A | 
1887.] 39 [Haupt. 
the magnitude and position of the bar. Storms and winds 
may modify and shift the deposits, but eventually the 
flood re-establishes the original conditions. 
9. The free circulation and ingress given to the flood by the 
detached breakwater, so designed as both to oppose a por- 
tion of the flood and produce interfering waves which 
deposit sand outside of the channel whilst it also aids the 
ebb in its attack on the bar by defending its channel and 
concentrating its volume. 
10. For a given site and stage of water the flood movement ap- 
proaches in the same direction, hence the resisting and regu- 
lating works should be placed on the near side of the pro- 
posed channel. If on the far side, they would be worse than 
useless, unless for shore protection. 
11. No artificial re-opening of an outlet which has been closed 
by this flood component, can be maintained without 
auxiliary works to deflect and modify its action, Dredg- 
ing is only justified when the interests of navigation are 
sufficient to maintain a continuance of the expense and 
no other reasonable methods are available. 
12. The ability resulting from these general principles to con- 
. struct works requiring a lesser linear development which 
will produce greater navigable depths at less cost. 
18. The abolition of-the risks and difficulties attending the 
navigation of narrow jetty entrances in times of danger. 
14, It frequently happens that the requirements of navigation 
and tidal concentration are conflicting, the former de- 
manding wide entrances, the latter, on account of insuffi- 
cient tidal volume, narrow ones. This debars the usual 
jetties and prevents improvement. The plans herein 
proposed are eminently adapted to meet such exigencies. 
As, for example, at Absecon Inlet. 
