238 MARK S. W. JEFFERSON 



is at the junction of the Nahant barrier beach with the mainland, 

 about one hundred yards north of Hotel Nahant. It opens to 

 the Atlantic a little south of east and is on the Boston Bay sheet 

 of the topographic map, in latitude 42° 27' 30", longitude west 

 70 56' 7". A masonry wall with a concrete walk above here 

 caps the beach. Just below this is a mass of rounded stones 

 from two to six inches in diameter, which have been flung 

 up in storms. These are attached to seaweed, having been 

 derived from the bottom off shore. 1 This belt of cobblestones 

 passes into the sand of the beach proper by the series of cusps 

 above mentioned. The seaward side of the heap of cobbles is, 

 as it were, eaten out in bays, twenty to thirty feet wide with 

 residual points of cobbles between. In the bays, the slope 

 descends one foot in four to the almost level beach of fine sea 

 sand. Along a line roughly tangent to the bay heads, and thus 

 cutting across the stony promontories between, there is found 

 an almost continuous wall of seaweed. The bays in the cobble 

 line are floored with a gravel of texture intermediate between the 

 stones above and the sands below. The stony points terminate 

 in slopes much steeper than the bay floors. The gravel of the 

 bay floors itself advances upon the beach in a series of capes, 

 well outside the stony points and alternating with them. 



The outer undulating margin of the gravel points on the sand 

 is usually thinly strewn with cobbles from the belt above. These 

 details may be made out more clearly with the help of the 

 accompanying diagram, Fig. 2. The constant recurrence of bay 

 and point as one walks along the beach suggests that there is a 

 regularity in width of intervals. This is not so, however, on 

 Lynn Beach, as appears from the diagram, measures from point 

 to point along the beach being 21, 20, 18, 16, 22, 17, 6, 7, and 22 

 paces. Fainter cusps farther south toward Nahant show similar 

 irregularity. It might be said, however, that on Lynn Beach 

 they are commonly about twenty paces wide. 



The work of the waves on the beach depends on their magni- 

 tude and direction, and on the stage of the tide. The magnitude 



'Shaler: National Geographic Monographs, Beaches and Marshes, p. 144. 



