314 The National Geographic Magazine 



The Wreck of the Priscilla 



been buried beneath the sand wave for a 

 number of years, but this has Deen quite 

 recently resurrected and its houses are 

 again occupied. On Currituck, below 

 Caffey's Inlet life-saving station, the sand 

 has advanced entirely across the land, 

 and one man, moving before the advanc- 

 ing sand, has at last built his house on 

 piles in the sound. 



The writer has found by experiment 

 that heterogeneous sands, consisting es- 

 sentially of quartz, orthoclase, some mica, 



iron, bits of shell, and many mineral sub- 

 stances, showing little if any decomposi- 

 tion,* ripple readily in the wind and are 

 easily arrested. This he accomplished in 

 one instance by planting the seed of 

 a native pine and covering the dune 

 with brush. In another case the 

 movement was checked by the unassisted 

 growth of grass upon dunes from which 

 hogs and cattle were fenced out. Several 

 native grasses on these islands are ex- 

 cellent sand-binders ; but so far he has 

 found no means of checking the 

 movement of homogeneous sands 

 that do not ripple, these consist- 

 ing entirely of well rounded and 

 wind-sorted quartz grains of the 

 same size throughout a 

 dune. 



Other trees besides the pine 

 may be used as sand-binders. 

 Some live oaks and myrtles serve 

 well in this capacity, and on Hat- 



single 



Cemetery on Hatteras Island, N. C. 

 bv the winds 



laid bare 



* I consider these sands to be of gla- 

 cial origin, scraped ofF the granite 

 rocks of New England by the ice- 

 sheet of the last glacial epoch. — C. C. 



