Glass Xylophones are known to have been in existence since 1825. David Ironmonger of London, England was one manufacturer of these instruments and wrote two books for the “Harmonicon Glasses.” The earliest method book, entitled Instructions for the new Improved Harmonicon Glasses, shows a drawing of a 3 1/2 octave instrument. The instructions for playing read, “In performing on this Instrument the hammers must be held lightly striking the Glasses gently in the Centre over the letters.”
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