ABSTRACT 
The mathematical theory of the purely binocular space sense provides 
a systematic means of describing the distortions in the perception of real 
space produced by stereogrammetric techniques. The ideal method of analysis 
consists of a comparison between the sensory spatial attributes of the stereo- 
scopic stimulus and those of the real stimulus. There is no constant over-all 
distortion as, for example, a constant magnification of depth relative to breadth; 
it is necessary to compare the two perceptions in their entirety. However, for 
practical purposes a rough characterization will often suffice. Furthermore, it 
is possible to give an approximate correction of the distortion which will be 
adequate for most technical uses. The principles involved are exhibited in ex- 
amples which demonstrate their application.