Chrome Hebdomas Patent Open-Face Watch, Circa 1910, Swiss Made

• Circa - A Latin term meaning 'about', often used in the antique trade to give an approximate date for the piece, usually considered to be five years on either side of the circa year. Thus, circa 1900 means the piece was made about 1900, probably between 1895 and 1905. The expression is sometimes abbreviated to c.1900.
• Chapter Ring - A separate metal plate on the face of a clock, on which the numerals for the hours and sometimes parts of the hours, are displayed, usually wheel shaped and sitting on top of the dial plate. The chapter ring is often a feature of the clock and can be silvered or enamelled to stand as a contrast to its background. The hours are usually shown in Roman numerals, although in the late 19th and earlt 20th century, Arabic numerals became fashionable.
• Lever Escapement - A lever escapement is a type of escapement mechanism used in mechanical clocks and watches to regulate the timekeeping of the movement. It was invented by British clockmaker Thomas Mudge in the 18th century and is now widely used in modern mechanical timepieces.
  
  The lever escapement consists of three main parts: the escape wheel, the pallet fork, and the lever. The escape wheel is a wheel with teeth that is driven by the clock or watch's main spring or weight. The pallet fork is a two-pronged component that is positioned so that it can engage with the teeth of the escape wheel, and the lever is a small, L-shaped component that is attached to the pallet fork.
  
  When the escape wheel turns, one of its teeth pushes against one of the pallet fork's prongs, causing the fork to pivot. As the pallet fork pivots, it releases the tooth and engages with the next tooth on the opposite side of the escape wheel. At the same time, the lever, which is connected to the pallet fork, rocks back and forth, allowing the escape wheel to turn at a regulated rate.
  
  The lever escapement is prized for its accuracy and reliability and is commonly used in high-end mechanical watches. It allows for precise timekeeping by ensuring that the movement of the watch or clock is regulated and consistent, and its compact size makes it an ideal choice for use in small, portable timepieces.
• Movement - The technical name for the workings of a clock or watch, and does not include the dial or case.
• Barrel (in a Clock) - In a clock or watch, the barrel is a cylindrical component that stores the energy from the mainspring. As the mainspring is wound, it stores energy in the barrel. As the clock or watch runs, the energy is gradually released from the barrel, turning the clock's gears and keeping the time.
  
  The barrel is typically located near the centre of the movement (the mechanism that powers the clock) and is connected to the center wheel, which drives the rest of the gears. The barrel typically has teeth on its outer surface that mesh with the gears in the movement, allowing it to transmit energy to the rest of the clock. Some barrels are designed to be wound by hand, while others are automatically wound by the motion of the wearer's arm.

This item has been included into following indexes:

• pocket watches, case type - nickel, white metal, gun metal, chrome and steel 91
• pocket watches, country - Swiss made 463