The Robert Wolf Marine Chronometer Gallery

In 1759, John Harrison advanced the practical method of finding longitude with his prizewinning chronometer, H-4. His successors faced the problem of making Harrison’s design easily reproducible and affordable. During the late 1700s, individuals from around the world produced chronometers, including Thomas Mudge, John Arnold, and Thomas Earnshaw in England as well as Pierre Le Roy and Ferdinand Berthoud in France.

Benefiting from technical improvements such as the detent escapement and temperature-compensated balance wheel, a simplified version of H-4 remained the basis of chronometer design. However, significant advances improved chronometer production.

Arnold and Earnshaw first showed that quality sea clocks could be produced in quantity, and by the end of the 1700s, standard movements were produced in England. Meanwhile, French chronometer-making followed more traditional lines of individual craftsmanship, with each maker turning out a limited number of innovative hand-finished clocks.

The World Wars saw the rise of other methods of navigation based on radio and radar, which eclipsed the chronometer. Although considered a secondary means of navigation today, the chronometer is the only navigational method that is completely self-reliant. In the event of power failure, loss of radio communications, or satellite malfunction, the chronometer remains a reliable means of navigating the seas.