Benjamin Franklin invented a radically new arrangement of the glasses in 1761 after seeing water-filled wine glasses played by Edmund Delaval at Cambridge in England in 1758. Franklin, who called his invention the “armonica” after the Italian word for harmony, worked with London glassblower Charles James to build one, and it had its world premiere in early 1762, played by Marianne Davies.
In Franklin’s treadle operated version 37 bowls were mounted horizontally on an iron spindle. The whole spindle turned by means of a foot pedal. The sound was produced by touching the rims of the bowls with moistened fingers. Rims were painted different colors according to the pitch of the note. A’s were dark blue, B’s purple, C’s red, D’s orange, E’s yellow, F’s green, G’s blue, and accidentals white. With the Franklin design it is possible to play ten glasses simultaneously if desired, a technique that is very difficult if not impossible to execute using upright goblets. Franklin also advocated the use of a small amount of powdered chalk on the fingers which helped produce a clear tone in the same way rosin is applied to the bows of string instruments.