A George III engraved brass draughtsman’s protractor rule, George Adams, London, circa 1770 The rectangular plate with canted edges engraved with radial protractor divided into half degrees with every ten numbered in each direction, the plain centre signed G. Adams, London, the reverse engraved with mathematical plotting scales, 15cm (6ins) long. George Adams is recorded in Clifton, Gloria Directory of British Scientific Instrument Makers 1550-1851 as working from several addresses in Fleet Street, London 1734-72. He was an outstanding barometer maker, optician and instrument maker who was apprenticed to James Parker in 1724 and Thomas Heath in 1726 (who was also a maker of some note). Adams served as instrument maker to His Majesty's Office of Ordnance between 1746 and 1748 and became Maker to the Prince of Wales in the 1750s, then to his Majesty King George III in 1760. George Adams died in 1773 leaving the business initially in the hands of his wife, Anne, who was subsequently succeeded by their two sons by the names of George and Dudley who carried on the business into the 19th century. Numerous instruments by George Adams can be found in the personal collection of George III which now resides in the Science Museum, London.