PHOTOGRAMMETRIC SCRIBING
as applied by
the Geographical Survey of Norway
(Norges geografiske oppmaling).
The scribing technique as a method of reproduction has become a very important
factor in map-making.
The Geographical Survey of Norway is now developing a new routine in the photo-
grammetric section by combining scribing with the photogrammetric stereocompi-
latin of maps.
COMPLETE COLOUR SEPARATION, which so far has been a part of the regular
reproduction work, is now being executed in the stereoplotter, giving as the immediate
product of the compilation in the stereoplotter colour-separated negatives for which
there are a variety of uses. The main idea, of course, is to save much work in the
drawing of manuscript maps before reproduction.
This change in method means that the pencil in the plotting instrument is substi-
tuted by a STYLUS (saphire), and, correspondingly, the metalmounted paper is substi-
tuted by COATED PLASTIC sheets (Stabilene).
In the stereoplotter are scribed directly as many different coated sheets as there
are colours on the map, each sheet containing only the details to be shown in that parti-
cular colour. The compilation scale equals the scale of the printed map.
In our case the following sheets are scribed in the stereoplotter:
Culture, black colour on map.
Drainage, blue colour on map.
Contours, brown colour on map.
>“ N =
Outline of vegetation, green colour on map.
Some of the scribed negatives, such as drainage and contours can be used direct as
final reproduction originals for the making of press plates. Spot heights are mounted on
the back side of contour scribing, swamps are added by scribing in ruling machine by