photo-maps and photogrammetric line maps, aerial triangulations in the 
Autograph A 5, and also terrestrial photogrammetric work. Control 
work is done by graphical and mechanical radial triangulation, and to 
some extent by determining coordinates in stereoscopic instruments. 
The instruments available to the Section are 
Wild Autograph A 5 
Zeiss Stereopantometer 
Mirror Stereoscopes with Stereometers 
Oude Delft Scanning Stereoscope 
Zeiss Rectifiers SEG I and IV 
Odencrants Rectifiers 
Zeiss Sketch Master 
Equipments for mechanical radial triangulation (Lazy Daisy and 
Slotted Templates). 
The Boliden Mining Company 
At the Prospecting Department, there is a special section for airborne 
prospecting under the Research Engineer. This section takes air pho 
tographs for the whole Company from a plane of the type De Havilland 
Rapide Seeplane with a simple camera of the Eagle F 24 type. As a 
rule the scale is 1:25 000. The activity of this work is very limited, and 
its annual output being less than 500 pictures. 
The photos are in the first place intended for prospecting. They are 
used as stereo-pictures for geological photo-interpretation in a simple 
stereoscope, or as mosaics for air-navigational purposes. 
The photos are also used for primary planning of ways and mines. 
For other photogrammetric adaptations, however, the Company applies 
to contractors out by the Company. 
D. Institutions mainly using Air Photogrammetric Pictures and 
Maps for Agricultural and Forestry Purposes 
The Royal Board of Agriculture and the Provincial Agricultural 
Organization 
Photogrammetric material is very extensively used by the Board of 
Agriculture and the Provincial Agricultural Organizations in planning 
the rationalization of farming and in dealing with matters touching the 
agricultural policy as expressed in the current laws on Land Purchase. 
It is also used to some extent in drainage operations. 
The Economic Map, scale 1:10 000, or —- if required — enlarge 
ments of this are used for these purposes in already mapped districts. 
Photographs, generally rectified, are used when such maps are not 
available.