suit the type of -work. 



In many instances, the use of asphalt mixtures in hydraulic 

 works has not led to favorable results, which seems only natural 

 in view of the fact that this material originally was unsuitable 

 for this purpose. However these failures should not make us look 

 for other methods instantly. The age old science of hydraulic 

 engineering has produced many an ingenious method to fight the 

 water which undoubtedly may be used once more in the application 

 of asphalt in hydraulic works. Only if this proves to be impossible 

 will new working methods have to be found to solve the problem. 



Certainly the motto of J.F.W. Conrad, which he used in I864. 

 for his prize-winning contribution to a contest regarding the 

 improvement of the Hondsbossche sea dike, still holds a truth: 

 "Don't condemn the old because it's old, nor the new because 

 it' s new. ff 



64 



