more at the surface, than in deeper water. Thus, thb horizontal 

 particle speed will not only increase at the crest of the Pj^^-waTe, 

 but at the same time the vertical velocity gradient will become 

 steeper too. Both effects support an extensive breaking of the 

 crest of the superimposed steep p -wave. Now the long wave over- 

 takes the breaking crest and approaches the next p -crest in the 

 leeward direction, where after some time the same thing happens, 

 and so on. Thus, as long as the faster traveling long wave over- 

 takes a train of undisturbed a -waves (with originally maximum steep- 

 ness 5 ) breakers may occur at the crest of the long wave disturb- 

 ance, and every new breaker is placed to the leeward of the previous 

 one, looking in the direction of wave propagation. It may be men- 

 tioned that perhaps this may be offered as an explanation for the 

 "law of breakers" by K. Wegener [24], who states: "Die See brlcht 

 so, dass sich eine brechende See immer vor die vorhergehende setzt." 

 Furthermore, the foam patches (at higher velocities) will orient 

 themselves in rows, extending to leeward and gradually disappearing 

 at the windward end. 



The particle speed of the p -waves at a given wind velocity is 

 greater than the particle speed of any other wave with (T > v and a 

 maximum steepness given by (17) » as shown in the following Table 7 



by the values u at different wind velocities. The maximum hori- 

 •' o 



zontal component of particle speed at the surface is given by 



u = Tr6<T . 



The table shows 6 and <r „ at different wind velocities for the 



m m 



fully arisen p -wave, as well as for the p(l)-wave and f?^ -wave. 

 From this, amplitudes of particle speed u are computed. At a wind 



88 



