The chronometer timepiece is a specific way of keeping time mechanically. Chronometers can be quite accurate in timekeeping and are known for their high quality.
When Jeremy Thacker invented a clock set in a vacuum chamber in 1714, he gave it the name “chronometer”.
Switzerland timepieces can only be given the “chronometer” label if they’ve been certified by the Controle Officiel Suisse des Chronometres (COSC). Other countries also often regulate what can be called a chronometer. According to the COSC, a chronometer watch must not lose more than four or gain more than six seconds a day.
Historically, chronometers have been the stuff of innovation. Some chronometers have stones in them, like diamond, ruby and sapphire to function as jewel bearings to decrease wear via friction.
After the invention of the chronometer for timepieces, John Harrison invented the marine chronometer, a tool used to measure longitude through celestial navigation (much like the sextant!). The marine chronometer uses the same basic mechanical structure as the original chronometer, and came in very handy for navigation.
After the invention of these devices, astronomy observatories created competitions to judge their accuracy. The observatories ran and tested the devices for 30 to 50 days under strict guidelines. These guidelines were even stricter than the COSC’s standards today, ensuring the accuracy of the chronometers.
Today, chronometers aren’t as necessary to make timepieces, as inventors have further evolved clock making. But distinctive watch companies like Rolex still pride themselves on quality watches and clocks that use chronometer technology.