National Geographic : 1904 Jan
CON'I'ROLLING 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 SAND DUNES 43 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 Sand D snow. The drifts may attain the size of hills, in some cases The dun 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- 'une Overwhelming a Forest, Cape Henry, Virginia e is moving slowly northward, burying the forest as it goes *An address to the National Geographic Society, November 20, 19 03.