An early 20th-century rose quartz and gem-set thermometer, by Cartier, circa 1915. Sold for £22,500 on 13 June 2017 at Christie’s London

An early 20th-century rose quartz and gem-set thermometer, by Cartier, circa 1915. Sold for £22,500 on 13 June 2017 at Christie’s London

An early 20th-century rose quartz and gem-set thermometer, by Cartier, circa 1915. Sold for £22,500 on 13 June 2017 at Christie’s London

An early 20th-century rose quartz and gem-set thermometer, by Cartier, circa 1915. Sold for £22,500 on 13 June 2017 at Christie’s London