207 



derived from a topographic survey made in 1928; and the consequent 

 values of /=aL7i\fo=0.000, 1405 L'72400 are shown in the following 

 tabulation. 



The storage stations are midway between the velocity stations. 



399. Initial computation of priniary tides and currents. — The compu- 

 tation of the tides and currents, by the procedure previously explained, 

 is tabulated in figure 69 facing page 208. In columns (2) and (3) the 

 coordinate amplitudes, A sin a. and A cos a, of the tides at stations 5 

 and 77 are computed from the values of A and a at these stations, 

 found in paragraphs 394 and 395. In the initial computation the 

 values at the other stations are interpolated from equations (273) and 

 (274). The values of Bq sin /So and Bq cos jSq at station 37, columns 

 (7) and (8), are determined from the head between stations 29 and 45. 

 From columns (2) and (3) ,in this subsection: 



fl'sini7° = -1.86-(-2.10) = +0.24 



H cos H°=-0.37- (-0.75) = +0.38 



H° = 32°20', H=0A5, *S=0.45/16,000 = 0.000,0281 



log P=0.28785, log P/S'=4.83914 

 <^=17°10', |3o-77°-(/)-90° = 



■74°50' 



Bo=lM, Bo sin /3o=-1.83, So cos /3o=0.50 



The initial computation is completed as explained in the first ex- 

 ample, with due regard to the algebraic sign of the items. The minor 

 discharge through the branch outlets from Biddies Point to the Dela- 

 ware is neglected. 



400. Becomputation of priTnary tides and currents. — In the recom- 

 putation, also shown in figure 69, the primary currents at the entrances, 

 and the primary tides and currents at Biddies Point (station 19 + 500), 

 and at Summit Bridge (station 51+200) are included. The under- 

 lined coordinate amplitudes of the tides in columns (2) and (3) are 

 at the ends of the subsections, and are derived from the adjusted 

 coordinate amplitudes of the heads found in the initial computation. 

 Those at the other stations shown are interpolated. As in the pre- 

 vious example, no correction of the values of Bo sin /3o and Bq cos /3o 



