Detailed information has been given to the Centres for each point of the ground, 
as to whether the quality of its idenfication is to be taken for good or bad. 
III. Mean errors of x and y resulting from the comparison between the transformed 
machine-coordinates of points determined in two adjacent models; determination 
of eventual systematic portions of differences in coordinates. 
IV. Mean errors of x 23d y for the map coordinates 
a) resulting from the comparison between transformed machine-coordinates and 
map coordinates, 
b) resulting from the comparison between terrestrial coordinates and map coor- 
dinates. 
V. Mean errors of distances resulting from the comparison between distances directly 
measured by terrestrial methods, or computed from terrestrial coordinates, and 
distances computed from transformed machine-coordinates separately according to 
its lengths, the distances from 0 to 400 m being devided into 10 groups and, within 
each group subdivided according to 
a) distances, the end points of which are located in the same model, 
b) distances, the end points of which are located in two adjacent models. 
VI. Mean errors of distances, as mentioned in par. V above but pertaining to the 
distances taken from the map drafting. 
VII. a) Comparison between the transformed machine-coordinates for the models plotted 
twice, ie. with internal and external bases. 
b) Comparison between the transformed machine-coordinates for the models plotted 
twice, ie. by two different observers. 
In both cases the eventual systematic differences are to be determined at first, and 
subsequently the mean errors of x and y must be computed from the irregular 
errors. 
VIII. Comparison between the drafted non-signalized lines of the map and the terrestrial 
survey of these lines. 
B. Accuracy of elevation. 
The elevations taken from the plotting apparatus are transformed to the elevations 
of the 5 pass points of each model by linear method. Thereupon error values are com- 
puted for such improved machine-coordinates in the same way as with the planimetric 
accuracy mentioned in para. À I, II. III, and VII above. 
The computation of error values will be performed uniformly by the Austrian Bun- 
desamt für Eich- und Vermessungswesen, as far as the coordinates and elevations of the 
control points as well as the lengths of control distances must be known. For these exten- 
sive calculations and compilations that Office uses the electronic IBM computing instal- 
lation in Vienna. Moreover the Austrian Bundesamt is disposed also to undertake the 
determination of all error values left, as well as the transformation of machine-coor- 
dinates into terrestrial coordinates on behalf of the Centres so that these may eventually 
cede all computing operations to that Office. 
THE RESTITUTIONS FOR THE TEST PROGRAMME OBERRIET. 
Within the scope of the test programme (see report about the works of Commission 
C of the OEEPE executed so far) the restitutions of 141 models have been carried out. 
The following table indicates the distribution over the Centres, the flight groups and 
restitution instruments: