2 BEACH GRASS 



collects behind tufts of grass or bits of driftwood 

 and builds up into dunes. The dunes devoid of 

 binding grass or bushes — the desert dunes — move 

 in the direction of the strongest winds, those of 

 the winter months which blow from the north 

 towards the south. Like magnified ripple- 

 marks, the windward side is hard packed and 

 slopes upward at a gentle angle of about nine de- 

 grees, while the leeward side rests at the steeper 

 angle of repose of the sand, an angle df thirty- 

 two degrees. On this side each foot of the trav- 

 eller sinks deeply into the soft sand and starts it 

 rolling downward. 



The two most striking examples of this desert 

 type of dune at Ipswich, described in my former 

 volume, still continue their devastating career. 

 The '"glacier" dune has buried still more of the 

 living pitch pine grove and has uncovered more 

 of the dead one. In its uncovering process, the 

 bleached skeleton of a horse has ben exposed to- 

 day, and its bones lie about among the relics of 

 trees where the animal laid itself down to die, 

 many years before. The other great desert dune, 

 the one near the mouth of the Essex River, has 



