NO. 65 - October 1955 



II-B "Sand Variation at Point Reyes Beach, California" by 

 C Parker D. Trask and Charles A. Johnson 



Characteristics of the beach sands and their vari- 

 ability were investigated by taking a series of 

 samples during three seasons, June at the end of the 

 winter season, October at the end of the summer season, 

 and February and March during the middle of the winter 

 season. The sediments on the beach are highly variable 

 and the average variation within a distance of 16 feet 

 of selected points is 60 to 65 percent of the total 

 variation encountered. Samples taken in October at 

 the end of the summer season are definitely more fine- 

 grained than in June or January. The sediments show a 

 distinct relationship to position on the beach, coarse 

 on the lower foreshore, fine on the upper foreshore, 

 and slightly coarser on the berra than on the upper 

 foreshore. The grain size shows no variation with 

 slope of the beach, which is a steep beach, sloping in 

 general 6 to 12 degrees. 



NO. 66 - December 1955 



II-B "Factors Affecting the Economic Life of Timber in Coastal 

 F Structures" by R. A. Jachowski 



Information concerning durability of timber in coastal 

 structures including such factors as marine borers, 

 geographic factors affecting deterioration, and methods 

 of protection and treatment, is presented. Appendices 

 showing intensity of marine borer attack by geographic 

 location and data from service records of timber coastal 

 structures are also included. 



NO. 67 - December 1955 



I -A "A Model Study of the Run-Up of Wind-Generated Waves on 



Levees With Slopes of 1;3 and 1;6" by Osvald J. Sibul and 

 Ernest G. Tickner 



Wave run-up under wind action was investigated in a 

 laboratory wind tunnel to determine relative importance 

 of the wind force in increasing run-up over that observed 

 for mechanically-generated waves or that might be observed 

 in nature under calm conditions. For lower wind velocities 



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