6 FINLAND 
The mapping is carried out in scales 1 : 2000—1 : 8000. The unmistakable 
terrain features and, when needed, the form lines are plotted with autograph A8. 
The photographs are rectified and enlarged into the mapping scale by using the 
values which were obtained with the stereoplanigraph. The different classes of 
land are delineated, classified, and appraised in the field on these enlargements. 
This information is then transferred to the base map which was plotted in the auto- 
graph. 
The new boundaries which are drawn up when the land division is accomplished 
are staked on the ground starting from the control points. 
Development plans of rural agglomerations shall also frequently be made in 
connection of the new divisions. The mapping of these areas is carried out in the 
same way as the mapping of other development areas. 
The method of graphic radial-plotting has been experimented on such areas 
where the highest accuracy is not required. The method has been found uneconomi- 
cal on large continuous areas, but it has been used successfully on small mapping 
areas in connection with old photography. 
From the year 1956 on about 800 km? has been mapped for cadastral purposes 
with stereoscopic instruments. Besides, about 700 km? has been mapped similarily 
in the scale 1 : 10 000 for planning new rural settlements. Different small surveys 
have been made by using the graphic methods, making a total of about 100 km”, 
Geologic Mapping 
Transition into use of photogrammetric methods in the geological mapping 
of rock formations has taken place during the reporting period. Controlled mosaics 
1 : 20 000 are used as base map. The structure of the bedrock is investigated on 
stereophotographs and the results of the aerogeophysical investigations are used 
as an aid in this work. A comparison between the terrain and the photographs 
is made on different types of terrain before the final interpretation. Special formations 
and such areas which are difficult to interpret are investigated in the field. About 
5000 km? a year are analyzed stereoscopically. The maps are published in the com- 
mon sheet-layout system in the scale 1 : 100 000, and 20 sheets are already published. 
The soil maps are made on the basis of the General Map 1 : 400 000. Stereoscopic 
investigation on aerial photographs in scale 1:30 000—1 :40 000 has been 
taken into use in North-Finland. The checking is carried out in the field along 
suitably chosen lines. These maps were made in 1959 over an area of about 1500 
km?. 
The aerogeophysical investigation is continuing about the same way which was 
described in the Report of 1956. Approximately 20 000 km? has been investigated 
recently each year. 
Stereoscopic investigation and Stereotop-mapping have also been used in different 
scientific works. 
Forestry 
During the reporting period the use of aerial photographs in forest mapping 
and appraisal works has continuously increased. An area of about 1500—2000 km* 
is photographed each year especially for these purposes. The photographs are taken 
in the densely settled South-Finland mostly in scale 1 : 20 000 and in the less im- 
portant areas of the sparsely settled North-Finland in 1:30 000—1 :40 000. In 
addition to this, good use is also made of photographs which have been taken for 
other purposes. The photographs are taken with Pleogon and Aviogon wide-angle 
cameras, besides also the Topogon horizon camera is used in North-Finland. The 
film has been mostly panchromatic. Successful tests with colour film have also been 
made, but going over to the use of colour photographs is still under closer investi- 
gation.