History of Mechanical Watches

The first spring-powered pocket watch was created by Peter Henlein in 1524. In 1556, Taqi al-Din created a spring-powered pocket watch that could measure time in minutes, by having three dials for the hours, degrees and minutes.

Until the quartz revolution of the 1960's, all watches were mechanical. Early watches were terribly imprecise; a good one could vary as much as 15 minutes in a day. Modern precision (a few seconds per day) was not attained by any watch until 1760, when John Harrison created his marine chronometer.

Mecahnical watches are powered by a mainspring. Because the mainspring provides an uneven source of power (its torque steadily decreases as the spring unwinds), watches from the early 1500s to the early 1800s featured a chain-driven fusee which served to regulate the torque output of the mainspring throughout its winding. Unfortunately, the fusees were very brittle, were very easy to break, and were the source many problems, especially inaccuracy of timekeeping when the fusee chain became loose or lost its velocity after the lack of maintenance.

As new kinds of escapements were created which served to better isolate the watch from its time source, the balance spring, watches could be built without a fusee and still be accurate.
Basically three types of escapements have been industrially used: "lever", "pin-lever", and "Roskopf", latter invented by Georges Frederic Roskopf for cheaper watches.
As manual-wound mechanical watches became less popular and less favored in the 1970s, watch design and industrialists came out with the Automatic Watch Movement. Whereas a mechanically-wound watch must be wound with the pendant or a levered setting, an Automatic watch does not require to be wound by the pendant, but by simply shaking the watch winds the watch automatically. The interior of an Automatic Watch houses a swivelling metal or brass "plate", that swivels on its axes when the watch is shaken horizontally.

3345, Watches Australia.