John Harrison: How His Chronometer Saved the Lives of Sailors

Reconstruction Of The John Harrison H4, The World’s First Precision Marine Chronometer, By Derek Pratt And Roger Stevenson/Frodsham - Quill & Pad

Derek Pratt’s Reconstruction Of John Harrison's H4, The World's First Precision Marine Chronometer (Part 1 of 3) - Quill & Pad

John Harrison — the genius who made the marine chronometer possible

John Harrison’s ‘Clock B’ sets a world record over 250 years after it was designed

Burgess Clock B, The World's Most Precise Pendulum Clock, Is Made To A 250-Year-Old Design By John Harrison, Longitude Prize Winner And Inventor Of The Marine Chronometer - Quill & Pad

The Longitude Prize and the Harrison Chronometer

John Harrison's marine timekeepers

Making The Escapement, Remontoir, And Timing For Derek Pratt’s Reconstruction Of John Harrison‘s H4, The World’s First Precision Marine Chronometer (Part 3 of 3) - Quill & Pad