CONTENTS. 



Page. 



FIGURE 63. Curves showing the relations of various 

 quantities to the proportions of fine 

 and coarse components in a mixture of 

 two grades of debris, (C) and (G) 179 



64. Logarithmic plots of capacity in relation 



to linear fineness, for related mixtures 



of debris 181 



65. Curve illustrating the range and dis- 



tribution of finenesses in natural and 

 artificial grades of debris 181 



66. Typical curves illustrating the distri- 



bution of the sensitiveness of capacity 

 for traction to various controlling con- 

 ditions 191 



67. Plans of troughs used in experiments to 



show the influence of bends on trac- 

 tion 196 



68. Contoured plat of stream bed, as shaped 



by a current 198 



69. Curves illustrating the relation of ca- 



pacity for flume traction to fineness 



of debris 211 



70. Diagram of forces 224 



71. Interference by suspended particle 



with freedom of shearing 226 



72. Suggested apparatus for automatic feed 



of debris 241 



73. Modification of vertical velocity curve 



by approach to outfall 244 



74. Modification of vertical velocity curve 



by approach to contracted outfall . . 245 



75. Plan of experiment trough with local 



contraction 245 



76. Profile of water surface in trough shown 



in figure 75 245 



77. Modification of vertical velocity curve 



by local contraction of channel 245 



Page. 



FIGURE 78. Modification of vertical velocity curve 

 when mean velocity is increased by 

 change of slope 245 



79. Modification of vertical velocity curve 



when mean velocity is increased by 

 change of discharge 246 



80. Modification of vertical velocity curve 



by changes in the roughness of the 

 channel bed 246 



81. Modification of vertical velocity curve 



by addition of load to stream, with 

 corresponding increase of slope 246 



82. Modification of vertical velocity curve 



by addition and progressive increase 



of load 246 



83. Ideal longitudinal section of a stream, 



illustrating hypothesis to account 

 for the subsurface position of the level 

 of maximum velocity 248 



84. Diagrammatic plan of suggested mov- 



ing-field apparatus 250 



85. Longitudinal section of lower end of 



receiver of Pitot-Darcy gage No. 3, 

 with transverse sections at three 

 points 251 



86. Cross section of prism of water in trough, 



showing positions given to gage open- 

 ing in various ratings 255 



87. Graphic table for interpolating values of 



A in.V=A TJHH!, for observations 

 made with gage 3b in different parts 

 of a stream 256 



88. Arrangement of apparatus connected 



with the rating of the discharge- 

 measuring gate 257 



89. Elevation and sections of gate for the 



measurement of discharge 258 



