PHOTOGRAMMETRIC ENGINEERING 
  
Fıc. 6. Aspheric-plate diapositive printer, 153/153 showing location of aspheric plate. 
close to the publication scale. The key problem in instituting these procedures 
has been the production of an efficient variable-ratio pantograph having the 
required degree of accuracy (See Figure 7). This problem has been one of con- 
siderable difficulty; however, the problem has been solved and a variable-ratio 
pantograph of the highest quality has been engineered and is now in production. 
The reduction ratio that can be obtained with the latest model is continuously 
variable from 1.45 to 1 to 6.5 to 1. 
8. ORTHOPHOTOSCOPE 
At the same time that work was progressing on instruments for the inte- 
grated system, investigations were made into photogrammetric instrumentation 
  
Fic. 7. Variable-ratio pantograph. 
  
    
  
     
  
  
  
  
  
  
   
    
  
  
  
  
  
   
   
   
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
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