Haupt. ] 30 [Dec. 16, 
tance of twenty-six (26) miles, when it again bends to the 
westward through an angle of 30°, and continues in an un- 
broken stretch of ninety-four (94) miles to Cape Henry. The 
only outlets on the eastern cordon of Hatteras are near the 
point of deflection where the northward component from the 
cape and the normal wave commingle. 
The cotidal curve of eleven and one-half (11}) hour interval 
envelopes the cape in an arc of a circle whose radius is seventy- 
three (73) miles, whilst the shore line changes its direction 
through an angle of 74°. The limiting radii of this sector 
also pass through the main openings of the cordon at Oregon 
and Ocracoke Inlets, which are opposite the tangent points of 
the arc, and hence indicate the locus of the change of direction 
and weakening of the tidal wave. The coast line will also be 
found to be inclined to these radii at an angle of 80° which 
indicates the direction of the shore component at the points of 
intersection. At Ocracoke the chord of the bay lies 10° north 
of the tangent, and at Oregon (Plate II) 10° to the west, show- 
ing the movements to be east and north. 
The velocity of the wave is greatest along the normal at 
Cape Hatteras and least along the radii limiting the sector. 
An examination of the interval between the cotidal lines shows 
also that the rate of movement of the general crest is consid- 
erably returded as it approaches the shore. The twelve (12) 
hour crest will be seen with its flanks rolling along the receding 
shores of the bays, as already described. The earliest points 
of contact of the tidal wave are readily discovered from this 
chart to be at or near the points formerly indicated in this 
paper, whilst the latest point is at Jekyl’s island, which is 
found by measurement to be just midway between Capes 
Florida and Hatteras, thus making the times of transit to this 
point of meeting of the flood components, equal. 
