II 12 13 14 15 



PERIOD OF SWELL, Tp, IN SECONDS 



19 20 



:-^^^ 



II 12 13 14 IS 



PERIOD OF SWELL, To, IN SECONDS 



16 17 



19 20 



PLATE VII. DISTANCE FROM WHICH SWELL COMES, TRAVEL TIME, AND WIND SPEED IN 



GENERATING AREA AS FUNCTIONS OF OBSERVED HEIGHT AND PERIOD OF SWELL 



■jSrU. S. GOVERNMENT PRINTING OFFICE: 51-922028 



37 



