Définition

• Microscope.  An optical instrument which magnifies the surface of minute area of
   an object. Dies can be engraved but it requires the microscope to be mounted above the engravers’ ball, a vice that holds the die. (See engraving.) Coin and medal surfaces are studied in a microscope for attribution, to examine small detail to indicate a particular variety, and for authentication, to determine if a specimen is genuine
  and original. Compound microscopes have two eyepieces, giving a stereo view (or comparative views); magnification ranges from five to forty or more times (5x to 40x). The surface to be examined is mounted on a table or stage built into the microscope. A light source is required, particularly if the images are to be photographed.  See also magnification.
     

  excerpted with permission from

  An Encyclopedia of Coin and Medal Technology

  For Artists, Makers, Collectors and Curators

  COMPILED AND WRITTEN BY D. WAYNE JOHNSON

  Roger W. Burdette, Editor

Des relations