ha 
bonded to aluminum, these assembled prints becoming the final 
map compilations. 
The second group of maps consisted of twenty sheets in 
the Notre Dame Bay area. Advantage was taken of the many 
deep bays and islands and an unorthodox method of compilation 
employed. The maps were first compiled as planimetric sheets, 
the slotted templet system being used for obtaining photogram- 
metric control and detail being transferred by vertical sketch- 
master. Following this stage, plots were prepared for short 
multiplex bridges of two or three overlaps at 1:15, 000 scale by 
enlarging the control information on the manuscript. Contours 
were drawn using small multiplex units and this information was 
subsequently added to the planimetric maps by vertical reflect- 
ing projector or sketchmaster. 
A radically different approach was used for the remaining 
map sheets, permitting both a reduction in the number and more 
latitude in the selection of horizontal control points. Multiplex 
extensions were run from vertically well-controlled models at 
a scale computed from the flight altitude of the photography. 
Horizontal positions of lateral pass points, principal points, and 
ground control points were plotted on acetate strips and vertical 
values recorded. The vertical adjustment to these recorded 
values was accomplished by the spline curve method, the cor- 
rection curve being made to fit the known field values. After 
the tip and tilt corrections had been applied, adjacent flights 
were then brought into sympathy. The horizontal adjustments 
were made by the slotted templet method, templets being pre- 
pared from the acetate plot at multiplex scale. The topo- | 
graphical detail was then plotted on small multiplex tables on 
good quality drawing paper, positions being based on the slotted 
templet laydown and adjusted vertical values. About three or 
four overlaps were plotted on each sheet of paper, after which 
plots were inked and photographically reduced, and positive 
prints were obtained on a vinyl base. These prints were 
assembled on a 1:40,000 scale manuscript using a special wax 
adhesive which was subsequently used in all assembly work. 
After some experimenting, it was found that by keeping 
plots clean and pencil lines sharp, and by improving photographic 
techniques, the inking of plots could be eliminated. Another