f) The maps of the Dutch country on the scale 1:25 000, 1:50 000 
and 1:200 000 are military topographic maps, also obtainable for eivil 
purposes. 
The above — mentioned maps of the tropics are technical maps 
specially for road-planning. 
g) No preexistant maps are put up to date with the help of pho- 
togrammetry. 
D) MaPS ON SCALE SUPERIOR TO 1:25 000. 
1) Cadastre and similar applications. 
a) In the field of cadastre and similar applications the photogram- 
metric surveys have not taken a large extent. The making of cadastral 
plans by means of the photogrammetry is still in the initial stage. For 
certain watery districts, which are difflcult to tread, satisfying results 
have been obtained. The results of some projects in execution are awaited 
with interest. 
Executed: 
District Loosdrecht. 
In execution: 
District Leiden. 
District Utrecht. 
Contrary to the foregoing the photogrammetry is more used for 
re-allotment purposes. 150 km? are mapped a year. 
b) The scale for cadastral maps is 1:1000, 
for re - allotment - maps 1:2500. 
The photo-scale is mostly 1:20 000 and in a special case 1:18 000. 
If 1t 1$ possible those photo's are used, which have been photographed for 
the topographic mapping. If these are insufficient or out of date new 
aerial views have to be taken. 
€) g) The re-allotments: 
De Zeevang (Noort Holland) photoscale 1:12 500 
Schelphoek (Schouwen) . photoseale 1:12 500 
Beltrum (Gelderland) photoscale 1:7500 
The accuracy-research is published by J. J. Gorter in Photogram- 
metria 1942. 
Further more an impression of the accuracy was obtained by com- 
parising the position of points of intersection of checking-lines both in 
the field and on the map. 
82 —