hand. The stylus used is made to give the standardized weights of lines and the sufficient
quality for direct reproduction. For drainage several stylus are used to vary the
weight of brooks.
The culture (black) plate has such a variety of different lines and symbols that it
seems impracticable or at least uneconomic to scribe it in final form during the stereo-
compilation. Also the black plate will be subject to numerous changes, suppressions and
supplements after the field checking of the compilation. Therefore this sheet is scribed
in a simplified way, using different circular symbols made by a slightly excentric stylus
instead of the square, rectangular and triangular symbols to be used on the final map.
The black plate has therefore to be rescribed with final symbols, using the field checked
negätive from the stereoplotter as a key. The symbols may then either be scribed or
added by stickup.
Reproduction originals for bue water tint, for green (vegetation) and for red
filling in roads are made by using the strip-mask method starting from the scribed
drainage, vegetation outline and the final scribing for the black plate.
Exact register is assured by corresponding punched holes and studs in all plastic
sheets involved.
The base sheet on which all control points are plotted is used for the scaling and
levelling of the models, and is of sufficient size to give control for a full-size sheet.
In the Geographical Survey of Norway we use for this work plotters equipped
with coordinatograph as well as those equipped with pantograph.
The advantages of this method are the following:
1. Considerable increase in quality compared to India ink drafting.
2. Essential saving of time between compilation and printing.
3. Suppression of several time-consuming and errorproducing operations.
4. The field check material on plastic is in size, much clearer and more readable
than before (colourproofs instead of blueprints).
So far the results seem very promising. The average output from a compiler
applying scribing is just about the same as that from the compiler using the conventional
pencil stylus and metal mounted drawing paper. But it must be stated that the method
requires plotting instruments of the highest quality, and operators with skill and know-
ledge, as the operator is, by this method, entrusted with a still more important and
responsible job than before.