Source : Webster's Revised Unabridged Dictionary (1913)

Phototheodolite \Pho`to*the*od"o*lite\, n.
   An arrangement of two photographic cameras, the plates of
   which may be brought into exactly the same plane, used in
   surveying and map making. From the differences between two
   pictures taken at the same moment, measurements in all
   dimensions of the region may be obtained.