BELGIQUE 3. 
Among the principal facts of these reports, the following should be men 
tioned here : 
— the participation of Belgian institutions to the experimental work, 
organized by the International Society of Photogrammetry and by 
the European Organization for Experimental Photogrammetric 
Research; 
— the complete aerial photography of the Belgian territory; and, in 
Belgian Congo, the extension up to 900.000 km 2 (350.000 sq miles) 
of the areas photographed by the I. G. C. B., to which more than 
360.000 km 2 (140.000 sq miles) are to be added, photographed by 
the I. G. M., for the use of other institutions; 
— the use of infra-red material, at an industrial level by the I. G. C. B., 
and at an experimental one by the I. G. M.; 
— the close collaboration between metropolitan and African institutions; 
— the archeological sites discovered on aerial photographs by the 
Ministère des Travaux publics (together with Ministry of Education) ; 
— the constitution of systematic photographic architectural Archives, by 
the same Ministry (collaboration with the Departement of Interior) ; 
— also at the Ministère des Travaux publics, the collaboration with 
the Ministry of Finance in the experiments of cadastral photogram 
metric mapping; 
— the promising conclusions drawn by the Cadastral Survey after these 
experiments; the means used to lower the expensive ground work, 
and, among these means, the advantages of not marking ground- 
points at all; 
—- at the I. G. M., a planned Section of Photogrammetric Research; 
— the stabilization of the plotting methods; 
— the research work on aerial triangulation and on the adjustment of 
photogrammetric blocks with several parallel strips; the coordination 
of this research by the Belgian Society, which celebrates in 1956 
its twenty-fifth anniversary; 
— the recent inprovements in Gevaert’s photographical products, 
concerning, among others, glass plates with high mechanical accuracy, 
and a new type of filmspool, very easy to handle. 
* * * 
Dieser Bericht besteht aus den gesammelten partiellen Berichten, von den 
belgischen Organisationen aufgestellt, die eine photogrammetrische Aktivität 
haben. Anschliessend wird man die Neubearbeitung eines geschichtlichen 
Ueberblicks finden, der früher im « Bulletin de la Société belge de Photogram- 
métrie » (Nr. 28, Juni 1952) erschienen ist, jedoch im belgischen Bericht an 
das Internationale Kongress 1952 keinen Platz gefunden hat. 
Die Abschnitte des Berichtes lauten wie folgt : 
I. — Institut Géographique Militaire (I.G.M.); 
II. — Service de Topographie et de Photogrammétrie, Ministerium 
für Oeffentliche Arbeiten;