BEACH CUSPS 



A frequent feature of our New England beaches is a suc- 

 cession of stony or gravelly cusps with sharp points toward the 

 water, situated on the upper part of the beach where the waves 

 play only at high stages of the tide. My attention was first 

 called to these cusps by Mr. J. B. Woodworth, of Harvard Uni- 

 versity, under whose direction the general view, Fig. I, was 

 taken for the U. S. Geological Survey. Subsequent study on 

 Lynn Beach, Mass., where 1 obtained twenty instantaneous wave 

 photographs, has satisfied me that on that particular shore the 

 cusps must be ascribed to the agency of the seaweed piled up 

 on the beach, modifying the action of the greater waves. The 

 successive stages of construction shed so clear a light on the local 



Fig. i. — Westquage Beach, R. I. 



forms, and the weed control has seemed so clear through a great 

 variety of details observed on this beach during more than two 

 years, that it seems time to call the attention of other observers to 

 "the point involved. Any beach photograph may have a record 

 on it of some stage of these beach cusps. 



The portion of Lynn Beach where these studies were made 



237 



