Death of Sir John Barton On August 25, 1834, Sir John Barton died at Windsor Castle. He was buried in the cloisters of St. Greorge's Chapel and a memorial tablet was erected to him by command of William IV. For forty-six years he had served as secretary and treasurer first to William IV when he was Duke of Clarence and then to Queen Adelaide. He was born at Plymouth in 1771. At one time Barton was comptroller of the Mint and he made several im provements in coining machinery. One obituary notice of him said that he was the inventor of a floating compass, a hydrostatic balance, a hydro static floating lamp, a draw-bench for use at the Mint and an “atometer” with which a millionth of an inch was rendered a sensible measure to the eye. He originated the ornamental effect produced by the decomposition of the rays of light reflected from polished metallic surfaces covered with a series of very minute lines or grooves, ruled upon them by a diamond point, and also a method of producing a cube in a lathe, which he applied to a scheme for the prevention of the forgery of Bank of England notes, by engraving upon these cubes and printing from them an interpolated coloured line.