spectra which show appreciable power in bands throughout the entire 
analysis. A second powerful argument lies in the spectra obtained 
by Barber and Ursell [1948] and Deacon [1949] which show a gradual 
essentially continuous shift as the power spectrum of a swell follows 
the theories derived herein. One is forced to conclude that discrete 
sine waves of appreciable amplitude have not been proved to be pre- 
sent in wave records, and that the best interpretation of a wave re- 
cord is that it is just colored noise. 
The free surface power spectrum given in tigure 39 is a function 
of # alone and nothing can be said about the short crestedness of 
the free surface. All power in the power spectrum for periods less 
than four seconds has been lost due to the filtering effect. Extra- 
polation of the high end of the spectrum suggests that the power 
lost above # equal to 27/4 is not too great. 
If it is assumed that most of the wave energy flux is in one 
direction and if this direction is assumed to be very nearly direct- 
ly toward the shore since the winds were almost directly on shore, 
then the flux of energy toward the shore can be computed from equation 
(12550) 5 
The top part of figure 43 is a graph of the integrand of the 
integral given in equation (12.50) for the particular power spectrum 
under study with pe /4 absorbed in the scale on the left. For the 
depth under consideration (30.5 feet), values of » near 27/4 seconds 
yield essentially the form (pg/2)+(A(,))°-(g/2u ) which means that 
the energy flows forward with the group velocity of "deep" water waves, 
(g/2). For low values of » , the energy is essentially moving 
105 
