photographs wavS taken offshore from i'lonterey, California, the remaining 

 photographs off Hawaii. 



In the ancjysi;; ci' the photographs it was found that the value 

 of the film appcrently depended on the brightness of the calibrating 

 life;ht source. This anomalous beh-vior hes been ascribed to internal 

 scattering within the densitometer (welch "Densichron") , fxid appropriate 

 (>.crrecticns h?.ve been inr-ie from an absolute calibration of the densito- 

 meter. These corrections have been completed. 



Calculations of corrections to compensate for slight errors in 

 flying have been completed for the thirty photographs. The effects of 

 skylight and internal scattering have been computed. The latter seems 

 to obey Lambert's law. About $ of the 30 photographs have been completely 

 worked up. These indicate that the slopes are normally aistributed. 



High-Frequency Vi/ave Records 



Prof. Duntley of fflT has designed a Sea State iieter for the re- 

 cording of high-frequency waves. The output of the instrument consists 

 of a fluctuating voltage which is proportional to the relative emersion of 

 thin vertical wires. We have recorded this output on slow-moving magnetic 

 tape suitable for frequency analysis upon playback. The difficulty with 

 this kind of method is that the recording instrument is placed on floats 

 which respond to the longer waves and swell. Thus the vertical wires 

 themselves move through the water, and the interpretation of the recorded 

 frequencies is a matter of considerable uncertainty. 



VJind-Stress Investigation 



The fortunate occurrence of an unusual number of days with high 

 winds has made it possible to obtain a number of additional records of 

 water slope in the basin at Mission Bay. This measuretaent phase of the pro- 

 gram can now be considered as completed. There is evidence that heavy rains 

 add significantly to the stress exerted by the wind on the water. A report 

 on the work is now being prepared. 



Construction of Refraction Diagrams 



Preliminary copies of a manuscript "The Direct Construction of Wave 

 Rays," which was discussed in the previous progress report, have been 

 circulated. The suggestions received have been incorporated and the paper 

 will be given at the meetings of the American Geophysical Union in Washington, 

 D. C, in M^. 



Refraction of a Wave Pattern by Islands 



The effect of an island with circular contours in refracting a 

 wave pattern is being considered. The pattern is assumed to possess both 

 variability in direction of travel (finite crest length)and variability in 



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