328 PROCEEDINGS OF THE AMERICAN ACADEMY. 



forms, trending eastward, were seen on the south shore near Long 

 point light, at the time of my visit to the Cape last summer. 



The Wasting Shore from Race PoixNt to AVood End. 



The seconil consequence of the outward deflection of the current 

 around the peninsula is the rapid consumption of the bar, VW, that 

 extends south from Race point inlet to Wood End, the long "finger " 

 at the end of the Cape. This suggests a preliminary digression. 

 Wonder is often expressed at the ability of sand bars to withstand the 

 violence of the surf that breaks unceasingly upon them. The sands 

 are entirely unconsolidated, and their surface layers are moved by 

 every surge of the waters. Yet the form of the bar changes very 

 slowly. The reason for this must be found in the continual feeding, 

 from the cliffs and from the bottom off shore, by which the volume of 

 the bars is sustained. The bars of our southern Atlantic coast pre- 

 sumably receive much of their sand from the l)otti)Di. Sandy hook 

 receives much of its supply from the retreating cliffs at Long Branch. 

 If the supply be withheld, the bar will be rapidly swept away. It 

 may not be that llie grains of sand are actually ground to dust, but 

 that they are brushed along, and when no followers come to take their 

 place, it is left vacant, and the face of the bar retreats ; its dunes are 

 cut back, and a low cliff-shore is formed. 



As long as the outside of the peninsula formed a continuous curve, 

 sand was carried along it in plenty from the cliff and the sea floor 

 on the back of the Cape, and probably also from the shoals where 

 Webbs island and its vanished mates once stood off Chatham. This 

 condition is represented in line DGVAV. But as the cliff from Nauset 

 to Highland was cut fartlier back, and the shore current became unable 

 to follow its earlier path along the margin of the peninsula, the additional 

 bar, ending in Race point, was laid out, and tlie long marshy " slash " 

 was enclosed behind it. From the beginning of this additional bar 

 until the present time, the supply of sand carried around the western 

 curve of the peninsula was greatly reduced ; at times it may have 

 ceased entirely. The supply being thus reduced or cut off, the bar 

 southward from Race point inlet nearly to Wood End rapidly wasted ; 

 and the sand taken from it by northwest gales went to supply the cor- 

 respondingly rapid growth of Long point, WX, into Provincetown 

 harbor, which Whiting shows to have extended many feet eastward in 

 the fifty years past. Like Race point, Long point has advanced into 

 comparatively deep water; the 20-fathom curve lies only 600 feet 

 off shore ; the same depth is not found for almost three miles off the 

 cliffed shore of the " back " of the Cape, 



