May, 1960 COMMENTS ON THE MAPPING EXPERIMENT 169 
  
NS Fic. 2. Physiographical divisions 
3 NN 3 of the map area. 1. Alluvial 
marine deposits, clay. Nearly 
plan, some shallow gullies. 2. 
Rock-knob rounded by the 
glaciers of the ice age. 3. Till, 
ground moraine with very detail- 
ed surface. Rather difficult to 
plot where general inclination 
is small. 4. Valley in the till area 
flowing into the Bonnechere 
valley near the town area. There 
the valley has carved into the 
bedrock. 5. Gravel pits. 6. Town 
  
  
  
area. 
  
FIrsT- AND SECOND-ORDER PLOTTING 
The comparison between anaglyphic and non-anaglyphic plotters is an essential 
part of the experiment. One can perform this comparison from elevation readings at 
control points, and this was very well organized by the National Research Council. 
The figures submitted by the participants doubtless give a good indication of the 
efficiency of both types of plotters. 
Besides numerical results the topographic and cartographic task involves the repre- 
sentation of the landscape by contour lines and planimetry, including boundary lines 
of forest, fields, etc. Here it is much more difficult to assess the quality of plots from 
the two types of plotters. The quantitative evaluation of the plots by the National 
Research Council was very valuable. But only the combination of qualitative and 
quantitative data with the time spent in plotting will lead to conclusions on the efficiency 
of the plotters used and the economic aspects. One can also draw some conclusions 
regarding the skill of the operators at the instruments. Obviously the result is influ- 
enced by many factors. For a future experiment these factors should be separated as 
far as possible. Special specifications could then be prepared for first-, second- and 
perhaps also for third-order plotting. All experimental work must be based on identical 
photographs. In addition, a physiographical description of the test area should be 
supplied to define the desired contents cf the plotting for different-order instruments. 
The contents for the first-order plotting can be defined most easily. The alti- 
metric and planimetric presentation must include all details of the terrain, with the 
exception of unimportant features that may be excluded in view of the mapping scale. 
The contours should be drawn with the greatest possible accuracy. 
Checking first-order plots is relatively simple because the map is supposed to be 
an exact replica of the terrain. For the evaluation of the quality of plots, precise plots 
of selected check areas produced from photographs taken from a lower altitude or 
from direct field survey are used. 
For second-order plotting, naturally, lesser accuracy and completeness are allowed. 
It would be important to specify both the details that could be omitted and those that 
must be represented. This applies also to the generalization of contour lines. 
Checking second-order plots is considerably more difficult because some omissions 
and generalizations cannot be marked as errors. They are necessary if the typical and 
essential forms only are to be shown. Figure 3 shows two contourings of the same area 
but of different quality. The second-order contour lines give fewer details. For 
instance, the structures on the side walls of the rock-knob are omitted, but the typical