- 

 ure 50 151 



45. Values of T t , compared with slope, dis- 

 charge, and width 154 



Values of Ivq 157 



Means based on Table 46, illustrating the 

 control of /FQ by discharge, fineness, 



and width 158 



48. Synthetic indexes, comparing the con- 

 trol of capacity by mean velocity with 

 the control by slope 158 



44 



46 



47 



