1960s Omega Seamaster with Cross Hair Dial

• 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.
• Date Aperture - A date aperture is a cut out section in the face of a watch or clock, displaying the day of the month.
• Movement - The technical name for the workings of a clock or watch, and does not include the dial or case.
• Back Plate - On many types of clocks, the movement operates between two plates, usually made of brass, one at the back, and the other at the front, which forms a mount for the dial.
  
  On English bracket, mantle and table clocks the backplate was often visible through a glass door or panel from the late 17th century, and could be profusely engraved with scrolling decorations, flowers, foliage, birds, and figures. The engraving could also include the maker?s name.
  
  The amount of engraving reduced and became simpler as the 18th century progressed, and by 1800, had been reduced to a border, often with the maker's name in the centre. By the early 1800s all decoration had ceased, and only the maker's name was added, and by the Victorian era, most bracket, mantle and table clocks had no engraving.
• Baton Numerals - A watch that instead of displaying numerals on the face, displays a marker in the form of a baton, or lower case letter "L". Since the baton-like marks are not numerals, the feature is also called baton markers, baton indexes and baton indicators.

This item has been included into following indexes:

• Omega - wristwatches, Seamaster 287