THE PRACTICAL USE OF 
THE « NISTRI,, PHOTOCARTOGRAPH 
IN ITS VARIOUS APPLICATIONS 
From 1923 onwards I have been collaborating with the brothers A. and 
U. Nistri, and I ean therefore say that I was present at the birth and 
during the development of the science of aerial photogrammetric surveying 
The knowledge and experience gained during this thirty-year period of 
really intense activity enable me to illustrate the results obtained with 
the Photocartograph, to describe the teething diffieulties which we have 
managed to overcome and to point to the work which has been done in the 
cadastral and engineering fields. 
i will pass over the camera itself and the Photocartograph, because 
to some extent this is already cominon knowledge, and for the rest it has 
already been dealt with in another communication. 
I would rather pass straight on to the productive technical field and 
mention the first experiments carried out and the results obtained. 
THE « NISTRI» PHOTOCARTOGRAPH IN CADASTRAL SURVEYING 
The cadastral map obtained by the systems of aerial surveying whicb 
permit altimetric integration turns out to be so rich in topographical 
details that it is of very great value indeed to operators in technical fields, 
such as land-drainage, railway and road-building engineers. 
In the case of technical maps for engineering purposes, the altimetric 
representation of the ground is, of course, indispensable; but this represen- 
tation is also very useful in other specific cadastral operations. 
On the other hand it would be ridiculous today to carry out a survey 
solely for cadastral purposes when the carrying out of an altimetric sur- 
vey by the aerophotogrammetrical system involves an expense which is 
only slightly greater than that necessary for a simple planimetric survey 
by normal methods. 
The aerophotogrammetrical method is no longer in dispute nowadays. 
No-one doubts its accuracy and convenience. Surveyors are now agreed 
that a survey carried out by aerophotogrammetry is preferable to one 
carried out by the classical methods of surveying.