The purpose of a chronometer is to measure accurately the time of a known fixed location. This is particularly important for navigation.

What is special about chronometer?

The word chronometer was first used by English clockmaker Jeremy Thacker in the year 1714. ... In the 300-plus years since, the word has been stretched and twisted and leveraged for sales and good marketing, but it's mostly maintained its original spirit: chronometers are the most accurate of timepieces.

Why was the chronometer made?

In the middle part of the eighteenth century, John Harrison (1693-1776) solved the longitude problem by constructing a series of chronometers that kept time more accurately than any previous such devices. Running without lubrication, changing temperatures could not cause grease or oil to thicken or thin.