th 
  
ar 
be 
ce 
    
   
  
   
      
  
       
    
   
  
  
N 
: m 
: at 
| ) TERRESTRE 90° 
- c he AUN A 
/ ; 
  
  
d TRACCIA DEL PIANO X-Y (AEREA) 
  
  
Fig. 11 — Diagram of the position of the three horizontalizing axes in the « Nistri » 
Photostereograph Mod. Beta. — Traccia del piano — plane track; 
terrestre — terrestrial; 
Obliqua — oblique; . Aerea = aerial. 
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