198 



383. Final computation. — The values of 77 cos H° derived from the 

 second computation are practically the same as those determined from 

 the first. While the recomputed values of H sin H° also are in suffi- 

 cient concordance to be reasonably acceptable, a third computation, 

 as shown in figure 62, affords a desirable check. In this final compu- 

 tation the primary currents at the entrances to the canal are derived 

 by correcting those at the adjacent velocity stations for the inter- 

 vening storage. The primary current at the initial entrance, station 0, 

 is derived from that at station 20 by subtracting the increment of the 

 velocity due to the fluctuation of current at station 10. The values 

 of A sin a and A cos a at station 10 are obtained by interpolation 

 between their values at station and station 40. For the half sub- 

 section, to 20, A.r = 20,000 and 7=0.0935. The primary current at 

 the other entrance, station 200, is similarly derived from that at 

 station 180, by correcting for the storage due to the tidal fluctuations 

 at station 190. 



384. Summary of computations. — The results of the computations 

 are tabulated below. The values of A sin a and A cos a, derived from 

 the final computations of the subsection heads, are shown in columns 

 (2) and (3), and the resultmg amplitudes A, and initial phases a of 

 the tides at the ends of the subsections in columns (6) and (5). Those 

 at the middle of the canal are inserted by interpolation. The ampli- 

 tudes, B, and initial phases, /?, of the primary currents are the final 



values found in figure 62. 



Summary 



This summary aftords the data for writing the equations of the 

 primary currents and tides at the stations. Thus the equation of the 

 primary current at station is: 



i;= 1.14 sin (m2f + 47°20'), 



and of the primary tide at station 40: 



2/=3.70 cos (mof-ono'). 



