CONTENTS. 



Page. 

 TABLE 49. Values of I t >, 159 



50. Means based on Table 49, illustrating 



the control of Iv a by slope, fineness, 



and width 159 



51. Values of In 160 



52. Means based on Table 51, illustrating the 



control of Ira by fineness and width. . 160 



53. Comparison of synthetic indexes for ca- 



pacity and mean velocity, under the 

 several conditions of constant discharge, 

 constant depth, and constant slope 161 



54. Values of las 164 



55. Means based on Table 54, illustrating 



the control of Ids by slope, fineness, 



and width 165 



56. Synthetic indexes comparing the control 



of capacity by depth with control by 

 discharge 165 



57. Values of I,iv 165 



58. Means based on Table 57, illustrating the 



control of Irir by mean velocity, fine- 

 ness, and width 166 



59. Comparison of synthetic indexes for ca- 



pacity and depth under the several 

 conditions of constant discharge, con- 

 stant elope, and constant mean velocity 167 



60. Adjusted values of capacity for mixtures 



of two or more grades of d<5bris 169 



61. Capacities for traction, with varied mix- 



tures of two grades 172 



62. Percentages of voids in certain mixed 



grades of debris 179 



63. Fineness of mixed grades and their com- 



ponents 180 



63a. Data on subaqueous dunes of the Loire. 194 



64. Comparison of slopes required forstraight 



and crooked channels 197 



65. Grades of debris 199 



Pag,-. 



TABLE 66. Relative speeds of coarse and fine de- 

 bris in flume traction 200 



67. Observations on flume traction, showing 



the relation of load to slope and other 

 conditions 202 



68. Values of capacity for flume traction, ad- 



justed in relation to slope 204 



69. Comparison of capacities associated with 



different characters of channel bed 206 



70. Values of /, for flume traction 208 



71. Comparison of values of 7, for flume trac- 



tion with corresponding values for 

 stream traction 209 



72. Data illustrating the relation of capacity 



for flume traction to discharge 209 



73. Values of capacity for flume traction, 



illustrating the control of capacity by 

 fineness 210 



74. Capacities for mixed grades and their 



components 212 



75. Depths and form ratios of unloaded 



streams 213 



76. Capacities for flume traction in troughs 



of different widths 213 



77. Data on flume traction in a semicylindric 



trough 214 



78. Observations by Blackwell on velocity 



competent for traction 216 



79. Values of n in C oc V m " based on Blue's 



experiments 218 



80. Velocities of streams with and without 



fractional loads 230 



81. Ratio of the suction at one opening of the 



Pitot-Darcy gage to the pressure at the 



other 254 



82. Values of K and u in 77 7/,=A'K" 254 



83. Values of A in V= A^II^II, 255 



ILLUSTRATIONS. 



Pago. 

 PLATE I. Apparatus on campus of the University 



of California Frontispiece. 



II. De'bris used in experiments 22 



III. Rough surfaces used in experiments on 



flume traction 200 



FIGURE 1. Diagrammatic view of shorter experi- 

 ment trough 19 



2. Diagram of water circuit 20 



3. The contractor 25 



4. Diagrammatic view of part of experi- 



ment trough with glass panels and 

 sliding screen 27 



5. Appearance of the zone of saltation 27 



6. The beginning of a leap, in saltation. . 28 



7. Diagram of accelerations affecting a 



saltatory grain 28 



8. Theoretic trajectory of a saltatory par- 



ticle 29 



9. Ideal transverse section of zone of sal- 



tation at side of experiment trough. . 30 



FIGURE 10. Longitudinal section illustrating the 

 dune mode of traction 



11. Longitudinal section illustrating the 



antidune mode of traction 



12. Profiles of water surface, automatically 



recorded, showing undulations asso- 

 ciated with the antidune mode of 

 traction 



Plot of a single series of observations of 

 capacity and elope 



Logarithmic plot of a series of observa- 

 tions on capacity and slope 



Diagrammatic longitudinal section of 

 outfall end of experiment trough, 

 illustrating influence of sand arrester 

 on water slope 



Diagrammatic longitudinal section of 

 debris bed and stream, in a long 

 trough , 



Page. 

 ;j 1 



33 



13. 



14. 



16. 



56 



57 



57 



