Clockmaker John Harrison vindicated 250 years after Ďabsurdí claims
58ths of a second over 100 day accuracy is proven with Harrison's design in April of 2015.
A true sea shanty: the story behind the Longitude prize
John Harrison's 'longitude' clock sets new record - 300 years on
Three hours. Superb.
Nova one hour video on Harrison.
Revolution in time
Clocks and the Making of the Modern World, Revised and Enlarged Edition
David S. Landes