13 



The actual wave profiles do not agree with either theoretical profile. 

 The irregular profile of these waves is believed to be due to phenomena 

 of reflection at the wave absorber, and to certain mechanical defici- 

 encies in the wave generator. The elimination of the irregularities 

 wiU require further study; the purposes of this investigation are not 

 believed to require their elimination, though desirable. 



The dimensions of the paths described by individual water particles 

 are given in table 4. The theoretical values of the orbit radii are the 

 same for the Gerstner and Stokes-Levi-Civita theories, their value 

 being given by 



B,=ae-^^' (8) 



where i2<= theoretical orbit radius at depth h' below stUl water level. 

 The last column of Table 4 lists the percentage differences between 

 measured and theoretical values, the positive sign indicating that the 

 measured value is larger than the theoretical. The data are presented 

 graphically in Figures 6 and 7. 



The comparison of measured and theoretical values of surface mass 

 transport is shown in table 5. The theoretical values are given by 

 the formula: 



U,=k'a'C-^ (9) 



derived by Stokes. It will be recalled that Gerstner's theory does not 

 admit the existence of mass transport. 



Figure 6. 



