d » specific -weight of material of the stones in tons* (metric) 



per cubic meter 

 <X = angle of the dike's side slope with the horizontal. 



Before the preliminary determination of those tentative values 

 of N, each based only on a single observed case - the natural rock 

 fill dike of Orio and the artificial rock fill dike of San Juan de 

 Luz - the booklet also stated: 



"It only remains now to determine the coefficient N and verify 

 if it is sensibly constant, as seems to follow from the material 

 presented, or varies with the other elements of the formula. 



w In the worst case, a coefficient similar to the classic and 

 variable coefficient C of the formula of uniform flow, V = C VR i, 

 will be considered." 



In spite of the .twelve years intervening, during which the 

 reasoning follomred for the deduction of the formula has been re- 

 fined, in a manner that might have been advantageously taken into 

 account by the recent translators of the booklet, the coefficients 

 15 and 19 still stand, due to the satisfactory results always ob- 

 tained in numerous cases of practical application. 



The formula is actually derived for the upper slope of the 

 dikes, and a generalization for all the depths of the work was 

 indicated only tentatively at the end of the booklet. In this 

 connection substantially the following was said: 



"This generalization of the formula assumes a certain margin 

 of security ^ but it is not logical to apply on the sea the 

 strict results obtained from theoretical formulas when on land it 

 is usual to multiply them by ample safety factors. 



"I should be most grateful to my colleagues who, acquainted 

 in detail with concrete practical cases, would kindly furnish me 

 information for refining the coefficients." 



Unfortunately those necessary details of each particular case, 

 and especially the damages experienced x are difficult to obtain. 

 Therefore, in this study, we are going to make special mention of 

 one of singular interest. 



We refer to the interesting compilation on the port of Argel 

 concerning weights of stones or blocks and their corresponding 

 stable slopes at various depths, after repairs of numerous damages 

 to deficient slopes. This outstanding compilation was made by 



#In this paper j the ton unit is the metric ton of 1000 kilograms » 

 2205 lbs. - Trans. 



