The maker of this clock is Alexander Cumming, a Scottish clockmaker who was one of the founding members of the Royal Society in Edinburgh. He was working with his brother, John, in Inverarary by 1752 and moved to London by 1763 supplying the first self-recording barograph to George III which is still in the Royal collection at Buckingham Palace (M.Cosh, 'Clockmaker Extraordinary: The Career of Alexander Cumming', Country Life, 12 June 1969, pp.1528-35). Other barographs by Cumming are in the Science Museum and the Victoria and Albert Museum, London. A wall barograph by this maker was sold by Sotheby's New York, 25 January 1997, lot 60.
A history of this clock's ownership appears on an engraved plaque. The clock was reputedly a gift from King William IV to Augusta Emma D'Este, 'Mademoiselle D'Este', whose marriage to Baron Truro in 1845 was celebrated in the following verses: 'Happy the pair who fondly sigh/By Fancy and by love beguiled/He views as heaven his D'Este nigh She vows her fate will make her wild'. Lady Truro was the daughter of H.R.H. Augustus Frederick, Duke of Sussex (sixth son of George III) and Augusta Murray, daughter of the 4th Earl of Dunmore, who were enjoined in a 'ecclesiastic' but not legal marriage.