Frederic Charles Dreyer Admiral Sir Frederic Charles Dreyer , GBE , KCB ( 8 January 1878 – 11 December 1956 ) was an officer of the Royal Navy . A gunnery expert , he developed a fire control system for British warships , and served as Jellicoe ' s flag captain at Jutland . He retired with the rank of Admiral in 1943 , having served through two world wars and having already retired once . Frederic Dreyer was born on 8 January 1878 in the Irish town of Parsonstown ( now Birr ) in King ' s County ( now County Offaly ) , the second son of the Danish - born astronomer John Louis Emil Dreyer who was director of the Armagh Observatory . Educated at The Royal School , Armagh , in 1891 Dreyer joined the Royal Navy and entered the Royal Naval College , Dartmouth . Royal Navy career . Early years . At Dartmouth he performed well in his examinations and was placed fifth in his term . He then served as a Midshipman in HMS " Anson " ( 1893 – 1896 ) and HMS " Barfleur " ( 1896 – 1897 ) . In nearly all his subsequent examinations for promotions he obtained Class 1 certificates — for Sub - Lieutenant , Lieutenant ( July , 1898 , while aboard HMS " Repulse " ) and then gunnery Lieutenant . In 1900 he authored a book called " How to Get a First Class in Seamanship " . He came first in his class of three in the advanced course for gunnery and torpedo lieutenants at the Royal Naval College , Greenwich in 1901 , after which he was posted to the staff of the gunnery school at Sheerness . He then served as gunnery officer in the cruiser HMS " Scylla " and in 1902 was in HMS " Hawke " . In 1903 Dreyer was posted as gunnery officer to the newly commissioned battleship HMS " Exmouth " in the Mediterranean . In 1904 " Exmouth " became the flagship of the British Home Fleet whereupon he became gunnery advisor to the Commander - in - Chief Admiral Sir Arthur Wilson From 1904 to 1907 " Exmouth " came first in the Home Fleet ' s ( later Channel Fleet ) gunlayer tests and battle practices . In 1905 he served on a calibration committee chaired by the Inspector of Target Practice Rear - Admiral Percy Scott . He was posted as experimental gunnery officer to the first dreadnought battleship HMS " Dreadnought " on her experimental cruise of 1907 on " Special Service " to assist with gunnery trials . Admiralty and war service . On his return , upon the recommendation of Admiral Wilson , he was promoted Commander and appointed Assistant to the Director of Naval Ordnance ( DNO ) , John Jellicoe . At the end of 1907 he assisted in the trials of Arthur Hungerford Pollen ' s " Argo " rangefinder mounting and plotter on the cruiser HMS " Ariadne " . He returned to the Admiralty , under the new DNO Captain Reginald Bacon and remained there until 1909 , when he was appointed commander ( executive officer ) in the new dreadnought HMS " Vanguard " , then completing in Barrow - in - Furness . In 1910 Dreyer was invited by Vice - Admiral Jellicoe to be his flag commander , first in HMS " Prince of Wales " ( flagship of the Atlantic Fleet ) and then in HMS " Hercules " ( flagship of the 2nd Division of the Home Fleet ) . On Jellicoe ' s advice , Dreyer was given command of the scout cruiser HMS " Amphion " in 1913 , with promotion to Captain in June . That year " Amphion " came first out of the entire navy in the gunlayer ' s test and first in the vessel ' s type in battle practice . In October , 1913 he became flag captain ( commander of the flagship ) to Rear - Admiral Sir Robert Arbuthnot in the battleship HMS " Orion " ( flagship Rear - Admiral 2nd Battle Squadron ) until 1915 . At the behest of Jellicoe , now Commander - in - Chief of the Grand Fleet Dreyer was made flag captain of HMS " Iron Duke " , serving at the Battle of Jutland in 1916 . He moved to the Admiralty with Jellicoe as the Assistant Director of the Anti - Submarine Division . In March , 1917 he was appointed DNO , where he formed a committee to design and produce a new type of armour - piercing shell , as the existing type had proved woefully unreliable . He was appointed to the Naval Staff as Director of Naval Artillery and Torpedoes in 1918 . Following the Armistice he was appointed Commodore , 2nd Class and served as Chief of Staff to Admiral Jellicoe on his Naval Mission to India and the Dominions on HMS " New Zealand " , between 1919 and 1920 . Post war . This was followed by a return to the Admiralty as Director of the Gunnery Division from 1920 to 1922 . He returned to sea commanding the battlecruiser HMS " Repulse " for a year before serving as Aide - de - camp to HM the King . In late 1923 he was promoted Rear - Admiral . In 1924 he became a Lord Commissioner of Admiralty as Assistant Chief of the Naval Staff and instituted the Tactical School at Portsmouth . In 1927 Dreyer returned to sea as commander of the Battlecruiser Squadron , flying his flag in . In 1929 he became a Vice - Admiral and the following year became Deputy Chief of the Naval Staff . He had previously entertained hopes of becoming the commander of the Atlantic Fleet after his tenure at the Admiralty . However , the tainting by association of the Board of which he was part by the Invergordon Mutiny in 1931 , with the consequent effect on that fleet , meant that Dreyer was destined never to command it . In 1932 he was promoted to full Admiral and in 1933 given command of the China Station where he served until 1936 . He retired in 1939 only to volunteer as a Convoy Commodore in the Royal Naval Reserve upon the outbreak of the Second World War . He was on the staff of the General Officer Commanding - in - Chief , Home Forces in 1940 as an advisor on anti - invasion measure , before becoming Inspector of Merchant Navy Gunnery ( 1941 – 1942 ) . He then was appointed as Chief of Naval Air Services ( 1942 ) before his final brief appointment as Deputy Chief of Naval Air Equipment in 1943 . He then returned to the retired list for the second time . His memoirs were published as " The Sea Heritage : a Study in Maritime Warfare " ( Museum Press , 1955 ) Family life . On 26 June 1901 Dreyer married Una Maria Hallett ( 1876 – 1959 ) , daughter of John Thomas Hallett , vicar of Bishop ' s Tachbrook , Warwickshire ; they had three sons and two daughters . His elder brother was Major - General John Tuthill Dreyer , RA , with whom he worked on his fire control devices . All three sons and his two sons - in - law were naval officers . His second son was the late Vice - Admiral Sir Desmond Dreyer , GCB , CBE , DSC who also became as a gunnery officer and won his DSC at the Battle of the River Plate , going onto become Second Sea Lord . Honours . In 1914 Dreyer was awarded the civilian CB for his services to naval gunnery . Following the Battle of Jutland he was awarded the military CB for the behaviour and shooting of " Iron Duke " in the battle . After the naval mission to the Empire in 1919 he was made CBE . In 1932 he was promoted to KCB and to GBE in 1936 . Dreyer Fire Control Table . The introduction of centralized fire control for warships gave a significant improvement to the accuracy of gunnery . The increasing range of naval guns led by several years the necessary advances to control their fire . Over a ten - year period techniques such as centralised spotting of fall of shot , mechanical computation of rate of change of range ( rate ) , mechanical clocks to calculate range over time for any given " rate " and long baselength optical rangefinders were introduced . In order to make sense of such data , manual plotting of rangefinder ranges , from single or multiple rangefinders as well as other data began to find favour . The Royal Navy sponsored research into these techniques , and two groups emerged , a commercial group led by Arthur Pollen , and a Naval group led by Dreyer . Both camps aimed to produce a combined mechanical computer and automatic plot of ranges and rates for use in centralised fire control . Both systems were ordered for new and existing ships of the Royal Navy , although the Dreyer Table , as the Dreyer system was called eventually found most favour with the Navy in its definitive Mark IV * form . The addition of director control facilitated a full , practicable fire control system for World War I ships , and most RN capital ships were so fitted by mid 1916 . The director was high up over the ship where operators had a superior view over any gunlayer in the turret s . It was also able to co - ordinate the fire of the turrets so that their combined fire worked together . This improved aiming and larger optical rangefinders improved the estimate of the enemy ' s position at the time of firing . But with the longer practical ranges came the increased time of flight . The Fire Control System now had to account for more variations and more complicated corrections than was originally planned . The Dreyer Table had some mechanical flaws , particularly when additional loads were introduced in the form of unauthorised accoutrements concocted by individual gunnery personnel , but on the whole performed in a satisfactory manner . The system was eventually replaced by the improved " Admiralty Fire Control Table " for ships built after 1927 , although Dreyer Tables went to war a second time in World War II , notably in Britain ' s unmodernised battleships and battlecruisers . The choice between the Dreyer and Pollen systems was controversial at the time . The Royal Navy had repeatedly tested Pollen ' s designs and had given him what it considered very preferential terms for them . Pollen in 1925 won an award for £30 , 000 from the Royal Commission on Awards to Inventors for elements of his " Argo Clock " that had been used without his permission . At the same time Dreyer applied for a similar grant but due to the fact that in 1915 he had been awarded £5 , 000 for his services to fire control his request was denied .