Quill was Master of the Worshipful Company of Clockmakers and the author of a fine biography of John Harrison. He had brought a manuscript to show Howse, who thought at first it was a collection of notes by Maskelyne in preparation for an autobiography. Howse decided "there and then" to write the book that was to appear over 20 years later.
The story is interesting on several counts. Quill and Howse were sitting in the building where for 46 years Maskelyne had carried on his astronomical work. Howse leaves the reader of his preface to notice another coincidence: the date he is careful to mention, 1967, was the 200th anniversary of Maskelyne's greatest achievement, the inaugural year of the annual Nautical Almanac.
At that point in his career Howse had no publications to his credit; indeed he had been professionally involved with historical and curatorial work only since 1963, when he had joined the Museum as an Assistant Keeper. It seems rather a sudden resolution on the basis of a slight command of the available sources. But whether instinctively or on account of some prior knowledge, Howse may have recognised a rapport between his subject and himself. As a young man Maskelyne went to sea on astronomical and navigational ventures at the behest of the Royal Society and the Admiralty, before spending most of his working life in the Observatory at Greenwich. Howse was a seamen and navigator, who enjoyed a second career in the Old Royal Observatory much in the company of astronomers.
In an excellent biography, Howse describes a likeable, helpful, clubbable, friendly man, who enjoyed the company of family, friends and colleagues, and who enjoyed his work. The parallels are obvious. At the end of the standard recital of acknowledgements, Howse takes the unusual step of thanking his subject for having a legible hand and a "pleasant personality", which "made the writing of this book a most agreeable task for me".
Howse was born in Weymouth in 1919. His father was a Captain in the Royal Navy, and after entering the Royal Naval College, Dartmouth, in 1933 as a cadet, Howse was at sea as a Midshipman by 1937. As Sub-Lieutenant and Lieutenant in destroyers and minesweepers he served throughout the Second World War, in the Battle of the Atlantic, in the Dover Straits and North Sea, and in the Mediterranean. He specialised in navigation and in aircraft detection, was mentioned in dispatches three times and was awarded the Distinguished Service Cross in 1945.
It was typical of Howse to be modest about his war service and his friends learnt little about what lay behind this distinguished record. He rose to the rank of Lieutenant- Commander in 1949, and his post-war service included navigating the cruiser Newcastle during the Korean War. He retired in 1958.
After several positions in the commercial world, Howse found his metier in 1963, when he joined the National Maritime Museum as an Assistant Keeper in the department of the distinguished historian of navigation Lt-Cdr D.W. Waters. His timing had been perfect: the museum was set for a period of development unimaginable today and Howse had the challenge of turning the observatory buildings recently vacated by the astronomers, the historic meridian building in particular, into one of the world's great astronomical museums. Howse grasped the opportunity with characteristic energy, delighting in recovering and restoring the original instruments to their proper settings, and founding his displays on scholarly research preserved in his 1975 volume Greenwich Observatory: the buildings and instruments.
Howse became Head of Navigation and Astronomy in 1976, with the rank of Keeper in 1979. He ran a good-humoured and productive department, promoting esprit de corps, encouraging his staff in their various projects and taking pride in their success. He wrote one of his most successful books, Greenwich Time and the Discovery of the Longitude (1980), recently republished, among many authored and edited books and articles on the histories of navigation, hydrography, astronomy and horology.
As his scholarly work gathered pace, Howse gave the impression that he was enjoying it all enormously. It gave him particular pleasure that, having been a naval cadet by the age of fourteen and without having attended university, he was becoming respected in an academic role. Yet there was nothing pompous about his occasional reference to his lack of formal qualifications, rather a modest and genuine surprise at what was happening to him. This aspect of his career reached its zenith in 1983 when, in retirement, he was appointed to a Visiting Professorship attached to the Clark Library of the University of California, Los Angeles.
His productivity was scarcely affected by retirement in 1982, when he was appointed a Caird Research Fellow at the National Maritime Museum. Among other work, his valuable international compilation of observatory instruments to 1850, the Greenwich List of Observatories, appeared as a special issue of the Journal for the History of Astronomy in 1986, his biography of Maskelyne was published in 1989, and a history of Radar at Sea in 1993.
Among other marks of distinction, Howse became President of the British Astronomical Association, President of the Scientific Instrument Commission of the International Union of the History and Philosophy of Science, and a Liveryman of the Clockmakers' Company. He served on the councils of numerous societies and had a wide circle of friends who shared his interests. He particularly relished being secretary of the Royal Astronomical Society Club, whose dinners are linked to the monthly meetings of the Society, and also enjoyed the meetings of the Equinoctial Club of instrument enthusiasts who, as might be imagined, dine less frequently.
A final and signal award to Derek Howse will be posthumous. The Gold Medal of the Royal Institute of Navigation will be presented in October to mark his service to the history of navigation. It is a recognition in which his many friends will take particular pleasure.
Humphrey Derek Howse, naval officer and historian of astronomy and navigation: born Weymouth, Dorset 10 October 1919; DSC 1945; MBE 1954; Assistant Keeper, Department of Navigation and Astronomy, National Maritime Museum 1963- 69, Head of Astronomy 1969-76, Deputy Keeper and Head of Navigation and Astronomy 1976-79, Keeper 1979-82, Caird Research Fellow 1982-86; married 1946 Elizabeth de Warrenne Waller (three sons, one daughter); died London 26 July 1998.