As the name implies, a pocket watch is a watch designed to be carried in the pocket. Prior to the cheap mass production of wrist watches after World War 1 the pocket watch was the most ubiquitous type of watch available and worn.
Typically a pocket watch is composed of the watch itself, and a chain with a clip for securing the watch to an article of clothing such as a belt loop or lapel. Traditionally the pocket watch is worn with a waistcoat. It is secured with a chain attached to one of the buttonholes and stored in a so-called 'Fob Pocket'. Due to their relative high cost, the chain is considered to be an essential security accessory, though it does not necessarily have to be original to the watch.
One of the first mentions of a pocket watch was by Bartholomew Manfredi, an Italian watch maker, when he presented his creation of a ‘pocket clock’ to the Marchesse di Manta in 1462.
Unlike most wrist watches that rely on batteries to maintain time, pocket watches are traditionally mechanical and work through a complex action of storing potential energy in springs. The first pocket watches had to be wound with a special key able to reach inside the clock housing, however later watches did away with the key and allowed users to wind the watch through use of a knob on watch bezel.
Today pocket watches are popular accessories with formal wear, and come in many different styles and are made out of many different materials. Their charm and austereness have cemented their place in fashion.