report the expression for slopes (reciprocal of batter) theoretically 

 limiting; between breaking and reflections 



i = 4_ / h 

 T V g 



the wave period being 2T, its height 2h, and g, the acceleration of 

 gravity. 



In continuation, we are going to examine whether the degree of 

 approximation, or rather the exactitude, of that simple formula is 

 really satisfactory „ 



Using the notation indicated in Figure 1, adopted to facilitate 

 the comparisons that we are going to make in our notation, the 

 representatives of the Laboratory of Delft indicated, in one of the 

 sessions of the Congress, their determination that always if 



t_ _ 1 



2L < 4 



the reflection was complete ; and that always if 



t_ _ 1 

 2L > 2 



the breaking was complete „ 



At the first simple view of these results we estimated then and 

 there that they could not be acceptable as general expressions for 

 criteria of breaking or reflection of the waves „ 



In the first place, it would not be admissible that the con- 

 ditions of breaking should not be a function of the wave height as 

 well as the length or rather period of the ■waves anc * neither would 

 it seem admissible that the relation t/2L defined said conditions of 

 breaking except in the particular cases in which 2L/H were to be 

 constant, given that the batter, which according to our understand- 

 ing of the question is the appropriate variable, can be expressed 



t = t_ x 2L 



H 2L II 



The horizontal dimension of the batter, t, can only define 

 the batter, or its inverse the slope, with depth, K, constant., 



These logical objections are in accord with our formula 



