which we shall use to 8 large extent in the following considera- 

 tions, is that the steepness of the waves, 8 = H/a , depends on 

 the stage of wave development. Such a relationship has already 

 been suggested by 0. Krftmmel [5], but H, U. Sverdrup and W, H. 

 Munk [1] first related the ratio H/a to the "age" of the waves 

 and used this relationship for theoretical discussions. The stage 

 of development or the "wave age" can be conveniently expressed by 

 the ratio of velocity of wave propagation tr to wind speed v, that 

 is p = <5/v. The relationship 6 = f (p) is shown in Fig. 12 where 

 the observed corresponding values of H/a and Vv were plotted. 

 While Sverdrup-Munk did not fit an empirical curve S = f (p) to the 

 observed data and chose another way to the solution of the problem, 

 we put, in accordance with a previous paper [8] 



6 = 2n e"^P for l/3<p^Pm* , (17) 



where n = 0.1075, r = 1.667, pj^^* = 1.37> and later carry out the 

 integrations numerically. 



For the initial state of wave development of very young waves, 

 we put 



6 = 2p = const, for p^l/3 (18) 



with p = 0,062. These empirical relationships are represented in 

 Fig. 3 by full lines. While for p>l/3 a definite relationship be- 

 tween the steepness and the wave age already appeared fairly well 

 established by older observations (see [1] and [8]), this is not 

 the case for the "initial state" where p<l/3. Based on the collect- 

 ion of data by Sverdrup-Munk only four not very reliable meastire- 

 ments in the state p<l/3 were available. In Fig. 12 some further 



60 



