National Geographic : 1960 Jan
Before dinner, we drove up their sand mountain to the radio tower in a Dodge Powerwagon. With its oversize tires churning up a miniature storm, the powerful vehicle gathered frightening speed on gentler slopes in order to carry the steeper ones. These mountains of sand forever reflect the force of their maker, the wind. Graceful ripples in symmetrical patterns mark the ever shifting surface. The sheerest slopes are called slip faces, where the sand is pitched so steeply that it is always on the verge of slid 106 ing, like snow on a timberless mountainside. We all walked out onto one such face, and the sand began to slide under our feet. It did not move rapidly, as powder snow some times does, but very slowly. As the movement began, I heard a deep, faint droning sound, as if from planes flying at great altitude. What I heard were the "singing sands" of Arabia. This phenomenon of the great desert seems to be caused by the sliding of one layer of sand over another, creating so strong a vibration that I could feel it through my shoes.