Haupt. ] 28 [Dec. 16. 
So far as the ebb is concerned, it merely rolls off from the 
fore-shore, chiefly under the influence of terrestrial gravita- 
tion, and: having its initial velocity at high-water line, its 
| transporting energy is feeble, and it, therefore, exerts no ma- 
terial influence in modifying the exterior lines of the coast. 
THe SOUTHERN Bay. 
These generalities are more clearly exemplified and con- 
firmed by the facts exhibited on the accompanying chart 
(Plate III). Beginning at Cape Florida, the heights of the tides 
at the various external stations are marked in feet, whilst the 
cotidal lines are plotted as enlarged from the United States 
Survey Report of 1854. 
By following the coast northwardly from Cape Florida, it 
will be found that the height of the tide increases from 1.5 to 
about 7.4 feet at Jekyl Island, between St. Simon and St. An- 
drew’s Sounds, which is the most remote point, about two 
hundred (200) miles, from the chord of the arc; also, that 
the outer ends of the main or ebb channels are flexed 
| northwardly, and that even the land drainage extends in 
the same general direction. As the bight of the bay is 
| approached, the land discharge becomes more nearly nor- 
mal to the coast and the shore line more deeply indented, 
and after passing this point, the tidal elevations decrease 
(with one exception), the directions of the land and 
channel discharges are reversed and the shore lines be- 
come smoother. ‘This reach of coast is characterized by 
three secondary bays, separated by the groins of Cape 
Lookout and Cape Fear. These capes are the resultants of 
the opposition of the tidal wave to the fresh water dis- 
charge, which being unable to effect its escape in the face of 
the flood is turned to the west and south by the pressure of the 
