GENERAL MEETING. 29 
increase in depth of channel at a distance from their mouths; 
while the sounds are 12 to 15 and 20 to 22 feet deep, the rivers are 
often 30 and 40 feet and upwards. This can only be accounted for 
by supposing a subsidence of the region to be in progress, the 
sounds and open bays being silted up by the deposits brought down 
by the floods of the Roanoake and other large rivers, while no 
particle of sediment can reach the sheltered depths of the narrow 
windings of the upper reaches of these minor streams. This theory 
of subsidence is abundantly confirmed by the disappearance under 
water of large tracts of swamp bordering the rivers, as the Chowan, 
within the observation of men now living, and by the existence 
of rooted stumps of cypress and juniper in the bottom of the bays 
and sounds, even to the depth of 15 and 20 feet, and also by the 
vertical and crumbling shores of the sounds, undermined and 
eroded by the advancing waves. 
The Atlantic ocean is walled off from this region by a narrow 
fringe of sand islands, or dunes, blown shoreward by the wind and 
thrown up into reefs and hillocks like snow-drifts 50, 80, and even 
more than 100 feet high. The movement of these sand.waves 
being inland, the sounds are silting up next the sea, and are in 
many places converted into marshes 3 to 5 miles wide. The reef is 
increasing in continuity and breadth, most of the inlets above Hat- 
teras that were open 300 years ago being closed and obliterated. 
An inspection of the form of the curves of the submarine contours 
off Hatteras and adjoining coasts will show that the action of the 
tides and ocean currents, the Gulf stream and Arctic current meet- 
ing at this point, accumulate upon Hatteras the river silt which 
reaches the sea by way of the Chesapeake as well as that of the 
rivers which discharge their burdens through the inlets about this 
point and southwards. Which amounts to this—that Hatteras may 
be described as a sort of delta, whose materials are derived from the 
drainage of more than 100,000 square miles of the Atlantic slope. 
A subsidence of about 20 feet would bring the sea again 
over the entire Sound region and carry the shore 75 miles inland, 
bringing Hatteras to coincide with Cape Lookout. A sand reef, 
like that north of Hatteras, marks the line of the ancient shore, 
when these conditions obtained. A depression of fifty feet would 
move the shore 100 miles west of Hatteras and carry the point of 
meeting of the conflicting ocean currents and waves to Cape Fear. 
A subsidence of 500 feet, as in the glacial period, would carry 
