Keyed monochord

"The instrument, which is mounted on a central stand, consists of a narrow box of pine containing a key action, fixed by iron brackets to a longitudinal central member. On the right is an oval soundbox of pine, with two C-shaped soundholes with central nicks, placed back to back, and with a knob-like peg for tuning the single string, which passes over a bridge and runs through the keybox. The string is sounded with a separate bow. On the front of the keybox is a three-octave keyboard with twenty-two ivory natural keys and fifteen sharps. The keys actuate brass levers which strick and stop the string in the manner of the keys of a clavichord'. - Anthony Baines, Catalogue of Musical Instruments in the Victoria and Albert Museum - Part II: Non-keyboard instruments (London, 1998), pp. 27 - 28.