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PROCEEDINGS OF THE AMERICAN ACADEMY. 



increase of load in tending to build the land out iuto the sea. Here 

 rivers and 'long-shore currents have unlike behavior. 



One of the best examples of this kind that has come to my notice is 

 found on the coast of Georgia and Florida, where the better adjust- 

 ment of coastal bars to shore currents and the consequent increase in 

 volume and strength of the latter seems to have led to the out-building 

 of the several bars that are involved in the southward migration of 

 Cape Canaveral.* The accompanying digaram, Figure 5, illustrates the 



essential features of the changes here 

 inferred. The genei-al attack that is at 

 first made nearly all along the ragged 

 coast soon comes to be resolved into 

 two diverse actions ; a persistent attack 

 on the chief medial headlands, while 

 the subordinate headlands are protected 

 by the growth of off-shore bars. Let 

 the ragged outline of Figure 5 repre- 

 sent, the original shore line of an un- 

 compacted land mass. The general 

 attack by the sea first cuts off all the 

 headlands, forming cliffs 2, 3, more or 

 less connected by bars. When longer 

 and higher cliffs, 4, are developed, they 

 supply so large an amount of waste and 

 allow the movement of so large a vol- 

 ume of water along shore that the less 

 exposed cliff of earlier intention in the 

 upper part of the figure is no longer 

 attacked, but is protected by a spit, 4', that springs out from the main 

 cliflP, prolonging its curve in one direction or the other, — here, up- 

 ward, — according as the tides and the on-shore winds determine the 

 direction of the 'long-shore movement. In this case, on-and-oflP-shore 

 action and depth of water have little to say. Wherever the dominant 

 'long-shore movement advances, there the tangent bar must grow, 

 whether the water is shallow or deep. 



Fig. 5. 



* This peculiar chancre in the situation of the cuspate foreland known as 

 Cape Canaveral was briefly stated by the writer in Science, 1895, 1. 606. It has 

 later been found that Weule had previously noted the fact of migration {loc. cit., 

 p. 253), although not mentioning the cause here suggested to account for it. 



