This is part 3 of a three-part series about Derek Pratt’s reconstruction of John Harrison’s Longitude Prize-winning H4, which was the world’s first precision marine chronometer. This article was first published in ‘The Horological Journal’ (HJ) in April 2015, who we thank for graciously granting permission to republish on Quill & Pad.
Posted In: Derek Pratt, H4, Highlights, John Harrson, Longitude Prize, marine chronometer, Technology