OEEPE, COMMISSION B, PRESENTATION OF THE REPORT 43 
instruments, either in flights for large scales (flights 2.1 and 2.4 with statoscope) or in 
flights for medium scales (3.1, 3.3, 3.4 with solar periscope). 
The Institut für Angewandte Geodäsie of Frankfurt will now prepare the photo- 
graphic material which will be distributed to the Centres and will calculate the coordi- 
nates of the determined terrestrial points. 
The materials, which the new flights put at the disposal of the work Centres of the 
O.E.E.P.E. have already been approved of. Thus, the problems connected with the Com- 
mission B have caused a new interest and a considerable number of Centres is carrying 
out work on this material. 
In order to increase the efficiency of the research work, the Commission B has tried 
to define better its programme, sometimes by reducing it, to make the investigation of 
certain arguments more profound. 
These subjects, the importance of which is clear to everybody, are as follows: 
a. Investigation of the accuracy of aerial triangulations in relation to their lengths. 
b. Problem of strip blocks for large scales. 
c. Triangulations with convergent photographs and their comparison with triangulations 
carried out by using nadir photographs. 
d. Use of auxiliary elements exclusively in carrying out aerial triangulations for large 
and medium scales. 
e. Analytical triangulation and its use for large scale triangulations. 
The Commission has also declared that each Centre should undertake to carry out a 
group of experimental tests which would form, even if isolated, a complete contribution 
to above mentioned investigations, in order to prevent that part of the work of the Cen- 
tres would prove to be unusable. The new position of the investigations called for new 
rules for the works of the Centres. These rules contain some basic novelties which can 
be resumed as follows: 
1. To document the work of the Centres in the most uniform and detailed way, even by 
giving them a greater independence. 
2. To uniformize some fundamental procedures in order to make the results comparable 
and to allow their exploitation for other investigations, even besides those which the 
Centre has proposed to carry out. 
3. To ask for the collaboration of the Centres from the beginning of the work engage- 
ment for carrying out some calculations on the experimental material in view of its 
uniform representation. 
4. To stimulate the special studies and investigations on behalf of the Centres. 
As already mentioned, the engagements according to these new rules have been 
very numerous. Seven work centres, Delft, Ziirich, Firenze, Milano, Frankfurt, Stuttgart 
and Messrs. Zeiss have engaged themselves to carry out a mass of work which gives us 
rise to optimistic expectations, hoping that the problems connected with the five study 
subjects will be explained. 
Presentation of the Report 
Professeur M. CUNIETTI: Monsieur le Prési- 
dent, Messieurs, je rappelle à votre attention les 
rapports que le professeur Solaini et l’ingénieur 
Belfiori ont présenté à Stockholm sur l’activité 
de la Commission II, concernant notamment les 
applications de la triangulation aérienne pour la 
cartographie à grande et moyenne échelle. 
Après le Congrès de Stockholm l’on a commen- 
cé sous la direction de l’ingénieur Belfiori qui 
était à l’époque le Président de la Commission, 
le travail de calcul et d'élaboration du matériel 
accumulé. Les résultats de ces travaux, qui sont 
à certains points de vue trés intéressants et 
dignes d'un examen plus approfondi, présentai- 
ent au point de vue précision une dispersion 
notable des chiffres. Du fait du nombre minime 
d'essais comparables, de la différence considé- 
rable entre les procédés adoptés, et du défaut 
d'uniformité du matériel employé, il est diffi- 
cile d'utiliser les résultats disponibles pour ana- 
lyser les causes réelles de cette dispersion. Dans 
le tableau No. 1 que vous trouverez dans la 
publication spéciale de ,,Photogrammetria” 
(voir page 40 de ce Fascicule) les résultats 
obtenus dans plusieurs centres sont résumés 
synthétiquement. L’ensemble des données re- 
cueillies dans ce tableau suggèrent les considé- 
rations générales suivantes: la plupart des trian- 
gulations exécutées et compensées présentent 
des erreurs résiduelles en z plus grandes que 
celles en x et en y. Les valeurs des erreurs rési- 
duelles maxima sur les trois coordonnées dépen-