1851 Great Exhibition: Official Catalogue: Class X.: William H. H. Akerman
490. AKERMAN, WILLIAM H. H., Bridgwater, Somerset — Inventor and Manufacturer.
Pianoforte, with new improvement; a bevel action for the dampers, applicable to all kinds; intended to give precision of touch by the certain rising of the key. It preserves also the dampers by gentle instead of jerking movement. Octave action at pleasure, to use the octave of the key struck.