H p = 35 m.; Ap -'2 hp - 7 m., 



2 L = 1.56 (2T) 2 = 1.56 x 13.75 2 = 295 mj L Q = 147.5 m. 



For various values of the depth H, measured from the mean level 

 of movement, we obtain the information shown in Table 1. 



The curves of variation of A' and 2h as functions of the 

 depth H, referred to the mean level of movement, are shown in 

 Figure 1, in which also are drawn the curves of surface super- 

 elevations Sh and the line of theoretical breaking H = h, 

 corresponding to steep slopes of the rock-fill dikes.* 



The point of intersection of this straight line with the 

 curve 2h determines for us the height of 9.70 meters of the 

 wave on breaking over the dike, approximating, though somewhat 

 greater than, the 9 meters adopted by the Argel engineers. 



In Figure 2 are shown the wave heights 2h referred to the 

 level of the calm sea, H r ■ H = S^, the superelevations S n 

 taken into account, and the corresponding curve that gives us 

 the virtual heights A 1 > which we must take into account for the 

 calcuation of the dike in its submerged zones. 



The type section of the dikes of Argel, sanctioned by 

 very long experience and deduced from the interesting table 

 compiled by MM. Larras and Colin, is that indicated by the solid 

 line in Figure 3. 



If, in a given zone, the slope of a dike is steeper than 

 that required for equilibrium or stability, settling will result 

 during storms, which, flattening the slope, will tend to adapt 

 it to said equilibrium. It is, therefore, logical to make 

 the corresponding confirmations, determining by means of 

 theoretical calcula tions and the coefficients which it is 

 desired to compare with actuality, the slopes corresponding to 

 the points or zones whose characteristics are known through pro- 

 longed direct observation. 



For this, from the formula 



P = N A^ d 



(coscc - sin a )3 (d-1)- 



•* Note the section h, Rotura de las olas (Breaking of the Waves) 

 page 26 et seq., of the cited report presented to the XVII 

 International Congress of Navigation, convened in Lisbon. 



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