Source:
http: http://en.wikipedia.org/wiki/Glass_harmonica.htm
Rubbing the rim of a drinking glass must be quite an old pass time. Different dimensions of glasses create different pitches. This may be achieved by filling glasses with water or wine to create the different pitches of a particular scale, and which makes possible playing a melody. The "harmonica" part of the name refers to harmony rather than to the air instrument by that name.
The bowl part of the glass serves as soundbox, while a moist finger rubbing on the glass rim creates a resonance, similarly to the bow on a violin.
A mechanical glass harmonica was invented by the American Benjamin Franklin in 1761. His instrument contained 37 bowls mounted horizontally on an iron spindle, turned by treadle.
Source:
http: http://en.wikipedia.org/wiki/Glass_harmonica.htm
Source: http://en.wikipedia.org/wiki/File:Glass.harmonica.in.rome.arp.jpg
http://en.wikipedia.org/wiki/File:Stars-GlassArmonica.ogg