Wheatstone's symphonium, c 1829.
© Science Museum / Science & Society Picture Library
Charles Wheatstone (1802-1875) patented his symphonium (a mouth organ controlled by keys) in 1829 and this example was made soon afterwards. The arrangement of the keys at each end for convenient fingering is one of the distinctive features of the instrument. The diatonic scale is fingered by the right and left hand alternately on the middle two rows of keys, the sharps and flats being given by the other two rows.