Navigation at sea and the need for consistent timekeeping

 

The history of the invention of marine timekeeping instruments is a far bigger subject than can be covered adequately here. By the early 1900s the marine chronometer had evolved into a fairly standard form, with gradual improvements made by subsequent makers to compensate for temperature, weather, indeed any variable that could be experienced during sea travel from the tropics to the poles.

 

Marine chronometers rely on consistency, rather than absolute accuracy (although this would be set as close as possible when the instrument is serviced). A navigator will have the "Rating" of the instrument to factor into the calculations, combined with observations from a sextant, which will give the longitude, the position which had eluded seafarers for so long.

 

This ability to know where a ship is on the globe enabled so much exploration in relative safety, map making on land as well as at sea (areas of Southern Africa's land mass were mapped by chronometer) and can be regarded as one of the founding elements of the British Empire.