History of longitude instant in time, local solar time at a location varies by one hour for every 15 degrees change of longitude (360 degrees divided by 24 hours), there is a direct relationship between time and longitude. If the navigator knew the time at a fixed reference point when some event occurred at the ship's location, the difference between the reference time and the apparent local time would give the ship's position relative to the fixed location. Finding apparent local time is relatively easy. The problem, ultimately, was how to determine the time at a distant reference point while on a ship.
Adlard Coles Nautical Adlard Coles Nautical Adlard Coles Nautical is a nautical publisher, with over 300 books in print. The company publishes books on topics of interest to sailors and motorboaters and also ‘landlubbers’ with an interest in the sea. Their list includes almanacs, cruising guides, pilot books and how-to instruction books, as well as large format photographic books, sailing narratives and sea-related reference, maritime history, humour and trivia books. Adlard Coles Nautical has been part of Bloomsbury Publishing since 2003. The company was founded by yachtsman Kaines Adlard Coles in 1947. He wrote many of the books, including pilots, sailing narratives and