The gear boxes are to all practical purposes unlimited: therefore each 
plotter is furnished with a certain number of gear-boxes varying from 
a minimum of 1:6 to a maximum of 3 : 1. 
Besides, for one of the two coordinates of the drawing a set of equal 
but with inverted rotation gear boxes is available, for the case one has to 
invert the representation with respect to that given by the coordina- 
tometer. 
Fig. 10 shows the respective position of the three axes of reference on 
the Photostereograph under consideration for the two cases: terrestrial 
(T) and aerial (A) photogrammetry; in the two said conditions, and, i. e. 
with plumb point axis and with oblique axis. The left side of the figure 
represents the various taking positions, whereas on the right side is indi- 
cated the location of the plates within their housing for said cases and 
besides the tracks of the X-Y plane (front side). 
The Photostereograph weighs kg. 1050 (lbs. 2300) and is contained 
inside a parallelepiped of cm. 150x150 (4° 11!/,,”) and 160 em. (5' 3") 
of height. 
PRINTED IN ITALY 
  
1952 (1000)