some degree of theoretical guidance a correlation- 

 prediction formula is evolved, and its application 

 to (1938) design hurricane showed maximum storm tide 

 height of 8.9 ft. in reasonable agreement with an 

 empirical estimate based on central pressure in the 

 hurricane. Parallel surge predictions are made for 

 (1944) design hurricane for three cases of storm size 

 and speed, and that predicted for a probable maximum 

 hurricane turns out to be 15.3 ft. The flux and 

 discharge of flood waters through the bay entrance 

 channel are also investigated. 



NO. 120-A April 1961 



" Discussion of Technical Memorandum No. 120, "The Pre- 

 diction of Hurricane Storm-Tides in New York Bay* (and 

 Closure by Author) " by D. L. Harris and B. W. Wilson 



Mr. Harris has carefully examined Dr. Wilson's methods 

 and prediction formula for hurricane storm-tides pre- 

 sented in Tech. Memo. No. 120 and discusses certain 

 points which he believes limit its general applicability 

 for storms other than those used in its development. Mr. 

 Harris has independently applied Wilson's formula to 

 Hurricane Hazel (1954) and has presented an alternative 

 prediction formula. Wilson amplifies the points raised 

 by Harris and makes further explanation for their treat- 

 ment in his own prediction formula, noting shortcomings 

 in Harris* approach which in Wilson* s opinion indicate 

 the Wilson formula to be more versatile in application. 



NO. 121 - September 1960 



'Development and Tests of a Radioactive Sediment Density 

 Probe " by J. M. Caldwell 



The development, calibration, and laboratory and field . 

 testing of an instrument for in-place determination of 

 sediment density is described. The device encased in a 

 submersible probe and utilizing 3 millicuries of radium 

 to detect reflected gamma rays transmits a preamplified 

 signal through a 75-foot cable to a scaler, the signal 

 being correlated to the density of the sediment-fluid 

 mixture. The probe senses the in-place bulk density of 

 sediment surrounding the probe over a sphere of material 

 of about 1-foot radius centered on the probe. Evidence 

 is presented that this device is an accurate and prac- 

 tical tool for use in the field, and that its accuracy 

 is greater and costs less than for other methods 

 presently in use. 



109 



