204 DOUGLAS WILSON JOHNSON 



currents. Dana records the drifting of large quantities of coal and 

 brick from wrecked vessels many miles from where they were dropped 

 (p. 224). An anchor with ten fathoms of chain attached was carried 

 one and a half miles in three weeks (p. 225). The effect of such 

 storm-made waves and currents on small gravel, sand, and the finer 

 sediments must be profound. Coarse gravel on Moray Firth is 

 drifted eastward for over fifteen miles (Geikie, p. 418); the ground- 

 swell off Land's End washes cobbles weighing as much as one pound 

 into lobster pots at a depth of thirty fathoms (Douglas, quoted by 

 Geikie, p. 419). Much of the material forming the great barrier 

 beaches along the Atlantic coast is believed to have been brought 

 from considerable distances. As a result of the strong southward 

 drift along the coast of the southeastern United States, according to 

 Professor Bache, the siliceous sands are carried the whole length of 

 the limestone coast of Florida (LeConte, p. 36). Dana tells us that 

 the large amount of sediments brought to the sea by all of the rivers 

 of the Atlantic coast is widely distributed (p. 224). It is believed, 

 then, that however closely the estimates of material eroded from a 

 river basin and of material found opposite the mouth of that river 

 agree, or how widely they may disagree, no conclusions as to the 

 former extent of those river basins can be rightly based on such 

 estimates, in the face of the strong probability, amounting almost 

 to a certainty, that an unknown amount of sediments carried out to 

 sea by that river have been transported by marine action beyond the 

 area in front of the river, while an unknown amount of sediments 

 brought out by other rivers has been carried into that area. 



There are still other considerations which seem to place difficulties 

 in the way of accepting this line of argument. As Mr. White has 

 pointed out, a large proportion of the sediments in question is of 

 limestone, containing quantities of corals and other fossils (E. A. 

 Smith, et al., pp. 226-31). It is not believed that the Alabama River 

 can properly be held responsible for those deposits which are trans- 

 ported in solution and in a very finely divided state, and which may 

 originally have come, in part at least, from far-distant rivers. Mr. 

 White notes still another objection to this argument in the following 

 words : 



The thickest and most important of the beds attributed to the Appalachian 

 River, the Lignitic (900 feet), is composed of cross-bedded sands and clays, and 



