The fascinating story of John Harrison who, in the 18th century, believed he could make a clock that would work on board a ship—and so solve the problem of finding longitude at sea.

Michael Gambonas John Harrison
Jeremy Ironsas Rupert Gould
Peter Cartwrightas Army Doctor
Gemma Jonesas Elizabeth Harrison
Anna Chancelloras Muriel Gould
Barbara Leigh-Huntas Dodo Gould
Peter-Hugo Dalyas John Jefferies
Alec McCowenas Sir Frank Dyson
Charles Sturridge
Geoffrey Burgon