of the gimbal supported b, the bridge determine the direction on which 
the mark is adjusted. 
The above mentioned support for the two types is: A for the aerial 
and T for the terrestrial; the latter displaces the doubling gimbal posi- 
tively for 100 mm. (3 "/,,") along the Y, and 300 mm. (11 */,,") along 
the Z (see fig. 9, 10) with respect to the position which it has for the 
aerial plotting. 
All adjustment controls (of the angular orientation, of the cameras, 
of the bridge) are located within easy reach of the seated operator 
whereas those for the base components are furnished with oppurtune flex- 
ible rod controls. 
The carriage system consists of the main carriage, Z, which can move 
along the Z direction; and bears a carriage which on its turn bears, soli- 
darly connected with it, the colum of Y (on which slides the carriage Y) 
with the system for the adjustment of the base. 
Each carriage moves on supporting bearings and on two slides, all 
of which can be adjusted for ensuring the orthogonality of the three axes. 
The width of the scanning fields dependent from the run of the 
carriages can be inferred by the diagram in fig. 9. They are for X, Y, Z: 
from —3 mm. to+300 mm. (+ 11/,"), from — 300 mm. to +400 mm. 
(—11%/,.7 to 1' 3?/,") and from 0 to 900 mm. (2^ 117/,,") respectively. 
e) The pencil bearing coordinatograph is a normal « Nistri» pencil 
bearing electrocoordinatograph (5), made of two slides which can be used 
indifferently for the X, Y coordinate of the planimetric system of 
reference. 
One of the slides (the principal one), by means of its electro-magne- 
tical system, controls the displacement along its side of the origin of the 
second slide (secondary), which on its turn by means of its electroma- 
gnetical system controls the movement of the pencil along its side. 
The condition of perpendicularity is assured when rectifying. 
The displacements of the pencil along the two axes of the coordina- 
tograph are read on their respective numerators, purposedly studied in 
order to give a reading within 1/100 of millimeter, since one complete re- 
volution of the last roller represents a displacement of 0,01 mm. 
The principal slide has two adjustable reference lines, for the azi- 
muthal orientation of the drawing sheet. 
The ratio between the displacement of the coordinatometer and that 
of the coordinatograph can be changed at will, by simply substituting a 
small gear-box. 
f) Group of the controls, of the transmissions, of the gear-boxes, 
and of the numerators. 
(8) See. G. Boaga — Gli elettrocoordinatografi « Nistri» — (The « Nistri» Elec- 
trocoordinatographic Sets) edited by « Tecnica italiana » yearbook 1948. 
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