A NATURAL SEA-WALL. 539 



water. After a severe storm the road is sometimes strewed thickly 

 with these great pebbles, and some trouble is necessary to clear it. 

 So, at least, says popular tradition, but it is probable that very many 

 of the larger stones, found some rods inland, were deposited there be- 

 fore the wall existed in anything like its present condition. For it is 

 almost certain, from the character of the formation and its known his- 

 tory, that it has been piled up in comparatively recent times. 



Some of the old inhabitants assert that the terrific storm that in 

 1851 devastated the whole New England coast and snapped like pipe- 

 stems the iron pillars of the Minot's Ledge light-house, is responsible, 

 too, for the wall. While that noted storm certainly did perform some 

 tremendous feats, and in some places permanently changed the con- 

 tour of the shore, no one storm could do its work in a very systematic 

 or regular fashion. No one storm could have formed the three ter- 

 races that compose the sea-face of our wall. The Minot's Ledge 

 storm may have greatly augmented an existing pile and changed its 

 shape somewhat (as there is reason to believe it did), but, powerful as 

 it was, it did not do anything more than this. 



It is said that the above-mentioned storm so blockaded the exist- 

 ing highway that it was moved a short distance inland, and there is 

 evidence to show that this road once ran near the present high-water 

 mark, on or about the line now occupied by the wall. 



It is, then, probable that a double process has been going on. The 

 sea has been encroaching on the beach, and at the same time obstruct- 

 ing its own course with the debris of former invasions. It is worthy of 

 notice that the wall has only been thrown up along the sandy beach, 

 whei-e the waves had an unobstructed passage. On the ledges that 

 are of frequent occurrence no signs of any extensive deposit are visi- 

 ble. The wall is absent or much modified where a shoal intervenes. 

 These facts show that the deposit has been the result of successive 

 storms heaping up the material, and the ordinary course of the waves 

 and tides molding and arranging it. When the angle of the pile 

 exceeded the natural slope of such materials, growth in that particular 

 plane ceased, and a terrace was formed. Thus the wall, as far as its 

 seaward side is concerned, seems to be a sort of concretion, the ter- 

 races being formed in succession, partly out of new material furnished 

 by annual storms and partly from what was left after the first terrace 

 had reached its present angle. Constant pounding of the waves has 

 solidified the wall, though various storms have partially undermined 

 it and necessitated the re-formation of its face. To these storms is due 

 the motion landward that has from time to time taken place. The 

 materials of the wall have been collected from a large area, as is 

 shown by their diverse character, and why they should have been de- 

 posited at this particular point is a matter of some doubt. It may 

 be that submarine ledges off this part of the coast have furnished 

 a quarry for the waves. The method of formation, however, has 



