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