Keywords: PennyCyclopediaWornumFig12.svg illustration captioned Mr Wornum's double or Piccolo Action fig 12 Piano-forte Penny Cyclopaedia vol 18 Charles Knight Co London 1840 p 142 also fig 3 Edward F Rimbault The Pianoforte Its Origin Progress and Construction Robert Cocks Co London 1860 p 191 ~ 1840 unsigned not credited http //books google com/books id U4i0pf5N-foC pg PA142 http //www archive org/details/pianoforteitsori00rimbuoft a Key b Hopper and spring c Hammer d Hammer rail e Tie and wire f Check g g Damper and wire actual damper missing in original drawings h Setting off screw PD-old Musical instruments schemes Musical instruments technical diagrams Piano action SVG music |