A fine lacquered brass ‘Concorde’ skeleton timepiece with Harrison’s grasshopper escapement, Fred Whitlock for Dent, London, 1970’s The substantial five pillar A-shaped pierced plates enclosing wheel train driven by Harrison type twenty-second spring rementoire powered by a weight with Huygen’s type endless chain drive automatically wound by an electric motor every seven minutes, with large diameter six-spoke escape wheel and grasshopper regulated by large compound ‘dumb bell’ balance oscillating within and above the frame, the front applied with pierced brass and large black cushion-shaped hour buttons to the abstract chapter ring and black steel hands, the rear with brass plate inscribed E. DENT & CO. LTD. LONDON ENGLAND, NO JEWELS, No. 034, F. Whitlock, 66cm (26ins) high; on mahogany plinth base with rectangular glass cover 75cm (29.5ins) high overall. Provenance: Purchased in these rooms on 9th December 2009 (lot 57); acquired directly from the family of the maker by the former vendor. The current timepiece was conceived and constructed by Fred Whitlock for retail by Dent and is based on a design by Martin Burgess. Approximately 25 examples were constructed during the 1970’s with a further batch of around 10 produced from unused parts discovered in around 2000.The grasshopper escapement was developed by John Harrison in the early 1720's, first used in his precision longcases and turret clocks it was later employed in his marine timekeepers H1-3. The spring rementoire (a device enabling power to be isolated and delivered to the escapewheel alone thus alleviating error caused by varying friction in the wheel train) was developed by Harrison in the 1730's whilst refining the design of H2. In essence this clock serves to demonstrate the escapement action and rementoire design employed in Harrison's marine timekeeper H2.