sheets at 1 : 1.000 planimetric scale; here numerical height data were completed 
by contour lines, having 1 mt. of interval. 
The precision levelling of the territory which was taken as a basis for the 
introduction of all the altitude data, was referred to and based up on the datum 
points of the nearest levelling lines of the Italian territory. 
A particular plotting and cartographic operation was performed for the 
argillous zones, which show the erosion of soil; special sheets of the map, pro- 
viding fully detailed contour lines were made; such maps will be used for the 
study of the works designed to the fertilization of the soil. 
The results of the map accuracy tests carried out by Italian Cadastral engi- 
neers are collected in about 6.300 planimetric measurements, only the 6,5 % of 
which exceeds the close requirements of the Italian Government for aerial pho- 
togrammetric sutvey. 
As for elevation tests, trigonometric or tacheometric levelling with taped 
distances on an overall length of 20 Kms was performed, by totally testing 1.132 
contour lines, only the 0,35 % of which exceeded Italian Cadastral requirements 
while the average elevation error on controlled contour lines was ascertained 
to be of 0,85 mets. 
As soon as the plotting operation were completed, the maps were copied on 
copyrite sheets and immediately printed in two colours, using black for the re- 
presentation of the planimetric details and brown for contour lines and elevation 
numerical data. : 
After collecting all topographic data, land estimate operations were imme- 
diately begun and rapidly performed. These operations will allow to apply well 
distributed and not heavy taxes on the real estate patrimony of San Marino. 
The survey and estimate operations relating to residential buildings have 
also been extremely facilitated by the fact that flights had already been made and 
plotted maps were available. 
Although it does not relate to a very wide territory, get the accomplished 
work can be considered a model for the accuracy of the maps, the elegance of 
the drawing, the neat details and for modern criterion which have been adopted 
in carrying out all the operational steps. 
The broad minded members of San Marino Government and particularly 
the Director of the Republic Tributary Department have afforded the application 
of up to date, syntetic provisions of the law, wich will make the new Cadastral 
unit - now almost ready - one the simplest and most useful in the world.