IEWLIAN ACCU'MULA'TIONS ( from .Eol us, the god of the winds). Dust, fine par ticles of soil, and even sand grains of a diameter of two millimeters are transported by the wind and brought together in sheltered places, in much the same manner as these particles are transported and deposited by water. Such a olian avpmmumm1ations occur in both humid and arid regions, they attain a more puce flounced degree of development in those regions of litle rainfall. where the scant vegetation per mits the usually powerful winds to exert a con siderable erosive action upon the lintel' weath ered rocks and dry soil. In humid regions de posits of this nature may he found along the coasts of seas aud ocean and also upon upland plains, where the superficial layers of the earth's erust eonsist of loose sand that may be easily blown away, to be accumulated elsewhere as sand-dunes. In arid regions. dust and sand are being continually transported and deposited in distant places. there to form teolian deposits which are often of considerable geological and also of eeonomic importance. Desert sands tra verse wide areas, burying vegetation that may lie in the way, even sometimes destroying forests. On the other hand, the fine calcareous dust blown over the prairies of the west settles in the grass and adds to the fertile covering of soil. The
fertility of many regions of the :Missouri Valley is due to these wind-deposited soils, which are under the name of "loess:" some of the loess is, however, of aqueous origin. Eolinn accumulations have been recognized also in ancient rock formations of various geological systems, notably the Cambrian, Devonian, Juras sic, etc. For description of the erosive and transporting power of wind, and for the charac ters and distribution of the various kinds of :Kilian deposits. see the articles on DESERT; DINE; SAND: SITORE; WIND; and GEOLOGY, para graph on Wind Work.
lEOLIAN HARP. A musical instrument, consisting of a number (usually S or 10) of catgut strings of varying thickness tuned to produce the same fundamental tone. and stretched over a narrow. oblong box. When placed in a current of air the _Eolian harp pro duces full chords, composed of the harmonics of the common fundamental. The sounds change from a breezy, fairy-like pianissimo to an im posing forte. which again dies away with the passing of the gust. For illustration, see MUSI CAL INSTRUMENTS.