reflection occurred when the angle of incidence was 45 . This contract 

 also partially supported some work on non-linear wave theory in shallow 

 water, on which a report "Higher Approximation to Non-linear Water Waves 

 and the Limitimg Heights of Cnoidal, Solitary, and Stokes* Waves" was pre- 

 pared and issued in limited distribution as University of California IER 

 Report, Series 89, Issue 6. This report presents higher order approxima- 

 tions, and determines limiting conditions for waves of various form. For 

 example, the maximum limiting amplitude for the solitary wave is found to 

 be 8/11 of the free water depth, and it is shown that Stokes* waves with 

 the largest amplitudes are restricted to wave lengths less than 8.15 times 

 the free water depth. Application of the theoretical results is also made 

 to formulate rather severe limitations upon the hydraulic analogy between 

 shallow water waves and isentropic perfect gas flow. Exploratory work in 

 the ripple tank on refraction of wind-generated waves was also carried out, 

 but considerable difficulty was observed in differentiating the effects of 

 refraction from generation effects in the generating area. 



V. Agricultural and Mechanical College of Texas, Contracts DA-49-055- 

 eng-56-4, and 58-9. Estimation of Hurricane Surges . 



Additional work was done on the research problem in Narragansett Bay 

 (eng-56-4). Detailed computations of the sequence of water level and flow 

 at various points and sections of the Narragansett Bay region were made 

 utilizing an IBM 704 computer. This program incorporated the effect of 

 longshore winds which had not been included in the previous 650 calculations. 

 Following obtention of values for various possible design hurricanes for use 

 in determining design criteria for possible hurricane protection for the 

 Narragansett Bay region, the contract was considered completed. Computa- 

 tions made for storm surge estimates in the New York Harbor entrance area 

 (eng-58-9) were summarized in a report "The Prediction of Hurricane Storm 

 Tides in New York Bay" published as Technical Memorandum No. 120 of the 

 Board. This report describes the effort made to correlate storm surges in 

 New York Bay with the meteorological characteristics of the storms producing 

 them, and thus to predict the nature of the storm surge resulting from the 

 hypothetical design hurricane. The method used was largely empirical, but 

 had theoretical guidance. Therefore, though the constants involved apply 

 only to the specific areas studied, the general method and procedure may 

 well have more general application. A discussion of the method presented 

 was made by Mr. D. Lee Harris (Chief, Hurricane Surge Unit, U. S. Weather 

 Bureau) in view of possible usage of the method by the Weather Bureau, in 

 which he suggested a slightly alternative approach. This discussion, and 

 the reply thereto by the author of the report (Dr. Basil Wilson, A& M 

 College of Texas) were published as Technical Memorandum No. 120-A of the 

 Board. 



VI. Dr. W. C. Krumbein (Consultant). Study of Beach Sampling Methods. 



The initial phase of a continuing program to determine the use of 

 computer techniques to study the dominant factors influencing beach 



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