the great forest companies. The years 1948-1952 must be regarded as 
the break-through of forest photogrammetry. This 1s specially marked 
by the report « Flygbilden 1 Skogsbrukets tjanst » (The aerial picture in 
the service of forestry) which has been worked out by a special committee 
during the years mentioned. The report contains an all-round and sy- 
stematic survey of the problems of photogrammetry in forestry and also 
reports from certain experiments. 
Photogrammetry seems up to now to have been used chiefly for 
forest mappings in connection with forest management, forest valuation 
and sylviculture-planning. 
For forest management one of the following 4 methods were used. 
1. The Photo-Map 1:10 000 was used as a base-map, after being com- 
pleted with estate-boundaries, roads, watercourses, informations of 
heights or contours. 
2. Old forest maps have been modernized by the aid of rectified 
photographs. 
3. Old forest maps have received countors by means of photogram- 
metry. 
4. Where ordinary forest maps would bee too expensive, controlled 
or non-controlled mosaics were produced. 
For forest valuation were used: 
1. The Economic Map 1:10 000 in some cases supplemented by the 
Photo-Map. 
2. Prints of the draft of the Photo-Map 1:10 000. 
3. Rectified photographs on a scale of 1:10 000. 
4. Contact-prints 1:20 000 or enlargements of them. 
For sylviculture-planning contact-prints 1:20 000 were used with 
certain advantage over older methods. 
The Photo-Map was supplemented so, that details were drawn on to 
its reproduction-negative. During the years 1948-1952 the Geographical 
Survey Office mapped 8500 km? forest in this way. 
In the report, mentioned above, points of view and wishes concer- 
ning forest photogrammetry have been put forth, but cannot be further 
mentioned here. 
f) Geology, hydrography, glaciology, orography. 
I. The Geological Survey Office of Sweden has used photogrammetric 
maps as a basis for certain mapping of bedrocks and soils. From the 
maps, it was possible to find out the dispersion of different kinds of 
rock and the tectonique in certain areas with bare bedrock, and the 
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