fully arisen with ^ ^^ = O.Sl'v = 13 m/sec at the end of a fetch 

 X = 300 km (Table 10). (Considering the growth with time t over 

 an unlimited fetch, or over a fetch long enough, it would take 16. 8 

 hours, if the wind starts to blow over an undisturbed water surface.) 

 The development of these p waves with increasing fetch and duration 

 is Illustrated in figures 20 and 22, Fig. 20 shows the height and 

 the period of the p -waves, as functions of the distance from the 

 coast, for various wind durations. When the wind has blown, say, 

 for 5 hours, a very rapid increase in wave height out to a distance 

 of 62 km from the coast is found. The steepness of these waves Is 

 considerable, and the steepness graph in Fig. 21 gives for a dura- 

 tion of 5 hours and a fetch of 62 km H/a = 0.0855. The wave height 

 of the waves is 4.28 m, and their period (see curve T in Fig. 22) 

 is T = 5.65 sec. ( A = 50 ra.) Beyond 62 km the waves are similar 

 at a duration of 5 hours, but still in the growing state, whereas 

 inside of 62 km a steady state has been reached. That means, at 

 any given point along the fetch from x = to x = 62 km the waves do 

 not change with increasing duration of wine action, while beyond 62 

 km the waves continue to grow for a length of time which depends upon 

 the fetch. Thus, for example, a steady state is to be found after 

 a duration of 10 hours inside of a fetch of about 150 km. If the 

 wind continues to blow with constant velocity (I6 m/sec), the fully 

 arisen ^^-vave with G" ^ = O.8I v, T = 8.3 sec, A = IO7 m, H = 5.9 m 

 appears after I6.8 hours, and inside of the fetch x = 3OO km a steady 

 state is attained as given by the curves H and T in figures 20 and 

 22. Correspondingly, the other graphs may be used for determining 

 the state of the sea, that is, the steepness graph (Fig, 21) and 

 the wave age graph (Fig, 23). (Similar graphs and tables for other 



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