Mechanical Watch - History

History

Peter Henlein has often been described as the inventor of the first pocket watch, the "Nuremberg egg", in 1510, but this claim appears to be a 19th century invention and does not appear in older sources.

Until the quartz revolution of the 1960s, 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 chronometers. Precision was attained as from 1854 first by the Waltham Watch Company, through the industrialisation of the manufacturing process of the movement part, in order to attain the necessary precision: they won a Gold Medal at the 1876 Philadelphia Centennial Exposition with a lot of watches taken at random out of the production line, showing the way to their peers in U.S.A. (e.g. Elgin Watch Company) and the worldwide watch industry.

Mechanical 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 16th century to the early 19th century 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 of 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.

In the 18th century the original verge escapement, which required a fusee, was gradually replaced in better French watches with the cylinder escapement, and in British watches with the duplex escapement. Then in the 19th century both were superseded by the lever escapement which has been used almost exclusively ever since. A cheaper version of the lever, the pin lever escapement, patented in 1867 by Georges Frederic Roskopf was used in inexpensive watches until the 1970s.

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 need to be wound by the pendant; simply shaking the watch winds the watch automatically. The interior of an Automatic Watch houses a swiveling metal or brass "plate" that swivels on its axis when the watch is shaken horizontally.