E.J. Dent 18ct Half Hunter Pocket Chronometer

• Date Aperture - A date aperture is a cut out section in the face of a watch or clock, displaying the day of the month.
• Half Hunter - A half-hunter (or "demi hunter") pocket watch is one in which the outer lid over the face of the watch has a cut out centre section, enabling the owner to view the hands to tell the time, without having to open the lid. On some half-hunter watches, the hours are marked on the outer lid.
• Movement - The technical name for the workings of a clock or watch, and does not include the dial or case.
• Keyless Watch - A keyless watch is a type of pocket watch or wristwatch that does not require a separate winding key to wind or set the time. Instead, a keyless watch is wound and set by a small knob or button located on the side of the watch, called a crown.
  
  Keyless watches were first introduced in the late 19th century and quickly became popular due to their convenience and ease of use. Prior to the development of keyless watches, pocket watches were typically wound and set using a small key that was inserted into a hole in the watch case. The key would be turned to wind the watch's mainspring, and then turned again to set the time.
  
  With the introduction of the keyless watch, watchmakers were able to simplify the winding and setting process by eliminating the need for a separate key. Instead, the crown on the side of the watch could be pulled out to set the time, and then pushed back in to wind the watch's mainspring.
  
  The keyless watch design has since become the standard for most modern watches, both pocket and wristwatches. In addition to being more convenient to use, keyless watches are also typically more reliable and accurate than earlier models that used winding keys.
• Hunter - A hunter pocket watch is the type where the case includes a spring-hinged circular metal lid or cover, that closes over the glass face of the watch, protecting it from dust, scratches and other damage or debris. The majority of antique and vintage hunter-case watches have the lid-hinges at the 9 o?clock position, suiting the right handed user.

This item has been included into following indexes:

• chronometers - pocket 44
• Dent, Edward (Britain) - clocks, maker or retailer 46
• Nicole Nielsen & Co. - pocket watches 12
• pocket watches, case type - half-hunter, gold cased 113