Haupt.] -*-4" [Jan. 18, 



(4) That the term flood component is more comprehensive than flood 

 current, and includes the dynamic action of the breakers racing along the 

 shore, as well as the littoral currents generated by the on-shore mov^e- 

 ment of the flood tide. 



If it can be shown that the flood currents have sufficient energy to 

 move materials, such as bricks, coal, wreckage, etc., in a direction opposed 

 to the winds, even during storms, and for distances measured by miles in 

 the direction of the flood, it would seem to be sufficient evidence to prove 

 not only the existence of such a force, but that it is "sufficiently powerful" 

 to move sand beneath the surface in the same direction. 



(a) As to measuring this particular force, I can only reply that instru- 

 ments can do little more than give an imperfect record of a special condi- 

 tion for a comparatively short interval of time, and that the only intelligi- 

 ble gauge of the combined action of the physical forces is to be found in 

 the effects produced, as revealed by Nature herself. 



A board of engineers, in reporting on Galveston harbor, expressed the 

 hopelessness of measuring this particular force when they said : 



"It will be seen that the board does not attempt any prediction of the 

 precise depth the jetties will maintain. Such predictions can best be made 

 by those ignorant of experience in tidal entrances elsewhere, and having 

 great confidence in the credulity of mankind." 



Yet, notwithstanding this statement, it is immediately preceded by the 

 statement of the expectation "that the proposed jetties, when the channel 

 is once formed, will maintain some such depth as twenty-five or thirty 

 feet." 



As yet the channel has not been formed, although dredging has been 

 tried and abandoned, and $1,581,783.84 have been expended, chiefly on 

 the outer bar, and the latest survey shows a reduction of depth to twelve 

 and three-fourths feet, or less than existed, at times, before the works 

 were begun. 



In short, the measurement of this force is impracticable, since it will 

 diff"er not only for diS"erent entrances, but at diflferent points of the same 

 entrance, and will also vary with the stages of the tide, duration and direc- 

 tion of wind, etc. 



Speaking of the action of these natural forces, General Gillmore says : 

 "The question is full of perplexing difficulties, which elude all the known 

 methods of research by formulae." 1876, p. 458, Rep. Chief of Eng'rs. 



THE PKOOP OF THE EXISTENCE OP THE FLOOD COMPONENTS. 



(6) The Report says : 



"Littoral currents, due to the tidal waves, if they exist, are masked and 

 controlled hy other forces, and especially by the well-known powerful action of 

 wind waves on all sandy shores." * * * "The observed effects may be 

 explained quite as well by the accepted wind-wave tlieory." * * * "The 



