and figures. In view of the high cost of construction and maintenance, 
this procedure should be given primary importance, It has become obvious 
that only through such methodical measurement and systematic investigation, 
patterned after G. Hagen's ideas, would conclusive judgment be possible 
to some degree. Besides the necessary measurements in nature, theoretical 
hydrodynamic investigations, measurements and observations on model tests 
should be promoted. New measuring instruments will have to be developed 
and a good start has already been made. 
Systematic observation of coastal development trends, carried out 
over a period of decades, may help to avoid obviously unsound investments. 
It was shown in some cases that seawalls and other protective structures 
should not have been built because the pattern of natural behavior of the 
coast indicates that they will be destroyed. Also the construction of 
beach protective installations on the East Friesian Islands should have 
been postponed, as the current observations would have indicated a natural 
tendency toward ultimate silting of protective structures. Generally, 
disappointments can be avoided at the construction stage if reports are 
critically drafted and failures made known. 
Observing development outside of Germany, we can verify that in 
general the same problems are encountered in places where surge exists in 
front of a sandy beach, and that all pertinent coastal countries are work- 
ing on the development of a satisfactory procedure for coastal protection. 
Opinions on the effectiveness of seagroins also differ considerably in 
other countries, indicated by the new Dutch studies which attribute beach 
stabilizing effect to the groins on one side while denying them any effect 
on the other, The trend toward artificial beach nourishment is increasing. 
Close and substantial cooperation between scientists and practical 
men seems to be needed more than ever before in order to avoid duplication 
of work and to recognize problems and the proper approach to their solu- 
tion. The Coastal Commissions of the Baltic Sea and North Sea represent 
an established arrangement which offers the possibility for exchange of 
ideas for the purpose of promoting coordinated investigation. 
Furthermore, it should be required that all available literature on 
coastal regions, both domestic and foreign, be collected at the Coastal 
Commissions of the Baltic Sea and North Sea and be publicized. A re- 
searcher of a coastal problem, in most cases, due to lack of time to 
undertake a survey of information sources, has not sufficient knowledge 
of previous achievements in a particular field. 
The present status of coastal research and coastal engineering make 
combined action of all participating disciplines mandatory; only then can 
the physical, technological and economic fundamentals be found for cre- 
ating functionally correct and structurally acceptable coastal protective 
structures. 
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