1887,] 25 (Haupt. 
which lies behind and parallel to the barricade formed by the 
flood, and effect its maximum result at the point of minimum 
resistance, which is that point of the bar farthest removed 
from the direct action of the flood. This enceinte formed by 
the flood is also the cause of the beach channel lying under the 
near spit, since a portion of the flood is deflected by the bar 
into the re-entrant between it and the shore, whilst another 
portion is rolled along the beach, and these two components 
unite in a resultant cutting across the inner angle of the bar 
and carrying silt into the gorge. 
The action of these forces may possibly be made clearer by 
reference to a simple diagram : 
A. Point of maximum flood force. 
B. Point of minimum flood resistance. 
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THe TrpaAn Movements Propucine THESE PHENOMENA. 
Thus far I have been considering the local features, and de- 
ducing therefrom the general condition of the hydrodynamic 
PROC, AMER. PHILOS. 80C. xxv. 127. D. PRINTED FEB. 20, 1887. 
