-15- 
8.1 - Material 
Unitex hardboard, size 12'x4 , xl/8" y was used. As each 
3’ of latitude corresponds approximately to 22" at 1/10,000, the 
unitex board were cut into twelve 2' feet square sections which ma 
kes them somewhat larger than the actual size of mosaics. 
8.2 - Coordinates of the corner points 
The U.T.M. projection system was used. In this way all 
the geographical coordinates of the corner points, which amounted to 
450, were transformed into U.T.M. . Each point was checked through 
the inverse transformation. 
/ / 
For easy reference double entry tables, spanning between 
@ the extimo values of latitude and longitude involved, and per inter 
vals of 3’ <> were elaborated. On the top is written the longitude 
and on the left side margin the latitude, 
8.3- Plottirgof the mosaic corner points 
The A,7 being engaged in aerial triangulation, its co- 
ordinatograph was used for plotting the mosaic corner points on the 
unitex sections. For this purpose the sections were roughly orienta 
ted according to the axes on the plotting table and the first corner 
point pricked in one of the base vertices leaving a margin of about 
on inch. The remaining corner points as well as the grid intersec 
tions and some control points were then plotted. The diagram which 
was prepared in the first stage of the work, and includes the ground 
control, as well as the U S T 0 M, coordinates and the mosaic lay out, 
was a great help, 
8.4- - Cutting of the bases 
The edges of each mosaic base were then drawn by connec 
ting its corners, by means of a steel point. Next the unitex boards 
were sawn along the outer side of these lines. The base boards were 
finally planed and sand papered for tight fitting. 
As soon as all the mosaic bases of one of the 4 parts of 
the work were ready, they were assembled. 
The results achieved were excellent. The control- of the 
layout was made through the grid points. Occasionally one or ano 
ther base edge had to be further planed. The maximum error found 
between grid points 2 meters apart was of the order of 1 mm. 
After a general check up, the unitex bases were stapled 
in position. 
@ - extreme