Wrist Watches

History
A mechanical watch is a watch that uses a mechanical mechanism to measure the passage of time, as opposed to modern quartz watches which function electronically. It is driven by a spring (called a mainspring) which must be wound periodically.

Its force is transmitted through a series of gears to power the balance wheel, a weighted wheel which oscillates back and forth at a constant rate. A device called an escapement releases the watch's wheels to move forward a small amount with each swing of the balance wheel, moving the watch's hands forward at a constant rate. This makes the 'ticking' sound characteristic of all mechanical watches. Mechanical watches evolved in Europe in the 17th century.