The Collaborative International Dictionary of English v.0.48:

Skiagraph \Ski"a*graph\, n. Skiagraphy \Ski*ag"ra*phy\, n., etc.
   See Sciagraph, Sciagraphy, etc.
   [Webster 1913 Suppl.] Skiascope

WordNet (r) 3.0 (2006):

skiagraphy
    n 1: the process of making a radiograph; producing an image on a
         radiosensitive surface by radiation other than visible
         light [syn: radiography, skiagraphy]