Every watch is primarily made up of the case, the setting and/or winding button (crown), dial and hands, and the movement or mechanism.
Even though analogue battery powered watches are using mechanical components and wheels in order to function and display the time, the term “mechanical” is applied to watches whose energy is supplied by a mainspring.
The movement of a simple watch can display hours, minutes and seconds.
The simple mechanical watch is composed by:
- The winding and setting mechanism for hand winding and time setting,
- The barrel with mainspring comprising the source of power,
- The train wheels transmitting the motion.
- The escapement, distributing the motion to the balance wheel - which is probably the most critical part of the watch as it is the regulating organ giving the time base to the watch- and finally,
- The motion work and display for time indication-which is directly linked to the train wheels.
On the simple watch, different mechanisms and functions can be added, either to enhance functionality and performance or to indicate further instances of time. In brief they are:
- The Automatic, or Self-Winding watch: A simple mechanical watch with the addition of a mechanism that is using the motions of the person to wind-up the mainspring. A big advantage of the automatic watch is that it is providing a more constant force to the wheels.
- Day/date indication.
- Moon phase, showing the age of moon.
- Week of the year.
- Perpetual calendar: A watch with a self-adjusted date. It is programmed with a series of wheels so as to show the right date when the month has 28, 30 or 31 days and also to take into account the leap years that have 29 days in February.
- Alarm: A watch with an alarm function.
- Chiming mechanism.
- Split Second Chronograph also referred to as rattrappante.
- Fusee chain: Mostly used on old pocket watches to compensate for the loss of power of the mainspring due to its unwinding.
- Running Reserve or Up and Down indication: Showing how many hours the watch will keep working until the mainspring is unwound and the watch stops.
- Tourbillon: A system where the escapement and balance wheel are assembled inside a rotating cage, so as to diminish the effects of gravity. It was invented in 1795 by the famous watch maker Abraham-Louis Breguet and is considered today as the ultimate kind of craftsmanship in a watch.