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heliography


heliography


  2  definitions  found 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Heliography  \He`li*og"ra*phy\,  n. 
  1.  The  description  of  the  sun. 
 
  2.  The  system,  art,  or  practice  of  telegraphing,  or 
  signaling,  with  the  heliograph. 
 
  3.  An  early  photographic  process  invented  by  Nic['e]phore 
  Niepce,  and  still  used  in  photo-engraving.  It  consists 
  essentially  in  exposing  under  a  design  or  in  a  camera  a 
  polished  metal  plate  coated  with  a  preparation  of  asphalt, 
  and  subsequently  treating  the  plate  with  a  suitable 
  solvent.  The  light  renders  insoluble  those  parts  of  the 
  film  which  is  strikes,  and  so  a  permanent  image  is  formed, 
  which  can  be  etched  upon  the  plate  by  the  use  of  acid. 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Heliography  \He`li*og"ra*phy\,  n.  [Helio-  +  -graphy.] 
  Photography.  --R.  Hunt.