204 



TRANSPORTATION OP DEBRIS BY RUNNING WATER. 



of the mode of flume traction by rough sur- 

 faces, but here omitted, a scheme of values of a 

 for the observational series of Table 67 was 

 made out. The adjustments were then made, 

 by the graphic methods described in Chapter 

 II; and their results appear in Table 68. The 

 same table records the parameters of the adjust- 

 ing equations, and also the probable errors. 



No adjusted values are given for grade (I) 

 in the first division of the table, for the reason 

 that the data, although apparently based on 

 good observations, are strongly discordant. 

 The observations were retained in the record 

 because an aberrant fact, if established, may 

 prove peculiarly valuable; but in this case the 

 interpretation has not been discovered. 



TABLE 68. -Values of capacity for flujne. traction, adjusted in relation to slope of channel. 

 a. Traction over a surface of wood, planed and painted. 



