Source:
http://en.wikipedia.org/wiki/Tubular_bell.htm
Tubular bells may be regarded as a type of xylophone (or, being made of metal, rather the glockenspiel), consisting not of solid bars, but hollow tubes. The orientation of the tubes to the musician may be different to that of the xylophone, being upright (vertical) rather than horizontal, but strucurally they are the same - except of course the materials used on the manufacturing process. The tubes are struck with a hammer or mallet, while the instrument might have a damping pedal to prevent the ringing of harmonics to flow over into folling notes.
Source:
http://en.wikipedia.org/wiki/Tubular_bell.htm
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