+ 
J 
tions will be made regarding how these can be adapted. In conjunction 
with the research work, experiments will be carried on to try out sui- 
table implements and other equipment for practical use. 
To ensure that the results attained can be made directly available, 
use will be made of photograph material that is at disposal in the 
country, or may be expected to be produced in the near future. Pro- 
gress in the photographic field will be followed, however, to avoid the 
results of investigations becoming too quickly out of date. 
The aim of the experimental work will be to furnish those engaged 
in practical forestry work with recommendations concerning photo- 
graphic material, methods, instruments and other equipment. A start 
has been made by taking up for treatment the question of suitable ne- 
gative scale and degree of magnification of air photographs for employ- 
ment in forestry. This question is of fundamental importance, seeing 
that separate photographing for different purposes is scarcely practi- 
sed to any great extent, the same photographic material being used as a 
rule for different purposes. The results of experiments carried out 
will be reported to the 1956 International Congress of Photogrammet- 
ry. 
The Committee has four fixed experimental areas, representatives of 
different types of forest regions in the country. All of these were pho- 
tographed during the summer of 1955 from three separate heights. 
Otherwise the subjects of investigation are selected on the basis of 
existing photograph material, practical work in progress and investiga- 
tions planned in other quarters. As the Committee's own resources are 
extremely limited, a first necessity in the experimental work is coope- 
ration with the various branches of practical forestrv, and also with 
those engaged on forest and technical research. Such cooperation can 
be of benefit to all parties. With the object of widening the basis of 
the work the Committee secures collaborators outside its regular wor- 
king group, to whom it entrusts special missions. 
Alongside the above experimental work, it is the intention of the 
Committee to carry on fundamental research with a view to future de- 
velopments in its field. 
Continuous investigations are proceeding concerning the possibility 
of measuring and estimating various forestry factors, such as tree spe- 
cies, tree heights, volume, quality class etc. 
For more advanced employment of photographs in estimating work, 
there are required investigations into the correlation between tree fac- 
tors that can be gauged in the air photographs and tree factors that 
can be gauged from the ground, such as the relation between crown 
diameter and breast-high diameter. These investigations will be extre- 
mely comprehensive and to a substantial extent belong to the field of 
pure forest research, so that some collaboration will be necessary.