Sweden 14 
Scales 1:1 000, 1:2 000, 1 m interval, some 3 000 ha. 
„ 1:4 000, 1:5 000, 2 „ „ „ 13 000 „ 
„ 1:8 000,1:10 000,5,, „ „ 52 500,, 
For its planning of large power transmission lines the State Power 
Board has also made use of photogrammetry. This work is as yet part 
ly experimental. The Board is thus attempting to stake out a 100 km 
long section of a 380 000 volt line in the middle part of Sweden by a 
far reaching application of photo-interpretation and photogrammetric 
plotting. Parts of the line have been photographed on scales between 
1:4 000 and 1:40 000. 
Some other photogrammetric measuring and recording methods, 
mainly based on single pictures, are used in the hydraulic laboratory of 
the Board. 
The Organisation. The photogrammetric work of the State Power 
Board is done in close collaboration with the Geographical Survey 
Office, which carries out the requisite aerial triangulations, precision 
plottings, and other more extensive mapping operations. At present 
more than 10 of the Board’s officials are doing photogrammetric work 
and many others are using aerial pictures for preliminary planning. 
Principal Methods and Instruments. Besides the usual methods and 
the already mentioned combination of Geodimeter observations with 
photogrammetric measurements the State Power Board generally em 
ploys a method based on a small scale aerial triangulation of high alti 
tude pictures to determine control points, subsequently used for both 
general mapping and the large scale triangulation of low altitude pic 
tures. The small scale triangulations are often supported by bases fixed 
on ice. Triangulations and precision adaptations are done at the Geo 
graphical Survey Office in an Autograph A 7 belonging to the State 
Power Board. 
In order to delimit the areas to be plotted and rapidly investigate al 
ternatives of projects, the State Power Board very extensively recon 
noitres the latter in stereoscopic instruments, at the same time deter 
mining altitude differences and distances far more accurately than can 
be done by the usual geodetic methods during brief visits to the respec 
tive places. Such reconnaissances in stereoscopic instruments are not 
made, however, instead of field reconnaissances, but are an aid to make 
them more effective and concentrated at the most important points. An 
Autograph A 6 was formerly used for these studies of the stereoscopic 
models, but nowadays a Kelsh Plotter is used. Mirror stereoscopes are 
also extensively used for reconnaissances in connection with problems 
of forestry, timber floating, erosion and road construction. 
When a map is to be used in legal proceedings relating to claims for 
damages, specially critical parts of it — e. g. where the ground slopes