A brief history of timekeeping
Humans’ concept of time has evolved with our ability to track it
![marine chronometer](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/07/timelineclock_main-1.jpg?fit=860%2C460&ssl=1)
John Harrison’s marine chronometer eventually won the British government’s prize for determining longitude at sea. An earlier version, ca. 1735, is shown here.
© National Maritime Museum, London