鈥楻ear-Admiral Sir W.R. Hall'. Admiral Sir William Reginald "Blinker" Hall; KCMG; CB; RN (28 June 1870 - 22 October 1943) was the British Director of Naval Intelligence (DNI) from 1914 to 1919. Together with Sir Alfred Ewing he was responsible for the establishment of the Royal Navy's codebreaking operation; Room 40; which decoded the Zimmermann telegram; a major factor in the entry of the United States in World War I.London: Hutchinson & Co. 1920.From: Sidney Theodore Felstead; German Spies at Bay: being an actual record of the German espionage in Great Britain during the years 1914-1918. With illustrations.09083. cc. 58 plate facing page 86London; British Library.