Clerke, London retailer, a French carriage clock: the eight-day duration movement having a platform lever escapement and striking the hours and half-hours on a gong with a push button to the top to repeat the last hour at will, the backplate stamped with initials GLC for Gay, Lemaille & Company, and numbered 2653 along with the wording Patent Surety Roller, the silvered dial having an inset centre painted with black Roman numerals and signed for the retailer Clerke, I Royal Exchange, London and having blued steel spade hands, the anglaise case with shaped mouldings to the top and bottom and with a fluted handle, height 17.25cms handle up,15cms handle down. *Notes The patent surety roller was invented by German-born Moritz Immisch whose brevet for it in 1879 was reported in the Revue Chronométrique. Gay, Lemaille & Company acquired the patent in 1880 and it was described in The Horological Journal, March 1880, as an "Improvement in Carriage Clocks, to prevent Accidental Shifting of the Star Wheel", being a further wheel with a crescent-shaped cut-out set within the strike-work which enabled the strike at each hour to keep in synchronization with the hour hand. * Notes Horology, Vol. 38, issue 2 June 2017, the journal of the Antiquarian Horological Society.