Controlling Sand Dunes 



43 



one who has known him could be igno- 

 rant of his peculiarly lovable person- 

 ality. I have touched in these remarks 

 merely on the geographic side of his 

 work and interests. While his recent 

 transfer to the Assistant Secretaryship 

 of the Carnegie Institution in a sense 

 separated him from purely geographic 

 matters, I cannot doubt that had his life 



been spared to round out the normal 

 tale of days allotted by the Psalmist he 

 would have continued to give us worthy 

 contributions to the most inclusive of 

 sciences until the very end. As it is, 

 his contributions have been noteworthy, 

 and will form, in the eyes of future 

 students, an imperishable monument of 

 our departed associate and friend. 



CONTROLLING SAND DUNES IN THE 

 UNITED STATES AND EUROPE* 



By A. S. Hitchcock, 



Assistant Agrostologist, U. S. Department of Agriculture 



IN many parts of the United States 

 there are areas of drifting sand 

 which are of much economic im- 

 portance from the fact that they not 

 only are useless for agricultural pur- 

 poses, but may seriously encroach upon 

 valuable property. These areas, known 

 as sand dunes, consist of hills of sand 

 which, when bare of vegeta- 

 tion, readily shift from place 

 to place when acted upon by 

 the wind, and are then called 

 wandering or shifting dunes. 

 Such dunes occur along sandy 

 shores of the ocean, of the 

 Great Lakes, or even along our 

 large rivers, notably the Co- 

 lumbia River in Washington 

 and Oregon. These dunes are 

 formed from the sand which 

 is washed up during the tides, 

 storms, or high water in case 

 of rivers. The sand soon dries, 

 s blown in the direction of the 

 prevailing winds, and forms 

 drifts in the same manner as 

 snow. The drifts may attain 

 the size of hills, in some cases 

 as much as 200 feet in height. 



Continuous winds blow the sand over 

 the brow, and the whole dune thus 

 moves slowly but irresistibly forward, 

 covering whatever is in its track — -fields, 

 forests, ponds, rivers, buildings. The 

 direction of the prevailing winds deter- 

 mines whether dunes will be formed 

 along a sandy coast. On Lake Michi- 



Sand Dune Overwhelming a Forest, Cape Henry, 

 Virginia 



The dune is moving slowly northward, burying the forest 

 as it uoes 



*An address to the National Geographic Society, November 20, 1903. 



