DRIFT SAND is sand thrown up by the waves of the sea and blown when dry some distance inland until arrested by large stones, tree roots, or other obstacles, round which it gradually accumulates until the heaps or dunes attain considerable dimensions. Except in the case of violent storm winds the action is gen erally a gentle rippling motion, the sand being pushed up by the wind on the seaward side of the ripple and rolling down into the hollow on the other side, thus traveling steadily land ward. When these mounds have reached a certain elevation they are urged farther inland. ((The same wind," says Cuvier, drives the sand from the sea upon the mound, drives the sand from its summit to its land side." In some parts of the coasts of France, the Landes of Brittany, in particular, these inroads upon the land have been attended with destructive con sequences. The quantity of sand annually de posited along that coast is estimated at 3,000,000 cubic feet, and its annual progress inland some 72 feet. Such has been its destructive effects
upon a village of Brittany that nothing is visible of it except a portion of the church steeple. In one or two such instances the sand dunes have moved away, exposing again the buried villages. For the purpose of arresting the inland prog ress of drift sand various measures have been adopted, the most successful being the planting of sand-loving plants with long creeping roots, such as Carex arenaria, which help to fix the sand and break the influence of the wind. In France the drift sands of the Biscay gales when unhindered advance upon the land at the rate of 16 to 17 feet per year. They have been checked in their encroachments by the planting of fir-trees in solid belts along the shores. Con sult Cornish, V., of Sand and Snow) (London 1914).