217 



fluctuation, are shown in figure 73, page 218; and the instantaneous 

 profiles derived therefrom in figure 74, page 219. In these figures 

 the tides are referred to a datum 10 feet below mean sea level. It 

 may be noted that the changes produced in the tides by the adjust- 



Lunar Hours 



V . . . . .'? 



J — I — I — L_J I 1—1 1 I L_l I I I L 



7 12 18 O 



Standard Time 



Computed primary current 



Adjusted current 



Recorded currents o oo 

 Figure 72.— Computed and observed currents, Chesapeake and Delaware Canal, November 27-2*?, 1 928 



ment are very small. The currents derived from the second adjust- 

 ment do not differ materially from those derived in the first. The 

 weaker currents at the initial entrance show a considerable distortion. 

 A plot of the distorted discharges at the two entrances, not here 

 shown, develops no material departures from the relation between 

 the storage and discharges due the primary currents in the canal, 

 discussed in paragraph 388. 



416. Preponderance oj flow in a connecting canal.- — The flow in the 

 two directions through a connecting canal ordinarily is at dift'erent 

 stages of the tide. Because of the consequent difference in the mean 



