, illumi- 
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9 
The limits of a stand can be very largely determined on moderately good 
aerial photographs, even if the scale is only 1:15 000—1: 20 000. It is 
usually necessary or advisable, however, to pay a visit to the forests in 
order to check and adjust results. The pictures often show clearly, also, 
the situation of lakes, swamps, streams, roads, and paths, as well as the 
limit of each property. 
How useful the photographs will be for various forestry purposes 
(Chapt. 5) will depend not cnly on the selection of suitable methods and 
good pictures, but on thorough practice and experience in pheto interpre- 
tation. In addition to this a gcod forestry education, both theoretical and 
practical, is required for many purposes, as well as practice in the use of 
certain auxiliary instruments, especially the stereoscope. 
It is easier to produce large fcrest maps thanks to the fact that photo- 
grammetric methods offer a quick and cheap way of making an accep- 
table basis and framework for them. Drawing of stand limits and other 
details on the map can be done for the most part indoors and on the spot, 
particularly if a suitable cartographic instrument is available. Here the 
committee has mostly used the Multiscope. In small forests as well as in 
many large ones, especially in Northern Sweden, the photographs are 
expected to prove directly useful as forest maps, perhaps after certain 
adjustments have been made to them. In South Sweden, on the cther hand, 
drawn forest maps will long be retained. Which method is most suitable 
when making forest maps in Sweden has not yet been fully established 
experimentally. 
As for the estimation of the stem volume of trees, stands, and forests, 
there are good chances that photogrammetrie methods may be used, com- 
bined with certain minor studies carried out on the ground. It is so far 
only possible to attach practical value to certain rough estimates, however. 
Much depends on how far the demands hitherto made on statistical in- 
formation can be adapted to the photogrammetric possibilities. 
Aerial photographs can offer much valuable information when planning 
clearances, regeneration measures, etc. in the daily administration of the 
forests. When making visits to the forests, aerial photographs facilitate 
one's personal orientation, and this is of great value in the large forests, 
as well as giving a good notion of the conditions to be studied. 
Many special sorts of work are also considerably facilitated by the use 
of aerial photographs. This is one of the facts appearing from our studies 
concerning the proper way to plan forest motor-roads and fire protection ' 
for the forests. The pictures can also be used when planning ditching, 
although here the conditions in Sweden do not seem to show much ad- 
vantage from such a proceeding. Taken together, these various applica- 
tions are expected to assume great value for forest management in the fu- 
ture, when photogrammetry will have been incorporated in forestry and 
other comparable fields. 
Thus, photogrammetry has a big part to play in Swedish forestry. But 
properly arranged experiments must be continued. The committee pro- 
poses that the Government founds an organ for this purpose. The com-