Wind chime
From Free net encyclopedia
Image:Windchimes.jpg Wind chimes or Aeolian chimes are often hollow or solid metal or wooden tubes which are usually hung outside of a building and are intended to be played by the wind, which causes the chimes to strike each other or a metal, wood, or rubber ball which may be hung in the center.
Wind chimes produce inharmonic (as opposed to harmonic) spectra, although if they are hung at about 1/5th of their length (22.4%), the higher partials are dampened and the fundamental is brought out. This is common practice in high-quality wind chimes, which are also usually hung so the center ball strikes the center of the wind chime's length. Frequency is determined by the length, width, thickness, and material. There are formulas that help predict the proper length to achieve a particular note, though a bit of fine tuning is often needed. Wind chimes are thought to be good luck in Africa and are used in Feng Shui.
Chimes are also made of materials other than metal or wood and in shapes other than tubes or rods. Many people accept bamboo, stones, horseshoes, mechanics tools, PVC pipe, glass, seashells, old silverware, etc., as chimes. The sounds these make are not tunable to specific notes and range from pleasant tinkling to dull thuds. The idea seems to be that if it is moved by the wind and makes a noise, it is a wind chime.
In some areas of the world chimes are used to predict the weather changes. For instance, if the wind comes from the north or north west, it may mean a storm or colder weather is on its way. Thus, if a chime is positioned on the north side of the house so only a north wind will move it, it can alert the inhabitants to a weather change. Conversely, a south wind could mean milder temperatures are on their way, so that chime is mounted on the south side.