6 
hitherto been executed by human hand. Analytical aerial triangulation 
will exhibits its true merits, we hope, with the increasing utilization 
of electronic computer for wider domain of business which in our company 
are hitherto treated by numerical procedures. It is our recognition by 
practice that almost all the mistakes made by numerical procedure in our 
company affect the efficiency and accuracy of our analytical aerial trian< 
gulations. 
3. General consideration 
Process of analytical method consists of measurement and computation. 
In our system, the measurement consits of marking of points on diapositives 
and observation of the points marked on diapositives. The computation 
is, in general, subdivided into some programs according as the individual 
organization prefers to be convenient. .Ve have adoped our own system 
learned by our own experiences. It is a remarkable fact that this system 
which we adopted was quite resembled to t he one which was proposed by 
Prof. Van der Weele on the occasion of Milan symposium held on October 
19b2. That system was as follows, (Fig.5). 
Our system was first organized mainly because our computer has not 
sufficient capacity to keep long program at once. But afterward it became 
clear that such a system as ours may be most adequate for electronic data 
processing of materials similar as of aerial photogrammetry in a factory. 
Not in a laboratory but in a factory, it is preferable to depend on not 
skillful many persons, and as few skillful operators as possible. And 
expecting some mistakes or errors of not skillful operators, it is an 
essential point how to settle a system best compatible to compensate the 
mistakes or errors automatically and economically. Mistakes or errors 
affect the results in different ways according as their characters and 
can only be detected in different steps of computations. Vie have learnt 
by the practice that in the system illustrated above, the each step of 
computation corresponds to the one only in which the mistakes or errors of 
individual different character can be detected. Accordingly, we must 
expect that in the each step of computation we will find some mistakes or 
errors and we will have to make the interruption of computation and after 
inspections to make remeasurements. Interruption of computation more or 
less involves a waste of computer. Scale of computer must be selected 
from the economical standpoint considering the above. Too large content