Stratigraphy is a chronometric dating method
Watches progressed in the 17th century from spring-powered clocks, which appeared as early as the 14th century.During most of its history the watch was a mechanical device, driven by clockwork, powered by winding a mainspring, and keeping time with an oscillating balance wheel.
A great leap forward in accuracy occurred in 1657 with the addition of the balance spring to the balance wheel, an invention disputed both at the time and ever since between Robert Hooke and Christiaan Huygens.Time-related features such as timers, chronographs and alarm functions are common.Some modern designs incorporate calculators, GPS and Bluetooth technology or have heart-rate monitoring capabilities.During the First Boer War, the importance of coordinating troop movements and synchronizing attacks against the highly mobile Boer insurgents became paramount, and the use of wristwatches subsequently became widespread among the officer class.The company Mappin & Webb began production of their successful "campaign watch" for soldiers during the campaign at the Sudan in 1898 and accelerated production for the Second Boer War a few years later.Some watches use radio clock technology to regularly correct the time.
Developments in the 2010s include smartwatches, which are elaborate computer-like electronic devices designed to be worn on a wrist.
The oldest surviving wristwatch (then described as a bracelet watch) is one made in 1806 and given to Joséphine de Beauharnais.
Wristwatches were first worn by military men towards the end of the 19th century, when the importance of synchronizing manoeuvres during war, without potentially revealing the plan to the enemy through signaling, was increasingly recognized.
The concept of the wristwatch goes back to the production of the very earliest watches in the 16th century.
Elizabeth I of England received a wristwatch from Robert Dudley in 1571, described as an arm watch.
This innovation increased watches' accuracy enormously, reducing error from perhaps several hours per day resulting in the addition of the minute hand to the face from around 1680 in Britain and 1700 in France.