A Detailed Study of H4 - John Harrison's Longitude Timekeeper Reconstruction

Buy DVD at https://martinmatthewswatchcasemaker.... A reconstruction of John Harrison's successful Longitude timekeeper H4. Derek Pratt, one of the 20th century’s most talented watchmakers, had always been a fan of John Harrison and was determined that a re-creation of his most successful timekeeper H4 should be constructed. Derek started work in 1997, using other talented craftsman for the case, dial and engraving. Then in 2009, due to ill health, when approximately half of the watch had been completed, Charles Frodsham & Co took on the project which was finished in 2014. Displayed worldwide at the Ships, Clocks and Stars: The Quest for Longitude exhibitions at the National Maritime Museum, America and Australia. This is the story of that remarkable achievement.