A pocket watch (or pocketwatch) is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist. They were the most common type of watch from their development in the 16th century until wristwatches became popular after World War 1. Pocket watches generally have an attached chain to allow them to be secured to a waistcoat, lapel, or belt loop, and to prevent them from being dropped. The chain or ornaments on it is known as a fob. They often have a hinged metal cover to protect the face of the watch; pocketwatches with a fob and cover are often called "fob watches". Also common are fasteners designed to be put through a buttonhole and worn in a jacket or waistcoat, this sort being frequently associated with and named after train conductors.
An early reference to the pocket watch is in a letter in November 1462 from the Italian clockmaker Bartholomew Manfredi to the Marchese di Manta, where he offers him a 'pocket clock' better than that belonging to the Duke of Modena. By the end of the 15th Century, spring-driven clocks appeared in Italy, and in Germany. Peter Henlein, a master locksmith of Nuremberg, was regularly manufacturing pocket watches in England by 1524. The first pocket watch to measure time in minutes was invented in the Ottoman Empire by Taqi al-Din in 1556.[1] Thereafter, pocket watch manufacture spread throughout the rest of Europe as the 16th century progressed. Another early example of a pocket watch measured in minutes was created by the Ottoman watchmaker Meshur Sheyh Dede in 1702
Pocket watches are commonly regarded as being one of two types: the open-faced watch or the hunter-cased watch (also called savonette from the French). The latter has a hinged front cover that protects the face and crystal of the watch. It can also serve as a light collector to illuminate the dial in relatively dim lighting conditions.
Since the separate dial that marks the passage of seconds is traditionally placed closest to the six o'clock position, this means usually the stem (or pendant) of an open-faced pocket watch is set at its twelve o'clock position. The hunter's stem is placed most commonly at the three o'clock position. When read, the open-faced watch is held with the stem straight up and the hunter is read by turning the watch 90° with the stem pointing to the right. A third style, the demi-hunter case, is a hunter-case with the center designed to allow the position of the hands to be seen without opening the case, such as a hole or small crystal.[3]
Modern manufacturers of pocket watches, especially those watches with a quartz movement, are not bound by tradition when regarding the orientation of movements and the cases they are inserted into (open-faced or hunter).
Sometimes, what appears to be a mechanism intended for use in a wristwatch is used as the mechanism for a pocket watch.
The rise of railroading during the last half of the 19th century led to the widespread use of pocket watches. Because of the likelihood of train wrecks and other accidents if all railroad workers did not accurately know the current time, pocket watches became required equipment for all railroad workers.
The first steps toward codified standards for railroad-grade watches were taken in 1887 when the American Railway Association held a meeting to define basic standards for watches. However, it took a disaster to bring about widespread acceptance of stringent standards. A famous train wreck on the Lake Shore and Michigan Southern Railway in Kipton, Ohio on April 19, 1891 occurred because one of the engineers' watches had stopped for 4 minutes. The railroad officials commissioned Webb C. Ball as their Chief Time Inspector, in order to establish precision standards and a reliable timepiece inspection system for Railroad chronometers. This led to the adoption in 1893 of stringent standards for pocket watches used in railroading. These railroad-grade pocket watches, as they became colloquially known, had to meet the General Railroad Timepiece Standards adopted in 1893 by almost all railroads.
These standards read, in part:
"...open faced, size 16 or 18, have a minimum of 17 jewels, adjusted to at least five positions, keep time accurately to within 30 seconds a week, adjusted to temps of 34 to 100 °F (38 °C). have a double roller, steel escape wheel, lever set, regulator, winding stem at 12 o'clock, and have bold black Arabic numerals on a white dial, with black hands."
Railroad employees to this day are required to keep their watches on time, and are subject to spot checks by their superiors at any time. Failure to keep their watches on time can lead to disciplinary action, due to the gravely serious safety issues involved.
Additional requirements were adopted in later years in response to additional needs; for example, the adoption of the diesel-electric locomotive led to new standards from the 1940s on specifying that timekeeping accuracy could not be affected by electromagnetic fields.
