John Harrison, 66 year old English carpenter,
completes H4, a 3 pound timekeeper for
determining longitude at sea eventually making
it possible for England to control the shipping
trade. Go Back to 1757 or
forward to 1772
Lasky, Kathryn. The Man Who Made Time
Travel. Canada: Douglas & McIntyre,
2003.
Sobel, Dava. Longitude. New York:
Walker, 1995.