-9-
5o - SLOTTED TEMPLET
5.1 " Strip T>rer-.
T - Xciil t1.6 If
To starb with, the carry over and tie points were ap
proximately located in the r.iddlo cf the side and long overlaps-
as usual,
Th: .36 of on adequate transparent templet for the
location of the Principal Points was fc• md very convenient.
As far as we know it is common practice to number the
triangulalion auxiliary points after the three figures of the expo
sure numbers, within each film This is likely to cause repetition
of numbers of nearby photographs of different films- resulting in
confusion and loss of time. If, besides the lettering of the points
w\ thin each j ‘ otograph, wo still add ~a-i strip or film figures, then
a rather awkward number wil” resil < ’ r i.c. vo use the 3 last figu-
res of the aerial earner;
couni
is.ible on the margin of the pho-
tographs, we avoiding xc a great extent those disadvantages.
The transfer and point pricking was, whenever possible,
done in well identified points, with the aid of a glass magnifier*
In difficult zones stereoscopic transfer was used. The progress of
the work was controlled by means of rough sketches, which were found
to be most practical.
5.2 - Templets
Exposed X-Ray fi . j.. iD. ci nd polished and transparent viny-
lite, in 37” x 35 5: -X 0, 02
were used.
The templet scale was that cf the photography, because
the scale of 1/10*000 would bring about unsurpassable difficulties,
namely, the size and quantity of material, the cumberscmeness in
cutting and handling, assembling space, bending, etc, The total
number of templets was 1,244,
Although a Zeiss RS II radial seoator was available,
a set of lover type radial secators of local manufacture was prefer
red instead. The Zeiss radial center hole punch was found unsatis
factory and the cylindrical cutter not very durable, mainly when
perforating hard materials, like vinylite* Ic is believed that a
lever type hole cutter would be more in line with the good quality
of the R8 II seoator itself.
5« 3 ~ Base beard and grid
The base board :s 5x6 meters and was made of tempered
masonite (waterproof', 1/3 thick, coated with plastic white paint.
In the frame, well dried wood narrow gridding was used,