L'estro armonico National Library of Wales in Aberystwyth. The 1797 Encyclopædia Britannica records that the fifth concerto was also played on an Irish variant of Benjamin Franklin's celebrated invention, the glass harmonica. Under the entry for "Harmonica" or "Armonica", a 35-glass harmonica is described, about which its inventor, the Dublin physician Edward Cullen, writes: There were numerous arrangements for keyboard instruments in the eighteenth century, as described in the next section. One surviving eighteenth century transcription of Op.3, No.3 has been interpreted as an arrangement for glockenspiel. Themes from movements in the concertos were borrowed by other composers for vocal works: the
Glass harmonica produce a clear tone. Some attempted improvements on the armonica included adding keyboards, placing pads between the bowls to reduce sympathetic vibrations, and using violin bows. Another supposed improvement claimed in ill-informed post-period observations of non-playing instruments was to have the glasses rotate into a trough of water. However, William Zeitler put this idea to the test by rotating an armonica cup into a basin of water; the water has the same effect as putting water in a wine glass – it changes the pitch. With several dozen glasses, each a different diameter and thus rotating with a different depth,